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abseil-cpp
Commit ff5644bb by Derek Mauro Committed by Copybara-Service
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Allow Cord to store chunked checksums 

PiperOrigin-RevId: 494587777
Change-Id: I41504edca6fcf750d52602fa84a33bc7fe5fbb48
parent 0b8e676c
Showing with 544 additions and 35 deletions
CMake/AbseilDll.cmake
...@@ -100,6 +100,8 @@ set(ABSL_INTERNAL_DLL_FILES ...@@ -100,6 +100,8 @@ set(ABSL_INTERNAL_DLL_FILES
"crc/internal/crc32_x86_arm_combined_simd.h" "crc/internal/crc32_x86_arm_combined_simd.h"
"crc/internal/crc.cc" "crc/internal/crc.cc"
"crc/internal/crc.h" "crc/internal/crc.h"
"crc/internal/crc_cord_state.cc"
"crc/internal/crc_cord_state.h"
"crc/internal/crc_internal.h" "crc/internal/crc_internal.h"
"crc/internal/crc_x86_arm_combined.cc" "crc/internal/crc_x86_arm_combined.cc"
"crc/internal/crc_memcpy_fallback.cc" "crc/internal/crc_memcpy_fallback.cc"
......
absl/crc/BUILD.bazel
...@@ -163,6 +163,34 @@ cc_test( ...@@ -163,6 +163,34 @@ cc_test(
], ],
) )
cc_library(
name = "crc_cord_state",
srcs = ["internal/crc_cord_state.cc"],
hdrs = ["internal/crc_cord_state.h"],
copts = ABSL_DEFAULT_COPTS,
linkopts = ABSL_DEFAULT_LINKOPTS,
visibility = ["//absl/strings:__pkg__"],
deps = [
":crc32c",
"//absl/base:config",
"//absl/numeric:bits",
"//absl/strings",
],
)
cc_test(
name = "crc_cord_state_test",
srcs = ["internal/crc_cord_state_test.cc"],
copts = ABSL_TEST_COPTS,
linkopts = ABSL_DEFAULT_LINKOPTS,
visibility = ["//visibility:private"],
deps = [
":crc32c",
":crc_cord_state",
"@com_google_googletest//:gtest_main",
],
)
cc_binary( cc_binary(
name = "crc32c_benchmark", name = "crc32c_benchmark",
testonly = 1, testonly = 1,
......
absl/crc/CMakeLists.txt
...@@ -146,3 +146,31 @@ absl_cc_test( ...@@ -146,3 +146,31 @@ absl_cc_test(
absl::non_temporal_memcpy absl::non_temporal_memcpy
GTest::gtest_main GTest::gtest_main
) )
absl_cc_library(
NAME
crc_cord_state
HDRS
"internal/crc_cord_state.h"
SRCS
"internal/crc_cord_state.cc"
COPTS
${ABSL_DEFAULT_COPTS}
DEPS
absl::crc32c
absl::config
absl::strings
)
absl_cc_test(
NAME
crc_cord_state_test
SRCS
"internal/crc_cord_state_test.cc"
COPTS
${ABSL_DEFAULT_COPTS}
DEPS
absl::crc_cord_state
absl::crc32c
GTest::gtest_main
)
absl/crc/internal/crc32_x86_arm_combined_simd.h
...@@ -38,7 +38,8 @@ ...@@ -38,7 +38,8 @@
#define ABSL_CRC_INTERNAL_HAVE_X86_SIMD #define ABSL_CRC_INTERNAL_HAVE_X86_SIMD
#elif defined(__aarch64__) && defined(__LITTLE_ENDIAN__) && \ #elif defined(__aarch64__) && defined(__LITTLE_ENDIAN__) && \
defined(__ARM_FEATURE_CRC32) && defined(__ARM_NEON) defined(__ARM_FEATURE_CRC32) && defined(__ARM_NEON) && \
defined(__ARM_FEATURE_CRYPTO)
#include <arm_acle.h> #include <arm_acle.h>
#include <arm_neon.h> #include <arm_neon.h>
...@@ -254,7 +255,7 @@ inline int64_t V128_Low64(const V128 l) { ...@@ -254,7 +255,7 @@ inline int64_t V128_Low64(const V128 l) {
} }
inline V128 V128_ShiftLeft64(const V128 l, const V128 r) { inline V128 V128_ShiftLeft64(const V128 l, const V128 r) {
return vshlq_u64(l, r); return vshlq_u64(l, vreinterpretq_s64_u64(r));
} }
#endif #endif
......
absl/crc/internal/crc_cord_state.cc 0 → 100644
// Copyright 2022 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/crc/internal/crc_cord_state.h"
#include <cassert>
#include "absl/base/config.h"
#include "absl/numeric/bits.h"
namespace absl {
ABSL_NAMESPACE_BEGIN
namespace crc_internal {
CrcCordState::RefcountedRep* CrcCordState::RefSharedEmptyRep() {
static CrcCordState::RefcountedRep* empty = new CrcCordState::RefcountedRep;
assert(empty->count.load(std::memory_order_relaxed) >= 1);
assert(empty->rep.removed_prefix.length == 0);
assert(empty->rep.prefix_crc.empty());
Ref(empty);
return empty;
}
CrcCordState::CrcCordState() : refcounted_rep_(new RefcountedRep) {}
CrcCordState::CrcCordState(const CrcCordState& other)
: refcounted_rep_(other.refcounted_rep_) {
Ref(refcounted_rep_);
}
CrcCordState::CrcCordState(CrcCordState&& other)
: refcounted_rep_(other.refcounted_rep_) {
// Make `other` valid for use after move.
