client/length_delimited_ring_buffer_test.cc - crashpad/crashpad - Git at Google

 // Copyright 2023 The Crashpad 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
 //
 //     http://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 "client/length_delimited_ring_buffer.h"

 #include <stdint.h>

 #include <array>
 #include <string>
 #include <vector>

 #include "gmock/gmock.h"
 #include "gtest/gtest.h"

 namespace crashpad {
 namespace test {
 namespace {

 using testing::Eq;
 using testing::IsFalse;
 using testing::IsTrue;

 // Buffer with magic 0xcab00d1e, version 1, read_pos 0, length 3, and 3 bytes of
 // data (1 varint length, 2 bytes data)
 constexpr char kValidBufferSize3[] =
     "\x1e\x0d\xb0\xca\x01\x00\x00\x00\x00\x00\x00\x00\x03\x00\x00\x00\x02\x42"
     "\x23";
 constexpr size_t kValidBufferSize3Len =
     sizeof(kValidBufferSize3) - 1;  // Remove trailing NUL.

 // Buffer with magic 0xcab00d1e, version 8, read_pos 0, length 3, and 3 bytes of
 // data (1 varint length, 2 bytes data).
 constexpr char kInvalidVersionBuffer[] =
     "\x1e\x0d\xb0\xca\x08\x00\x00\x00\x00\x00\x00\x00\x03\x00\x00\x00\x02\xab"
     "\xcd";
 constexpr size_t kInvalidVersionBufferLen =
     sizeof(kInvalidVersionBuffer) - 1;  // Remove trailing NUL.

 // Buffer representing process which crashed while in the middle of a Push()
 // operation, with a previously-Push()ed buffer whose length was zeroed out at
 // the start.
 constexpr char kMidCrashBuffer[] =
     "\x1e\x0d\xb0\xca\x01\x00\x00\x00\x00\x00\x00\x00\x03\x00\x00\x00\x00\x42"
     "\x23";
 constexpr size_t kMidCrashBufferLen =
     sizeof(kMidCrashBuffer) - 1;  // Remove trailing NUL.

 constexpr uint8_t kHello[] = {0x68, 0x65, 0x6c, 0x6c, 0x6f};

 // Invalid buffer containing malformed varint in data payload (Base 128 varint
 // with length 6, which would represent a data length > 32 bits).
 constexpr char kInvalidBase128VarintBuffer[] =
     "\x1e\x0d\xb0\xca\x01\x00\x00\x00\x00\x00\x00\x00\x06\x00\x00\x00\x80\x80"
     "\x80\x80\x80\x01";
 constexpr size_t kInvalidBase128VarintBufferLen =
     sizeof(kInvalidBase128VarintBuffer) - 1;  // Remove trailing NUL.

 // Invalid buffer containing malformed varint in data payload (Base 128 varint
 // with length 5 but bits 33 and 34 set, which would represent a data length >
 // 32 bits).
 constexpr char kInvalidBase128VarintBits33And34SetBuffer[] =
     "\x1e\x0d\xb0\xca\x01\x00\x00\x00\x00\x00\x00\x00\x05\x00\x00\x00\x80\x80"
     "\x80\x80\x60";
 constexpr size_t kInvalidBase128VarintBits33And34SetBufferLen =
     sizeof(kInvalidBase128VarintBits33And34SetBuffer) -
     1;  // Remove trailing NUL.

 // Invalid buffer containing too-short data payload (varint length indicates
 // payload length is 4 but payload only contains 3 bytes).
 constexpr char kInvalidPayloadBufferTooShort[] =
     "\x1e\x0d\xb0\xca\x01\x00\x00\x00\x00\x00\x00\x00\x04\x00\x00\x00\x04"
     "\x42\x42\x42";
 constexpr size_t kInvalidPayloadBufferTooShortLen =
     sizeof(kInvalidPayloadBufferTooShort) - 1;  // Remove trailing NUL.

