// 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.
// 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/cord_buffer.h"
#include <algorithm>
#include <cstring>
#include <limits>
#include <string>
#include <utility>
#include "gmock/gmock.h"
#include "gtest/gtest.h"
#include "absl/base/config.h"
#include "absl/strings/internal/cord_internal.h"
#include "absl/strings/internal/cord_rep_flat.h"
#include "absl/strings/internal/cord_rep_test_util.h"
#include "absl/strings/string_view.h"
#include "absl/types/span.h"
using testing::Eq;
using testing::Ge;
using testing::Le;
using testing::Ne;
namespace absl {
ABSL_NAMESPACE_BEGIN
class CordBufferTestPeer {
public:
static cord_internal::CordRep* ConsumeValue(CordBuffer& buffer,
absl::string_view& short_value) {
return buffer.ConsumeValue(short_value);
}
};
namespace {
using ::absl::cordrep_testing::CordToString;
constexpr size_t kInlinedSize = sizeof(CordBuffer) - 1;
constexpr size_t kDefaultLimit = CordBuffer::kDefaultLimit;
constexpr size_t kCustomLimit = CordBuffer::kCustomLimit;
constexpr size_t kMaxFlatSize = cord_internal::kMaxFlatSize;
constexpr size_t kMaxFlatLength = cord_internal::kMaxFlatLength;
constexpr size_t kFlatOverhead = cord_internal::kFlatOverhead;
constexpr size_t k8KiB = 8 << 10;
constexpr size_t k16KiB = 16 << 10;
constexpr size_t k64KiB = 64 << 10;
constexpr size_t k1MB = 1 << 20;
class CordBufferTest : public testing::TestWithParam<size_t> {};
INSTANTIATE_TEST_SUITE_P(MediumSize, CordBufferTest,
testing::Values(1, kInlinedSize - 1, kInlinedSize,
kInlinedSize + 1, kDefaultLimit - 1,
kDefaultLimit));
TEST_P(CordBufferTest, MaximumPayload) {
EXPECT_THAT(CordBuffer::MaximumPayload(), Eq(kMaxFlatLength));
EXPECT_THAT(CordBuffer::MaximumPayload(512), Eq(512 - kFlatOverhead));
EXPECT_THAT(CordBuffer::MaximumPayload(k64KiB), Eq(k64KiB - kFlatOverhead));
EXPECT_THAT(CordBuffer::MaximumPayload(k1MB), Eq(k64KiB - kFlatOverhead));
}
TEST(CordBufferTest, ConstructDefault) {
CordBuffer buffer;
EXPECT_THAT(buffer.capacity(), Eq(sizeof(CordBuffer) - 1));
EXPECT_THAT(buffer.length(), Eq(0));
EXPECT_THAT(buffer.data(), Ne(nullptr));
EXPECT_THAT(buffer.available().data(), Eq(buffer.data()));
EXPECT_THAT(buffer.available().size(), Eq(buffer.capacity()));
memset(buffer.data(), 0xCD, buffer.capacity());
}
TEST(CordBufferTest, CreateSsoWithDefaultLimit) {
CordBuffer buffer = CordBuffer::CreateWithDefaultLimit(3);
EXPECT_THAT(buffer.capacity(), Ge(3));
EXPECT_THAT(buffer.capacity(), Le(sizeof(CordBuffer)));
EXPECT_THAT(buffer.length(), Eq(0));
memset(buffer.data(), 0xCD, buffer.capacity());
memcpy(buffer.data(), "Abc", 3);
buffer.SetLength(3);
EXPECT_THAT(buffer.length(), Eq(3));
absl::string_view short_value;
EXPECT_THAT(CordBufferTestPeer::ConsumeValue(buffer, short_value),
Eq(nullptr));
EXPECT_THAT(absl::string_view(buffer.data(), 3), Eq("Abc"));
EXPECT_THAT(short_value, Eq("Abc"));
}
TEST_P(CordBufferTest, Available) {
const size_t requested = GetParam();
CordBuffer buffer = CordBuffer::CreateWithDefaultLimit(requested);
EXPECT_THAT(buffer.available().data(), Eq(buffer.data()));
EXPECT_THAT(buffer.available().size(), Eq(buffer.capacity()));
buffer.SetLength(2);
EXPECT_THAT(buffer.available().data(), Eq(buffer.data() + 2));
EXPECT_THAT(buffer.available().size(), Eq(buffer.capacity() - 2));
}
TEST_P(CordBufferTest, IncreaseLengthBy) {
const size_t requested = GetParam();
CordBuffer buffer = CordBuffer::CreateWithDefaultLimit(requested);
buffer.IncreaseLengthBy(2);
EXPECT_THAT(buffer.length(), Eq(2));
buffer.IncreaseLengthBy(5);
EXPECT_THAT(buffer.length(), Eq(7));
}
TEST_P(CordBufferTest, AvailableUpTo) {
const size_t requested = GetParam();
CordBuffer buffer = CordBuffer::CreateWithDefaultLimit(requested);
size_t expected_up_to = std::min<size_t>(3, buffer.capacity());
EXPECT_THAT(buffer.available_up_to(3).data(), Eq(buffer.data()));
EXPECT_THAT(buffer.available_up_to(3).size(), Eq(expected_up_to));
buffer.SetLength(2);
expected_up_to = std::min<size_t>(3, buffer.capacity() - 2);
EXPECT_THAT(buffer.available_up_to(3).data(), Eq(buffer.data() + 2));
EXPECT_THAT(buffer.available_up_to(3).size(), Eq(expected_up_to));
}
// Returns the maximum capacity for a given block_size and requested size.
