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Commit 22771d47 by Abseil Team Committed by vslashg
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Export of internal Abseil changes 

--
642ab296a2c9629c44f3f2ce6911cd2488bcf416 by Derek Mauro <dmauro@google.com>:

Remove an obsolete check in CMakeLists.txt

PiperOrigin-RevId: 352852564

--
ce78cb96bcfd162737dbcf35005da3d1d6a3486b by Abseil Team <absl-team@google.com>:

Clarify that the calling *thread* must have locked the mutex in order to unlock
it.

PiperOrigin-RevId: 352801804

--
24e1f5f72756046f5265abf618e951c341f09b8d by Derek Mauro <dmauro@google.com>:

Fixes failing CMake string comparisons
https://cmake.org/cmake/help/latest/policy/CMP0054.html

Fixes #791

PiperOrigin-RevId: 352791054

--
0ac10bc3f4dca2c4c4b51d7b8196a2eaee9537a1 by Abseil Team <absl-team@google.com>:

Introduce CordRepRing class

This change introduces the CordRepRing class that implements all the lower level / internal implementation for upcoming CordRepRing ring buffer support in cord.

PiperOrigin-RevId: 352771994

--
4bd36dda61760785844f0f29f26d90cc18046f75 by Abseil Team <absl-team@google.com>:

Optimize InlineData representation for cord sampling (cordz)

This CL changes InlineData to allow us to store a (future) Cordz Info pointer directly into the inline representation:

- make InlineData a class that provides a public API to set the active union members (tree or chars) and safely access that data.
- change 'tree' and 'profiled' bits to be the 2 least significant bits, allowing us 62 continquous bits for storing a Cordz Info pointer.

PiperOrigin-RevId: 352642411

--
dc55ba71bbce0e6a83e05a453990c51ac3d68426 by Mark Barolak <mbar@google.com>:

Add unit test coverage for the mutating overload of absl::AsciiStrToLower.