 TEST(LengthDelimitedRingBufferTest,
      RingBufferDataShouldStartWithMagicAndVersion) {
   RingBufferData ring_buffer;
   const void* ring_buffer_bytes = static_cast<const void*>(&ring_buffer);
   EXPECT_THAT(memcmp(ring_buffer_bytes, "\x1e\x0d\xb0\xca\x01\x00\x00\x00", 8),
               Eq(0));
 }

 TEST(LengthDelimitedRingBufferTest,
      EmptyBufferSizeShouldIncludeHeaderInRingBufferLength) {
   RingBufferData ring_buffer;
   EXPECT_THAT(ring_buffer.GetRingBufferLength(),
               Eq(16U));  // 4 for uint32 magic, 4 for uint32 version, 4 for
                          // uint32 read_pos, 4 for uint32 length
 }

 TEST(LengthDelimitedRingBufferTest,
      NonEmptyBufferSizeShouldIncludeHeaderAndData) {
   RingBufferData ring_buffer;
   LengthDelimitedRingBufferWriter writer(ring_buffer);
   ASSERT_THAT(writer.Push(kHello, sizeof(kHello)), IsTrue());
   EXPECT_THAT(ring_buffer.GetRingBufferLength(),
               Eq(22U));  // 16 for header, 1 for varint length, 5 for data
 }

 TEST(LengthDelimitedRingBufferTest, PopOnEmptyBufferShouldFail) {
   RingBufferData ring_buffer;
   LengthDelimitedRingBufferReader reader(ring_buffer);
   std::vector<uint8_t> result;
   EXPECT_THAT(reader.Pop(result), IsFalse());
 }

 TEST(LengthDelimitedRingBufferTest, PushZeroLengthShouldFail) {
   RingBufferData ring_buffer;
   LengthDelimitedRingBufferWriter writer(ring_buffer);
   ASSERT_THAT(writer.Push(nullptr, 0), IsFalse());
 }

 TEST(LengthDelimitedRingBufferTest, PushExactlyBufferSizeThenPopShouldSucceed) {
   RingBufferData ring_buffer;
   LengthDelimitedRingBufferWriter writer(ring_buffer);
   ASSERT_THAT(writer.Push(kHello, sizeof(kHello)), IsTrue());

   LengthDelimitedRingBufferReader reader(ring_buffer);
   std::vector<uint8_t> result;
   EXPECT_THAT(reader.Pop(result), IsTrue());
   const std::vector<uint8_t> expected_first = {0x68, 0x65, 0x6c, 0x6c, 0x6f};
   EXPECT_THAT(result, Eq(expected_first));
 }

 TEST(LengthDelimitedRingBufferTest, PushLargerThanBufferSizeShouldFail) {
   RingBufferData<4> ring_buffer;
   LengthDelimitedRingBufferWriter writer(ring_buffer);
   EXPECT_THAT(writer.Push(kHello, sizeof(kHello)), IsFalse());
 }

 TEST(LengthDelimitedRingBufferTest,
      PushUntilFullThenPopUntilEmptyShouldReturnInFIFOOrder) {
   RingBufferData<4> ring_buffer;
   LengthDelimitedRingBufferWriter writer(ring_buffer);
   constexpr uint8_t a = 0x41;
   EXPECT_THAT(writer.Push(&a, sizeof(a)),
               IsTrue());  // Writes 2 bytes (1 for length)
   constexpr uint8_t b = 0x42;
   EXPECT_THAT(writer.Push(&b, sizeof(b)),
               IsTrue());  // Writes 2 bytes (1 for length)