other.refcounted_rep_ = RefSharedEmptyRep();
}
CrcCordState& CrcCordState::operator=(const CrcCordState& other) {
if (this != &other) {
Unref(refcounted_rep_);
refcounted_rep_ = other.refcounted_rep_;
Ref(refcounted_rep_);
}
return *this;
}
CrcCordState& CrcCordState::operator=(CrcCordState&& other) {
if (this != &other) {
Unref(refcounted_rep_);
refcounted_rep_ = other.refcounted_rep_;
// Make `other` valid for use after move.
other.refcounted_rep_ = RefSharedEmptyRep();
}
return *this;
}
CrcCordState::~CrcCordState() {
Unref(refcounted_rep_);
}
crc32c_t CrcCordState::Checksum() const {
if (rep().prefix_crc.empty()) {
return absl::crc32c_t{0};
}
if (IsNormalized()) {
return rep().prefix_crc.back().crc;
}
return absl::RemoveCrc32cPrefix(
rep().removed_prefix.crc, rep().prefix_crc.back().crc,
rep().prefix_crc.back().length - rep().removed_prefix.length);
}
CrcCordState::PrefixCrc CrcCordState::NormalizedPrefixCrcAtNthChunk(
size_t n) const {
assert(n < NumChunks());
if (IsNormalized()) {
return rep().prefix_crc[n];
}
size_t length = rep().prefix_crc[n].length - rep().removed_prefix.length;
return PrefixCrc(length,
absl::RemoveCrc32cPrefix(rep().removed_prefix.crc,
rep().prefix_crc[n].crc, length));
}
void CrcCordState::Normalize() {
if (IsNormalized() || rep().prefix_crc.empty()) {
return;
}
Rep* r = mutable_rep();
for (auto& prefix_crc : r->prefix_crc) {
size_t remaining = prefix_crc.length - r->removed_prefix.length;
prefix_crc.crc = absl::RemoveCrc32cPrefix(r->removed_prefix.crc,
prefix_crc.crc, remaining);
prefix_crc.length = remaining;
}
r->removed_prefix = PrefixCrc();
}
void CrcCordState::Poison() {
Rep* rep = mutable_rep();
if (NumChunks() > 0) {
for (auto& prefix_crc : rep->prefix_crc) {
// This is basically CRC32::Scramble().
uint32_t crc = static_cast<uint32_t>(prefix_crc.crc);
crc += 0x2e76e41b;
crc = absl::rotr(crc, 17);
prefix_crc.crc = crc32c_t{crc};
}
} else {
// Add a fake corrupt chunk.
rep->prefix_crc.push_back(PrefixCrc(0, crc32c_t{1}));
}
}
} // namespace crc_internal
ABSL_NAMESPACE_END
} // namespace absl
absl/crc/internal/crc_cord_state.h 0 → 100644
// Copyright 2022 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_CRC_INTERNAL_CRC_CORD_STATE_H_
#define ABSL_CRC_INTERNAL_CRC_CORD_STATE_H_
#include <atomic>
#include <cstddef>
#include <deque>
#include "absl/base/config.h"
#include "absl/crc/crc32c.h"
namespace absl {
ABSL_NAMESPACE_BEGIN
namespace crc_internal {
// CrcCordState is a copy-on-write class that holds the chunked CRC32C data
// that allows CrcCord to perform efficient substring operations. CrcCordState
// is used as a member variable in CrcCord. When a CrcCord is converted to a
// Cord, the CrcCordState is shallow-copied into the root node of the Cord. If
// the converted Cord is modified outside of CrcCord, the CrcCordState is
// discarded from the Cord. If the Cord is converted back to a CrcCord, and the
// Cord is still carrying the CrcCordState in its root node, the CrcCord can
// re-use the CrcCordState, making the construction of the CrcCord cheap.
//
// CrcCordState does not try to encapsulate the CRC32C state (CrcCord requires
// knowledge of how CrcCordState represents the CRC32C state). It does
// encapsulate the copy-on-write nature of the state.
class CrcCordState {
public:
// Constructors.
CrcCordState();
CrcCordState(const CrcCordState&);
CrcCordState(CrcCordState&&);
// Destructor. Atomically unreferences the data.
~CrcCordState();
// Copy and move operators.
CrcCordState& operator=(const CrcCordState&);
CrcCordState& operator=(CrcCordState&&);
// A (length, crc) pair.
struct PrefixCrc {
PrefixCrc() = default;
PrefixCrc(size_t length_arg, absl::crc32c_t crc_arg)
: length(length_arg), crc(crc_arg) {}
size_t length = 0;
// TODO(absl-team): Memory stomping often zeros out memory. If this struct
// gets overwritten, we could end up with {0, 0}, which is the correct CRC
// for a string of length 0. Consider storing a scrambled value and
// unscrambling it before verifying it.
absl::crc32c_t crc = absl::crc32c_t{0};
};
// The representation of the chunked CRC32C data.
struct Rep {
// `removed_prefix` is the crc and length of any prefix that has been
// removed from the Cord (for example, by calling
// `CrcCord::RemovePrefix()`). To get the checkum of any prefix of the cord,
// this value must be subtracted from `prefix_crc`. See `Checksum()` for an
// example.