PiperOrigin-RevId: 352626006
GitOrigin-RevId: 642ab296a2c9629c44f3f2ce6911cd2488bcf416
Change-Id: I6c5929dd830d3c630e14e7fd5387fc3e25a69100
parent b2dcbba1
Showing with 3375 additions and 148 deletions
CMake/AbseilDll.cmake
......@@ -196,6 +196,8 @@ set(ABSL_INTERNAL_DLL_FILES
"strings/internal/cord_internal.cc"
"strings/internal/cord_internal.h"
"strings/internal/cord_rep_flat.h"
"strings/internal/cord_rep_ring.cc"
"strings/internal/cord_rep_ring.h"
"strings/internal/charconv_bigint.cc"
"strings/internal/charconv_bigint.h"
"strings/internal/charconv_parse.cc"
......
CMake/AbseilHelpers.cmake
......@@ -104,7 +104,7 @@ function(absl_cc_library)
endif()
endforeach()
if("${ABSL_CC_SRCS}" STREQUAL "")
if(ABSL_CC_SRCS STREQUAL "")
set(ABSL_CC_LIB_IS_INTERFACE 1)
else()
set(ABSL_CC_LIB_IS_INTERFACE 0)
......@@ -142,7 +142,7 @@ function(absl_cc_library)
endif()
# Generate a pkg-config file for every library:
if(${_build_type} STREQUAL "static" OR ${_build_type} STREQUAL "shared")
if(_build_type STREQUAL "static" OR _build_type STREQUAL "shared")
if(NOT ABSL_CC_LIB_TESTONLY)
if(absl_VERSION)
set(PC_VERSION "${absl_VERSION}")
......@@ -183,7 +183,7 @@ Cflags: -I\${includedir}${PC_CFLAGS}\n")
endif()
if(NOT ABSL_CC_LIB_IS_INTERFACE)
if(${_build_type} STREQUAL "dll_dep")
if(_build_type STREQUAL "dll_dep")
# This target depends on the DLL. When adding dependencies to this target,
# any depended-on-target which is contained inside the DLL is replaced
# with a dependency on the DLL.
......@@ -212,7 +212,7 @@ Cflags: -I\${includedir}${PC_CFLAGS}\n")
"${_gtest_link_define}"
)
elseif(${_build_type} STREQUAL "static" OR ${_build_type} STREQUAL "shared")
elseif(_build_type STREQUAL "static" OR _build_type STREQUAL "shared")
add_library(${_NAME} "")
target_sources(${_NAME} PRIVATE ${ABSL_CC_LIB_SRCS} ${ABSL_CC_LIB_HDRS})
target_link_libraries(${_NAME}
......@@ -273,7 +273,7 @@ Cflags: -I\${includedir}${PC_CFLAGS}\n")
$<INSTALL_INTERFACE:${ABSL_INSTALL_INCLUDEDIR}>
)
if (${_build_type} STREQUAL "dll")
if (_build_type STREQUAL "dll")
set(ABSL_CC_LIB_DEPS abseil_dll)
endif()
......
CMakeLists.txt
......@@ -51,7 +51,7 @@ set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin)
# when absl is included as subproject (i.e. using add_subdirectory(abseil-cpp))
# in the source tree of a project that uses it, install rules are disabled.
if(NOT "^${CMAKE_SOURCE_DIR}$" STREQUAL "^${PROJECT_SOURCE_DIR}$")
if(NOT CMAKE_SOURCE_DIR STREQUAL PROJECT_SOURCE_DIR)
option(ABSL_ENABLE_INSTALL "Enable install rule" OFF)
else()
option(ABSL_ENABLE_INSTALL "Enable install rule" ON)
......
absl/copts/AbseilConfigureCopts.cmake
......@@ -12,16 +12,16 @@ else()
set(ABSL_BUILD_DLL FALSE)
endif()
if("${CMAKE_SYSTEM_PROCESSOR}" MATCHES "x86_64|amd64|AMD64")
if(CMAKE_SYSTEM_PROCESSOR MATCHES "x86_64|amd64|AMD64")
if (MSVC)
set(ABSL_RANDOM_RANDEN_COPTS "${ABSL_RANDOM_HWAES_MSVC_X64_FLAGS}")
else()
set(ABSL_RANDOM_RANDEN_COPTS "${ABSL_RANDOM_HWAES_X64_FLAGS}")
endif()
elseif("${CMAKE_SYSTEM_PROCESSOR}" MATCHES "arm.*|aarch64")
if ("${CMAKE_SIZEOF_VOID_P}" STREQUAL "8")
elseif(CMAKE_SYSTEM_PROCESSOR MATCHES "arm.*|aarch64")
if (CMAKE_SIZEOF_VOID_P STREQUAL "8")
set(ABSL_RANDOM_RANDEN_COPTS "${ABSL_RANDOM_HWAES_ARM64_FLAGS}")
elseif("${CMAKE_SIZEOF_VOID_P}" STREQUAL "4")
elseif(CMAKE_SIZEOF_VOID_P STREQUAL "4")
set(ABSL_RANDOM_RANDEN_COPTS "${ABSL_RANDOM_HWAES_ARM32_FLAGS}")
else()
message(WARNING "Value of CMAKE_SIZEOF_VOID_P (${CMAKE_SIZEOF_VOID_P}) is not supported.")
......@@ -32,10 +32,10 @@ else()
endif()
if("${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU")
if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
set(ABSL_DEFAULT_COPTS "${ABSL_GCC_FLAGS}")
set(ABSL_TEST_COPTS "${ABSL_GCC_FLAGS};${ABSL_GCC_TEST_FLAGS}")
elseif("${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang")
elseif(CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
# MATCHES so we get both Clang and AppleClang
if(MSVC)
# clang-cl is half MSVC, half LLVM
......@@ -45,7 +45,7 @@ elseif("${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang")
else()
set(ABSL_DEFAULT_COPTS "${ABSL_LLVM_FLAGS}")
set(ABSL_TEST_COPTS "${ABSL_LLVM_FLAGS};${ABSL_LLVM_TEST_FLAGS}")
if("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang")
if(CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
# AppleClang doesn't have lsan
# https://developer.apple.com/documentation/code_diagnostics
if(NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 3.5)
......@@ -54,7 +54,7 @@ elseif("${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang")
endif()
endif()
endif()
elseif("${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC")
elseif(CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
set(ABSL_DEFAULT_COPTS "${ABSL_MSVC_FLAGS}")
set(ABSL_TEST_COPTS "${ABSL_MSVC_FLAGS};${ABSL_MSVC_TEST_FLAGS}")
set(ABSL_DEFAULT_LINKOPTS "${ABSL_MSVC_LINKOPTS}")
......
absl/strings/BUILD.bazel
......@@ -269,10 +269,12 @@ cc_library(
name = "cord_internal",
srcs = [
"internal/cord_internal.cc",
"internal/cord_rep_ring.cc",
],
hdrs = [
"internal/cord_internal.h",
"internal/cord_rep_flat.h",
"internal/cord_rep_ring.h",
],
copts = ABSL_DEFAULT_COPTS,
visibility = [
......@@ -281,9 +283,13 @@ cc_library(
deps = [
":strings",
"//absl/base:base_internal",
"//absl/base:config",
"//absl/base:core_headers",
"//absl/base:raw_logging_internal",
"//absl/base:throw_delegate",
"//absl/container:compressed_tuple",
"//absl/container:inlined_vector",
"//absl/container:layout",
"//absl/meta:type_traits",
],
)
......@@ -348,6 +354,23 @@ cc_test(
)
cc_test(
name = "cord_ring_test",
size = "medium",
srcs = ["cord_ring_test.cc"],
copts = ABSL_TEST_COPTS,
visibility = ["//visibility:private"],
deps = [
":cord_internal",
":strings",
"//absl/base:config",
"//absl/base:core_headers",
"//absl/base:raw_logging_internal",
"//absl/debugging:leak_check",
"@com_google_googletest//:gtest_main",
],
)
cc_test(
name = "substitute_test",
size = "small",
srcs = ["substitute_test.cc"],
......
absl/strings/CMakeLists.txt
......@@ -558,6 +558,8 @@ absl_cc_library(
"cord.cc"
"internal/cord_internal.cc"
"internal/cord_internal.h"
"internal/cord_rep_ring.h"
"internal/cord_rep_ring.cc"
"internal/cord_rep_flat.h"
COPTS
${ABSL_DEFAULT_COPTS}
......@@ -565,6 +567,7 @@ absl_cc_library(
absl::base
absl::base_internal
absl::compressed_tuple
absl::config
absl::core_headers
absl::endian
absl::fixed_array
......@@ -574,6 +577,7 @@ absl_cc_library(
absl::raw_logging_internal
absl::strings
absl::strings_internal
absl::throw_delegate
absl::type_traits
PUBLIC
)
......@@ -609,3 +613,20 @@ absl_cc_test(
absl::fixed_array
gmock_main
)
absl_cc_test(
NAME
cord_ring_test
SRCS
"cord_ring_test.cc"
COPTS
${ABSL_TEST_COPTS}
DEPS
absl::config
absl::cord
absl::strings
absl::base
absl::core_headers
absl::raw_logging_internal
gmock_main
)
absl/strings/ascii_test.cc
......@@ -197,11 +197,15 @@ TEST(AsciiStrTo, Lower) {
const std::string str("GHIJKL");
const std::string str2("MNOPQR");
const absl::string_view sp(str2);
std::string mutable_str("STUVWX");
EXPECT_EQ("abcdef", absl::AsciiStrToLower(buf));
EXPECT_EQ("ghijkl", absl::AsciiStrToLower(str));
EXPECT_EQ("mnopqr", absl::AsciiStrToLower(sp));
absl::AsciiStrToLower(&mutable_str);
EXPECT_EQ("stuvwx", mutable_str);
char mutable_buf[] = "Mutable";
std::transform(mutable_buf, mutable_buf + strlen(mutable_buf),
mutable_buf, absl::ascii_tolower);
......
absl/strings/cord.cc
......@@ -255,50 +255,49 @@ inline void Cord::InlineRep::set_data(const char* data, size_t n,
bool nullify_tail) {
static_assert(kMaxInline == 15, "set_data is hard-coded for a length of 15");
cord_internal::SmallMemmove(data_.as_chars, data, n, nullify_tail);
set_tagged_size(static_cast<char>(n));
cord_internal::SmallMemmove(data_.as_chars(), data, n, nullify_tail);
set_inline_size(n);
}
inline char* Cord::InlineRep::set_data(size_t n) {
assert(n <= kMaxInline);
ResetToEmpty();
set_tagged_size(static_cast<char>(n));
return data_.as_chars;
set_inline_size(n);
return data_.as_chars();
}
inline CordRep* Cord::InlineRep::force_tree(size_t extra_hint) {
size_t len = tagged_size();
if (len > kMaxInline) {
return data_.as_tree.rep;
if (data_.is_tree()) {
return data_.as_tree();
}
size_t len = inline_size();
CordRepFlat* result = CordRepFlat::New(len + extra_hint);
result->length = len;
static_assert(kMinFlatLength >= sizeof(data_.as_chars), "");
memcpy(result->Data(), data_.as_chars, sizeof(data_.as_chars));
static_assert(kMinFlatLength >= sizeof(data_), "");
memcpy(result->Data(), data_.as_chars(), sizeof(data_));
set_tree(result);
return result;
}
inline void Cord::InlineRep::reduce_size(size_t n) {
size_t tag = tagged_size();
size_t tag = inline_size();
assert(tag <= kMaxInline);
assert(tag >= n);
tag -= n;
memset(data_.as_chars + tag, 0, n);
set_tagged_size(static_cast<char>(tag));
memset(data_.as_chars() + tag, 0, n);
set_inline_size(static_cast<char>(tag));
}
inline void Cord::InlineRep::remove_prefix(size_t n) {
cord_internal::SmallMemmove(data_.as_chars, data_.as_chars + n,
tagged_size() - n);
cord_internal::SmallMemmove(data_.as_chars(), data_.as_chars() + n,
inline_size() - n);
reduce_size(n);
}
void Cord::InlineRep::AppendTree(CordRep* tree) {
if (tree == nullptr) return;
size_t len = tagged_size();
if (len == 0) {
if (data_.is_empty()) {
set_tree(tree);
} else {
set_tree(Concat(force_tree(0), tree));
......@@ -307,8 +306,7 @@ void Cord::InlineRep::AppendTree(CordRep* tree) {
void Cord::InlineRep::PrependTree(CordRep* tree) {
assert(tree != nullptr);
size_t len = tagged_size();
if (len == 0) {
if (data_.is_empty()) {
set_tree(tree);
} else {
set_tree(Concat(tree, force_tree(0)));
......@@ -363,12 +361,14 @@ void Cord::InlineRep::GetAppendRegion(char** region, size_t* size,
}
// Try to fit in the inline buffer if possible.
size_t inline_length = tagged_size();
if (inline_length < kMaxInline && max_length <= kMaxInline - inline_length) {
*region = data_.as_chars + inline_length;
*size = max_length;
set_tagged_size(static_cast<char>(inline_length + max_length));
return;
if (!is_tree()) {
size_t inline_length = inline_size();
if (max_length <= kMaxInline - inline_length) {
*region = data_.as_chars() + inline_length;
*size = max_length;
set_inline_size(inline_length + max_length);
return;
}
}
CordRep* root = force_tree(max_length);
......@@ -390,12 +390,14 @@ void Cord::InlineRep::GetAppendRegion(char** region, size_t* size) {
const size_t max_length = std::numeric_limits<size_t>::max();
// Try to fit in the inline buffer if possible.
size_t inline_length = tagged_size();
if (inline_length < kMaxInline) {
*region = data_.as_chars + inline_length;
*size = kMaxInline - inline_length;
set_tagged_size(kMaxInline);
return;
if (!data_.is_tree()) {
size_t inline_length = inline_size();
if (inline_length < kMaxInline) {
*region = data_.as_chars() + inline_length;
*size = kMaxInline - inline_length;
set_inline_size(kMaxInline);
return;
}
}
CordRep* root = force_tree(max_length);
......@@ -549,24 +551,25 @@ template Cord& Cord::operator=(std::string&& src);
// we keep it here to make diffs easier.
void Cord::InlineRep::AppendArray(const char* src_data, size_t src_size) {
if (src_size == 0) return; // memcpy(_, nullptr, 0) is undefined.
// Try to fit in the inline buffer if possible.
size_t inline_length = tagged_size();
if (inline_length < kMaxInline && src_size <= kMaxInline - inline_length) {
// Append new data to embedded array
set_tagged_size(static_cast<char>(inline_length + src_size));
memcpy(data_.as_chars + inline_length, src_data, src_size);
return;
}
CordRep* root = tree();
size_t appended = 0;
if (root) {
CordRep* root = nullptr;
if (is_tree()) {
root = data_.as_tree();
char* region;
if (PrepareAppendRegion(root, &region, &appended, src_size)) {
memcpy(region, src_data, appended);
}
} else {
// Try to fit in the inline buffer if possible.
size_t inline_length = inline_size();
if (src_size <= kMaxInline - inline_length) {
// Append new data to embedded array
memcpy(data_.as_chars() + inline_length, src_data, src_size);
set_inline_size(inline_length + src_size);
return;
}
// It is possible that src_data == data_, but when we transition from an
// InlineRep to a tree we need to assign data_ = root via set_tree. To
// avoid corrupting the source data before we copy it, delay calling
......@@ -578,7 +581,7 @@ void Cord::InlineRep::AppendArray(const char* src_data, size_t src_size) {
root = CordRepFlat::New(std::max<size_t>(size1, size2));
appended = std::min(
src_size, root->flat()->Capacity() - inline_length);
memcpy(root->flat()->Data(), data_.as_chars, inline_length);
memcpy(root->flat()->Data(), data_.as_chars(), inline_length);
memcpy(root->flat()->Data() + inline_length, src_data, appended);
root->length = inline_length + appended;
set_tree(root);
......@@ -684,18 +687,19 @@ void Cord::Prepend(const Cord& src) {
void Cord::Prepend(absl::string_view src) {
if (src.empty()) return; // memcpy(_, nullptr, 0) is undefined.
size_t cur_size = contents_.size();
if (!contents_.is_tree() && cur_size + src.size() <= InlineRep::kMaxInline) {
// Use embedded storage.
char data[InlineRep::kMaxInline + 1] = {0};
data[InlineRep::kMaxInline] = cur_size + src.size(); // set size
memcpy(data, src.data(), src.size());
memcpy(data + src.size(), contents_.data(), cur_size);
memcpy(reinterpret_cast<void*>(&contents_), data,
InlineRep::kMaxInline + 1);
} else {
contents_.PrependTree(NewTree(src.data(), src.size(), 0));
if (!contents_.is_tree()) {
size_t cur_size = contents_.inline_size();
if (cur_size + src.size() <= InlineRep::kMaxInline) {
// Use embedded storage.
char data[InlineRep::kMaxInline + 1] = {0};
memcpy(data, src.data(), src.size());
memcpy(data + src.size(), contents_.data(), cur_size);
memcpy(contents_.data_.as_chars(), data, InlineRep::kMaxInline + 1);
contents_.set_inline_size(cur_size + src.size());
return;
}
}
contents_.PrependTree(NewTree(src.data(), src.size(), 0));
}
template <typename T, Cord::EnableIfString<T>>
......@@ -888,7 +892,7 @@ Cord Cord::Subcord(size_t pos, size_t new_size) const {
} else if (new_size <= InlineRep::kMaxInline) {
Cord::ChunkIterator it = chunk_begin();
it.AdvanceBytes(pos);
char* dest = sub_cord.contents_.data_.as_chars;
char* dest = sub_cord.contents_.data_.as_chars();
size_t remaining_size = new_size;
while (remaining_size > it->size()) {
cord_internal::SmallMemmove(dest, it->data(), it->size());
......@@ -897,7 +901,7 @@ Cord Cord::Subcord(size_t pos, size_t new_size) const {
++it;
}
cord_internal::SmallMemmove(dest, it->data(), remaining_size);
sub_cord.contents_.set_tagged_size(new_size);
sub_cord.contents_.set_inline_size(new_size);
} else {
sub_cord.contents_.set_tree(NewSubRange(tree, pos, new_size));
}
......@@ -1086,9 +1090,8 @@ bool ComputeCompareResult<bool>(int memcmp_res) {
// Helper routine. Locates the first flat chunk of the Cord without
// initializing the iterator.
inline absl::string_view Cord::InlineRep::FindFlatStartPiece() const {
size_t n = tagged_size();
if (n <= kMaxInline) {
return absl::string_view(data_.as_chars, n);
if (!is_tree()) {
return absl::string_view(data_.as_chars(), data_.inline_size());
}
CordRep* node = tree();
......
absl/strings/cord.h
......@@ -665,8 +665,6 @@ class Cord {
public:
static constexpr unsigned char kMaxInline = cord_internal::kMaxInline;
static_assert(kMaxInline >= sizeof(absl::cord_internal::CordRep*), "");
static constexpr unsigned char kTreeFlag = cord_internal::kTreeFlag;
static constexpr unsigned char kProfiledFlag = cord_internal::kProfiledFlag;
constexpr InlineRep() : data_() {}
InlineRep(const InlineRep& src);
......@@ -685,6 +683,7 @@ class Cord {
char* set_data(size_t n); // Write data to the result
// Returns nullptr if holding bytes
absl::cord_internal::CordRep* tree() const;
absl::cord_internal::CordRep* as_tree() const;
// Discards old pointer, if any
void set_tree(absl::cord_internal::CordRep* rep);
// Replaces a tree with a new root. This is faster than set_tree, but it
......@@ -728,13 +727,13 @@ class Cord {
memcpy(&(*dst)[0], &data_, sizeof(data_) - 1);
// erase is faster than resize because the logic for memory allocation is
// not needed.
dst->erase(tagged_size());
dst->erase(inline_size());
}
// Copies the inline contents into `dst`. Assumes the cord is not empty.
void CopyToArray(char* dst) const;
bool is_tree() const { return tagged_size() > kMaxInline; }
bool is_tree() const { return data_.is_tree(); }
private:
friend class Cord;
......@@ -745,14 +744,8 @@ class Cord {
void ResetToEmpty() { data_ = {}; }
// This uses reinterpret_cast instead of the union to avoid accessing the
// inactive union element. The tagged size is not a common prefix.
void set_tagged_size(char new_tag) {
reinterpret_cast<char*>(&data_)[kMaxInline] = new_tag;
}
char tagged_size() const {
return reinterpret_cast<const char*>(&data_)[kMaxInline];
}
void set_inline_size(size_t size) { data_.set_inline_size(size); }
size_t inline_size() const { return data_.inline_size(); }
cord_internal::InlineData data_;
};
......@@ -948,35 +941,39 @@ inline void Cord::InlineRep::Swap(Cord::InlineRep* rhs) {
}
inline const char* Cord::InlineRep::data() const {
return is_tree() ? nullptr : data_.as_chars;
return is_tree() ? nullptr : data_.as_chars();
}
inline absl::cord_internal::CordRep* Cord::InlineRep::as_tree() const {
assert(data_.is_tree());
return data_.as_tree();
}
inline absl::cord_internal::CordRep* Cord::InlineRep::tree() const {
if (is_tree()) {
return data_.as_tree.rep;
return as_tree();
} else {
return nullptr;
}
}
inline bool Cord::InlineRep::empty() const { return tagged_size() == 0; }
inline bool Cord::InlineRep::empty() const { return data_.is_empty(); }
inline size_t Cord::InlineRep::size() const {
const char tag = tagged_size();
if (tag <= kMaxInline) return tag;
return static_cast<size_t>(tree()->length);
return is_tree() ? as_tree()->length : inline_size();
}
inline void Cord::InlineRep::set_tree(absl::cord_internal::CordRep* rep) {
if (rep == nullptr) {
ResetToEmpty();
} else {
bool was_tree = is_tree();
data_.as_tree = {rep, {}, tagged_size()};
if (!was_tree) {
// If we were not a tree already, set the tag.
// Otherwise, leave it alone because it might have the profile bit on.
set_tagged_size(kTreeFlag);
if (data_.is_tree()) {
// `data_` already holds a 'tree' value and an optional cordz_info value.
// Replace the tree value only, leaving the cordz_info value unchanged.
data_.set_tree(rep);
} else {
// `data_` contains inlined data: initialize data_ to tree value `rep`.
data_.make_tree(rep);
}
}
}
......@@ -987,7 +984,7 @@ inline void Cord::InlineRep::replace_tree(absl::cord_internal::CordRep* rep) {
set_tree(rep);
return;
}
data_.as_tree = {rep, {}, tagged_size()};
data_.set_tree(rep);
}
inline absl::cord_internal::CordRep* Cord::InlineRep::clear() {
......@@ -998,9 +995,9 @@ inline absl::cord_internal::CordRep* Cord::InlineRep::clear() {
inline void Cord::InlineRep::CopyToArray(char* dst) const {