   LengthDelimitedRingBufferReader reader(ring_buffer);
   std::vector<uint8_t> first;
   EXPECT_THAT(reader.Pop(first), IsTrue());
   const std::vector<uint8_t> expected_first = {0x41};
   EXPECT_THAT(first, Eq(expected_first));

   std::vector<uint8_t> second;
   EXPECT_THAT(reader.Pop(second), IsTrue());
   const std::vector<uint8_t> expected_second = {0x42};
   EXPECT_THAT(second, Eq(expected_second));

   std::vector<uint8_t> empty;
   EXPECT_THAT(reader.Pop(empty), IsFalse());
 }

 TEST(LengthDelimitedRingBufferTest,
      PushThenPopBuffersOfDifferingLengthsShouldReturnBuffers) {
   RingBufferData<5> ring_buffer;
   LengthDelimitedRingBufferWriter writer(ring_buffer);
   constexpr uint8_t ab[2] = {0x41, 0x42};
   EXPECT_THAT(writer.Push(ab, sizeof(ab)),
               IsTrue());  // Writes 3 bytes (1 for length)
   constexpr uint8_t c = 0x43;
   EXPECT_THAT(writer.Push(&c, sizeof(c)),
               IsTrue());  // Writes 2 bytes (1 for length)

   LengthDelimitedRingBufferReader reader(ring_buffer);
   std::vector<uint8_t> first;
   EXPECT_THAT(reader.Pop(first), IsTrue());
   const std::vector<uint8_t> expected_first = {0x41, 0x42};
   EXPECT_THAT(first, Eq(expected_first));

   std::vector<uint8_t> second;
   EXPECT_THAT(reader.Pop(second), IsTrue());
   const std::vector<uint8_t> expected_second = {0x43};
   EXPECT_THAT(second, Eq(expected_second));

   std::vector<uint8_t> empty;
   EXPECT_THAT(reader.Pop(empty), IsFalse());
 }

 TEST(LengthDelimitedRingBufferDataTest, PushOnFullBufferShouldOverwriteOldest) {
   RingBufferData<4> ring_buffer;
   LengthDelimitedRingBufferWriter writer(ring_buffer);
   constexpr uint8_t a = 0x41;
   EXPECT_THAT(writer.Push(&a, sizeof(a)),
               IsTrue());  // Writes 2 bytes (1 for length)
   constexpr uint8_t b = 0x42;
   EXPECT_THAT(writer.Push(&b, sizeof(b)),
               IsTrue());  // Writes 2 bytes (1 for length)
   constexpr uint8_t c = 0x43;
   EXPECT_THAT(writer.Push(&c, sizeof(c)), IsTrue());  // Should overwrite "A"

   LengthDelimitedRingBufferReader reader(ring_buffer);
   std::vector<uint8_t> first;
   EXPECT_THAT(reader.Pop(first), IsTrue());
   const std::vector<uint8_t> expected_first = {uint8_t{0x42}};
   EXPECT_THAT(first, Eq(expected_first));

   std::vector<uint8_t> second;
   EXPECT_THAT(reader.Pop(second), IsTrue());
   const std::vector<uint8_t> expected_second = {uint8_t{0x43}};
   EXPECT_THAT(second, Eq(expected_second));
 }

 TEST(LengthDelimitedRingBufferDataTest,
      PushOnFullBufferShouldOverwriteMultipleOldest) {
   RingBufferData<4> ring_buffer;
   LengthDelimitedRingBufferWriter writer(ring_buffer);
   constexpr uint8_t a = 0x41;
   EXPECT_THAT(writer.Push(&a, sizeof(a)),
               IsTrue());  // Writes 2 bytes (1 for length)
   constexpr uint8_t b = 0x42;
   EXPECT_THAT(writer.Push(&b, sizeof(b)),
               IsTrue());  // Writes 2 bytes (1 for length)
   constexpr uint8_t cd[] = {0x43, 0x44};
   EXPECT_THAT(writer.Push(cd, sizeof(cd)),
               IsTrue());  // Needs 3 bytes; should overwrite "A" and "B"

   LengthDelimitedRingBufferReader reader(ring_buffer);
   std::vector<uint8_t> first;
   EXPECT_THAT(reader.Pop(first), IsTrue());
   const std::vector<uint8_t> expected_first = {0x43, 0x44};
   EXPECT_THAT(first, Eq(expected_first));

   std::vector<uint8_t> empty;
   EXPECT_THAT(reader.Pop(empty), IsFalse());
 }

 TEST(LengthDelimitedRingBufferDataTest, PushThenPopWithLengthVarintTwoBytes) {
   RingBufferData ring_buffer;
   decltype(ring_buffer)::SizeType size = 150;
   std::string s(size, 'X');
   LengthDelimitedRingBufferWriter writer(ring_buffer);
   ASSERT_THAT(writer.Push(reinterpret_cast<const uint8_t*>(s.c_str()), size),
               IsTrue());