//
// CrcCordState is said to be "normalized" if removed_prefix.length == 0.
PrefixCrc removed_prefix;
// A deque of (length, crc) pairs, representing length and crc of a prefix
// of the Cord, before removed_prefix has been subtracted. The lengths of
// the prefixes are stored in increasing order. If the Cord is not empty,
// the last value in deque is the contains the CRC32C of the entire Cord
// when removed_prefix is subtracted from it.
std::deque<PrefixCrc> prefix_crc;
};
// Returns a reference to the representation of the chunked CRC32C data.
const Rep& rep() const { return refcounted_rep_->rep; }
// Returns a mutable reference to the representation of the chunked CRC32C
// data. Calling this function will copy the data if another instance also
// holds a reference to the data, so it is important to call rep() instead if
// the data may not be mutated.
Rep* mutable_rep() {
if (refcounted_rep_->count.load(std::memory_order_acquire) != 1) {
RefcountedRep* copy = new RefcountedRep;
copy->rep = refcounted_rep_->rep;
Unref(refcounted_rep_);
refcounted_rep_ = copy;
}
return &refcounted_rep_->rep;
}
// Returns the CRC32C of the entire Cord.
absl::crc32c_t Checksum() const;
// Returns true if the chunked CRC32C cached is normalized.
bool IsNormalized() const { return rep().removed_prefix.length == 0; }
// Normalizes the chunked CRC32C checksum cache by substracting any removed
// prefix from the chunks.
void Normalize();
// Returns the number of cached chunks.
size_t NumChunks() const { return rep().prefix_crc.size(); }
// Helper that returns the (length, crc) of the `n`-th cached chunked.
PrefixCrc NormalizedPrefixCrcAtNthChunk(size_t n) const;
// Poisons all chunks to so that Checksum() will likely be incorrect with high
// probability.
void Poison();
private:
struct RefcountedRep {
std::atomic<int32_t> count{1};
Rep rep;
};
// Adds a reference to the shared global empty `RefcountedRep`, and returns a
// pointer to the `RefcountedRep`. This is an optimization to avoid unneeded
// allocations when the allocation is unlikely to ever be used. The returned
// pointer can be `Unref()`ed when it is no longer needed. Since the returned
// instance will always have a reference counter greater than 1, attempts to
// modify it (by calling `mutable_rep()`) will create a new unshared copy.
static RefcountedRep* RefSharedEmptyRep();
static void Ref(RefcountedRep* r) {
assert(r != nullptr);
r->count.fetch_add(1, std::memory_order_relaxed);
}
static void Unref(RefcountedRep* r) {
assert(r != nullptr);
if (r->count.fetch_sub(1, std::memory_order_acq_rel) == 1) {
delete r;
}
}
RefcountedRep* refcounted_rep_;
};
} // namespace crc_internal
ABSL_NAMESPACE_END
} // namespace absl
#endif // ABSL_CRC_INTERNAL_CRC_CORD_STATE_H_
absl/crc/internal/crc_cord_state_test.cc 0 → 100644
// Copyright 2022 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/crc/internal/crc_cord_state.h"
#include <algorithm>
#include <cstdint>
#include <string>
#include <utility>
#include "gtest/gtest.h"
#include "absl/crc/crc32c.h"
namespace {
TEST(CrcCordState, Default) {
absl::crc_internal::CrcCordState state;
EXPECT_TRUE(state.IsNormalized());
EXPECT_EQ(state.Checksum(), absl::crc32c_t{0});
state.Normalize();
EXPECT_EQ(state.Checksum(), absl::crc32c_t{0});
}
TEST(CrcCordState, Normalize) {
absl::crc_internal::CrcCordState state;
auto* rep = state.mutable_rep();
rep->prefix_crc.push_back(
absl::crc_internal::CrcCordState::PrefixCrc(1000, absl::crc32c_t{1000}));
rep->prefix_crc.push_back(
absl::crc_internal::CrcCordState::PrefixCrc(2000, absl::crc32c_t{2000}));
rep->removed_prefix =
absl::crc_internal::CrcCordState::PrefixCrc(500, absl::crc32c_t{500});
// The removed_prefix means state is not normalized.
EXPECT_FALSE(state.IsNormalized());
absl::crc32c_t crc = state.Checksum();
state.Normalize();
EXPECT_TRUE(state.IsNormalized());
// The checksum should not change as a result of calling Normalize().