assert(!is_tree());
size_t n = tagged_size();
size_t n = inline_size();
assert(n != 0);
cord_internal::SmallMemmove(dst, data_.as_chars, n);
cord_internal::SmallMemmove(dst, data_.as_chars(), n);
}
constexpr inline Cord::Cord() noexcept {}
......@@ -1011,11 +1008,9 @@ constexpr Cord::Cord(strings_internal::StringConstant<T>)
cord_internal::kMaxInline
? cord_internal::InlineData(
strings_internal::StringConstant<T>::value)
: cord_internal::InlineData(cord_internal::AsTree{
: cord_internal::InlineData(
&cord_internal::ConstInitExternalStorage<
strings_internal::StringConstant<T>>::value,
{},
cord_internal::kTreeFlag})) {}
strings_internal::StringConstant<T>>::value)) {}
inline Cord& Cord::operator=(const Cord& x) {
contents_ = x.contents_;
......@@ -1107,12 +1102,12 @@ inline bool Cord::StartsWith(absl::string_view rhs) const {
inline Cord::ChunkIterator::ChunkIterator(const Cord* cord)
: bytes_remaining_(cord->size()) {
if (cord->empty()) return;
if (cord->contents_.is_tree()) {
stack_of_right_children_.push_back(cord->contents_.tree());
stack_of_right_children_.push_back(cord->contents_.as_tree());
operator++();
} else {
current_chunk_ = absl::string_view(cord->contents_.data(), cord->size());
current_chunk_ =
absl::string_view(cord->contents_.data(), bytes_remaining_);
}
}
......
absl/strings/cord_ring_test.cc 0 → 100644
// Copyright 2020 The Abseil Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include <cstdlib>
#include <ctime>
#include <memory>
#include <random>
#include <sstream>
#include "gmock/gmock.h"
#include "gtest/gtest.h"
#include "absl/base/config.h"
#include "absl/base/internal/raw_logging.h"
#include "absl/base/macros.h"
#include "absl/debugging/leak_check.h"
#include "absl/strings/internal/cord_internal.h"
#include "absl/strings/internal/cord_rep_ring.h"
#include "absl/strings/str_cat.h"
#include "absl/strings/string_view.h"
extern thread_local bool cord_ring;
// TOOD(b/177688959): weird things happened with the original test
#define ASAN_BUG_177688959_FIXED false
namespace absl {
ABSL_NAMESPACE_BEGIN
namespace {
using RandomEngine = std::mt19937_64;
using ::absl::cord_internal::CordRep;
using ::absl::cord_internal::CordRepConcat;
using ::absl::cord_internal::CordRepExternal;
using ::absl::cord_internal::CordRepFlat;
using ::absl::cord_internal::CordRepRing;
using ::absl::cord_internal::CordRepSubstring;
using ::absl::cord_internal::CONCAT;
using ::absl::cord_internal::EXTERNAL;
using ::absl::cord_internal::SUBSTRING;
using testing::ElementsAre;
using testing::ElementsAreArray;
using testing::Eq;
using testing::Ge;
using testing::Le;
using testing::Lt;
using testing::Ne;
using testing::SizeIs;
using index_type = CordRepRing::index_type;
enum InputShareMode { kPrivate, kShared, kSharedIndirect };
// TestParam class used by all test fixtures.
// Not all fixtures use all possible input combinations
struct TestParam {
TestParam() = default;
explicit TestParam(InputShareMode input_share_mode)
: input_share_mode(input_share_mode) {}
// Run the test with the 'rep under test' to be privately owned.
// Otherwise, the rep has a shared ref count of 2 or higher.
bool refcount_is_one = true;
// Run the test with the 'rep under test' being allocated with enough capacity
// to accommodate any modifications made to it. Otherwise, the rep has zero
// extra (reserve) capacity.
bool with_capacity = true;
// For test providing possibly shared input such as Append(.., CordpRep*),
// this field defines if that input is adopted with a refcount of one
// (privately owned / donated), or shared. For composite inputs such as
// 'substring of flat', we also have the 'shared indirect' value which means
// the top level node is not shared, but the contained child node is shared.
InputShareMode input_share_mode = kPrivate;
std::string ToString() const {
return absl::StrCat(refcount_is_one ? "Private" : "Shared",
with_capacity ? "" : "_NoCapacity",
(input_share_mode == kPrivate) ? ""
: (input_share_mode == kShared)
? "_SharedInput"
: "_IndirectSharedInput");
}
};
using TestParams = std::vector<TestParam>;
// Matcher validating when mutable copies are required / performed.
MATCHER_P2(EqIfPrivate, param, rep,
absl::StrCat("Equal 0x", absl::Hex(rep), " if private")) {
return param.refcount_is_one ? arg == rep : arg != rep;
}
// Matcher validating when mutable copies are required / performed.
MATCHER_P2(EqIfPrivateAndCapacity, param, rep,
absl::StrCat("Equal 0x", absl::Hex(rep),
" if private and capacity")) {
return (param.refcount_is_one && param.with_capacity) ? arg == rep
: arg != rep;
}
MATCHER_P2(EqIfInputPrivate, param, rep, "Equal if input is private") {
return param.input_share_mode == kPrivate ? arg == rep : arg != rep;
}
// Matcher validating the core in-variants of the CordRepRing instance.
MATCHER(IsValidRingBuffer, "RingBuffer is valid") {
std::stringstream ss;
if (!arg->IsValid(ss)) {
*result_listener << "\nERROR: " << ss.str() << "\nRING = " << *arg;
return false;
}
return true;
}
// Returns the flats contained in the provided CordRepRing
std::vector<string_view> ToFlats(const CordRepRing* r) {
std::vector<string_view> flats;
flats.reserve(r->entries());
index_type pos = r->head();
do {
flats.push_back(r->entry_data(pos));
} while ((pos = r->advance(pos)) != r->tail());
return flats;
}
class not_a_string_view {
public:
explicit not_a_string_view(absl::string_view s)
: data_(s.data()), size_(s.size()) {}
explicit not_a_string_view(const void* data, size_t size)
: data_(data), size_(size) {}
not_a_string_view remove_prefix(size_t n) const {
return not_a_string_view(static_cast<const char*>(data_) + n, size_ - n);
}
not_a_string_view remove_suffix(size_t n) const {
return not_a_string_view(data_, size_ - n);
}
const void* data() const { return data_; }
size_t size() const { return size_; }
private:
const void* data_;
size_t size_;
};
bool operator==(not_a_string_view lhs, not_a_string_view rhs) {
return lhs.data() == rhs.data() && lhs.size() == rhs.size();
}
std::ostream& operator<<(std::ostream& s, not_a_string_view rhs) {
return s << "{ data: " << rhs.data() << " size: " << rhs.size() << "}";
}
std::vector<not_a_string_view> ToRawFlats(const CordRepRing* r) {
std::vector<not_a_string_view> flats;
flats.reserve(r->entries());
index_type pos = r->head();
do {
flats.emplace_back(r->entry_data(pos));
} while ((pos = r->advance(pos)) != r->tail());
return flats;
}
// Returns the value contained in the provided CordRepRing
std::string ToString(const CordRepRing* r) {
std::string value;
value.reserve(r->length);
index_type pos = r->head();
do {
absl::string_view sv = r->entry_data(pos);
value.append(sv.data(), sv.size());
} while ((pos = r->advance(pos)) != r->tail());
return value;
}
// Creates a flat for testing
CordRep* MakeFlat(absl::string_view s, size_t extra = 0) {
CordRepFlat* flat = CordRepFlat::New(s.length() + extra);
memcpy(flat->Data(), s.data(), s.length());
flat->length = s.length();
return flat;
}
// Creates an external node for testing
CordRepExternal* MakeExternal(absl::string_view s) {
struct Rep : public CordRepExternal {
std::string s;
explicit Rep(absl::string_view s) : s(s) {
this->tag = EXTERNAL;
this->base = s.data();
this->length = s.length();
this->releaser_invoker = [](CordRepExternal* self) {
delete static_cast<Rep*>(self);
};
}
};
return new Rep(s);
}
CordRepExternal* MakeFakeExternal(size_t length) {
struct Rep : public CordRepExternal {
std::string s;
explicit Rep(size_t len) {
this->tag = EXTERNAL;
this->base = this->storage;
this->length = len;
this->releaser_invoker = [](CordRepExternal* self) {
delete static_cast<Rep*>(self);
};
}
};
return new Rep(length);
}
// Creates a flat or an external node for testing depending on the size.
CordRep* MakeLeaf(absl::string_view s, size_t extra = 0) {
if (s.size() <= absl::cord_internal::kMaxFlatLength) {
return MakeFlat(s, extra);
} else {
return MakeExternal(s);
}
}
// Creates a substring node
CordRepSubstring* MakeSubstring(size_t start, size_t len, CordRep* rep) {
auto* sub = new CordRepSubstring;
sub->tag = SUBSTRING;
sub->start = start;
sub->length = (len <= 0) ? rep->length - start + len : len;
sub->child = rep;
return sub;
}
// Creates a substring node removing the specified prefix
CordRepSubstring* RemovePrefix(size_t start, CordRep* rep) {
return MakeSubstring(start, rep->length - start, rep);
}
// Creates a substring node removing the specified suffix
CordRepSubstring* RemoveSuffix(size_t length, CordRep* rep) {
return MakeSubstring(0, rep->length - length, rep);
}
CordRepConcat* MakeConcat(CordRep* left, CordRep* right, int depth = 0) {
auto* concat = new CordRepConcat;
concat->tag = CONCAT;
concat->length = left->length + right->length;
concat->left = left;
concat->right = right;
concat->set_depth(depth);
return concat;
}
enum Composition { kMix, kAppend, kPrepend };
Composition RandomComposition() {
RandomEngine rng(testing::GTEST_FLAG(random_seed));
return (rng() & 1) ? kMix : ((rng() & 1) ? kAppend : kPrepend);
}
absl::string_view ToString(Composition composition) {
switch (composition) {
case kAppend:
return "Append";
case kPrepend:
return "Prepend";
case kMix:
return "Mix";
}
assert(false);
return "???";
}
constexpr const char* kFox = "The quick brown fox jumps over the lazy dog";
constexpr const char* kFoxFlats[] = {"The ", "quick ", "brown ",
"fox ", "jumps ", "over ",
"the ", "lazy ", "dog"};
constexpr const char* kAlphabet = "abcdefghijklmnopqrstuvwxyz";
CordRepRing* FromFlats(Span<const char* const> flats,
Composition composition = kAppend) {
if (flats.empty()) return nullptr;
CordRepRing* ring = nullptr;
switch (composition) {
case kAppend:
ring = CordRepRing::Create(MakeLeaf(flats.front()), flats.size() - 1);
for (int i = 1; i < flats.size(); ++i) {
ring = CordRepRing::Append(ring, MakeLeaf(flats[i]));
}
break;
case kPrepend:
ring = CordRepRing::Create(MakeLeaf(flats.back()), flats.size() - 1);
for (int i = static_cast<int>(flats.size() - 2); i >= 0; --i) {
ring = CordRepRing::Prepend(ring, MakeLeaf(flats[i]));
}
break;
case kMix:
size_t middle1 = flats.size() / 2, middle2 = middle1;
ring = CordRepRing::Create(MakeLeaf(flats[middle1]), flats.size() - 1);
if (!flats.empty()) {
if ((flats.size() & 1) == 0) {
ring = CordRepRing::Prepend(ring, MakeLeaf(flats[--middle1]));
}
for (int i = 1; i <= middle1; ++i) {
ring = CordRepRing::Prepend(ring, MakeLeaf(flats[middle1 - i]));
ring = CordRepRing::Append(ring, MakeLeaf(flats[middle2 + i]));
}
}
break;
}
EXPECT_THAT(ToFlats(ring), ElementsAreArray(flats));
return ring;
}
std::ostream& operator<<(std::ostream& s, const TestParam& param) {
return s << param.ToString();
}
std::string TestParamToString(const testing::TestParamInfo<TestParam>& info) {
return info.param.ToString();
}
class CordRingTest : public testing::Test {
public:
~CordRingTest() override {
#if ASAN_BUG_177688959_FIXED
for (CordRep* rep : unrefs_) {
CordRep::Unref(rep);
}
#endif
}
template <typename CordRepType>
CordRepType* NeedsUnref(CordRepType* rep) {
assert(rep);
#if ASAN_BUG_177688959_FIXED
unrefs_.push_back(rep);
#endif
return rep;
}
template <typename CordRepType>
CordRepType* Ref(CordRepType* rep) {
CordRep::Ref(rep);
return NeedsUnref(rep);
}
void Unref(CordRep* rep) {
#if !ASAN_BUG_177688959_FIXED
CordRep::Unref(rep);
#endif
}
private:
#if ASAN_BUG_177688959_FIXED
std::vector<CordRep*> unrefs_;
#endif
};
class CordRingTestWithParam : public testing::TestWithParam<TestParam> {
public:
~CordRingTestWithParam() override {
#if ASAN_BUG_177688959_FIXED
for (CordRep* rep : unrefs_) {
CordRep::Unref(rep);
}
#endif
}
CordRepRing* CreateWithCapacity(CordRep* child, size_t extra_capacity) {
if (!GetParam().with_capacity) extra_capacity = 0;
CordRepRing* ring = CordRepRing::Create(child, extra_capacity);
ring->SetCapacityForTesting(1 + extra_capacity);
return RefIfShared(ring);
}
bool Shared() const { return !GetParam().refcount_is_one; }
bool InputShared() const { return GetParam().input_share_mode == kShared; }
bool InputSharedIndirect() const {
return GetParam().input_share_mode == kSharedIndirect;
}
template <typename CordRepType>
CordRepType* NeedsUnref(CordRepType* rep) {
assert(rep);
#if ASAN_BUG_177688959_FIXED
unrefs_.push_back(rep);
#endif
return rep;
}
template <typename CordRepType>
CordRepType* Ref(CordRepType* rep) {
CordRep::Ref(rep);
return NeedsUnref(rep);
}
void Unref(CordRep* rep) {
#if !ASAN_BUG_177688959_FIXED
CordRep::Unref(rep);
#endif
}
template <typename CordRepType>
CordRepType* RefIfShared(CordRepType* rep) {
return Shared() ? Ref(rep) : rep;
}
void UnrefIfShared(CordRep* rep) {
if (Shared()) Unref(rep);
}
template <typename CordRepType>
CordRepType* RefIfInputShared(CordRepType* rep) {
return InputShared() ? Ref(rep) : rep;
}
void UnrefIfInputShared(CordRep* rep) {
if (InputShared()) Unref(rep);
}
template <typename CordRepType>
CordRepType* RefIfInputSharedIndirect(CordRepType* rep) {
return InputSharedIndirect() ? Ref(rep) : rep;
}
void UnrefIfInputSharedIndirect(CordRep* rep) {
if (InputSharedIndirect()) Unref(rep);
}
private:
#if ASAN_BUG_177688959_FIXED
std::vector<CordRep*> unrefs_;
#endif
};
class CordRingCreateTest : public CordRingTestWithParam {
public:
static TestParams CreateTestParams() {
TestParams params;
params.emplace_back(InputShareMode::kPrivate);
params.emplace_back(InputShareMode::kShared);
return params;
}
};
class CordRingSubTest : public CordRingTestWithParam {
public:
static TestParams CreateTestParams() {
TestParams params;
for (bool refcount_is_one : {true, false}) {
TestParam param;
param.refcount_is_one = refcount_is_one;
params.push_back(param);
}
return params;
}
};
class CordRingBuildTest : public CordRingTestWithParam {
public:
static TestParams CreateTestParams() {
TestParams params;
for (bool refcount_is_one : {true, false}) {
for (bool with_capacity : {true, false}) {
TestParam param;
param.refcount_is_one = refcount_is_one;
param.with_capacity = with_capacity;
params.push_back(param);
}
}
return params;
}
};
class CordRingCreateFromTreeTest : public CordRingTestWithParam {
public:
static TestParams CreateTestParams() {
TestParams params;
params.emplace_back(InputShareMode::kPrivate);
params.emplace_back(InputShareMode::kShared);
params.emplace_back(InputShareMode::kSharedIndirect);
return params;
}
};
class CordRingBuildInputTest : public CordRingTestWithParam {
public:
static TestParams CreateTestParams() {
TestParams params;
for (bool refcount_is_one : {true, false}) {
for (bool with_capacity : {true, false}) {
for (InputShareMode share_mode : {kPrivate, kShared, kSharedIndirect}) {
TestParam param;
param.refcount_is_one = refcount_is_one;
param.with_capacity = with_capacity;
param.input_share_mode = share_mode;
params.push_back(param);
}
}
}
return params;
}
};
INSTANTIATE_TEST_CASE_P(WithParam, CordRingSubTest,
testing::ValuesIn(CordRingSubTest::CreateTestParams()),
TestParamToString);
INSTANTIATE_TEST_CASE_P(
WithParam, CordRingCreateTest,
testing::ValuesIn(CordRingCreateTest::CreateTestParams()),
TestParamToString);
INSTANTIATE_TEST_CASE_P(
WithParam, CordRingCreateFromTreeTest,
testing::ValuesIn(CordRingCreateFromTreeTest::CreateTestParams()),
TestParamToString);
INSTANTIATE_TEST_CASE_P(
WithParam, CordRingBuildTest,
testing::ValuesIn(CordRingBuildTest::CreateTestParams()),
TestParamToString);
INSTANTIATE_TEST_CASE_P(
WithParam, CordRingBuildInputTest,
testing::ValuesIn(CordRingBuildInputTest::CreateTestParams()),
TestParamToString);
TEST_P(CordRingCreateTest, CreateFromFlat) {
absl::string_view str1 = "abcdefghijklmnopqrstuvwxyz";
CordRepRing* result = NeedsUnref(CordRepRing::Create(MakeFlat(str1)));
ASSERT_THAT(result, IsValidRingBuffer());
EXPECT_THAT(result->length, Eq(str1.size()));
EXPECT_THAT(ToFlats(result), ElementsAre(str1));
Unref(result);
}
TEST_P(CordRingCreateTest, CreateFromRing) {
CordRepRing* ring = RefIfShared(FromFlats(kFoxFlats));
CordRepRing* result = NeedsUnref(CordRepRing::Create(ring));
ASSERT_THAT(result, IsValidRingBuffer());
EXPECT_THAT(result, EqIfPrivate(GetParam(), ring));
EXPECT_THAT(ToFlats(result), ElementsAreArray(kFoxFlats));
UnrefIfShared(ring);
Unref(result);
}
TEST_P(CordRingCreateFromTreeTest, CreateFromSubstringRing) {
CordRepRing* ring = RefIfInputSharedIndirect(FromFlats(kFoxFlats));
CordRep* sub = RefIfInputShared(MakeSubstring(2, 11, ring));
CordRepRing* result = NeedsUnref(CordRepRing::Create(sub));
ASSERT_THAT(result, IsValidRingBuffer());
EXPECT_THAT(result, EqIfInputPrivate(GetParam(), ring));
EXPECT_THAT(ToString(result), string_view(kFox).substr(2, 11));
UnrefIfInputSharedIndirect(ring);
UnrefIfInputShared(sub);
Unref(result);
}
TEST_F(CordRingTest, CreateWithIllegalExtraCapacity) {
CordRep* flat = NeedsUnref(MakeFlat("Hello world"));
#if defined(ABSL_HAVE_EXCEPTIONS)
try {
CordRepRing::Create(flat, CordRepRing::kMaxCapacity);
GTEST_FAIL() << "expected std::length_error exception";
} catch (const std::length_error&) {
}
#elif defined(GTEST_HAS_DEATH_TEST)
EXPECT_DEATH(CordRepRing::Create(flat, CordRepRing::kMaxCapacity), ".*");
#endif
Unref(flat);
}
TEST_P(CordRingCreateFromTreeTest, CreateFromSubstringOfFlat) {
absl::string_view str1 = "abcdefghijklmnopqrstuvwxyz";
auto* flat = RefIfInputShared(MakeFlat(str1));
auto* child = RefIfInputSharedIndirect(MakeSubstring(4, 20, flat));
CordRepRing* result = NeedsUnref(CordRepRing::Create(child));
ASSERT_THAT(result, IsValidRingBuffer());
EXPECT_THAT(result->length, Eq(20));
EXPECT_THAT(ToFlats(result), ElementsAre(str1.substr(4, 20)));
Unref(result);
UnrefIfInputShared(flat);
UnrefIfInputSharedIndirect(child);
}
TEST_P(CordRingCreateTest, CreateFromExternal) {
absl::string_view str1 = "abcdefghijklmnopqrstuvwxyz";
auto* child = RefIfInputShared(MakeExternal(str1));
CordRepRing* result = NeedsUnref(CordRepRing::Create(child));
ASSERT_THAT(result, IsValidRingBuffer());
EXPECT_THAT(result->length, Eq(str1.size()));
EXPECT_THAT(ToFlats(result), ElementsAre(str1));
Unref(result);
UnrefIfInputShared(child);
}
TEST_P(CordRingCreateFromTreeTest, CreateFromSubstringOfExternal) {
absl::string_view str1 = "abcdefghijklmnopqrstuvwxyz";
auto* external = RefIfInputShared(MakeExternal(str1));
auto* child = RefIfInputSharedIndirect(MakeSubstring(1, 24, external));
CordRepRing* result = NeedsUnref(CordRepRing::Create(child));
ASSERT_THAT(result, IsValidRingBuffer());
EXPECT_THAT(result->length, Eq(24));
EXPECT_THAT(ToFlats(result), ElementsAre(str1.substr(1, 24)));
Unref(result);
UnrefIfInputShared(external);
UnrefIfInputSharedIndirect(child);
}
TEST_P(CordRingCreateFromTreeTest, CreateFromSubstringOfLargeExternal) {
auto* external = RefIfInputShared(MakeFakeExternal(1 << 20));
auto str = not_a_string_view(external->base, 1 << 20)
.remove_prefix(1 << 19)
.remove_suffix(6);
auto* child =
RefIfInputSharedIndirect(MakeSubstring(1 << 19, (1 << 19) - 6, external));
CordRepRing* result = NeedsUnref(CordRepRing::Create(child));
ASSERT_THAT(result, IsValidRingBuffer());
EXPECT_THAT(result->length, Eq(str.size()));