   LengthDelimitedRingBufferReader reader(ring_buffer);
   std::vector<uint8_t> first;
   EXPECT_THAT(reader.Pop(first), IsTrue());
   std::string result(reinterpret_cast<const char*>(first.data()), first.size());
   EXPECT_THAT(result, Eq(s));
 }

 TEST(LengthDelimitedRingBufferDataTest, DeserializeFromTooShortShouldFail) {
   RingBufferData<1> ring_buffer;
   EXPECT_THAT(ring_buffer.DeserializeFromBuffer(nullptr, 0), IsFalse());
 }

 TEST(LengthDelimitedRingBufferDataTest, DeserializeFromTooLongShouldFail) {
   RingBufferData<1> ring_buffer;
   // This buffer is size 3; it won't fit in the template arg (size 1).
   EXPECT_THAT(ring_buffer.DeserializeFromBuffer(
                   reinterpret_cast<const uint8_t*>(kValidBufferSize3),
                   kValidBufferSize3Len),
               IsFalse());
 }

 TEST(LengthDelimitedRingBufferDataTest,
      DeserializeFromInvalidVersionShouldFail) {
   RingBufferData<3> ring_buffer;
   EXPECT_THAT(ring_buffer.DeserializeFromBuffer(
                   reinterpret_cast<const uint8_t*>(kInvalidVersionBuffer),
                   kInvalidVersionBufferLen),
               IsFalse());
 }

 TEST(LengthDelimitedRingBufferDataTest,
      DeserializeFromInvalidVarintLengthShouldSucceedButPopShouldFail) {
   RingBufferData ring_buffer;
   EXPECT_THAT(ring_buffer.DeserializeFromBuffer(
                   reinterpret_cast<const uint8_t*>(kInvalidBase128VarintBuffer),
                   kInvalidBase128VarintBufferLen),
               IsTrue());
   LengthDelimitedRingBufferReader reader(ring_buffer);
   std::vector<uint8_t> data;
   EXPECT_THAT(reader.Pop(data), IsFalse());
 }

 TEST(LengthDelimitedRingBufferDataTest,
      DeserializeFromInvalidVarintBitsShouldSucceedButPopShouldFail) {
   RingBufferData ring_buffer;
   EXPECT_THAT(ring_buffer.DeserializeFromBuffer(
                   reinterpret_cast<const uint8_t*>(
                       kInvalidBase128VarintBits33And34SetBuffer),
                   kInvalidBase128VarintBits33And34SetBufferLen),
               IsTrue());
   LengthDelimitedRingBufferReader reader(ring_buffer);
   std::vector<uint8_t> data;
   EXPECT_THAT(reader.Pop(data), IsFalse());
 }

 TEST(LengthDelimitedRingBufferDataTest,
      DeserializeFromInvalidPayloadBufferTooShortShouldSucceedButPopShouldFail) {
   RingBufferData ring_buffer;
   EXPECT_THAT(
       ring_buffer.DeserializeFromBuffer(
           reinterpret_cast<const uint8_t*>(kInvalidPayloadBufferTooShort),
           kInvalidPayloadBufferTooShortLen),
       IsTrue());
   LengthDelimitedRingBufferReader reader(ring_buffer);
   std::vector<uint8_t> data;
   EXPECT_THAT(reader.Pop(data), IsFalse());
 }