size_t MaxCapacityFor(size_t block_size, size_t requested) {
requested = (std::min)(requested, cord_internal::kMaxLargeFlatSize);
// Maximum returned size is always capped at block_size - kFlatOverhead.
return block_size - kFlatOverhead;
}
TEST_P(CordBufferTest, CreateWithDefaultLimit) {
const size_t requested = GetParam();
CordBuffer buffer = CordBuffer::CreateWithDefaultLimit(requested);
EXPECT_THAT(buffer.capacity(), Ge(requested));
EXPECT_THAT(buffer.capacity(), Le(MaxCapacityFor(kMaxFlatSize, requested)));
EXPECT_THAT(buffer.length(), Eq(0));
memset(buffer.data(), 0xCD, buffer.capacity());
std::string data(requested - 1, 'x');
memcpy(buffer.data(), data.c_str(), requested);
buffer.SetLength(requested);
EXPECT_THAT(buffer.length(), Eq(requested));
EXPECT_THAT(absl::string_view(buffer.data()), Eq(data));
}
TEST(CordBufferTest, CreateWithDefaultLimitAskingFor2GB) {
constexpr size_t k2GiB = 1U << 31;
CordBuffer buffer = CordBuffer::CreateWithDefaultLimit(k2GiB);
// Expect to never be awarded more than a reasonable memory size, even in
// cases where a (debug) memory allocator may grant us somewhat more memory
// than `kDefaultLimit` which should be no more than `2 * kDefaultLimit`
EXPECT_THAT(buffer.capacity(), Le(2 * CordBuffer::kDefaultLimit));
EXPECT_THAT(buffer.length(), Eq(0));
EXPECT_THAT(buffer.data(), Ne(nullptr));
memset(buffer.data(), 0xCD, buffer.capacity());
}
TEST_P(CordBufferTest, MoveConstruct) {
const size_t requested = GetParam();
CordBuffer from = CordBuffer::CreateWithDefaultLimit(requested);
const size_t capacity = from.capacity();
memcpy(from.data(), "Abc", 4);
from.SetLength(4);
CordBuffer to(std::move(from));
EXPECT_THAT(to.capacity(), Eq(capacity));
EXPECT_THAT(to.length(), Eq(4));
EXPECT_THAT(absl::string_view(to.data()), Eq("Abc"));
EXPECT_THAT(from.length(), Eq(0)); // NOLINT
}
TEST_P(CordBufferTest, MoveAssign) {
const size_t requested = GetParam();
CordBuffer from = CordBuffer::CreateWithDefaultLimit(requested);
const size_t capacity = from.capacity();
memcpy(from.data(), "Abc", 4);
from.SetLength(4);
CordBuffer to;
to = std::move(from);
EXPECT_THAT(to.capacity(), Eq(capacity));
EXPECT_THAT(to.length(), Eq(4));
EXPECT_THAT(absl::string_view(to.data()), Eq("Abc"));
EXPECT_THAT(from.length(), Eq(0)); // NOLINT
}
TEST_P(CordBufferTest, ConsumeValue) {
const size_t requested = GetParam();
CordBuffer buffer = CordBuffer::CreateWithDefaultLimit(requested);
memcpy(buffer.data(), "Abc", 4);
buffer.SetLength(3);
absl::string_view short_value;
if (cord_internal::CordRep* rep =
CordBufferTestPeer::ConsumeValue(buffer, short_value)) {
EXPECT_THAT(CordToString(rep), Eq("Abc"));
cord_internal::CordRep::Unref(rep);
} else {
EXPECT_THAT(short_value, Eq("Abc"));
}
EXPECT_THAT(buffer.length(), Eq(0));
}
TEST_P(CordBufferTest, CreateWithCustomLimitWithinDefaultLimit) {
const size_t requested = GetParam();
CordBuffer buffer =
CordBuffer::CreateWithCustomLimit(kMaxFlatSize, requested);
EXPECT_THAT(buffer.capacity(), Ge(requested));
EXPECT_THAT(buffer.capacity(), Le(MaxCapacityFor(kMaxFlatSize, requested)));
EXPECT_THAT(buffer.length(), Eq(0));
memset(buffer.data(), 0xCD, buffer.capacity());
std::string data(requested - 1, 'x');
memcpy(buffer.data(), data.c_str(), requested);
buffer.SetLength(requested);
EXPECT_THAT(buffer.length(), Eq(requested));
EXPECT_THAT(absl::string_view(buffer.data()), Eq(data));