EXPECT_THAT(ToRawFlats(result), ElementsAre(str));
Unref(result);
UnrefIfInputShared(external);
UnrefIfInputSharedIndirect(child);
}
TEST_P(CordRingBuildInputTest, CreateFromConcat) {
CordRep* flats[] = {MakeFlat("abcdefgh"), MakeFlat("ijklm"),
MakeFlat("nopqrstuv"), MakeFlat("wxyz")};
auto* left = MakeConcat(RefIfInputSharedIndirect(flats[0]), flats[1]);
auto* right = MakeConcat(flats[2], RefIfInputSharedIndirect(flats[3]));
auto* concat = RefIfInputShared(MakeConcat(left, right));
CordRepRing* result = NeedsUnref(CordRepRing::Create(concat));
ASSERT_THAT(result, IsValidRingBuffer());
EXPECT_THAT(result->length, Eq(26));
EXPECT_THAT(ToString(result), Eq(kAlphabet));
UnrefIfInputSharedIndirect(flats[0]);
UnrefIfInputSharedIndirect(flats[3]);
UnrefIfInputShared(concat);
Unref(result);
}
TEST_P(CordRingBuildInputTest, CreateFromSubstringConcat) {
for (size_t off = 0; off < 26; ++off) {
for (size_t len = 1; len < 26 - off; ++len) {
CordRep* flats[] = {MakeFlat("abcdefgh"), MakeFlat("ijklm"),
MakeFlat("nopqrstuv"), MakeFlat("wxyz")};
auto* left = MakeConcat(RefIfInputSharedIndirect(flats[0]), flats[1]);
auto* right = MakeConcat(flats[2], RefIfInputSharedIndirect(flats[3]));
auto* concat = MakeConcat(left, right);
auto* child = RefIfInputShared(MakeSubstring(off, len, concat));
CordRepRing* result = NeedsUnref(CordRepRing::Create(child));
ASSERT_THAT(result, IsValidRingBuffer());
ASSERT_THAT(result->length, Eq(len));
ASSERT_THAT(ToString(result), string_view(kAlphabet).substr(off, len));
UnrefIfInputSharedIndirect(flats[0]);
UnrefIfInputSharedIndirect(flats[3]);
UnrefIfInputShared(child);
Unref(result);
}
}
}
TEST_P(CordRingCreateTest, Properties) {
absl::string_view str1 = "abcdefghijklmnopqrstuvwxyz";
CordRepRing* result = NeedsUnref(CordRepRing::Create(MakeFlat(str1), 120));
ASSERT_THAT(result, IsValidRingBuffer());
EXPECT_THAT(result->head(), Eq(0));
EXPECT_THAT(result->tail(), Eq(1));
EXPECT_THAT(result->capacity(), Ge(120 + 1));
EXPECT_THAT(result->capacity(), Le(2 * 120 + 1));
EXPECT_THAT(result->entries(), Eq(1));
EXPECT_THAT(result->begin_pos(), Eq(0));
Unref(result);
}
TEST_P(CordRingCreateTest, EntryForNewFlat) {
absl::string_view str1 = "abcdefghijklmnopqrstuvwxyz";
CordRep* child = MakeFlat(str1);
CordRepRing* result = NeedsUnref(CordRepRing::Create(child, 120));
ASSERT_THAT(result, IsValidRingBuffer());
EXPECT_THAT(result->entry_child(0), Eq(child));
EXPECT_THAT(result->entry_end_pos(0), Eq(str1.length()));
EXPECT_THAT(result->entry_data_offset(0), Eq(0));
Unref(result);
}
TEST_P(CordRingCreateTest, EntryForNewFlatSubstring) {
absl::string_view str1 = "1234567890abcdefghijklmnopqrstuvwxyz";
CordRep* child = MakeFlat(str1);
CordRep* substring = MakeSubstring(10, 26, child);
CordRepRing* result = NeedsUnref(CordRepRing::Create(substring, 1));
ASSERT_THAT(result, IsValidRingBuffer());
EXPECT_THAT(result->entry_child(0), Eq(child));
EXPECT_THAT(result->entry_end_pos(0), Eq(26));
EXPECT_THAT(result->entry_data_offset(0), Eq(10));
Unref(result);
}
TEST_P(CordRingBuildTest, AppendFlat) {
absl::string_view str1 = "abcdefghijklmnopqrstuvwxyz";
absl::string_view str2 = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
CordRepRing* ring = CreateWithCapacity(MakeExternal(str1), 1);
CordRepRing* result = NeedsUnref(CordRepRing::Append(ring, MakeFlat(str2)));
ASSERT_THAT(result, IsValidRingBuffer());
EXPECT_THAT(result, EqIfPrivateAndCapacity(GetParam(), ring));
EXPECT_THAT(result->length, Eq(str1.size() + str2.size()));
EXPECT_THAT(ToFlats(result), ElementsAre(str1, str2));
UnrefIfShared(ring);
Unref(result);
}
TEST_P(CordRingBuildTest, PrependFlat) {
absl::string_view str1 = "abcdefghijklmnopqrstuvwxyz";
absl::string_view str2 = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
CordRepRing* ring = CreateWithCapacity(MakeExternal(str1), 1);
CordRepRing* result = NeedsUnref(CordRepRing::Prepend(ring, MakeFlat(str2)));
ASSERT_THAT(result, IsValidRingBuffer());
EXPECT_THAT(result, EqIfPrivateAndCapacity(GetParam(), ring));
EXPECT_THAT(result->length, Eq(str1.size() + str2.size()));
EXPECT_THAT(ToFlats(result), ElementsAre(str2, str1));
UnrefIfShared(ring);
Unref(result);
}
TEST_P(CordRingBuildTest, AppendString) {
absl::string_view str1 = "abcdefghijklmnopqrstuvwxyz";
absl::string_view str2 = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
CordRepRing* ring = CreateWithCapacity(MakeExternal(str1), 1);
CordRepRing* result = NeedsUnref(CordRepRing::Append(ring, str2));
ASSERT_THAT(result, IsValidRingBuffer());
EXPECT_THAT(result, EqIfPrivateAndCapacity(GetParam(), ring));
EXPECT_THAT(result->length, Eq(str1.size() + str2.size()));
EXPECT_THAT(ToFlats(result), ElementsAre(str1, str2));
UnrefIfShared(ring);
Unref(result);
}
TEST_P(CordRingBuildTest, AppendStringHavingExtra) {
absl::string_view str1 = "1234";
absl::string_view str2 = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
CordRepRing* ring = CreateWithCapacity(MakeFlat(str1, 26), 0);
CordRepRing* result = NeedsUnref(CordRepRing::Append(ring, str2));
ASSERT_THAT(result, IsValidRingBuffer());
EXPECT_THAT(result->length, Eq(str1.size() + str2.size()));
EXPECT_THAT(result, EqIfPrivate(GetParam(), ring));
UnrefIfShared(ring);
Unref(result);
}
TEST_P(CordRingBuildTest, AppendStringHavingPartialExtra) {
absl::string_view str1 = "1234";
absl::string_view str2 = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
// Create flat with at least one extra byte. We don't expect to have sized
// alloc and capacity rounding to grant us enough to not make it partial.
auto* flat = MakeFlat(str1, 1);
size_t avail = flat->flat()->Capacity() - flat->length;
ASSERT_THAT(avail, Lt(str2.size())) << " adjust test for larger flats!";
// Construct the flats we do expect using all of `avail`.
absl::string_view str1a = str2.substr(0, avail);
absl::string_view str2a = str2.substr(avail);
CordRepRing* ring = CreateWithCapacity(flat, 1);
CordRepRing* result = NeedsUnref(CordRepRing::Append(ring, str2));
ASSERT_THAT(result, IsValidRingBuffer());
EXPECT_THAT(result->length, Eq(str1.size() + str2.size()));
EXPECT_THAT(result, EqIfPrivateAndCapacity(GetParam(), ring));
if (GetParam().refcount_is_one) {
EXPECT_THAT(ToFlats(result), ElementsAre(StrCat(str1, str1a), str2a));
} else {
EXPECT_THAT(ToFlats(result), ElementsAre(str1, str2));
}
UnrefIfShared(ring);
Unref(result);
}
TEST_P(CordRingBuildTest, AppendStringHavingExtraInSubstring) {
absl::string_view str1 = "123456789_1234";
absl::string_view str2 = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
CordRep* flat = RemovePrefix(10, MakeFlat(str1, 26));
CordRepRing* ring = CreateWithCapacity(flat, 0);
CordRepRing* result = NeedsUnref(CordRepRing::Append(ring, str2));
ASSERT_THAT(result, IsValidRingBuffer());
EXPECT_THAT(result, EqIfPrivate(GetParam(), ring));
EXPECT_THAT(result->length, Eq(4 + str2.size()));
if (GetParam().refcount_is_one) {
EXPECT_THAT(ToFlats(result), ElementsAre(StrCat("1234", str2)));
} else {
EXPECT_THAT(ToFlats(result), ElementsAre("1234", str2));
}
UnrefIfShared(ring);
Unref(result);
}
TEST_P(CordRingBuildTest, AppendStringHavingSharedExtra) {
absl::string_view str1 = "123456789_1234";
absl::string_view str2 = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
for (int shared_type = 0; shared_type < 2; ++shared_type) {
SCOPED_TRACE(absl::StrCat("Shared extra type ", shared_type));
// Create a flat that is shared in some way.
CordRep* flat = nullptr;
CordRep* flat1 = nullptr;
if (shared_type == 0) {
// Shared flat
flat = CordRep::Ref(MakeFlat(str1.substr(10), 100));
} else if (shared_type == 1) {
// Shared flat inside private substring
flat1 = CordRep::Ref(MakeFlat(str1));
flat = RemovePrefix(10, flat1);
} else {
// Private flat inside shared substring
flat = CordRep::Ref(RemovePrefix(10, MakeFlat(str1, 100)));
}
CordRepRing* ring = CreateWithCapacity(flat, 1);
CordRepRing* result = NeedsUnref(CordRepRing::Append(ring, str2));
ASSERT_THAT(result, IsValidRingBuffer());
EXPECT_THAT(result, EqIfPrivateAndCapacity(GetParam(), ring));
EXPECT_THAT(result->length, Eq(4 + str2.size()));
EXPECT_THAT(ToFlats(result), ElementsAre("1234", str2));
UnrefIfShared(ring);
Unref(result);
CordRep::Unref(shared_type == 1 ? flat1 : flat);
}
}
TEST_P(CordRingBuildTest, AppendStringWithExtra) {
absl::string_view str1 = "1234";
absl::string_view str2 = "1234567890";
absl::string_view str3 = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
CordRepRing* ring = CreateWithCapacity(MakeExternal(str1), 1);
CordRepRing* result = NeedsUnref(CordRepRing::Append(ring, str2, 26));
result = CordRepRing::Append(result, str3);
ASSERT_THAT(result, IsValidRingBuffer());
EXPECT_THAT(result->length, Eq(str1.size() + str2.size() + str3.size()));
EXPECT_THAT(result, EqIfPrivateAndCapacity(GetParam(), ring));
EXPECT_THAT(ToFlats(result), ElementsAre(str1, StrCat(str2, str3)));
UnrefIfShared(ring);
Unref(result);
}
TEST_P(CordRingBuildTest, PrependString) {
absl::string_view str1 = "abcdefghijklmnopqrstuvwxyz";
absl::string_view str2 = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
// Use external rep to avoid appending to first flat
CordRepRing* ring = CreateWithCapacity(MakeExternal(str1), 1);
CordRepRing* result = NeedsUnref(CordRepRing::Prepend(ring, str2));
ASSERT_THAT(result, IsValidRingBuffer());
if (GetParam().with_capacity && GetParam().refcount_is_one) {
EXPECT_THAT(result, Eq(ring));
} else {
EXPECT_THAT(result, Ne(ring));
}
EXPECT_THAT(result->length, Eq(str1.size() + str2.size()));
EXPECT_THAT(ToFlats(result), ElementsAre(str2, str1));
UnrefIfShared(ring);
Unref(result);
}
TEST_P(CordRingBuildTest, PrependStringHavingExtra) {
absl::string_view str1 = "abcdefghijklmnopqrstuvwxyz1234";
absl::string_view str2 = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
CordRep* flat = RemovePrefix(26, MakeFlat(str1));
CordRepRing* ring = CreateWithCapacity(flat, 0);
CordRepRing* result = NeedsUnref(CordRepRing::Prepend(ring, str2));
ASSERT_THAT(result, IsValidRingBuffer());
EXPECT_THAT(result, EqIfPrivate(GetParam(), ring));
EXPECT_THAT(result->length, Eq(4 + str2.size()));
if (GetParam().refcount_is_one) {
EXPECT_THAT(ToFlats(result), ElementsAre(StrCat(str2, "1234")));
} else {
EXPECT_THAT(ToFlats(result), ElementsAre(str2, "1234"));
}
UnrefIfShared(ring);
Unref(result);
}
TEST_P(CordRingBuildTest, PrependStringHavingSharedExtra) {
absl::string_view str1 = "123456789_ABCDEFGHIJKLMNOPQRSTUVWXYZ";
absl::string_view str2 = "abcdefghij";
absl::string_view str1a = str1.substr(10);
for (int shared_type = 1; shared_type < 2; ++shared_type) {
SCOPED_TRACE(absl::StrCat("Shared extra type ", shared_type));
// Create a flat that is shared in some way.
CordRep* flat = nullptr;
CordRep* flat1 = nullptr;
if (shared_type == 1) {
// Shared flat inside private substring
flat = RemovePrefix(10, flat1 = CordRep::Ref(MakeFlat(str1)));
} else {
// Private flat inside shared substring
flat = CordRep::Ref(RemovePrefix(10, MakeFlat(str1, 100)));
}
CordRepRing* ring = CreateWithCapacity(flat, 1);
CordRepRing* result = NeedsUnref(CordRepRing::Prepend(ring, str2));
ASSERT_THAT(result, IsValidRingBuffer());
EXPECT_THAT(result->length, Eq(str1a.size() + str2.size()));
EXPECT_THAT(result, EqIfPrivateAndCapacity(GetParam(), ring));
EXPECT_THAT(ToFlats(result), ElementsAre(str2, str1a));
UnrefIfShared(ring);
Unref(result);
CordRep::Unref(shared_type == 1 ? flat1 : flat);
}
}
TEST_P(CordRingBuildTest, PrependStringWithExtra) {
absl::string_view str1 = "1234";
absl::string_view str2 = "1234567890";
absl::string_view str3 = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
CordRepRing* ring = CreateWithCapacity(MakeExternal(str1), 1);
CordRepRing* result = NeedsUnref(CordRepRing::Prepend(ring, str2, 26));
ASSERT_THAT(result, IsValidRingBuffer());
result = CordRepRing::Prepend(result, str3);
EXPECT_THAT(result->length, Eq(str1.size() + str2.size() + str3.size()));
EXPECT_THAT(result, EqIfPrivateAndCapacity(GetParam(), ring));
EXPECT_THAT(ToFlats(result), ElementsAre(StrCat(str3, str2), str1));
UnrefIfShared(ring);
Unref(result);
}
TEST_P(CordRingBuildTest, AppendPrependStringMix) {
const auto& flats = kFoxFlats;
CordRepRing* ring = CreateWithCapacity(MakeFlat(flats[4]), 8);
CordRepRing* result = ring;
for (int i = 1; i <= 4; ++i) {
result = CordRepRing::Prepend(result, flats[4 - i]);
result = CordRepRing::Append(result, flats[4 + i]);
}
UnrefIfShared(ring);
NeedsUnref(result);
ASSERT_THAT(result, IsValidRingBuffer());
EXPECT_THAT(result, EqIfPrivateAndCapacity(GetParam(), ring));
EXPECT_THAT(ToString(result), kFox);
Unref(result);
}
TEST_P(CordRingBuildTest, AppendPrependStringMixWithExtra) {
const auto& flats = kFoxFlats;
CordRepRing* ring = CreateWithCapacity(MakeFlat(flats[4], 100), 8);
CordRepRing* result = ring;
for (int i = 1; i <= 4; ++i) {
result = CordRepRing::Prepend(result, flats[4 - i], 100);
result = CordRepRing::Append(result, flats[4 + i], 100);
}
NeedsUnref(result);
ASSERT_THAT(result, IsValidRingBuffer());
EXPECT_THAT(result, EqIfPrivateAndCapacity(GetParam(), ring));
if (GetParam().refcount_is_one) {
EXPECT_THAT(ToFlats(result),
ElementsAre("The quick brown fox ", "jumps over the lazy dog"));
} else {
EXPECT_THAT(ToFlats(result), ElementsAre("The quick brown fox ", "jumps ",
"over the lazy dog"));
}
UnrefIfShared(ring);
Unref(result);
}
TEST_P(CordRingBuildTest, AppendPrependStringMixWithPrependedExtra) {
const auto& flats = kFoxFlats;
CordRep* flat = MakeFlat(StrCat(std::string(50, '.'), flats[4]), 50);
CordRepRing* ring = CreateWithCapacity(RemovePrefix(50, flat), 0);
CordRepRing* result = ring;
for (int i = 1; i <= 4; ++i) {
result = CordRepRing::Prepend(result, flats[4 - i], 100);
result = CordRepRing::Append(result, flats[4 + i], 100);
}
result = NeedsUnref(result);
ASSERT_THAT(result, IsValidRingBuffer());
EXPECT_THAT(result, EqIfPrivate(GetParam(), ring));
if (GetParam().refcount_is_one) {
EXPECT_THAT(ToFlats(result), ElementsAre(kFox));
} else {
EXPECT_THAT(ToFlats(result), ElementsAre("The quick brown fox ", "jumps ",
"over the lazy dog"));
}
UnrefIfShared(ring);
Unref(result);
}
TEST_P(CordRingSubTest, SubRing) {
auto composition = RandomComposition();
SCOPED_TRACE(ToString(composition));
auto flats = MakeSpan(kFoxFlats);
string_view all = kFox;
for (size_t offset = 0; offset < all.size() - 1; ++offset) {
CordRepRing* ring = RefIfShared(FromFlats(flats, composition));
CordRepRing* result = CordRepRing::SubRing(ring, offset, 0);
EXPECT_THAT(result, nullptr);
UnrefIfShared(ring);
for (size_t len = 1; len < all.size() - offset; ++len) {
ring = RefIfShared(FromFlats(flats, composition));
result = NeedsUnref(CordRepRing::SubRing(ring, offset, len));
ASSERT_THAT(result, IsValidRingBuffer());
ASSERT_THAT(result, EqIfPrivate(GetParam(), ring));
ASSERT_THAT(ToString(result), Eq(all.substr(offset, len)));
UnrefIfShared(ring);
Unref(result);
}
}
}
TEST_P(CordRingSubTest, SubRingFromLargeExternal) {
auto composition = RandomComposition();
std::string large_string(1 << 20, '.');
const char* flats[] = {
"abcdefghijklmnopqrstuvwxyz",
large_string.c_str(),
"ABCDEFGHIJKLMNOPQRSTUVWXYZ",
};
std::string buffer = absl::StrCat(flats[0], flats[1], flats[2]);
absl::string_view all = buffer;
for (size_t offset = 0; offset < 30; ++offset) {
CordRepRing* ring = RefIfShared(FromFlats(flats, composition));
CordRepRing* result = CordRepRing::SubRing(ring, offset, 0);
EXPECT_THAT(result, nullptr);
UnrefIfShared(ring);
for (size_t len = all.size() - 30; len < all.size() - offset; ++len) {
ring = RefIfShared(FromFlats(flats, composition));
result = NeedsUnref(CordRepRing::SubRing(ring, offset, len));
ASSERT_THAT(result, IsValidRingBuffer());
ASSERT_THAT(result, EqIfPrivate(GetParam(), ring));
auto str = ToString(result);
ASSERT_THAT(str, SizeIs(len));
ASSERT_THAT(str, Eq(all.substr(offset, len)));
UnrefIfShared(ring);
Unref(result);
}
}
}
TEST_P(CordRingSubTest, RemovePrefix) {
auto composition = RandomComposition();
SCOPED_TRACE(ToString(composition));
auto flats = MakeSpan(kFoxFlats);
string_view all = kFox;
CordRepRing* ring = RefIfShared(FromFlats(flats, composition));
CordRepRing* result = CordRepRing::RemovePrefix(ring, all.size());
EXPECT_THAT(result, nullptr);
UnrefIfShared(ring);
for (size_t len = 1; len < all.size(); ++len) {
ring = RefIfShared(FromFlats(flats, composition));
result = NeedsUnref(CordRepRing::RemovePrefix(ring, len));
ASSERT_THAT(result, IsValidRingBuffer());
EXPECT_THAT(result, EqIfPrivate(GetParam(), ring));
EXPECT_THAT(ToString(result), Eq(all.substr(len)));
UnrefIfShared(ring);
Unref(result);
}
}
TEST_P(CordRingSubTest, RemovePrefixFromLargeExternal) {
CordRepExternal* external1 = MakeFakeExternal(1 << 20);
CordRepExternal* external2 = MakeFakeExternal(1 << 20);
CordRepRing* ring = CordRepRing::Create(external1, 1);
ring = CordRepRing::Append(ring, external2);
CordRepRing* result = NeedsUnref(CordRepRing::RemovePrefix(ring, 1 << 16));
EXPECT_THAT(
ToRawFlats(result),
ElementsAre(
not_a_string_view(external1->base, 1 << 20).remove_prefix(1 << 16),
not_a_string_view(external2->base, 1 << 20)));
Unref(result);
}
TEST_P(CordRingSubTest, RemoveSuffix) {
auto composition = RandomComposition();
SCOPED_TRACE(ToString(composition));
auto flats = MakeSpan(kFoxFlats);
string_view all = kFox;
CordRepRing* ring = RefIfShared(FromFlats(flats, composition));
CordRepRing* result = CordRepRing::RemoveSuffix(ring, all.size());
EXPECT_THAT(result, nullptr);
UnrefIfShared(ring);
for (size_t len = 1; len < all.size(); ++len) {
ring = RefIfShared(FromFlats(flats, composition));
result = NeedsUnref(CordRepRing::RemoveSuffix(ring, len));
ASSERT_THAT(result, IsValidRingBuffer());
EXPECT_THAT(result, EqIfPrivate(GetParam(), ring));
EXPECT_THAT(ToString(result), Eq(all.substr(0, all.size() - len)));
UnrefIfShared(ring);
Unref(result);
}
}
TEST_P(CordRingSubTest, AppendRing) {
auto composition = RandomComposition();
SCOPED_TRACE(ToString(composition));
auto flats = MakeSpan(kFoxFlats).subspan(1);
CordRepRing* ring = CreateWithCapacity(MakeFlat(kFoxFlats[0]), flats.size());
CordRepRing* child = FromFlats(flats, composition);
CordRepRing* result = NeedsUnref(CordRepRing::Append(ring, child));
ASSERT_THAT(result, IsValidRingBuffer());
EXPECT_THAT(result, EqIfPrivate(GetParam(), ring));
EXPECT_THAT(ToFlats(result), ElementsAreArray(kFoxFlats));
UnrefIfShared(ring);
Unref(result);
}
TEST_P(CordRingBuildInputTest, AppendRingWithFlatOffset) {
auto composition = RandomComposition();
SCOPED_TRACE(ToString(composition));
auto flats = MakeSpan(kFoxFlats);
CordRepRing* ring = CreateWithCapacity(MakeFlat("Head"), flats.size());
CordRep* child = RefIfInputSharedIndirect(FromFlats(flats, composition));
CordRep* stripped = RemovePrefix(10, child);
CordRepRing* result = NeedsUnref(CordRepRing::Append(ring, stripped));
ASSERT_THAT(result, IsValidRingBuffer());
EXPECT_THAT(result, EqIfPrivateAndCapacity(GetParam(), ring));
EXPECT_THAT(ToFlats(result), ElementsAre("Head", "brown ", "fox ", "jumps ",