EXPECT_EQ(state.Checksum(), crc);
EXPECT_EQ(rep->removed_prefix.length, 0);
}
TEST(CrcCordState, Copy) {
absl::crc_internal::CrcCordState state;
auto* rep = state.mutable_rep();
rep->prefix_crc.push_back(
absl::crc_internal::CrcCordState::PrefixCrc(1000, absl::crc32c_t{1000}));
absl::crc_internal::CrcCordState copy = state;
EXPECT_EQ(state.Checksum(), absl::crc32c_t{1000});
EXPECT_EQ(copy.Checksum(), absl::crc32c_t{1000});
}
TEST(CrcCordState, UnsharedSelfCopy) {
absl::crc_internal::CrcCordState state;
auto* rep = state.mutable_rep();
rep->prefix_crc.push_back(
absl::crc_internal::CrcCordState::PrefixCrc(1000, absl::crc32c_t{1000}));
const absl::crc_internal::CrcCordState& ref = state;
state = ref;
EXPECT_EQ(state.Checksum(), absl::crc32c_t{1000});
}
TEST(CrcCordState, Move) {
absl::crc_internal::CrcCordState state;
auto* rep = state.mutable_rep();
rep->prefix_crc.push_back(
absl::crc_internal::CrcCordState::PrefixCrc(1000, absl::crc32c_t{1000}));
absl::crc_internal::CrcCordState moved = std::move(state);
EXPECT_EQ(moved.Checksum(), absl::crc32c_t{1000});
}
TEST(CrcCordState, UnsharedSelfMove) {
absl::crc_internal::CrcCordState state;
auto* rep = state.mutable_rep();
rep->prefix_crc.push_back(
absl::crc_internal::CrcCordState::PrefixCrc(1000, absl::crc32c_t{1000}));
absl::crc_internal::CrcCordState& ref = state;
state = std::move(ref);
EXPECT_EQ(state.Checksum(), absl::crc32c_t{1000});
}
TEST(CrcCordState, PoisonDefault) {
absl::crc_internal::CrcCordState state;
state.Poison();
EXPECT_NE(state.Checksum(), absl::crc32c_t{0});
}
TEST(CrcCordState, PoisonData) {
absl::crc_internal::CrcCordState state;
auto* rep = state.mutable_rep();
rep->prefix_crc.push_back(
absl::crc_internal::CrcCordState::PrefixCrc(1000, absl::crc32c_t{1000}));
rep->prefix_crc.push_back(
absl::crc_internal::CrcCordState::PrefixCrc(2000, absl::crc32c_t{2000}));
rep->removed_prefix =
absl::crc_internal::CrcCordState::PrefixCrc(500, absl::crc32c_t{500});
absl::crc32c_t crc = state.Checksum();
state.Poison();
EXPECT_NE(state.Checksum(), crc);
}
} // namespace
absl/crc/internal/crc_x86_arm_combined.cc
...@@ -29,13 +29,8 @@ ...@@ -29,13 +29,8 @@
#include "absl/memory/memory.h" #include "absl/memory/memory.h"
#include "absl/numeric/bits.h" #include "absl/numeric/bits.h"
#if defined(__aarch64__) && defined(__LITTLE_ENDIAN__) && \ #if defined(ABSL_CRC_INTERNAL_HAVE_ARM_SIMD) || \
defined(__ARM_FEATURE_CRC32) && defined(__ARM_NEON) defined(ABSL_CRC_INTERNAL_HAVE_X86_SIMD)
#define ABSL_INTERNAL_CAN_USE_SIMD_CRC32C
#elif defined(__SSE4_2__) && defined(__PCLMUL__)
#define ABSL_INTERNAL_CAN_USE_SIMD_CRC32C
#elif defined(_MSC_VER) && defined(__AVX__)
// MSVC AVX support (/arch:AVX) implies SSE 4.2 and PCLMUL support.
#define ABSL_INTERNAL_CAN_USE_SIMD_CRC32C #define ABSL_INTERNAL_CAN_USE_SIMD_CRC32C
#endif #endif
......
absl/strings/BUILD.bazel
...@@ -324,6 +324,7 @@ cc_library( ...@@ -324,6 +324,7 @@ cc_library(
"//absl/container:compressed_tuple", "//absl/container:compressed_tuple",
"//absl/container:inlined_vector", "//absl/container:inlined_vector",
"//absl/container:layout", "//absl/container:layout",
"//absl/crc:crc_cord_state",
"//absl/functional:function_ref", "//absl/functional:function_ref",
"//absl/meta:type_traits", "//absl/meta:type_traits",
"//absl/types:span", "//absl/types:span",
...@@ -405,6 +406,7 @@ cc_test( ...@@ -405,6 +406,7 @@ cc_test(
":cord_internal", ":cord_internal",
":cord_rep_test_util", ":cord_rep_test_util",
"//absl/base:config", "//absl/base:config",
"//absl/crc:crc_cord_state",
"@com_google_googletest//:gtest_main", "@com_google_googletest//:gtest_main",
], ],
) )
...@@ -463,6 +465,7 @@ cc_library( ...@@ -463,6 +465,7 @@ cc_library(
"//absl/base:raw_logging_internal", "//absl/base:raw_logging_internal",
"//absl/container:fixed_array", "//absl/container:fixed_array",
"//absl/container:inlined_vector", "//absl/container:inlined_vector",
"//absl/crc:crc_cord_state",
"//absl/functional:function_ref", "//absl/functional:function_ref",
"//absl/meta:type_traits", "//absl/meta:type_traits",
"//absl/numeric:bits", "//absl/numeric:bits",
...@@ -659,6 +662,7 @@ cc_test( ...@@ -659,6 +662,7 @@ cc_test(
":cordz_update_scope", ":cordz_update_scope",
":cordz_update_tracker", ":cordz_update_tracker",
"//absl/base:config", "//absl/base:config",
"//absl/crc:crc_cord_state",
"//absl/synchronization", "//absl/synchronization",
"//absl/synchronization:thread_pool", "//absl/synchronization:thread_pool",
"@com_google_googletest//:gtest_main", "@com_google_googletest//:gtest_main",
......