}
TEST(CordLargeBufferTest, CreateAtOrBelowDefaultLimit) {
CordBuffer buffer = CordBuffer::CreateWithCustomLimit(k64KiB, kDefaultLimit);
EXPECT_THAT(buffer.capacity(), Ge(kDefaultLimit));
EXPECT_THAT(buffer.capacity(),
Le(MaxCapacityFor(kMaxFlatSize, kDefaultLimit)));
buffer = CordBuffer::CreateWithCustomLimit(k64KiB, 3178);
EXPECT_THAT(buffer.capacity(), Ge(3178));
}
TEST(CordLargeBufferTest, CreateWithCustomLimit) {
ASSERT_THAT((kMaxFlatSize & (kMaxFlatSize - 1)) == 0, "Must be power of 2");
for (size_t size = kMaxFlatSize; size <= kCustomLimit; size *= 2) {
CordBuffer buffer = CordBuffer::CreateWithCustomLimit(size, size);
size_t expected = size - kFlatOverhead;
ASSERT_THAT(buffer.capacity(), Ge(expected));
EXPECT_THAT(buffer.capacity(), Le(MaxCapacityFor(size, expected)));
}
}
TEST(CordLargeBufferTest, CreateWithTooLargeLimit) {
CordBuffer buffer = CordBuffer::CreateWithCustomLimit(k64KiB, k1MB);
ASSERT_THAT(buffer.capacity(), Ge(k64KiB - kFlatOverhead));
EXPECT_THAT(buffer.capacity(), Le(MaxCapacityFor(k64KiB, k1MB)));
}
TEST(CordLargeBufferTest, CreateWithHugeValueForOverFlowHardening) {
for (size_t dist_from_max = 0; dist_from_max <= 32; ++dist_from_max) {
size_t capacity = std::numeric_limits<size_t>::max() - dist_from_max;
CordBuffer buffer = CordBuffer::CreateWithDefaultLimit(capacity);
ASSERT_THAT(buffer.capacity(), Ge(kDefaultLimit));
EXPECT_THAT(buffer.capacity(), Le(MaxCapacityFor(kMaxFlatSize, capacity)));
for (size_t limit = kMaxFlatSize; limit <= kCustomLimit; limit *= 2) {
CordBuffer buffer = CordBuffer::CreateWithCustomLimit(limit, capacity);
ASSERT_THAT(buffer.capacity(), Ge(limit - kFlatOverhead));
EXPECT_THAT(buffer.capacity(), Le(MaxCapacityFor(limit, capacity)));
}
}
}
TEST(CordLargeBufferTest, CreateWithSmallLimit) {
CordBuffer buffer = CordBuffer::CreateWithCustomLimit(512, 1024);
ASSERT_THAT(buffer.capacity(), Ge(512 - kFlatOverhead));
EXPECT_THAT(buffer.capacity(), Le(MaxCapacityFor(512, 1024)));
// Ask for precise block size, should return size - kOverhead
buffer = CordBuffer::CreateWithCustomLimit(512, 512);
ASSERT_THAT(buffer.capacity(), Ge(512 - kFlatOverhead));
EXPECT_THAT(buffer.capacity(), Le(MaxCapacityFor(512, 512)));
// Corner case: 511 < block_size, but 511 + kOverhead is above
buffer = CordBuffer::CreateWithCustomLimit(512, 511);
ASSERT_THAT(buffer.capacity(), Ge(512 - kFlatOverhead));
EXPECT_THAT(buffer.capacity(), Le(MaxCapacityFor(512, 511)));
// Corner case: 498 + kOverhead < block_size
buffer = CordBuffer::CreateWithCustomLimit(512, 498);
ASSERT_THAT(buffer.capacity(), Ge(512 - kFlatOverhead));
EXPECT_THAT(buffer.capacity(), Le(MaxCapacityFor(512, 498)));
}
TEST(CordLargeBufferTest, CreateWasteFull) {
// 15 KiB gets rounded down to next pow2 value.
const size_t requested = (15 << 10);
CordBuffer buffer = CordBuffer::CreateWithCustomLimit(k16KiB, requested);
ASSERT_THAT(buffer.capacity(), Ge(k8KiB - kFlatOverhead));
EXPECT_THAT(buffer.capacity(), Le(MaxCapacityFor(k8KiB, requested)));
}
TEST(CordLargeBufferTest, CreateSmallSlop) {
const size_t requested = k16KiB - 2 * kFlatOverhead;
CordBuffer buffer = CordBuffer::CreateWithCustomLimit(k16KiB, requested);
ASSERT_THAT(buffer.capacity(), Ge(k16KiB - kFlatOverhead));
EXPECT_THAT(buffer.capacity(), Le(MaxCapacityFor(k16KiB, requested)));
}
} // namespace
ABSL_NAMESPACE_END
} // namespace absl
Codebase Browser
chromium