"over ", "the ", "lazy ", "dog"));
UnrefIfInputSharedIndirect(child);
UnrefIfShared(ring);
Unref(result);
}
TEST_P(CordRingBuildInputTest, AppendRingWithBrokenOffset) {
auto composition = RandomComposition();
SCOPED_TRACE(ToString(composition));
auto flats = MakeSpan(kFoxFlats);
CordRepRing* ring = CreateWithCapacity(MakeFlat("Head"), flats.size());
CordRep* child = RefIfInputSharedIndirect(FromFlats(flats, composition));
CordRep* stripped = RemovePrefix(21, child);
CordRepRing* result = NeedsUnref(CordRepRing::Append(ring, stripped));
ASSERT_THAT(result, IsValidRingBuffer());
EXPECT_THAT(result, EqIfPrivateAndCapacity(GetParam(), ring));
EXPECT_THAT(ToFlats(result),
ElementsAre("Head", "umps ", "over ", "the ", "lazy ", "dog"));
UnrefIfInputSharedIndirect(child);
UnrefIfShared(ring);
Unref(result);
}
TEST_P(CordRingBuildInputTest, AppendRingWithFlatLength) {
auto composition = RandomComposition();
SCOPED_TRACE(ToString(composition));
auto flats = MakeSpan(kFoxFlats);
CordRepRing* ring = CreateWithCapacity(MakeFlat("Head"), flats.size());
CordRep* child = RefIfInputSharedIndirect(FromFlats(flats, composition));
CordRep* stripped = RemoveSuffix(8, child);
CordRepRing* result = NeedsUnref(CordRepRing::Append(ring, stripped));
ASSERT_THAT(result, IsValidRingBuffer());
EXPECT_THAT(result, EqIfPrivateAndCapacity(GetParam(), ring));
EXPECT_THAT(ToFlats(result), ElementsAre("Head", "The ", "quick ", "brown ",
"fox ", "jumps ", "over ", "the "));
UnrefIfInputSharedIndirect(child);
UnrefIfShared(ring);
Unref(result);
}
TEST_P(CordRingBuildTest, AppendRingWithBrokenFlatLength) {
auto composition = RandomComposition();
SCOPED_TRACE(ToString(composition));
auto flats = MakeSpan(kFoxFlats);
CordRepRing* ring = CreateWithCapacity(MakeFlat("Head"), flats.size());
CordRep* child = RefIfInputSharedIndirect(FromFlats(flats, composition));
CordRep* stripped = RemoveSuffix(15, child);
CordRepRing* result = NeedsUnref(CordRepRing::Append(ring, stripped));
ASSERT_THAT(result, IsValidRingBuffer());
EXPECT_THAT(result, EqIfPrivateAndCapacity(GetParam(), ring));
EXPECT_THAT(ToFlats(result), ElementsAre("Head", "The ", "quick ", "brown ",
"fox ", "jumps ", "ov"));
UnrefIfInputSharedIndirect(child);
UnrefIfShared(ring);
Unref(result);
}
TEST_P(CordRingBuildTest, AppendRingMiddlePiece) {
auto composition = RandomComposition();
SCOPED_TRACE(ToString(composition));
auto flats = MakeSpan(kFoxFlats);
CordRepRing* ring = CreateWithCapacity(MakeFlat("Head"), flats.size());
CordRep* child = RefIfInputSharedIndirect(FromFlats(flats, composition));
CordRep* stripped = MakeSubstring(7, child->length - 27, child);
CordRepRing* result = NeedsUnref(CordRepRing::Append(ring, stripped));
ASSERT_THAT(result, IsValidRingBuffer());
EXPECT_THAT(result, EqIfPrivateAndCapacity(GetParam(), ring));
EXPECT_THAT(ToFlats(result),
ElementsAre("Head", "ck ", "brown ", "fox ", "jum"));
UnrefIfInputSharedIndirect(child);
UnrefIfShared(ring);
Unref(result);
}
TEST_P(CordRingBuildTest, AppendRingSinglePiece) {
auto composition = RandomComposition();
SCOPED_TRACE(ToString(composition));
auto flats = MakeSpan(kFoxFlats);
CordRepRing* ring = CreateWithCapacity(MakeFlat("Head"), flats.size());
CordRep* child = RefIfInputSharedIndirect(FromFlats(flats, composition));
CordRep* stripped = RefIfInputShared(MakeSubstring(11, 3, child));
CordRepRing* result = NeedsUnref(CordRepRing::Append(ring, stripped));
ASSERT_THAT(result, IsValidRingBuffer());
EXPECT_THAT(result, EqIfPrivateAndCapacity(GetParam(), ring));
EXPECT_THAT(ToFlats(result), ElementsAre("Head", "row"));
UnrefIfInputSharedIndirect(child);
UnrefIfInputShared(stripped);
UnrefIfShared(ring);
Unref(result);
}
TEST_P(CordRingBuildInputTest, AppendRingSinglePieceWithPrefix) {
auto composition = RandomComposition();
SCOPED_TRACE(ToString(composition));
auto flats = MakeSpan(kFoxFlats);
size_t extra_capacity = 1 + (GetParam().with_capacity ? flats.size() : 0);
CordRepRing* ring = CordRepRing::Create(MakeFlat("Head"), extra_capacity);
ring->SetCapacityForTesting(1 + extra_capacity);
ring = RefIfShared(CordRepRing::Prepend(ring, MakeFlat("Prepend")));
assert(ring->IsValid(std::cout));
CordRepRing* child = RefIfInputSharedIndirect(FromFlats(flats, composition));
CordRep* stripped = RefIfInputShared(MakeSubstring(11, 3, child));
CordRepRing* result = NeedsUnref(CordRepRing::Append(ring, stripped));
ASSERT_THAT(result, IsValidRingBuffer());
EXPECT_THAT(result, EqIfPrivateAndCapacity(GetParam(), ring));
EXPECT_THAT(ToFlats(result), ElementsAre("Prepend", "Head", "row"));
UnrefIfInputSharedIndirect(child);
UnrefIfInputShared(stripped);
UnrefIfShared(ring);
Unref(result);
}
TEST_P(CordRingBuildInputTest, PrependRing) {
auto composition = RandomComposition();
SCOPED_TRACE(ToString(composition));
auto fox = MakeSpan(kFoxFlats);
auto flats = MakeSpan(fox).subspan(0, fox.size() - 1);
CordRepRing* ring = CreateWithCapacity(MakeFlat(fox.back()), flats.size());
CordRepRing* child = RefIfInputShared(FromFlats(flats, composition));
CordRepRing* result = NeedsUnref(CordRepRing::Prepend(ring, child));
ASSERT_THAT(result, IsValidRingBuffer());
EXPECT_THAT(result, EqIfPrivateAndCapacity(GetParam(), ring));
EXPECT_THAT(ToFlats(result), ElementsAreArray(kFoxFlats));
UnrefIfInputShared(child);
UnrefIfShared(ring);
Unref(result);
}
TEST_P(CordRingBuildInputTest, PrependRingWithFlatOffset) {
auto composition = RandomComposition();
SCOPED_TRACE(ToString(composition));
auto flats = MakeSpan(kFoxFlats);
CordRepRing* ring = CreateWithCapacity(MakeFlat("Tail"), flats.size());
CordRep* child = RefIfInputShared(FromFlats(flats, composition));
CordRep* stripped = RefIfInputSharedIndirect(RemovePrefix(10, child));
CordRepRing* result = NeedsUnref(CordRepRing::Prepend(ring, stripped));
ASSERT_THAT(result, IsValidRingBuffer());
EXPECT_THAT(result, EqIfPrivateAndCapacity(GetParam(), ring));
EXPECT_THAT(ToFlats(result), ElementsAre("brown ", "fox ", "jumps ", "over ",
"the ", "lazy ", "dog", "Tail"));
UnrefIfInputShared(child);
UnrefIfInputSharedIndirect(stripped);
UnrefIfShared(ring);
Unref(result);
}
TEST_P(CordRingBuildInputTest, PrependRingWithBrokenOffset) {
auto composition = RandomComposition();
SCOPED_TRACE(ToString(composition));
auto flats = MakeSpan(kFoxFlats);
CordRepRing* ring = CreateWithCapacity(MakeFlat("Tail"), flats.size());
CordRep* child = RefIfInputShared(FromFlats(flats, composition));
CordRep* stripped = RefIfInputSharedIndirect(RemovePrefix(21, child));
CordRepRing* result = NeedsUnref(CordRepRing::Prepend(ring, stripped));
EXPECT_THAT(result, EqIfPrivateAndCapacity(GetParam(), ring));
EXPECT_THAT(ToFlats(result),
ElementsAre("umps ", "over ", "the ", "lazy ", "dog", "Tail"));
UnrefIfInputShared(child);
UnrefIfInputSharedIndirect(stripped);
UnrefIfShared(ring);
Unref(result);
}
TEST_P(CordRingBuildInputTest, PrependRingWithFlatLength) {
auto composition = RandomComposition();
SCOPED_TRACE(ToString(composition));
auto flats = MakeSpan(kFoxFlats);
CordRepRing* ring = CreateWithCapacity(MakeFlat("Tail"), flats.size());
CordRep* child = RefIfInputShared(FromFlats(flats, composition));
CordRep* stripped = RefIfInputSharedIndirect(RemoveSuffix(8, child));
CordRepRing* result = NeedsUnref(CordRepRing::Prepend(ring, stripped));
ASSERT_THAT(result, IsValidRingBuffer());
EXPECT_THAT(result, EqIfPrivateAndCapacity(GetParam(), ring));
EXPECT_THAT(ToFlats(result), ElementsAre("The ", "quick ", "brown ", "fox ",
"jumps ", "over ", "the ", "Tail"));
UnrefIfShared(ring);
UnrefIfInputShared(child);
UnrefIfInputSharedIndirect(stripped);
Unref(result);
}
TEST_P(CordRingBuildInputTest, PrependRingWithBrokenFlatLength) {
auto composition = RandomComposition();
SCOPED_TRACE(ToString(composition));
auto flats = MakeSpan(kFoxFlats);
CordRepRing* ring = CreateWithCapacity(MakeFlat("Tail"), flats.size());
CordRep* child = RefIfInputShared(FromFlats(flats, composition));
CordRep* stripped = RefIfInputSharedIndirect(RemoveSuffix(15, child));
CordRepRing* result = NeedsUnref(CordRepRing::Prepend(ring, stripped));
ASSERT_THAT(result, IsValidRingBuffer());
EXPECT_THAT(result, EqIfPrivateAndCapacity(GetParam(), ring));
EXPECT_THAT(ToFlats(result), ElementsAre("The ", "quick ", "brown ", "fox ",
"jumps ", "ov", "Tail"));
UnrefIfInputShared(child);
UnrefIfInputSharedIndirect(stripped);
UnrefIfShared(ring);
Unref(result);
}
TEST_P(CordRingBuildInputTest, PrependRingMiddlePiece) {
auto composition = RandomComposition();
SCOPED_TRACE(ToString(composition));
auto flats = MakeSpan(kFoxFlats);
CordRepRing* ring = CreateWithCapacity(MakeFlat("Tail"), flats.size());
CordRep* child = RefIfInputShared(FromFlats(flats, composition));
CordRep* stripped =
RefIfInputSharedIndirect(MakeSubstring(7, child->length - 27, child));
CordRepRing* result = NeedsUnref(CordRepRing::Prepend(ring, stripped));
ASSERT_THAT(result, IsValidRingBuffer());
EXPECT_THAT(result, EqIfPrivateAndCapacity(GetParam(), ring));
EXPECT_THAT(ToFlats(result),
ElementsAre("ck ", "brown ", "fox ", "jum", "Tail"));
UnrefIfInputShared(child);
UnrefIfInputSharedIndirect(stripped);
UnrefIfShared(ring);
Unref(result);
}
TEST_P(CordRingBuildInputTest, PrependRingSinglePiece) {
auto composition = RandomComposition();
SCOPED_TRACE(ToString(composition));
auto flats = MakeSpan(kFoxFlats);
CordRepRing* ring = CreateWithCapacity(MakeFlat("Tail"), flats.size());
CordRep* child = RefIfInputShared(FromFlats(flats, composition));
CordRep* stripped = RefIfInputSharedIndirect(MakeSubstring(11, 3, child));
CordRepRing* result = NeedsUnref(CordRepRing::Prepend(ring, stripped));
ASSERT_THAT(result, IsValidRingBuffer());
EXPECT_THAT(result, EqIfPrivateAndCapacity(GetParam(), ring));
EXPECT_THAT(ToFlats(result), ElementsAre("row", "Tail"));
UnrefIfInputShared(child);
UnrefIfInputSharedIndirect(stripped);
UnrefIfShared(ring);
Unref(result);
}
TEST_P(CordRingBuildInputTest, PrependRingSinglePieceWithPrefix) {
auto composition = RandomComposition();
SCOPED_TRACE(ToString(composition));
auto flats = MakeSpan(kFoxFlats);
size_t extra_capacity = 1 + (GetParam().with_capacity ? flats.size() : 0);
CordRepRing* ring = CordRepRing::Create(MakeFlat("Tail"), extra_capacity);
ring->SetCapacityForTesting(1 + extra_capacity);
ring = RefIfShared(CordRepRing::Prepend(ring, MakeFlat("Prepend")));
CordRep* child = RefIfInputShared(FromFlats(flats, composition));
CordRep* stripped = RefIfInputSharedIndirect(MakeSubstring(11, 3, child));
CordRepRing* result = NeedsUnref(CordRepRing::Prepend(ring, stripped));
ASSERT_THAT(result, IsValidRingBuffer());
EXPECT_THAT(result, EqIfPrivateAndCapacity(GetParam(), ring));
EXPECT_THAT(ToFlats(result), ElementsAre("row", "Prepend", "Tail"));
UnrefIfInputShared(child);
UnrefIfInputSharedIndirect(stripped);
UnrefIfShared(ring);
Unref(result);
}
TEST_F(CordRingTest, Find) {
constexpr const char* flats[] = {
"abcdefghij", "klmnopqrst", "uvwxyz", "ABCDEFGHIJ",
"KLMNOPQRST", "UVWXYZ", "1234567890", "~!@#$%^&*()_",
"+-=", "[]\\{}|;':", ",/<>?", "."};
auto composition = RandomComposition();
SCOPED_TRACE(ToString(composition));
CordRepRing* ring = NeedsUnref(FromFlats(flats, composition));
std::string value = ToString(ring);
for (int i = 0; i < value.length(); ++i) {
CordRepRing::Position found = ring->Find(i);
auto data = ring->entry_data(found.index);
ASSERT_THAT(found.offset, Lt(data.length()));
ASSERT_THAT(data[found.offset], Eq(value[i]));
}
Unref(ring);
}
TEST_F(CordRingTest, FindWithHint) {
constexpr const char* flats[] = {
"abcdefghij", "klmnopqrst", "uvwxyz", "ABCDEFGHIJ",
"KLMNOPQRST", "UVWXYZ", "1234567890", "~!@#$%^&*()_",
"+-=", "[]\\{}|;':", ",/<>?", "."};
auto composition = RandomComposition();
SCOPED_TRACE(ToString(composition));
CordRepRing* ring = NeedsUnref(FromFlats(flats, composition));
std::string value = ToString(ring);
#if defined(GTEST_HAS_DEATH_TEST)
// Test hint beyond valid position
index_type head = ring->head();
EXPECT_DEBUG_DEATH(ring->Find(ring->advance(head), 0), ".*");
EXPECT_DEBUG_DEATH(ring->Find(ring->advance(head), 9), ".*");
EXPECT_DEBUG_DEATH(ring->Find(ring->advance(head, 3), 24), ".*");
#endif
int flat_pos = 0;
size_t flat_offset = 0;
for (auto sflat : flats) {
string_view flat(sflat);
for (int offset = 0; offset < flat.length(); ++offset) {
for (int start = 0; start <= flat_pos; ++start) {
index_type hint = ring->advance(ring->head(), start);
CordRepRing::Position found = ring->Find(hint, flat_offset + offset);
ASSERT_THAT(found.index, Eq(ring->advance(ring->head(), flat_pos)));
ASSERT_THAT(found.offset, Eq(offset));
}
}
++flat_pos;
flat_offset += flat.length();
}
Unref(ring);
}
TEST_F(CordRingTest, FindInLargeRing) {
constexpr const char* flats[] = {
"abcdefghij", "klmnopqrst", "uvwxyz", "ABCDEFGHIJ",
"KLMNOPQRST", "UVWXYZ", "1234567890", "~!@#$%^&*()_",
"+-=", "[]\\{}|;':", ",/<>?", "."};
auto composition = RandomComposition();
SCOPED_TRACE(ToString(composition));
CordRepRing* ring = FromFlats(flats, composition);
for (int i = 0; i < 13; ++i) {
ring = CordRepRing::Append(ring, FromFlats(flats, composition));
}
NeedsUnref(ring);
std::string value = ToString(ring);
for (int i = 0; i < value.length(); ++i) {
CordRepRing::Position pos = ring->Find(i);
auto data = ring->entry_data(pos.index);
ASSERT_THAT(pos.offset, Lt(data.length()));
ASSERT_THAT(data[pos.offset], Eq(value[i]));
}
Unref(ring);
}
TEST_F(CordRingTest, FindTail) {
constexpr const char* flats[] = {
"abcdefghij", "klmnopqrst", "uvwxyz", "ABCDEFGHIJ",
"KLMNOPQRST", "UVWXYZ", "1234567890", "~!@#$%^&*()_",
"+-=", "[]\\{}|;':", ",/<>?", "."};
auto composition = RandomComposition();
SCOPED_TRACE(ToString(composition));
CordRepRing* ring = NeedsUnref(FromFlats(flats, composition));
std::string value = ToString(ring);
for (int i = 0; i < value.length(); ++i) {
CordRepRing::Position pos = ring->FindTail(i + 1);
auto data = ring->entry_data(ring->retreat(pos.index));
ASSERT_THAT(pos.offset, Lt(data.length()));
ASSERT_THAT(data[data.length() - pos.offset - 1], Eq(value[i]));
}
Unref(ring);
}
TEST_F(CordRingTest, FindTailWithHint) {
constexpr const char* flats[] = {
"abcdefghij", "klmnopqrst", "uvwxyz", "ABCDEFGHIJ",
"KLMNOPQRST", "UVWXYZ", "1234567890", "~!@#$%^&*()_",
"+-=", "[]\\{}|;':", ",/<>?", "."};
auto composition = RandomComposition();
SCOPED_TRACE(ToString(composition));
CordRepRing* ring = NeedsUnref(FromFlats(flats, composition));
std::string value = ToString(ring);
// Test hint beyond valid position
#if defined(GTEST_HAS_DEATH_TEST)
index_type head = ring->head();
EXPECT_DEBUG_DEATH(ring->FindTail(ring->advance(head), 1), ".*");
EXPECT_DEBUG_DEATH(ring->FindTail(ring->advance(head), 10), ".*");
EXPECT_DEBUG_DEATH(ring->FindTail(ring->advance(head, 3), 26), ".*");
#endif
for (int i = 0; i < value.length(); ++i) {
CordRepRing::Position pos = ring->FindTail(i + 1);
auto data = ring->entry_data(ring->retreat(pos.index));
ASSERT_THAT(pos.offset, Lt(data.length()));
ASSERT_THAT(data[data.length() - pos.offset - 1], Eq(value[i]));
}
Unref(ring);
}
TEST_F(CordRingTest, FindTailInLargeRing) {
constexpr const char* flats[] = {
"abcdefghij", "klmnopqrst", "uvwxyz", "ABCDEFGHIJ",
"KLMNOPQRST", "UVWXYZ", "1234567890", "~!@#$%^&*()_",
"+-=", "[]\\{}|;':", ",/<>?", "."};
auto composition = RandomComposition();
SCOPED_TRACE(ToString(composition));
CordRepRing* ring = FromFlats(flats, composition);
for (int i = 0; i < 13; ++i) {
ring = CordRepRing::Append(ring, FromFlats(flats, composition));
}
NeedsUnref(ring);
std::string value = ToString(ring);
for (int i = 0; i < value.length(); ++i) {
CordRepRing::Position pos = ring->FindTail(i + 1);
auto data = ring->entry_data(ring->retreat(pos.index));
ASSERT_THAT(pos.offset, Lt(data.length()));
ASSERT_THAT(data[data.length() - pos.offset - 1], Eq(value[i]));
}
Unref(ring);
}
TEST_F(CordRingTest, GetCharacter) {
auto flats = MakeSpan(kFoxFlats);
CordRepRing* ring = CordRepRing::Create(MakeFlat("Tail"), flats.size());
CordRep* child = FromFlats(flats, kAppend);
CordRepRing* result = NeedsUnref(CordRepRing::Prepend(ring, child));
std::string value = ToString(result);
for (int i = 0; i < value.length(); ++i) {
ASSERT_THAT(result->GetCharacter(i), Eq(value[i]));
}
Unref(result);
}
TEST_F(CordRingTest, GetCharacterWithSubstring) {
absl::string_view str1 = "abcdefghijklmnopqrstuvwxyz";
auto* child = MakeSubstring(4, 20, MakeFlat(str1));
CordRepRing* result = NeedsUnref(CordRepRing::Create(child));
ASSERT_THAT(result, IsValidRingBuffer());
std::string value = ToString(result);
for (int i = 0; i < value.length(); ++i) {
ASSERT_THAT(result->GetCharacter(i), Eq(value[i]));
}
Unref(result);
}
TEST_F(CordRingTest, Dump) {
std::stringstream ss;
auto flats = MakeSpan(kFoxFlats);
CordRepRing* ring = NeedsUnref(FromFlats(flats, kPrepend));
ss << *ring;
Unref(ring);
}
} // namespace
ABSL_NAMESPACE_END
} // namespace absl
absl/strings/internal/cord_internal.cc
......@@ -19,6 +19,7 @@
#include "absl/container/inlined_vector.h"
#include "absl/strings/internal/cord_rep_flat.h"
#include "absl/strings/internal/cord_rep_ring.h"
namespace absl {
ABSL_NAMESPACE_BEGIN
......@@ -48,6 +49,9 @@ void CordRep::Destroy(CordRep* rep) {
rep = left;
continue;
}
} else if (rep->tag == RING) {
CordRepRing::Destroy(rep->ring());
rep = nullptr;
} else if (rep->tag == EXTERNAL) {
CordRepExternal::Delete(rep);
rep = nullptr;
......
absl/strings/internal/cord_internal.h
// Copyright 2020 The Abseil Authors.
// Copyright 2021 The Abseil Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
......@@ -21,6 +21,7 @@
#include <cstdint>
#include <type_traits>
#include "absl/base/config.h"
#include "absl/base/internal/invoke.h"
#include "absl/base/optimization.h"
#include "absl/container/internal/compressed_tuple.h"
......@@ -145,13 +146,14 @@ struct CordRepConcat;
struct CordRepExternal;
struct CordRepFlat;
struct CordRepSubstring;
class CordRepRing;
// Various representations that we allow
enum CordRepKind {
CONCAT = 0,
EXTERNAL = 1,
SUBSTRING = 2,
RING = 3,
CONCAT = 0,
EXTERNAL = 1,
SUBSTRING = 2,
RING = 3,
// We have different tags for different sized flat arrays,
// starting with FLAT, and limited to MAX_FLAT_TAG. The 224 value is based on
......@@ -160,7 +162,7 @@ enum CordRepKind {
// as the Tag <---> Size logic so that FLAT stil represents the minimum flat
// allocation size. (32 bytes as of now).
FLAT = 4,
MAX_FLAT_TAG = 224,
MAX_FLAT_TAG = 224
};
struct CordRep {
......@@ -177,6 +179,8 @@ struct CordRep {
uint8_t tag;
char storage[1]; // Starting point for flat array: MUST BE LAST FIELD
inline CordRepRing* ring();
inline const CordRepRing* ring() const;
inline CordRepConcat* concat();
inline const CordRepConcat* concat() const;
inline CordRepSubstring* substring();
......@@ -306,45 +310,165 @@ CordRepExternal ConstInitExternalStorage<Str>::value(Str::value);
enum {
kMaxInline = 15,
// Tag byte & kMaxInline means we are storing a pointer.
kTreeFlag = 1 << 4,
// Tag byte & kProfiledFlag means we are profiling the Cord.
kProfiledFlag = 1 << 5
};