absl/strings/CMakeLists.txt
...@@ -605,6 +605,7 @@ absl_cc_library( ...@@ -605,6 +605,7 @@ absl_cc_library(
absl::compressed_tuple absl::compressed_tuple
absl::config absl::config
absl::core_headers absl::core_headers
absl::crc_cord_state
absl::endian absl::endian
absl::inlined_vector absl::inlined_vector
absl::layout absl::layout
...@@ -783,6 +784,7 @@ absl_cc_test( ...@@ -783,6 +784,7 @@ absl_cc_test(
absl::cordz_statistics absl::cordz_statistics
absl::cordz_update_scope absl::cordz_update_scope
absl::cordz_update_tracker absl::cordz_update_tracker
absl::crc_cord_state
absl::thread_pool absl::thread_pool
GTest::gmock_main GTest::gmock_main
) )
...@@ -882,6 +884,7 @@ absl_cc_library( ...@@ -882,6 +884,7 @@ absl_cc_library(
absl::cordz_update_scope absl::cordz_update_scope
absl::cordz_update_tracker absl::cordz_update_tracker
absl::core_headers absl::core_headers
absl::crc_cord_state
absl::endian absl::endian
absl::fixed_array absl::fixed_array
absl::function_ref absl::function_ref
...@@ -1054,6 +1057,7 @@ absl_cc_test( ...@@ -1054,6 +1057,7 @@ absl_cc_test(
absl::config absl::config
absl::cord_internal absl::cord_internal
absl::cord_rep_test_util absl::cord_rep_test_util
absl::crc_cord_state
GTest::gmock_main GTest::gmock_main
) )
......
absl/strings/cord.cc
...@@ -35,6 +35,7 @@ ...@@ -35,6 +35,7 @@
#include "absl/base/port.h" #include "absl/base/port.h"
#include "absl/container/fixed_array.h" #include "absl/container/fixed_array.h"
#include "absl/container/inlined_vector.h" #include "absl/container/inlined_vector.h"
#include "absl/crc/internal/crc_cord_state.h"
#include "absl/strings/cord_buffer.h" #include "absl/strings/cord_buffer.h"
#include "absl/strings/escaping.h" #include "absl/strings/escaping.h"
#include "absl/strings/internal/cord_data_edge.h" #include "absl/strings/internal/cord_data_edge.h"
...@@ -854,28 +855,44 @@ inline absl::string_view Cord::InlineRep::FindFlatStartPiece() const { ...@@ -854,28 +855,44 @@ inline absl::string_view Cord::InlineRep::FindFlatStartPiece() const {
return absl::string_view(node->external()->base + offset, length); return absl::string_view(node->external()->base + offset, length);
} }
void Cord::SetExpectedChecksum(uint32_t crc) { void Cord::SetCrcCordState(crc_internal::CrcCordState state) {
auto constexpr method = CordzUpdateTracker::kSetExpectedChecksum; auto constexpr method = CordzUpdateTracker::kSetExpectedChecksum;
if (empty()) { if (empty()) {
contents_.MaybeRemoveEmptyCrcNode(); contents_.MaybeRemoveEmptyCrcNode();
CordRep* rep = CordRepCrc::New(nullptr, crc); CordRep* rep = CordRepCrc::New(nullptr, std::move(state));
contents_.EmplaceTree(rep, method); contents_.EmplaceTree(rep, method);
} else if (!contents_.is_tree()) { } else if (!contents_.is_tree()) {
CordRep* rep = contents_.MakeFlatWithExtraCapacity(0); CordRep* rep = contents_.MakeFlatWithExtraCapacity(0);
rep = CordRepCrc::New(rep, crc); rep = CordRepCrc::New(rep, std::move(state));
contents_.EmplaceTree(rep, method); contents_.EmplaceTree(rep, method);
} else { } else {
const CordzUpdateScope scope(contents_.data_.cordz_info(), method); const CordzUpdateScope scope(contents_.data_.cordz_info(), method);
CordRep* rep = CordRepCrc::New(contents_.data_.as_tree(), crc); CordRep* rep = CordRepCrc::New(contents_.data_.as_tree(), std::move(state));
contents_.SetTree(rep, scope); contents_.SetTree(rep, scope);
} }
} }
void Cord::SetExpectedChecksum(uint32_t crc) {
// Construct a CrcCordState with a single chunk.
crc_internal::CrcCordState state;
state.mutable_rep()->prefix_crc.push_back(
crc_internal::CrcCordState::PrefixCrc(size(), absl::crc32c_t{crc}));
SetCrcCordState(std::move(state));
}
const crc_internal::CrcCordState* Cord::MaybeGetCrcCordState() const {
if (!contents_.is_tree() || !contents_.tree()->IsCrc()) {
return nullptr;
}
return &contents_.tree()->crc()->crc_cord_state;
}
absl::optional<uint32_t> Cord::ExpectedChecksum() const { absl::optional<uint32_t> Cord::ExpectedChecksum() const {
if (!contents_.is_tree() || !contents_.tree()->IsCrc()) { if (!contents_.is_tree() || !contents_.tree()->IsCrc()) {
return absl::nullopt; return absl::nullopt;
} }
return contents_.tree()->crc()->crc; return static_cast<uint32_t>(
contents_.tree()->crc()->crc_cord_state.Checksum());
} }
inline int Cord::CompareSlowPath(absl::string_view rhs, size_t compared_size, inline int Cord::CompareSlowPath(absl::string_view rhs, size_t compared_size,
...@@ -1255,7 +1272,7 @@ static void DumpNode(CordRep* rep, bool include_data, std::ostream* os, ...@@ -1255,7 +1272,7 @@ static void DumpNode(CordRep* rep, bool include_data, std::ostream* os,
*os << "NULL\n"; *os << "NULL\n";
leaf = true; leaf = true;
} else if (rep->IsCrc()) { } else if (rep->IsCrc()) {
*os << "CRC crc=" << rep->crc()->crc << "\n"; *os << "CRC crc=" << rep->crc()->crc_cord_state.Checksum() << "\n";
indent += kIndentStep; indent += kIndentStep;
rep = rep->crc()->child; rep = rep->crc()->child;
} else if (rep->IsSubstring()) { } else if (rep->IsSubstring()) {
......