 TEST(LengthDelimitedRingBufferDataTest,
      DeserializeFromFullBufferShouldSucceed) {
   RingBufferData<3> ring_buffer;
   EXPECT_THAT(ring_buffer.DeserializeFromBuffer(
                   reinterpret_cast<const uint8_t*>(kValidBufferSize3),
                   kValidBufferSize3Len),
               IsTrue());
   LengthDelimitedRingBufferReader reader(ring_buffer);
   std::vector<uint8_t> data;
   EXPECT_THAT(reader.Pop(data), IsTrue());
   const std::vector<uint8_t> expected = {0x42, 0x23};
   EXPECT_THAT(data, Eq(expected));
 }

 TEST(LengthDelimitedRingBufferDataTest,
      DeserializeFromMidCrashBufferShouldSucceedButSubsequentPopShouldFail) {
   RingBufferData ring_buffer;
   EXPECT_THAT(ring_buffer.DeserializeFromBuffer(
                   reinterpret_cast<const uint8_t*>(kMidCrashBuffer),
                   kMidCrashBufferLen),
               IsTrue());
   LengthDelimitedRingBufferReader reader(ring_buffer);
   // Pop should fail since the length was written to be 0.
   std::vector<uint8_t> data;
   EXPECT_THAT(reader.Pop(data), IsFalse());
 }

 }  // namespace
 }  // namespace test
 }  // namespace crashpad
	// Copyright 2023 The Crashpad 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
	//
	// http://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 "client/length_delimited_ring_buffer.h"

	#include <stdint.h>

	#include <array>
	#include <string>
	#include <vector>

	#include "gmock/gmock.h"
	#include "gtest/gtest.h"

	namespace crashpad {
	namespace test {
	namespace {

	using testing::Eq;
	using testing::IsFalse;
	using testing::IsTrue;

	// Buffer with magic 0xcab00d1e, version 1, read_pos 0, length 3, and 3 bytes of
	// data (1 varint length, 2 bytes data)
	constexpr char kValidBufferSize3[] =
	"\x1e\x0d\xb0\xca\x01\x00\x00\x00\x00\x00\x00\x00\x03\x00\x00\x00\x02\x42"
	"\x23";
	constexpr size_t kValidBufferSize3Len =
	sizeof(kValidBufferSize3) - 1; // Remove trailing NUL.

	// Buffer with magic 0xcab00d1e, version 8, read_pos 0, length 3, and 3 bytes of
	// data (1 varint length, 2 bytes data).
	constexpr char kInvalidVersionBuffer[] =
	"\x1e\x0d\xb0\xca\x08\x00\x00\x00\x00\x00\x00\x00\x03\x00\x00\x00\x02\xab"
	"\xcd";
	constexpr size_t kInvalidVersionBufferLen =
	sizeof(kInvalidVersionBuffer) - 1; // Remove trailing NUL.

	// Buffer representing process which crashed while in the middle of a Push()
	// operation, with a previously-Push()ed buffer whose length was zeroed out at
	// the start.
	constexpr char kMidCrashBuffer[] =
	"\x1e\x0d\xb0\xca\x01\x00\x00\x00\x00\x00\x00\x00\x03\x00\x00\x00\x00\x42"
	"\x23";
	constexpr size_t kMidCrashBufferLen =
	sizeof(kMidCrashBuffer) - 1; // Remove trailing NUL.

	constexpr uint8_t kHello[] = {0x68, 0x65, 0x6c, 0x6c, 0x6f};

	// Invalid buffer containing malformed varint in data payload (Base 128 varint
	// with length 6, which would represent a data length > 32 bits).
	constexpr char kInvalidBase128VarintBuffer[] =
	"\x1e\x0d\xb0\xca\x01\x00\x00\x00\x00\x00\x00\x00\x06\x00\x00\x00\x80\x80"
	"\x80\x80\x80\x01";
	constexpr size_t kInvalidBase128VarintBufferLen =
	sizeof(kInvalidBase128VarintBuffer) - 1; // Remove trailing NUL.

	// Invalid buffer containing malformed varint in data payload (Base 128 varint
	// with length 5 but bits 33 and 34 set, which would represent a data length >
	// 32 bits).
	constexpr char kInvalidBase128VarintBits33And34SetBuffer[] =
	"\x1e\x0d\xb0\xca\x01\x00\x00\x00\x00\x00\x00\x00\x05\x00\x00\x00\x80\x80"
	"\x80\x80\x60";
	constexpr size_t kInvalidBase128VarintBits33And34SetBufferLen =
	sizeof(kInvalidBase128VarintBits33And34SetBuffer) -
	1; // Remove trailing NUL.