// If the data has length <= kMaxInline, we store it in `as_chars`, and
// store the size in `tagged_size`.
// Else we store it in a tree and store a pointer to that tree in
// `as_tree.rep` and store a tag in `tagged_size`.
struct AsTree {
absl::cord_internal::CordRep* rep;
char padding[kMaxInline + 1 - sizeof(absl::cord_internal::CordRep*) - 1];
char tagged_size;
};
constexpr char GetOrNull(absl::string_view data, size_t pos) {
return pos < data.size() ? data[pos] : '\0';
}
union InlineData {
constexpr InlineData() : as_chars{} {}
explicit constexpr InlineData(AsTree tree) : as_tree(tree) {}
// We store cordz_info as 64 bit pointer value in big endian format. This
// guarantees that the least significant byte of cordz_info matches the last
// byte of the inline data representation in as_chars_, which holds the inlined
// size or the 'is_tree' bit.
using cordz_info_t = int64_t;
// Assert that the `cordz_info` pointer value perfectly overlaps the last half
// of `as_chars_` and can hold a pointer value.
static_assert(sizeof(cordz_info_t) * 2 == kMaxInline + 1, "");
static_assert(sizeof(cordz_info_t) >= sizeof(intptr_t), "");
// BigEndianByte() creates a big endian representation of 'value', i.e.: a big
// endian value where the last byte in the host's representation holds 'value`,
// with all other bytes being 0.
static constexpr cordz_info_t BigEndianByte(unsigned char value) {
#if defined(ABSL_IS_BIG_ENDIAN)
return value;
#else
return static_cast<cordz_info_t>(value) << ((sizeof(cordz_info_t) - 1) * 8);
#endif
}
class InlineData {
public:
// kNullCordzInfo holds the big endian representation of intptr_t(1)
// This is the 'null' / initial value of 'cordz_info'. The null value
// is specifically big endian 1 as with 64-bit pointers, the last
// byte of cordz_info overlaps with the last byte holding the tag.
static constexpr cordz_info_t kNullCordzInfo = BigEndianByte(1);
// kFakeCordzInfo holds a 'fake', non-null cordz-info value we use to
// emulate the previous 'kProfiled' tag logic in 'set_profiled' until
// cord code is changed to store cordz_info values in InlineData.
static constexpr cordz_info_t kFakeCordzInfo = BigEndianByte(9);
constexpr InlineData() : as_chars_{0} {}
explicit constexpr InlineData(CordRep* rep) : as_tree_(rep) {}
explicit constexpr InlineData(absl::string_view chars)
: as_chars{GetOrNull(chars, 0), GetOrNull(chars, 1),
GetOrNull(chars, 2), GetOrNull(chars, 3),
GetOrNull(chars, 4), GetOrNull(chars, 5),
GetOrNull(chars, 6), GetOrNull(chars, 7),
GetOrNull(chars, 8), GetOrNull(chars, 9),
GetOrNull(chars, 10), GetOrNull(chars, 11),
GetOrNull(chars, 12), GetOrNull(chars, 13),
GetOrNull(chars, 14), static_cast<char>(chars.size())} {}
AsTree as_tree;
char as_chars[kMaxInline + 1];
: as_chars_{
GetOrNull(chars, 0), GetOrNull(chars, 1),
GetOrNull(chars, 2), GetOrNull(chars, 3),
GetOrNull(chars, 4), GetOrNull(chars, 5),
GetOrNull(chars, 6), GetOrNull(chars, 7),
GetOrNull(chars, 8), GetOrNull(chars, 9),
GetOrNull(chars, 10), GetOrNull(chars, 11),
GetOrNull(chars, 12), GetOrNull(chars, 13),
GetOrNull(chars, 14), static_cast<char>((chars.size() << 1))} {}
// Returns true if the current instance is empty.
// The 'empty value' is an inlined data value of zero length.
bool is_empty() const { return tag() == 0; }
// Returns true if the current instance holds a tree value.
bool is_tree() const { return (tag() & 1) != 0; }
// Returns true if the current instance holds a cordz_info value.
// Requires the current instance to hold a tree value.
bool is_profiled() const {
assert(is_tree());
return as_tree_.cordz_info != kNullCordzInfo;
}
// Returns a read only pointer to the character data inside this instance.
// Requires the current instance to hold inline data.
const char* as_chars() const {
assert(!is_tree());
return as_chars_;
}
// Returns a mutable pointer to the character data inside this instance.
// Should be used for 'write only' operations setting an inlined value.
// Applications can set the value of inlined data either before or after
// setting the inlined size, i.e., both of the below are valid:
//
// // Set inlined data and inline size
// memcpy(data_.as_chars(), data, size);
// data_.set_inline_size(size);
//
// // Set inlined size and inline data
// data_.set_inline_size(size);
// memcpy(data_.as_chars(), data, size);
//
// It's an error to read from the returned pointer without a preceding write
// if the current instance does not hold inline data, i.e.: is_tree() == true.
char* as_chars() { return as_chars_; }
// Returns the tree value of this value.
// Requires the current instance to hold a tree value.
CordRep* as_tree() const {
assert(is_tree());
return as_tree_.rep;
}
// Initialize this instance to holding the tree value `rep`,
// initializing the cordz_info to null, i.e.: 'not profiled'.
void make_tree(CordRep* rep) {
as_tree_.rep = rep;
as_tree_.cordz_info = kNullCordzInfo;
}
// Set the tree value of this instance to 'rep`.
// Requires the current instance to already hold a tree value.
// Does not affect the value of cordz_info.
void set_tree(CordRep* rep) {
assert(is_tree());
as_tree_.rep = rep;
}
// Returns the size of the inlined character data inside this instance.
// Requires the current instance to hold inline data.
size_t inline_size() const {
assert(!is_tree());
return tag() >> 1;
}
// Sets the size of the inlined character data inside this instance.
// Requires `size` to be <= kMaxInline.
// See the documentation on 'as_chars()' for more information and examples.
void set_inline_size(size_t size) {
ABSL_ASSERT(size <= kMaxInline);
tag() = static_cast<char>(size << 1);
}
// Sets or unsets the 'is_profiled' state of this instance.
// Requires the current instance to hold a tree value.
void set_profiled(bool profiled) {
assert(is_tree());
as_tree_.cordz_info = profiled ? kFakeCordzInfo : kNullCordzInfo;
}
private:
// See cordz_info_t for forced alignment and size of `cordz_info` details.
struct AsTree {
explicit constexpr AsTree(absl::cord_internal::CordRep* tree)
: rep(tree), cordz_info(kNullCordzInfo) {}
absl::cord_internal::CordRep* rep;
alignas(sizeof(cordz_info_t)) cordz_info_t cordz_info;
};
char& tag() { return reinterpret_cast<char*>(this)[kMaxInline]; }
char tag() const { return reinterpret_cast<const char*>(this)[kMaxInline]; }
// If the data has length <= kMaxInline, we store it in `as_chars_`, and
// store the size in the last char of `as_chars_` shifted left + 1.
// Else we store it in a tree and store a pointer to that tree in
// `as_tree_.rep` and store a tag in `tagged_size`.
union {
char as_chars_[kMaxInline + 1];
AsTree as_tree_;
};
};
static_assert(sizeof(InlineData) == kMaxInline + 1, "");
static_assert(sizeof(AsTree) == sizeof(InlineData), "");
static_assert(offsetof(AsTree, tagged_size) == kMaxInline, "");
inline CordRepConcat* CordRep::concat() {
assert(tag == CONCAT);
......@@ -386,6 +510,16 @@ inline const CordRepFlat* CordRep::flat() const {
return reinterpret_cast<const CordRepFlat*>(this);
}
inline CordRepRing* CordRep::ring() {
assert(tag == RING);
return reinterpret_cast<CordRepRing*>(this);
}
inline const CordRepRing* CordRep::ring() const {
assert(tag == RING);
return reinterpret_cast<const CordRepRing*>(this);
}
inline CordRep* CordRep::Ref(CordRep* rep) {
assert(rep != nullptr);
rep->refcount.Increment();
......
absl/strings/internal/cord_rep_flat.h
......@@ -104,7 +104,8 @@ struct CordRepFlat : public CordRep {
// Flat CordReps are allocated and constructed with raw ::operator new and
// placement new, and must be destructed and deallocated accordingly.
static void Delete(CordRep*rep) {
assert(rep->tag >= FLAT);
assert(rep->tag >= FLAT && rep->tag <= MAX_FLAT_TAG);
#if defined(__cpp_sized_deallocation)
size_t size = TagToAllocatedSize(rep->tag);
rep->~CordRep();
......@@ -115,6 +116,7 @@ struct CordRepFlat : public CordRep {
#endif
}
// Returns a pointer to the data inside this flat rep.
char* Data() { return storage; }
const char* Data() const { return storage; }
......
absl/strings/internal/cord_rep_ring.cc 0 → 100644
// Copyright 2020 The Abseil Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "absl/strings/internal/cord_rep_ring.h"
#include <cassert>
#include <cstddef>
#include <cstdint>
#include <iostream>
#include <limits>
#include <memory>
#include <string>
#include "absl/base/internal/raw_logging.h"
#include "absl/base/internal/throw_delegate.h"
#include "absl/base/macros.h"
#include "absl/container/inlined_vector.h"
#include "absl/strings/internal/cord_internal.h"
#include "absl/strings/internal/cord_rep_flat.h"
namespace absl {
ABSL_NAMESPACE_BEGIN
namespace cord_internal {
// See https://bugs.llvm.org/show_bug.cgi?id=48477
#ifdef __clang__
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wshadow"
#pragma clang diagnostic ignored "-Wshadow-field"
#endif
namespace {
using index_type = CordRepRing::index_type;
enum class Direction { kForward, kReversed };
inline bool IsFlatOrExternal(CordRep* rep) {
return rep->tag >= FLAT || rep->tag == EXTERNAL;
}
// Verifies that n + extra <= kMaxCapacity: throws std::length_error otherwise.
inline void CheckCapacity(size_t n, size_t extra) {
if (ABSL_PREDICT_FALSE(extra > CordRepRing::kMaxCapacity - n)) {
base_internal::ThrowStdLengthError("Maximum capacity exceeded");
}
}
// Removes a reference from `rep` only.
// Asserts that the refcount after decrement is not zero.
inline bool UnrefNeverOne(CordRep* rep) {
bool result = rep->refcount.Decrement();
assert(result);
return result;
}
// Creates a flat from the provided string data, allocating up to `extra`
// capacity in the returned flat depending on kMaxFlatLength limitations.
// Requires `len` to be less or equal to `kMaxFlatLength`
CordRepFlat* CreateFlat(const char* s, size_t n, size_t extra = 0) { // NOLINT
assert(n <= kMaxFlatLength);
auto* rep = CordRepFlat::New(n + extra);
rep->length = n;
memcpy(rep->Data(), s, n);
return rep;
}
// Unrefs the provided `substring`, and returns `substring->child`
// Adds or assumes a reference on `substring->child`
CordRep* ClipSubstring(CordRepSubstring* substring) {
CordRep* child = substring->child;
if (substring->refcount.IsOne()) {
delete substring;
} else {
CordRep::Ref(child);
if (ABSL_PREDICT_FALSE(!substring->refcount.Decrement())) {
UnrefNeverOne(child);
delete substring;
}
}
return child;
}
// Unrefs the provided `concat`, and returns `{concat->left, concat->right}`
// Adds or assumes a reference on `concat->left` and `concat->right`.
std::pair<CordRep*, CordRep*> ClipConcat(CordRepConcat* concat) {
auto result = std::make_pair(concat->left, concat->right);
if (concat->refcount.IsOne()) {
delete concat;
} else {
CordRep::Ref(result.first);
CordRep::Ref(result.second);
if (ABSL_PREDICT_FALSE(!concat->refcount.Decrement())) {
UnrefNeverOne(result.first);
UnrefNeverOne(result.second);
delete concat;
}
}
return result;
}
// Unrefs the entries in `[head, tail)`.
// Requires all entries to be a FLAT or EXTERNAL node.
void UnrefEntries(const CordRepRing* rep, index_type head, index_type tail) {
rep->ForEach(head, tail, [rep](index_type ix) {
CordRep* child = rep->entry_child(ix);
if (!child->refcount.Decrement()) {
if (child->tag >= FLAT) {
CordRepFlat::Delete(child->flat());
} else {
CordRepExternal::Delete(child->external());
}
}
});
}
template <typename F>
void Consume(Direction direction, CordRep* rep, F&& fn) {
size_t offset = 0;
size_t length = rep->length;
struct Entry {
CordRep* rep;
size_t offset;
size_t length;
};
absl::InlinedVector<Entry, 40> stack;
for (;;) {
if (rep->tag >= FLAT || rep->tag == EXTERNAL || rep->tag == RING) {
fn(rep, offset, length);
if (stack.empty()) return;
rep = stack.back().rep;
offset = stack.back().offset;
length = stack.back().length;
stack.pop_back();
} else if (rep->tag == SUBSTRING) {
offset += rep->substring()->start;
rep = ClipSubstring(rep->substring());
} else if (rep->tag == CONCAT) {
auto res = ClipConcat(rep->concat());
CordRep* left = res.first;
CordRep* right = res.second;
if (left->length <= offset) {
// Don't need left node
offset -= left->length;
CordRep::Unref(left);
rep = right;
continue;
}
size_t length_left = left->length - offset;
if (length_left >= length) {
// Don't need right node
CordRep::Unref(right);
rep = left;
continue;
}
// Need both nodes
size_t length_right = length - length_left;
if (direction == Direction::kReversed) {
stack.push_back({left, offset, length_left});
rep = right;
offset = 0;
length = length_right;
} else {
stack.push_back({right, 0, length_right});
rep = left;
length = length_left;
}
} else {
assert("Valid tag" == nullptr);
return;
}
}
}
template <typename F>
void Consume(CordRep* rep, F&& fn) {
return Consume(Direction::kForward, rep, std::forward<F>(fn));
}
template <typename F>
void RConsume(CordRep* rep, F&& fn) {
return Consume(Direction::kReversed, rep, std::forward<F>(fn));
}
} // namespace
std::ostream& operator<<(std::ostream& s, const CordRepRing& rep) {
// Note: 'pos' values are defined as size_t (for overflow reasons), but that
// prints really awkward for small prepended values such as -5. ssize_t is not
// portable (POSIX), so we use ptrdiff_t instead to cast to signed values.
s << " CordRepRing(" << &rep << ", length = " << rep.length
<< ", head = " << rep.head_ << ", tail = " << rep.tail_
<< ", cap = " << rep.capacity_ << ", rc = " << rep.refcount.Get()
<< ", begin_pos_ = " << static_cast<ptrdiff_t>(rep.begin_pos_) << ") {\n";
CordRepRing::index_type head = rep.head();
do {
CordRep* child = rep.entry_child(head);
s << " entry[" << head << "] length = " << rep.entry_length(head)
<< ", child " << child << ", clen = " << child->length
<< ", tag = " << static_cast<int>(child->tag)
<< ", rc = " << child->refcount.Get()
<< ", offset = " << rep.entry_data_offset(head)
<< ", end_pos = " << static_cast<ptrdiff_t>(rep.entry_end_pos(head))
<< "\n";
head = rep.advance(head);
} while (head != rep.tail());
return s << "}\n";
}
void CordRepRing::AddDataOffset(index_type index, size_t n) {
entry_data_offset()[index] += static_cast<offset_type>(n);
}
void CordRepRing::SubLength(index_type index, size_t n) {
entry_end_pos()[index] -= n;
}
class CordRepRing::Filler {
public:
Filler(CordRepRing* rep, index_type pos) : rep_(rep), head_(pos), pos_(pos) {}
index_type head() const { return head_; }
index_type pos() const { return pos_; }
void Add(CordRep* child, size_t offset, pos_type end_pos) {
rep_->entry_end_pos()[pos_] = end_pos;
rep_->entry_child()[pos_] = child;
rep_->entry_data_offset()[pos_] = static_cast<offset_type>(offset);
pos_ = rep_->advance(pos_);
}
private:
CordRepRing* rep_;
index_type head_;
index_type pos_;
};
constexpr size_t CordRepRing::kMaxCapacity; // NOLINT: needed for c++11
bool CordRepRing::IsValid(std::ostream& output) const {
if (capacity_ == 0) {
output << "capacity == 0";
return false;
}
if (head_ >= capacity_ || tail_ >= capacity_) {
output << "head " << head_ << " and/or tail " << tail_ << "exceed capacity "
<< capacity_;
return false;
}
const index_type back = retreat(tail_);
size_t pos_length = Distance(begin_pos_, entry_end_pos(back));
if (pos_length != length) {
output << "length " << length << " does not match positional length "
<< pos_length << " from begin_pos " << begin_pos_ << " and entry["
<< back << "].end_pos " << entry_end_pos(back);
return false;
}
index_type head = head_;
pos_type begin_pos = begin_pos_;
do {
pos_type end_pos = entry_end_pos(head);
size_t entry_length = Distance(begin_pos, end_pos);
if (entry_length == 0) {
output << "entry[" << head << "] has an invalid length " << entry_length
<< " from begin_pos " << begin_pos << " and end_pos " << end_pos;
return false;
}
CordRep* child = entry_child(head);
if (child == nullptr) {
output << "entry[" << head << "].child == nullptr";
return false;
}
if (child->tag < FLAT && child->tag != EXTERNAL) {
output << "entry[" << head << "].child has an invalid tag "
<< static_cast<int>(child->tag);
return false;
}
size_t offset = entry_data_offset(head);
if (offset >= child->length || entry_length > child->length - offset) {
output << "entry[" << head << "] has offset " << offset
<< " and entry length " << entry_length
<< " which are outside of the childs length of " << child->length;
return false;
}
begin_pos = end_pos;
head = advance(head);
} while (head != tail_);
return true;
}
#ifdef EXTRA_CORD_RING_VALIDATION
CordRepRing* CordRepRing::Validate(CordRepRing* rep, const char* file,
int line) {
if (!rep->IsValid(std::cerr)) {
std::cerr << "\nERROR: CordRepRing corrupted";
if (line) std::cerr << " at line " << line;
if (file) std::cerr << " in file " << file;
std::cerr << "\nContent = " << *rep;
abort();
}
return rep;
}
#endif // EXTRA_CORD_RING_VALIDATION
CordRepRing* CordRepRing::New(size_t capacity, size_t extra) {
CheckCapacity(capacity, extra);
size_t size = AllocSize(capacity += extra);
void* mem = ::operator new(size);
auto* rep = new (mem) CordRepRing(static_cast<index_type>(capacity));
rep->tag = RING;
rep->capacity_ = static_cast<index_type>(capacity);
rep->begin_pos_ = 0;
return rep;
}
void CordRepRing::SetCapacityForTesting(size_t capacity) {
// Adjust for the changed layout
assert(capacity <= capacity_);
assert(head() == 0 || head() < tail());
memmove(Layout::Partial(capacity).Pointer<1>(data_) + head(),
Layout::Partial(capacity_).Pointer<1>(data_) + head(),
entries() * sizeof(Layout::ElementType<1>));
memmove(Layout::Partial(capacity, capacity).Pointer<2>(data_) + head(),
Layout::Partial(capacity_, capacity_).Pointer<2>(data_) + head(),
entries() * sizeof(Layout::ElementType<2>));
capacity_ = static_cast<index_type>(capacity);
}
void CordRepRing::Delete(CordRepRing* rep) {
assert(rep != nullptr && rep->tag == RING);
#if defined(__cpp_sized_deallocation)
size_t size = AllocSize(rep->capacity_);
rep->~CordRepRing();
::operator delete(rep, size);
#else
rep->~CordRepRing();
::operator delete(rep);
#endif
}
void CordRepRing::Destroy(CordRepRing* rep) {
UnrefEntries(rep, rep->head(), rep->tail());
Delete(rep);
}
template <bool ref>
void CordRepRing::Fill(const CordRepRing* src, index_type head,
index_type tail) {
this->length = src->length;
head_ = 0;
tail_ = advance(0, src->entries(head, tail));
begin_pos_ = src->begin_pos_;
// TODO(mvels): there may be opportunities here for large buffers.
auto* dst_pos = entry_end_pos();
auto* dst_child = entry_child();
auto* dst_offset = entry_data_offset();
src->ForEach(head, tail, [&](index_type index) {
*dst_pos++ = src->entry_end_pos(index);
CordRep* child = src->entry_child(index);
*dst_child++ = ref ? CordRep::Ref(child) : child;
*dst_offset++ = src->entry_data_offset(index);
});
}
CordRepRing* CordRepRing::Copy(CordRepRing* rep, index_type head,
index_type tail, size_t extra) {
CordRepRing* newrep = CordRepRing::New(rep->entries(head, tail), extra);
newrep->Fill<true>(rep, head, tail);
CordRep::Unref(rep);
return newrep;
}
CordRepRing* CordRepRing::Mutable(CordRepRing* rep, size_t extra) {