absl/strings/cord.h
...@@ -76,6 +76,7 @@ ...@@ -76,6 +76,7 @@
#include "absl/base/macros.h" #include "absl/base/macros.h"
#include "absl/base/port.h" #include "absl/base/port.h"
#include "absl/container/inlined_vector.h" #include "absl/container/inlined_vector.h"
#include "absl/crc/internal/crc_cord_state.h"
#include "absl/functional/function_ref.h" #include "absl/functional/function_ref.h"
#include "absl/meta/type_traits.h" #include "absl/meta/type_traits.h"
#include "absl/strings/cord_analysis.h" #include "absl/strings/cord_analysis.h"
...@@ -1002,6 +1003,10 @@ class Cord { ...@@ -1002,6 +1003,10 @@ class Cord {
}); });
return H::combine(combiner.finalize(std::move(hash_state)), size()); return H::combine(combiner.finalize(std::move(hash_state)), size());
} }
friend class CrcCord;
void SetCrcCordState(crc_internal::CrcCordState state);
const crc_internal::CrcCordState* MaybeGetCrcCordState() const;
}; };
ABSL_NAMESPACE_END ABSL_NAMESPACE_END
......
absl/strings/internal/cord_rep_crc.cc
...@@ -16,6 +16,7 @@ ...@@ -16,6 +16,7 @@
#include <cassert> #include <cassert>
#include <cstdint> #include <cstdint>
#include <utility>
#include "absl/base/config.h" #include "absl/base/config.h"
#include "absl/strings/internal/cord_internal.h" #include "absl/strings/internal/cord_internal.h"
...@@ -24,10 +25,10 @@ namespace absl { ...@@ -24,10 +25,10 @@ namespace absl {
ABSL_NAMESPACE_BEGIN ABSL_NAMESPACE_BEGIN
namespace cord_internal { namespace cord_internal {
CordRepCrc* CordRepCrc::New(CordRep* child, uint32_t crc) { CordRepCrc* CordRepCrc::New(CordRep* child, crc_internal::CrcCordState state) {
if (child != nullptr && child->IsCrc()) { if (child != nullptr && child->IsCrc()) {
if (child->refcount.IsOne()) { if (child->refcount.IsOne()) {
child->crc()->crc = crc; child->crc()->crc_cord_state = std::move(state);
return child->crc(); return child->crc();
} }
CordRep* old = child; CordRep* old = child;
...@@ -39,7 +40,7 @@ CordRepCrc* CordRepCrc::New(CordRep* child, uint32_t crc) { ...@@ -39,7 +40,7 @@ CordRepCrc* CordRepCrc::New(CordRep* child, uint32_t crc) {
new_cordrep->length = child != nullptr ? child->length : 0; new_cordrep->length = child != nullptr ? child->length : 0;
new_cordrep->tag = cord_internal::CRC; new_cordrep->tag = cord_internal::CRC;
new_cordrep->child = child; new_cordrep->child = child;
new_cordrep->crc = crc; new_cordrep->crc_cord_state = std::move(state);
return new_cordrep; return new_cordrep;
} }
......
absl/strings/internal/cord_rep_crc.h
...@@ -20,6 +20,7 @@ ...@@ -20,6 +20,7 @@
#include "absl/base/config.h" #include "absl/base/config.h"
#include "absl/base/optimization.h" #include "absl/base/optimization.h"
#include "absl/crc/internal/crc_cord_state.h"
#include "absl/strings/internal/cord_internal.h" #include "absl/strings/internal/cord_internal.h"
namespace absl { namespace absl {
...@@ -34,14 +35,14 @@ namespace cord_internal { ...@@ -34,14 +35,14 @@ namespace cord_internal {
// the contained checksum is the user's responsibility. // the contained checksum is the user's responsibility.
struct CordRepCrc : public CordRep { struct CordRepCrc : public CordRep {
CordRep* child; CordRep* child;
uint32_t crc; absl::crc_internal::CrcCordState crc_cord_state;
// Consumes `child` and returns a CordRepCrc prefixed tree containing `child`. // Consumes `child` and returns a CordRepCrc prefixed tree containing `child`.
// If the specified `child` is itself a CordRepCrc node, then this method // If the specified `child` is itself a CordRepCrc node, then this method
// either replaces the existing node, or directly updates the crc value in it // either replaces the existing node, or directly updates the crc state in it
// depending on the node being shared or not, i.e.: refcount.IsOne(). // depending on the node being shared or not, i.e.: refcount.IsOne().