// Get current number of entries, and check for max capacity.
size_t entries = rep->entries();
size_t min_extra = (std::max)(extra, rep->capacity() * 2 - entries);
if (!rep->refcount.IsOne()) {
return Copy(rep, rep->head(), rep->tail(), min_extra);
} else if (entries + extra > rep->capacity()) {
CordRepRing* newrep = CordRepRing::New(entries, min_extra);
newrep->Fill<false>(rep, rep->head(), rep->tail());
CordRepRing::Delete(rep);
return newrep;
} else {
return rep;
}
}
Span<char> CordRepRing::GetAppendBuffer(size_t size) {
assert(refcount.IsOne());
index_type back = retreat(tail_);
CordRep* child = entry_child(back);
if (child->tag >= FLAT && child->refcount.IsOne()) {
size_t capacity = child->flat()->Capacity();
pos_type end_pos = entry_end_pos(back);
size_t data_offset = entry_data_offset(back);
size_t entry_length = Distance(entry_begin_pos(back), end_pos);
size_t used = data_offset + entry_length;
if (size_t n = (std::min)(capacity - used, size)) {
child->length = data_offset + entry_length + n;
entry_end_pos()[back] = end_pos + n;
this->length += n;
return {child->flat()->Data() + used, n};
}
}
return {nullptr, 0};
}
Span<char> CordRepRing::GetPrependBuffer(size_t size) {
assert(refcount.IsOne());
CordRep* child = entry_child(head_);
size_t data_offset = entry_data_offset(head_);
if (data_offset && child->refcount.IsOne() && child->tag >= FLAT) {
size_t n = (std::min)(data_offset, size);
this->length += n;
begin_pos_ -= n;
data_offset -= n;
entry_data_offset()[head_] = static_cast<offset_type>(data_offset);
return {child->flat()->Data() + data_offset, n};
}
return {nullptr, 0};
}
CordRepRing* CordRepRing::CreateFromLeaf(CordRep* child, size_t offset,
size_t length, size_t extra) {
CordRepRing* rep = CordRepRing::New(1, extra);
rep->head_ = 0;
rep->tail_ = rep->advance(0);
rep->length = length;
rep->entry_end_pos()[0] = length;
rep->entry_child()[0] = child;
rep->entry_data_offset()[0] = static_cast<offset_type>(offset);
return Validate(rep);
}
CordRepRing* CordRepRing::CreateSlow(CordRep* child, size_t extra) {
CordRepRing* rep = nullptr;
Consume(child, [&](CordRep* child, size_t offset, size_t length) {
if (IsFlatOrExternal(child)) {
rep = rep ? AppendLeaf(rep, child, offset, length)
: CreateFromLeaf(child, offset, length, extra);
} else if (rep) {
rep = AddRing<AddMode::kAppend>(rep, child->ring(), offset, length);
} else if (offset == 0 && child->length == length) {
rep = Mutable(child->ring(), extra);
} else {
rep = SubRing(child->ring(), offset, length, extra);
}
});
return Validate(rep, nullptr, __LINE__);
}
CordRepRing* CordRepRing::Create(CordRep* child, size_t extra) {
size_t length = child->length;
if (IsFlatOrExternal(child)) {
return CreateFromLeaf(child, 0, length, extra);
}
if (child->tag == RING) {
return Mutable(child->ring(), extra);
}
return CreateSlow(child, extra);
}
template <CordRepRing::AddMode mode>
CordRepRing* CordRepRing::AddRing(CordRepRing* rep, CordRepRing* ring,
size_t offset, size_t length) {
assert(offset < ring->length);
constexpr bool append = mode == AddMode::kAppend;
Position head = ring->Find(offset);
Position tail = ring->FindTail(head.index, offset + length);
const index_type entries = ring->entries(head.index, tail.index);
rep = Mutable(rep, entries);
// The delta for making ring[head].end_pos into 'len - offset'
const pos_type delta_length =
(append ? rep->begin_pos_ + rep->length : rep->begin_pos_ - length) -
ring->entry_begin_pos(head.index) - head.offset;
// Start filling at `tail`, or `entries` before `head`
Filler filler(rep, append ? rep->tail_ : rep->retreat(rep->head_, entries));
if (ring->refcount.IsOne()) {
// Copy entries from source stealing the ref and adjusting the end position.
// Commit the filler as this is no-op.
ring->ForEach(head.index, tail.index, [&](index_type ix) {
filler.Add(ring->entry_child(ix), ring->entry_data_offset(ix),
ring->entry_end_pos(ix) + delta_length);
});
// Unref entries we did not copy over, and delete source.
if (head.index != ring->head_) UnrefEntries(ring, ring->head_, head.index);
if (tail.index != ring->tail_) UnrefEntries(ring, tail.index, ring->tail_);
CordRepRing::Delete(ring);
} else {
ring->ForEach(head.index, tail.index, [&](index_type ix) {
CordRep* child = ring->entry_child(ix);
filler.Add(child, ring->entry_data_offset(ix),
ring->entry_end_pos(ix) + delta_length);
CordRep::Ref(child);
});
CordRepRing::Unref(ring);
}
if (head.offset) {
// Increase offset of first 'source' entry appended or prepended.
// This is always the entry in `filler.head()`
rep->AddDataOffset(filler.head(), head.offset);
}
if (tail.offset) {
// Reduce length of last 'source' entry appended or prepended.
// This is always the entry tailed by `filler.pos()`
rep->SubLength(rep->retreat(filler.pos()), tail.offset);
}
// Commit changes
rep->length += length;
if (append) {
rep->tail_ = filler.pos();
} else {
rep->head_ = filler.head();
rep->begin_pos_ -= length;
}
return Validate(rep);
}
CordRepRing* CordRepRing::AppendSlow(CordRepRing* rep, CordRep* child) {
Consume(child, [&rep](CordRep* child, size_t offset, size_t length) {
if (child->tag == RING) {
rep = AddRing<AddMode::kAppend>(rep, child->ring(), offset, length);
} else {
rep = AppendLeaf(rep, child, offset, length);
}
});
return rep;
}
CordRepRing* CordRepRing::AppendLeaf(CordRepRing* rep, CordRep* child,
size_t offset, size_t length) {
rep = Mutable(rep, 1);
index_type back = rep->tail_;
const pos_type begin_pos = rep->begin_pos_ + rep->length;
rep->tail_ = rep->advance(rep->tail_);
rep->length += length;
rep->entry_end_pos()[back] = begin_pos + length;
rep->entry_child()[back] = child;
rep->entry_data_offset()[back] = static_cast<offset_type>(offset);
return Validate(rep, nullptr, __LINE__);
}
CordRepRing* CordRepRing::Append(CordRepRing* rep, CordRep* child) {
size_t length = child->length;
if (IsFlatOrExternal(child)) {
return AppendLeaf(rep, child, 0, length);
}
if (child->tag == RING) {
return AddRing<AddMode::kAppend>(rep, child->ring(), 0, length);
}
return AppendSlow(rep, child);
}
CordRepRing* CordRepRing::PrependSlow(CordRepRing* rep, CordRep* child) {
RConsume(child, [&](CordRep* child, size_t offset, size_t length) {
if (IsFlatOrExternal(child)) {
rep = PrependLeaf(rep, child, offset, length);
} else {
rep = AddRing<AddMode::kPrepend>(rep, child->ring(), offset, length);
}
});
return Validate(rep);
}
CordRepRing* CordRepRing::PrependLeaf(CordRepRing* rep, CordRep* child,
size_t offset, size_t length) {
rep = Mutable(rep, 1);
index_type head = rep->retreat(rep->head_);
pos_type end_pos = rep->begin_pos_;
rep->head_ = head;
rep->length += length;
rep->begin_pos_ -= length;
rep->entry_end_pos()[head] = end_pos;
rep->entry_child()[head] = child;
rep->entry_data_offset()[head] = static_cast<offset_type>(offset);
return Validate(rep);
}
CordRepRing* CordRepRing::Prepend(CordRepRing* rep, CordRep* child) {
size_t length = child->length;
if (IsFlatOrExternal(child)) {
return PrependLeaf(rep, child, 0, length);
}
if (child->tag == RING) {
return AddRing<AddMode::kPrepend>(rep, child->ring(), 0, length);
}
return PrependSlow(rep, child);
}
CordRepRing* CordRepRing::Append(CordRepRing* rep, absl::string_view data,
size_t extra) {
if (rep->refcount.IsOne()) {
Span<char> avail = rep->GetAppendBuffer(data.length());
if (!avail.empty()) {
memcpy(avail.data(), data.data(), avail.length());
data.remove_prefix(avail.length());
}
}
if (data.empty()) return Validate(rep);
const size_t flats = (data.length() - 1) / kMaxFlatLength + 1;
rep = Mutable(rep, flats);
Filler filler(rep, rep->tail_);
pos_type pos = rep->begin_pos_ + rep->length;
while (data.length() >= kMaxFlatLength) {
auto* flat = CreateFlat(data.data(), kMaxFlatLength);
filler.Add(flat, 0, pos += kMaxFlatLength);
data.remove_prefix(kMaxFlatLength);
}
if (data.length()) {
auto* flat = CreateFlat(data.data(), data.length(), extra);
filler.Add(flat, 0, pos += data.length());
}
rep->length = pos - rep->begin_pos_;
rep->tail_ = filler.pos();
return Validate(rep);
}
CordRepRing* CordRepRing::Prepend(CordRepRing* rep, absl::string_view data,
size_t extra) {
if (rep->refcount.IsOne()) {
Span<char> avail = rep->GetPrependBuffer(data.length());
if (!avail.empty()) {
const char* tail = data.data() + data.length() - avail.length();
memcpy(avail.data(), tail, avail.length());
data.remove_suffix(avail.length());
}
}
if (data.empty()) return rep;
const size_t flats = (data.length() - 1) / kMaxFlatLength + 1;
rep = Mutable(rep, flats);
pos_type pos = rep->begin_pos_;
Filler filler(rep, rep->retreat(rep->head_, static_cast<index_type>(flats)));
size_t first_size = data.size() - (flats - 1) * kMaxFlatLength;
CordRepFlat* flat = CordRepFlat::New(first_size + extra);
flat->length = first_size + extra;
memcpy(flat->Data() + extra, data.data(), first_size);
data.remove_prefix(first_size);
filler.Add(flat, extra, pos);
pos -= first_size;
while (!data.empty()) {
assert(data.size() >= kMaxFlatLength);
flat = CreateFlat(data.data(), kMaxFlatLength);
filler.Add(flat, 0, pos);
pos -= kMaxFlatLength;
data.remove_prefix(kMaxFlatLength);
}
rep->head_ = filler.head();
rep->length += rep->begin_pos_ - pos;
rep->begin_pos_ = pos;
return Validate(rep);
}
// 32 entries is 32 * sizeof(pos_type) = 4 cache lines on x86
static constexpr index_type kBinarySearchThreshold = 32;
static constexpr index_type kBinarySearchEndCount = 8;
template <bool wrap>
CordRepRing::index_type CordRepRing::FindBinary(index_type head,
index_type tail,
size_t offset) const {
index_type count = tail + (wrap ? capacity_ : 0) - head;
do {
count = (count - 1) / 2;
assert(count < entries(head, tail_));
index_type mid = wrap ? advance(head, count) : head + count;
index_type after_mid = wrap ? advance(mid) : mid + 1;
bool larger = (offset >= entry_end_offset(mid));
head = larger ? after_mid : head;
tail = larger ? tail : mid;
assert(head != tail);
} while (ABSL_PREDICT_TRUE(count > kBinarySearchEndCount));
return head;
}
CordRepRing::Position CordRepRing::FindSlow(index_type head,
size_t offset) const {
index_type tail = tail_;
// Binary search until we are good for linear search
// Optimize for branchless / non wrapping ops
if (tail > head) {
index_type count = tail - head;
if (count > kBinarySearchThreshold) {
head = FindBinary<false>(head, tail, offset);
}
} else {
index_type count = capacity_ + tail - head;
if (count > kBinarySearchThreshold) {
head = FindBinary<true>(head, tail, offset);
}
}
pos_type pos = entry_begin_pos(head);
pos_type end_pos = entry_end_pos(head);
while (offset >= Distance(begin_pos_, end_pos)) {
head = advance(head);
pos = end_pos;
end_pos = entry_end_pos(head);
}
return {head, offset - Distance(begin_pos_, pos)};
}
CordRepRing::Position CordRepRing::FindTailSlow(index_type head,
size_t offset) const {
index_type tail = tail_;
const size_t tail_offset = offset - 1;
// Binary search until we are good for linear search
// Optimize for branchless / non wrapping ops
if (tail > head) {
index_type count = tail - head;
if (count > kBinarySearchThreshold) {
head = FindBinary<false>(head, tail, tail_offset);
}
} else {
index_type count = capacity_ + tail - head;
if (count > kBinarySearchThreshold) {
head = FindBinary<true>(head, tail, tail_offset);
}
}
size_t end_offset = entry_end_offset(head);
while (tail_offset >= end_offset) {
head = advance(head);
end_offset = entry_end_offset(head);
}
return {advance(head), end_offset - offset};
}
char CordRepRing::GetCharacter(size_t offset) const {
assert(offset < length);
Position pos = Find(offset);
size_t data_offset = entry_data_offset(pos.index) + pos.offset;
return GetRepData(entry_child(pos.index))[data_offset];
}
CordRepRing* CordRepRing::SubRing(CordRepRing* rep, size_t offset,
size_t length, size_t extra) {
assert(offset <= rep->length);
assert(offset <= rep->length - length);
if (length == 0) {
CordRep::Unref(rep);
return nullptr;
}
// Find position of first byte
Position head = rep->Find(offset);
Position tail = rep->FindTail(head.index, offset + length);
const size_t new_entries = rep->entries(head.index, tail.index);
if (rep->refcount.IsOne() && extra <= (rep->capacity() - new_entries)) {
// We adopt a privately owned rep and no extra entries needed.
if (head.index != rep->head_) UnrefEntries(rep, rep->head_, head.index);
if (tail.index != rep->tail_) UnrefEntries(rep, tail.index, rep->tail_);
rep->head_ = head.index;
rep->tail_ = tail.index;
} else {
// Copy subset to new rep
rep = Copy(rep, head.index, tail.index, extra);
head.index = rep->head_;
tail.index = rep->tail_;
}
// Adjust begin_pos and length
rep->length = length;
rep->begin_pos_ += offset;
// Adjust head and tail blocks
if (head.offset) {
rep->AddDataOffset(head.index, head.offset);
}
if (tail.offset) {
rep->SubLength(rep->retreat(tail.index), tail.offset);
}
return Validate(rep);
}
CordRepRing* CordRepRing::RemovePrefix(CordRepRing* rep, size_t len,
size_t extra) {
assert(len <= rep->length);
if (len == rep->length) {
CordRep::Unref(rep);
return nullptr;
}
Position head = rep->Find(len);
if (rep->refcount.IsOne()) {
if (head.index != rep->head_) UnrefEntries(rep, rep->head_, head.index);
rep->head_ = head.index;
} else {
rep = Copy(rep, head.index, rep->tail_, extra);
head.index = rep->head_;
}
// Adjust begin_pos and length
rep->length -= len;
rep->begin_pos_ += len;
// Adjust head block
if (head.offset) {
rep->AddDataOffset(head.index, head.offset);
}
return Validate(rep);
}
CordRepRing* CordRepRing::RemoveSuffix(CordRepRing* rep, size_t len,
size_t extra) {
assert(len <= rep->length);
if (len == rep->length) {
CordRep::Unref(rep);
return nullptr;
}
Position tail = rep->FindTail(rep->length - len);
if (rep->refcount.IsOne()) {
// We adopt a privately owned rep, scrub.
if (tail.index != rep->tail_) UnrefEntries(rep, tail.index, rep->tail_);
rep->tail_ = tail.index;
} else {
// Copy subset to new rep
rep = Copy(rep, rep->head_, tail.index, extra);
tail.index = rep->tail_;
}
// Adjust length
rep->length -= len;
// Adjust tail block
if (tail.offset) {
rep->SubLength(rep->retreat(tail.index), tail.offset);
}
return Validate(rep);
}
#ifdef __clang__
#pragma clang diagnostic pop
#endif
} // namespace cord_internal
ABSL_NAMESPACE_END
} // namespace absl
absl/strings/internal/cord_rep_ring.h 0 → 100644
// Copyright 2020 The Abseil Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef ABSL_STRINGS_INTERNAL_CORD_REP_RING_H_
#define ABSL_STRINGS_INTERNAL_CORD_REP_RING_H_
#include <cassert>
#include <cstddef>
#include <cstdint>
#include <iosfwd>
#include <limits>
#include <memory>
#include "absl/container/internal/layout.h"
#include "absl/strings/internal/cord_internal.h"
#include "absl/strings/internal/cord_rep_flat.h"
namespace absl {
ABSL_NAMESPACE_BEGIN
namespace cord_internal {
// See https://bugs.llvm.org/show_bug.cgi?id=48477
#ifdef __clang__
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wshadow"
#pragma clang diagnostic ignored "-Wshadow-field"
#endif
// All operations modifying a ring buffer are implemented as static methods
// requiring a CordRepRing instance with a reference adopted by the method.
//
// The methods return the modified ring buffer, which may be equal to the input
// if the input was not shared, and having large enough capacity to accommodate
// any newly added node(s). Otherwise, a copy of the input rep with the new
// node(s) added is returned.
//
// Any modification on non shared ring buffers with enough capacity will then
// require minimum atomic operations. Caller should where possible provide
// reasonable `extra` hints for both anticipated extra `flat` byte space, as
// well as anticipated extra nodes required for complex operations.
//
// Example of code creating a ring buffer, adding some data to it,
// and discarding the buffer when done:
//
// void FunWithRings() {
// // Create ring with 3 flats
// CordRep* flat = CreateFlat("Hello");
// CordRepRing* ring = CordRepRing::Create(flat, 2);
// ring = CordRepRing::Append(ring, CreateFlat(" "));
// ring = CordRepRing::Append(ring, CreateFlat("world"));
// DoSomethingWithRing(ring);
// CordRep::Unref(ring);
// }
//
// Example of code Copying an existing ring buffer and modifying it:
//
// void MoreFunWithRings(CordRepRing* src) {
// CordRepRing* ring = CordRep::Ref(src)->ring();
// ring = CordRepRing::Append(ring, CreateFlat("Hello"));
// ring = CordRepRing::Append(ring, CreateFlat(" "));
// ring = CordRepRing::Append(ring, CreateFlat("world"));
// DoSomethingWithRing(ring);
// CordRep::Unref(ring);
// }
//
class CordRepRing : public CordRep {
public:
// `pos_type` represents a 'logical position'. A CordRepRing instance has a
// `begin_pos` (default 0), and each node inside the buffer will have an
// `end_pos` which is the `end_pos` of the previous node (or `begin_pos`) plus
// this node's length. The purpose is to allow for a binary search on this
// position, while allowing O(1) prepend and append operations.
using pos_type = uint64_t;
// `index_type` is the type for the `head`, `tail` and `capacity` indexes.
// Ring buffers are limited to having no more than four billion entries.
using index_type = uint32_t;
// `offset_type` is the type for the data offset inside a child rep's data.
using offset_type = uint32_t;
// Position holds the node index and relative offset into the node for
// some physical offset in the contained data as returned by the Find()
// and FindTail() methods.
struct Position {
index_type index;
size_t offset;
};
// The maximum # of child nodes that can be hosted inside a CordRepRing.
static constexpr size_t kMaxCapacity = (std::numeric_limits<uint32_t>::max)();
// CordRepring can not be default constructed, moved, copied or assigned.
CordRepRing() = delete;
CordRepRing(const CordRepRing&) = delete;
CordRepRing& operator=(const CordRepRing&) = delete;
// Returns true if this instance is valid, false if some or all of the
// invariants are broken. Intended for debug purposes only.
// `output` receives an explanation of the broken invariants.
bool IsValid(std::ostream& output) const;
// Returns the size in bytes for a CordRepRing with `capacity' entries.
static constexpr size_t AllocSize(size_t capacity);
// Returns the distance in bytes from `pos` to `end_pos`.
static constexpr size_t Distance(pos_type pos, pos_type end_pos);
// Creates a new ring buffer from the provided `rep`. Adopts a reference
// on `rep`. The returned ring buffer has a capacity of at least `extra + 1`
static CordRepRing* Create(CordRep* child, size_t extra = 0);
// `head`, `tail` and `capacity` indexes defining the ring buffer boundaries.
index_type head() const { return head_; }
index_type tail() const { return tail_; }
index_type capacity() const { return capacity_; }
// Returns the number of entries in this instance.
index_type entries() const { return entries(head_, tail_); }
// Returns the logical begin position of this instance.
pos_type begin_pos() const { return begin_pos_; }
// Returns the number of entries for a given head-tail range.
// Requires `head` and `tail` values to be less than `capacity()`.
index_type entries(index_type head, index_type tail) const {
assert(head < capacity_ && tail < capacity_);
return tail - head + ((tail > head) ? 0 : capacity_);
}
// Returns the logical end position of entry `index`.
pos_type const& entry_end_pos(index_type index) const {
assert(IsValidIndex(index));
return Layout::Partial().Pointer<0>(data_)[index];
}
// Returns the child pointer of entry `index`.
CordRep* const& entry_child(index_type index) const {
assert(IsValidIndex(index));
return Layout::Partial(capacity()).Pointer<1>(data_)[index];
}
// Returns the data offset of entry `index`
offset_type const& entry_data_offset(index_type index) const {
assert(IsValidIndex(index));
return Layout::Partial(capacity(), capacity()).Pointer<2>(data_)[index];
}
// Appends the provided child node to the `rep` instance.
// Adopts a reference from `rep` and `child` which may not be null.
// If the provided child is a FLAT or EXTERNAL node, or a SUBSTRING node
// containing a FLAT or EXTERNAL node, then flat or external the node is added
// 'as is', with an offset added for the SUBSTRING case.
// If the provided child is a RING or CONCAT tree, or a SUBSTRING of a RING or
// CONCAT tree, then all child nodes not excluded by any start offset or
// length values are added recursively.
static CordRepRing* Append(CordRepRing* rep, CordRep* child);
// Appends the provided string data to the `rep` instance.
// This function will attempt to utilize any remaining capacity in the last
// node of the input if that node is not shared (directly or indirectly), and
// of type FLAT. Remaining data will be added as one or more FLAT nodes.
// Any last node added to the ring buffer will be allocated with up to
// `extra` bytes of capacity for (anticipated) subsequent append actions.
static CordRepRing* Append(CordRepRing* rep, string_view data,
size_t extra = 0);
// Prepends the provided child node to the `rep` instance.
// Adopts a reference from `rep` and `child` which may not be null.
// If the provided child is a FLAT or EXTERNAL node, or a SUBSTRING node
// containing a FLAT or EXTERNAL node, then flat or external the node is
// prepended 'as is', with an optional offset added for the SUBSTRING case.
// If the provided child is a RING or CONCAT tree, or a SUBSTRING of a RING
// or CONCAT tree, then all child nodes not excluded by any start offset or
// length values are added recursively.
static CordRepRing* Prepend(CordRepRing* rep, CordRep* child);
// Prepends the provided string data to the `rep` instance.
// This function will attempt to utilize any remaining capacity in the first
// node of the input if that node is not shared (directly or indirectly), and
// of type FLAT. Remaining data will be added as one or more FLAT nodes.
// Any first node prepnded to the ring buffer will be allocated with up to
// `extra` bytes of capacity for (anticipated) subsequent prepend actions.
static CordRepRing* Prepend(CordRepRing* rep, string_view data,
size_t extra = 0);
// Returns a span referencing potentially unused capacity in the last node.
// The returned span may be empty if no such capacity is available, or if the
// current instance is shared. Else, a span of size `n <= size` is returned.
// If non empty, the ring buffer is adjusted to the new length, with the newly
// added capacity left uninitialized. Callers should assign a value to the
// entire span before any other operations on this instance.
Span<char> GetAppendBuffer(size_t size);
// Returns a span referencing potentially unused capacity in the first node.
// This function is identical to GetAppendBuffer except that it returns a span
// referencing up to `size` capacity directly before the existing data.
Span<char> GetPrependBuffer(size_t size);
// Returns a cord ring buffer containing `length` bytes of data starting at
// `offset`. If the input is not shared, this function will remove all head
// and tail child nodes outside of the requested range, and adjust the new
// head and tail nodes as required. If the input is shared, this function
// returns a new instance sharing some or all of the nodes from the input.
static CordRepRing* SubRing(CordRepRing* r, size_t offset, size_t length,
size_t extra = 0);
// Returns a cord ring buffer with the first `length` bytes removed.
// If the input is not shared, this function will remove all head child nodes
// fully inside the first `length` bytes, and adjust the new head as required.
// If the input is shared, this function returns a new instance sharing some
// or all of the nodes from the input.
static CordRepRing* RemoveSuffix(CordRepRing* r, size_t length,
size_t extra = 0);
// Returns a cord ring buffer with the last `length` bytes removed.
// If the input is not shared, this function will remove all head child nodes
// fully inside the first `length` bytes, and adjust the new head as required.
// If the input is shared, this function returns a new instance sharing some
// or all of the nodes from the input.
static CordRepRing* RemovePrefix(CordRepRing* r, size_t len,
size_t extra = 0);
// Returns the character at `offset`. Requires that `offset < length`.
char GetCharacter(size_t offset) const;
// Testing only: set capacity to requested capacity.
void SetCapacityForTesting(size_t capacity);
// Returns the CordRep data pointer for the provided CordRep.
// Requires that the provided `rep` is either a FLAT or EXTERNAL CordRep.
static const char* GetLeafData(const CordRep* rep);
// Returns the CordRep data pointer for the provided CordRep.
// Requires that `rep` is either a FLAT, EXTERNAL, or SUBSTRING CordRep.
static const char* GetRepData(const CordRep* rep);
// Advances the provided position, wrapping around capacity as needed.
// Requires `index` < capacity()
inline index_type advance(index_type index) const;
// Advances the provided position by 'n`, wrapping around capacity as needed.
// Requires `index` < capacity() and `n` <= capacity.
inline index_type advance(index_type index, index_type n) const;
// Retreats the provided position, wrapping around 0 as needed.
// Requires `index` < capacity()
inline index_type retreat(index_type index) const;
// Retreats the provided position by 'n', wrapping around 0 as needed.
// Requires `index` < capacity()
inline index_type retreat(index_type index, index_type n) const;
// Returns the logical begin position of entry `index`
pos_type const& entry_begin_pos(index_type index) const {
return (index == head_) ? begin_pos_ : entry_end_pos(retreat(index));
}
// Returns the physical start offset of entry `index`
size_t entry_start_offset(index_type index) const {
return Distance(begin_pos_, entry_begin_pos(index));
}
// Returns the physical end offset of entry `index`
size_t entry_end_offset(index_type index) const {
return Distance(begin_pos_, entry_end_pos(index));
}
// Returns the data length for entry `index`
size_t entry_length(index_type index) const {
return Distance(entry_begin_pos(index), entry_end_pos(index));
}
// Returns the data for entry `index`
absl::string_view entry_data(index_type index) const;
// Returns the position for `offset` as {index, prefix}. `index` holds the
// index of the entry at the specified offset and `prefix` holds the relative
// offset inside that entry.
// Requires `offset` < length.
//
// For example we can implement GetCharacter(offset) as:
// char GetCharacter(size_t offset) {
// Position pos = this->Find(offset);
// return this->entry_data(pos.pos)[pos.offset];
// }
inline Position Find(size_t offset) const;
// Find starting at `head`
inline Position Find(index_type head, size_t offset) const;
// Returns the tail position for `offset` as {tail index, suffix}.
// `tail index` holds holds the index of the entry holding the offset directly
// before 'offset` advanced by one. 'suffix` holds the relative offset from
// that relative offset in the entry to the end of the entry.
// For example, FindTail(length) will return {tail(), 0}, FindTail(length - 5)
// will return {retreat(tail), 5)} provided the preceding entry contains at
// least 5 bytes of data.
// Requires offset >= 1 && offset <= length.
//
// This function is very useful in functions that need to clip the end of some
// ring buffer such as 'RemovePrefix'.
// For example, we could implement RemovePrefix for non shared instances as:
// void RemoveSuffix(size_t n) {
// Position pos = FindTail(length - n);
// UnrefEntries(pos.pos, this->tail_);
// this->tail_ = pos.pos;
// entry(retreat(pos.pos)).end_pos -= pos.offset;
// }
inline Position FindTail(size_t offset) const;
// Find tail starting at `head`
inline Position FindTail(index_type head, size_t offset) const;
// Invokes f(index_type index) for each entry inside the range [head, tail>
template <typename F>
void ForEach(index_type head, index_type tail, F&& f) const {
index_type n1 = (tail > head) ? tail : capacity_;
for (index_type i = head; i < n1; ++i) f(i);
if (tail <= head) {
for (index_type i = 0; i < tail; ++i) f(i);
}
}
// Invokes f(index_type index) for each entry inside this instance.
template <typename F>
void ForEach(F&& f) const {
ForEach(head_, tail_, std::forward<F>(f));
}
// Dump this instance's data tp stream `s` in human readable format, excluding
// the actual data content itself. Intended for debug purposes only.
friend std::ostream& operator<<(std::ostream& s, const CordRepRing& rep);
private:
enum class AddMode { kAppend, kPrepend };
using Layout = container_internal::Layout<pos_type, CordRep*, offset_type>;
class Filler;
class Transaction;
class CreateTransaction;
static constexpr size_t kLayoutAlignment = Layout::Partial().Alignment();
// Creates a new CordRepRing.
explicit CordRepRing(index_type capacity) : capacity_(capacity) {}
// Returns true if `index` is a valid index into this instance.
bool IsValidIndex(index_type index) const;
// Debug use only: validates the provided CordRepRing invariants.
// Verification of all CordRepRing methods can be enabled by defining
// EXTRA_CORD_RING_VALIDATION, i.e.: `--copts=-DEXTRA_CORD_RING_VALIDATION`
// Verification is VERY expensive, so only do it for debugging purposes.
static CordRepRing* Validate(CordRepRing* rep, const char* file = nullptr,
int line = 0);
// Allocates a CordRepRing large enough to hold `capacity + extra' entries.
// The returned capacity may be larger if the allocated memory allows for it.
// The maximum capacity of a CordRepRing is capped at kMaxCapacity.
// Throws `std::length_error` if `capacity + extra' exceeds kMaxCapacity.
static CordRepRing* New(size_t capacity, size_t extra);
// Deallocates (but does not destroy) the provided ring buffer.
static void Delete(CordRepRing* rep);
// Destroys the provided ring buffer, decrementing the reference count of all
// contained child CordReps. The provided 1\`rep` should have a ref count of
// one (pre decrement destroy call observing `refcount.IsOne()`) or zero (post
// decrement destroy call observing `!refcount.Decrement()`).
static void Destroy(CordRepRing* rep);
// Returns a mutable reference to the logical end position array.
pos_type* entry_end_pos() {
return Layout::Partial().Pointer<0>(data_);
}
// Returns a mutable reference to the child pointer array.
CordRep** entry_child() {
return Layout::Partial(capacity()).Pointer<1>(data_);
}
// Returns a mutable reference to the data offset array.
offset_type* entry_data_offset() {
return Layout::Partial(capacity(), capacity()).Pointer<2>(data_);
}
// Find implementations for the non fast path 0 / length cases.
Position FindSlow(index_type head, size_t offset) const;
Position FindTailSlow(index_type head, size_t offset) const;
// Finds the index of the first node that is inside a reasonable distance
// of the node at `offset` from which we can continue with a linear search.
template <bool wrap>
index_type FindBinary(index_type head, index_type tail, size_t offset) const;
// Fills the current (initialized) instance from the provided source, copying
// entries [head, tail). Adds a reference to copied entries if `ref` is true.
template <bool ref>
void Fill(const CordRepRing* src, index_type head, index_type tail);
// Create a copy of 'rep', copying all entries [head, tail), allocating room
// for `extra` entries. Adds a reference on all copied entries.
static CordRepRing* Copy(CordRepRing* rep, index_type head, index_type tail,
size_t extra = 0);
// Returns a Mutable CordRepRing reference from `rep` with room for at least
// `extra` additional nodes. Adopts a reference count from `rep`.
// This function will return `rep` if, and only if:
// - rep.entries + extra <= rep.capacity
// - rep.refcount == 1
// Otherwise, this function will create a new copy of `rep` with additional
// capacity to satisfy `extra` extra nodes, and unref the old `rep` instance.
//
// If a new CordRepRing can not be allocated, or the new capacity would exceed
// the maxmimum capacity, then the input is consumed only, and an exception is
// thrown.
static CordRepRing* Mutable(CordRepRing* rep, size_t extra);
// Slow path for Append(CordRepRing* rep, CordRep* child). This function is
// exercised if the provided `child` in Append() is not a leaf node, i.e., a
// ring buffer or old (concat) cord tree.
static CordRepRing* AppendSlow(CordRepRing* rep, CordRep* child);
// Appends the provided leaf node. Requires `child` to be FLAT or EXTERNAL.
static CordRepRing* AppendLeaf(CordRepRing* rep, CordRep* child,
size_t offset, size_t length);
// Prepends the provided leaf node. Requires `child` to be FLAT or EXTERNAL.
static CordRepRing* PrependLeaf(CordRepRing* rep, CordRep* child,
size_t offset, size_t length);
// Slow path for Prepend(CordRepRing* rep, CordRep* child). This function is
// exercised if the provided `child` in Prepend() is not a leaf node, i.e., a
// ring buffer or old (concat) cord tree.
static CordRepRing* PrependSlow(CordRepRing* rep, CordRep* child);
// Slow path for Create(CordRep* child, size_t extra). This function is
// exercised if the provided `child` in Prepend() is not a leaf node, i.e., a
// ring buffer or old (concat) cord tree.
static CordRepRing* CreateSlow(CordRep* child, size_t extra);
// Creates a new ring buffer from the provided `child` leaf node. Requires
// `child` to be FLAT or EXTERNAL. on `rep`.
// The returned ring buffer has a capacity of at least `1 + extra`
static CordRepRing* CreateFromLeaf(CordRep* child, size_t offset,
size_t length, size_t extra);
// Appends or prepends (depending on AddMode) the ring buffer in `ring' to
// `rep` starting at `offset` with length `length`.
template <AddMode mode>
static CordRepRing* AddRing(CordRepRing* rep, CordRepRing* ring,
size_t offset, size_t length);
// Increases the data offset for entry `index` by `n`.
void AddDataOffset(index_type index, size_t n);
// Descreases the length for entry `index` by `n`.
void SubLength(index_type index, size_t n);
index_type head_;
index_type tail_;
index_type capacity_;
pos_type begin_pos_;
alignas(kLayoutAlignment) char data_[kLayoutAlignment];
friend struct CordRep;
};
constexpr size_t CordRepRing::AllocSize(size_t capacity) {
return sizeof(CordRepRing) - sizeof(data_) +
Layout(capacity, capacity, capacity).AllocSize();
}
inline constexpr size_t CordRepRing::Distance(pos_type pos, pos_type end_pos) {
return (end_pos - pos);
}
inline const char* CordRepRing::GetLeafData(const CordRep* rep) {
return rep->tag != EXTERNAL ? rep->flat()->Data() : rep->external()->base;
}
inline const char* CordRepRing::GetRepData(const CordRep* rep) {
if (rep->tag >= FLAT) return rep->flat()->Data();
if (rep->tag == EXTERNAL) return rep->external()->base;
return GetLeafData(rep->substring()->child) + rep->substring()->start;
}
inline CordRepRing::index_type CordRepRing::advance(index_type index) const {
assert(index < capacity_);
return ++index == capacity_ ? 0 : index;
}
inline CordRepRing::index_type CordRepRing::advance(index_type index,
index_type n) const {
assert(index < capacity_ && n <= capacity_);
return (index += n) >= capacity_ ? index - capacity_ : index;
}
inline CordRepRing::index_type CordRepRing::retreat(index_type index) const {
assert(index < capacity_);
return (index > 0 ? index : capacity_) - 1;
}
inline CordRepRing::index_type CordRepRing::retreat(index_type index,
index_type n) const {
assert(index < capacity_ && n <= capacity_);
return index >= n ? index - n : capacity_ - n + index;
}
inline absl::string_view CordRepRing::entry_data(index_type index) const {
size_t data_offset = entry_data_offset(index);
return {GetRepData(entry_child(index)) + data_offset, entry_length(index)};
}
inline bool CordRepRing::IsValidIndex(index_type index) const {
if (index >= capacity_) return false;
return (tail_ > head_) ? (index >= head_ && index < tail_)
: (index >= head_ || index < tail_);
}
#ifndef EXTRA_CORD_RING_VALIDATION
inline CordRepRing* CordRepRing::Validate(CordRepRing* rep,
const char* /*file*/, int /*line*/) {
return rep;
}
#endif
inline CordRepRing::Position CordRepRing::Find(size_t offset) const {
assert(offset < length);
return (offset == 0) ? Position{head_, 0} : FindSlow(head_, offset);
}
inline CordRepRing::Position CordRepRing::Find(index_type head,
size_t offset) const {
assert(offset < length);
assert(IsValidIndex(head) && offset >= entry_start_offset(head));
return (offset == 0) ? Position{head_, 0} : FindSlow(head, offset);
}
inline CordRepRing::Position CordRepRing::FindTail(size_t offset) const {
assert(offset > 0 && offset <= length);
return (offset == length) ? Position{tail_, 0} : FindTailSlow(head_, offset);
}
inline CordRepRing::Position CordRepRing::FindTail(index_type head,
size_t offset) const {
assert(offset > 0 && offset <= length);
assert(IsValidIndex(head) && offset >= entry_start_offset(head) + 1);
return (offset == length) ? Position{tail_, 0} : FindTailSlow(head, offset);
}
std::ostream& operator<<(std::ostream& s, const CordRepRing& rep);
#ifdef __clang__
#pragma clang diagnostic pop
#endif
} // namespace cord_internal
ABSL_NAMESPACE_END
} // namespace absl
#endif // ABSL_STRINGS_INTERNAL_CORD_REP_RING_H_
absl/synchronization/mutex.h
......@@ -162,7 +162,7 @@ class ABSL_LOCKABLE Mutex {
// Mutex::Unlock()
//
// Releases this `Mutex` and returns it from the exclusive/write state to the
// free state. Caller must hold the `Mutex` exclusively.
// free state. Calling thread must hold the `Mutex` exclusively.
void Unlock() ABSL_UNLOCK_FUNCTION();
// Mutex::TryLock()
......
absl/types/CMakeLists.txt
......@@ -353,9 +353,6 @@ absl_cc_test(
gmock_main
)
# TODO(cohenjon,zhangxy) Figure out why this test is failing on gcc 4.8
if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU" AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS 4.9)
else()
absl_cc_test(
NAME
variant_exception_safety_test
......@@ -370,4 +367,3 @@ absl_cc_test(
absl::memory
gmock_main
)
endif()
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