// `child` must only be null if the Cord is empty. Never returns null. // `child` must only be null if the Cord is empty. Never returns null.
static CordRepCrc* New(CordRep* child, uint32_t crc); static CordRepCrc* New(CordRep* child, crc_internal::CrcCordState state);
// Destroys (deletes) the provided node. `node` must not be null. // Destroys (deletes) the provided node. `node` must not be null.
static void Destroy(CordRepCrc* node); static void Destroy(CordRepCrc* node);
......
absl/strings/internal/cord_rep_crc_test.cc
...@@ -17,6 +17,7 @@ ...@@ -17,6 +17,7 @@
#include "gmock/gmock.h" #include "gmock/gmock.h"
#include "gtest/gtest.h" #include "gtest/gtest.h"
#include "absl/base/config.h" #include "absl/base/config.h"
#include "absl/crc/internal/crc_cord_state.h"
#include "absl/strings/internal/cord_internal.h" #include "absl/strings/internal/cord_internal.h"
#include "absl/strings/internal/cord_rep_test_util.h" #include "absl/strings/internal/cord_rep_test_util.h"
...@@ -38,33 +39,40 @@ TEST(CordRepCrc, RemoveCrcWithNullptr) { ...@@ -38,33 +39,40 @@ TEST(CordRepCrc, RemoveCrcWithNullptr) {
#endif // !NDEBUG && GTEST_HAS_DEATH_TEST #endif // !NDEBUG && GTEST_HAS_DEATH_TEST
absl::crc_internal::CrcCordState MakeCrcCordState(uint32_t crc) {
crc_internal::CrcCordState state;
state.mutable_rep()->prefix_crc.push_back(
crc_internal::CrcCordState::PrefixCrc(42, crc32c_t{crc}));
return state;
}
TEST(CordRepCrc, NewDestroy) { TEST(CordRepCrc, NewDestroy) {
CordRep* rep = cordrep_testing::MakeFlat("Hello world"); CordRep* rep = cordrep_testing::MakeFlat("Hello world");
CordRepCrc* crc = CordRepCrc::New(rep, 12345); CordRepCrc* crc = CordRepCrc::New(rep, MakeCrcCordState(12345));
EXPECT_TRUE(crc->refcount.IsOne()); EXPECT_TRUE(crc->refcount.IsOne());
EXPECT_THAT(crc->child, Eq(rep)); EXPECT_THAT(crc->child, Eq(rep));
EXPECT_THAT(crc->crc, Eq(12345u)); EXPECT_THAT(crc->crc_cord_state.Checksum(), Eq(crc32c_t{12345u}));
EXPECT_TRUE(rep->refcount.IsOne()); EXPECT_TRUE(rep->refcount.IsOne());
CordRepCrc::Destroy(crc); CordRepCrc::Destroy(crc);
} }
TEST(CordRepCrc, NewExistingCrcNotShared) { TEST(CordRepCrc, NewExistingCrcNotShared) {
CordRep* rep = cordrep_testing::MakeFlat("Hello world"); CordRep* rep = cordrep_testing::MakeFlat("Hello world");
CordRepCrc* crc = CordRepCrc::New(rep, 12345); CordRepCrc* crc = CordRepCrc::New(rep, MakeCrcCordState(12345));
CordRepCrc* new_crc = CordRepCrc::New(crc, 54321); CordRepCrc* new_crc = CordRepCrc::New(crc, MakeCrcCordState(54321));
EXPECT_THAT(new_crc, Eq(crc)); EXPECT_THAT(new_crc, Eq(crc));
EXPECT_TRUE(new_crc->refcount.IsOne()); EXPECT_TRUE(new_crc->refcount.IsOne());
EXPECT_THAT(new_crc->child, Eq(rep)); EXPECT_THAT(new_crc->child, Eq(rep));
EXPECT_THAT(new_crc->crc, Eq(54321u)); EXPECT_THAT(new_crc->crc_cord_state.Checksum(), Eq(crc32c_t{54321u}));
EXPECT_TRUE(rep->refcount.IsOne()); EXPECT_TRUE(rep->refcount.IsOne());
CordRepCrc::Destroy(new_crc); CordRepCrc::Destroy(new_crc);
} }
TEST(CordRepCrc, NewExistingCrcShared) { TEST(CordRepCrc, NewExistingCrcShared) {
CordRep* rep = cordrep_testing::MakeFlat("Hello world"); CordRep* rep = cordrep_testing::MakeFlat("Hello world");
CordRepCrc* crc = CordRepCrc::New(rep, 12345); CordRepCrc* crc = CordRepCrc::New(rep, MakeCrcCordState(12345));
CordRep::Ref(crc); CordRep::Ref(crc);
CordRepCrc* new_crc = CordRepCrc::New(crc, 54321); CordRepCrc* new_crc = CordRepCrc::New(crc, MakeCrcCordState(54321));
EXPECT_THAT(new_crc, Ne(crc)); EXPECT_THAT(new_crc, Ne(crc));
EXPECT_TRUE(new_crc->refcount.IsOne()); EXPECT_TRUE(new_crc->refcount.IsOne());
...@@ -72,19 +80,19 @@ TEST(CordRepCrc, NewExistingCrcShared) { ...@@ -72,19 +80,19 @@ TEST(CordRepCrc, NewExistingCrcShared) {
EXPECT_FALSE(rep->refcount.IsOne()); EXPECT_FALSE(rep->refcount.IsOne());
EXPECT_THAT(crc->child, Eq(rep)); EXPECT_THAT(crc->child, Eq(rep));
EXPECT_THAT(new_crc->child, Eq(rep)); EXPECT_THAT(new_crc->child, Eq(rep));
EXPECT_THAT(crc->crc, Eq(12345u)); EXPECT_THAT(crc->crc_cord_state.Checksum(), Eq(crc32c_t{12345u}));
EXPECT_THAT(new_crc->crc, Eq(54321u)); EXPECT_THAT(new_crc->crc_cord_state.Checksum(), Eq(crc32c_t{54321u}));
CordRep::Unref(crc); CordRep::Unref(crc);
CordRep::Unref(new_crc); CordRep::Unref(new_crc);
} }
TEST(CordRepCrc, NewEmpty) { TEST(CordRepCrc, NewEmpty) {
CordRepCrc* crc = CordRepCrc::New(nullptr, 12345); CordRepCrc* crc = CordRepCrc::New(nullptr, MakeCrcCordState(12345));
EXPECT_TRUE(crc->refcount.IsOne()); EXPECT_TRUE(crc->refcount.IsOne());
EXPECT_THAT(crc->child, IsNull()); EXPECT_THAT(crc->child, IsNull());
EXPECT_THAT(crc->length, Eq(0u)); EXPECT_THAT(crc->length, Eq(0u));
EXPECT_THAT(crc->crc, Eq(12345u)); EXPECT_THAT(crc->crc_cord_state.Checksum(), Eq(crc32c_t{12345u}));
EXPECT_TRUE(crc->refcount.IsOne()); EXPECT_TRUE(crc->refcount.IsOne());
CordRepCrc::Destroy(crc); CordRepCrc::Destroy(crc);
} }
...@@ -98,7 +106,7 @@ TEST(CordRepCrc, RemoveCrcNotCrc) { ...@@ -98,7 +106,7 @@ TEST(CordRepCrc, RemoveCrcNotCrc) {
TEST(CordRepCrc, RemoveCrcNotShared) { TEST(CordRepCrc, RemoveCrcNotShared) {
CordRep* rep = cordrep_testing::MakeFlat("Hello world"); CordRep* rep = cordrep_testing::MakeFlat("Hello world");
CordRepCrc* crc = CordRepCrc::New(rep, 12345); CordRepCrc* crc = CordRepCrc::New(rep, MakeCrcCordState(12345));
CordRep* nocrc = RemoveCrcNode(crc); CordRep* nocrc = RemoveCrcNode(crc);
EXPECT_THAT(nocrc, Eq(rep)); EXPECT_THAT(nocrc, Eq(rep));
EXPECT_TRUE(rep->refcount.IsOne()); EXPECT_TRUE(rep->refcount.IsOne());
...@@ -107,7 +115,7 @@ TEST(CordRepCrc, RemoveCrcNotShared) { ...@@ -107,7 +115,7 @@ TEST(CordRepCrc, RemoveCrcNotShared) {
TEST(CordRepCrc, RemoveCrcShared) { TEST(CordRepCrc, RemoveCrcShared) {
CordRep* rep = cordrep_testing::MakeFlat("Hello world"); CordRep* rep = cordrep_testing::MakeFlat("Hello world");
CordRepCrc* crc = CordRepCrc::New(rep, 12345); CordRepCrc* crc = CordRepCrc::New(rep, MakeCrcCordState(12345));
CordRep::Ref(crc); CordRep::Ref(crc);
CordRep* nocrc = RemoveCrcNode(crc); CordRep* nocrc = RemoveCrcNode(crc);
EXPECT_THAT(nocrc, Eq(rep)); EXPECT_THAT(nocrc, Eq(rep));
......
absl/strings/internal/cordz_info_statistics_test.cc
...@@ -19,6 +19,7 @@ ...@@ -19,6 +19,7 @@
#include "gmock/gmock.h" #include "gmock/gmock.h"
#include "gtest/gtest.h" #include "gtest/gtest.h"
#include "absl/base/config.h" #include "absl/base/config.h"
#include "absl/crc/internal/crc_cord_state.h"
#include "absl/strings/cord.h" #include "absl/strings/cord.h"
#include "absl/strings/internal/cord_internal.h" #include "absl/strings/internal/cord_internal.h"
#include "absl/strings/internal/cord_rep_btree.h" #include "absl/strings/internal/cord_rep_btree.h"
...@@ -451,7 +452,8 @@ TEST(CordzInfoStatisticsTest, BtreeNodeShared) { ...@@ -451,7 +452,8 @@ TEST(CordzInfoStatisticsTest, BtreeNodeShared) {
TEST(CordzInfoStatisticsTest, Crc) { TEST(CordzInfoStatisticsTest, Crc) {
RefHelper ref; RefHelper ref;
auto* left = Flat(1000); auto* left = Flat(1000);
auto* crc = ref.NeedsUnref(CordRepCrc::New(left, 12345)); auto* crc =
ref.NeedsUnref(CordRepCrc::New(left, crc_internal::CrcCordState()));
CordzStatistics expected; CordzStatistics expected;
expected.size = left->length; expected.size = left->length;
......
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