	// Invalid buffer containing too-short data payload (varint length indicates
	// payload length is 4 but payload only contains 3 bytes).
	constexpr char kInvalidPayloadBufferTooShort[] =
	"\x1e\x0d\xb0\xca\x01\x00\x00\x00\x00\x00\x00\x00\x04\x00\x00\x00\x04"
	"\x42\x42\x42";
	constexpr size_t kInvalidPayloadBufferTooShortLen =
	sizeof(kInvalidPayloadBufferTooShort) - 1; // Remove trailing NUL.

	TEST(LengthDelimitedRingBufferTest,
	RingBufferDataShouldStartWithMagicAndVersion) {
	RingBufferData ring_buffer;
	const void* ring_buffer_bytes = static_cast<const void*>(&ring_buffer);
	EXPECT_THAT(memcmp(ring_buffer_bytes, "\x1e\x0d\xb0\xca\x01\x00\x00\x00", 8),
	Eq(0));
	}

	TEST(LengthDelimitedRingBufferTest,
	EmptyBufferSizeShouldIncludeHeaderInRingBufferLength) {
	RingBufferData ring_buffer;
	EXPECT_THAT(ring_buffer.GetRingBufferLength(),
	Eq(16U)); // 4 for uint32 magic, 4 for uint32 version, 4 for
	// uint32 read_pos, 4 for uint32 length
	}

	TEST(LengthDelimitedRingBufferTest,
	NonEmptyBufferSizeShouldIncludeHeaderAndData) {
	RingBufferData ring_buffer;
	LengthDelimitedRingBufferWriter writer(ring_buffer);
	ASSERT_THAT(writer.Push(kHello, sizeof(kHello)), IsTrue());
	EXPECT_THAT(ring_buffer.GetRingBufferLength(),
	Eq(22U)); // 16 for header, 1 for varint length, 5 for data
	}

	TEST(LengthDelimitedRingBufferTest, PopOnEmptyBufferShouldFail) {
	RingBufferData ring_buffer;
	LengthDelimitedRingBufferReader reader(ring_buffer);
	std::vector<uint8_t> result;
	EXPECT_THAT(reader.Pop(result), IsFalse());
	}

	TEST(LengthDelimitedRingBufferTest, PushZeroLengthShouldFail) {
	RingBufferData ring_buffer;
	LengthDelimitedRingBufferWriter writer(ring_buffer);
	ASSERT_THAT(writer.Push(nullptr, 0), IsFalse());
	}

	TEST(LengthDelimitedRingBufferTest, PushExactlyBufferSizeThenPopShouldSucceed) {
	RingBufferData ring_buffer;
	LengthDelimitedRingBufferWriter writer(ring_buffer);
	ASSERT_THAT(writer.Push(kHello, sizeof(kHello)), IsTrue());

	LengthDelimitedRingBufferReader reader(ring_buffer);
	std::vector<uint8_t> result;
	EXPECT_THAT(reader.Pop(result), IsTrue());
	const std::vector<uint8_t> expected_first = {0x68, 0x65, 0x6c, 0x6c, 0x6f};
	EXPECT_THAT(result, Eq(expected_first));
	}

	TEST(LengthDelimitedRingBufferTest, PushLargerThanBufferSizeShouldFail) {
	RingBufferData<4> ring_buffer;
	LengthDelimitedRingBufferWriter writer(ring_buffer);
	EXPECT_THAT(writer.Push(kHello, sizeof(kHello)), IsFalse());
	}

	TEST(LengthDelimitedRingBufferTest,
	PushUntilFullThenPopUntilEmptyShouldReturnInFIFOOrder) {
	RingBufferData<4> ring_buffer;
	LengthDelimitedRingBufferWriter writer(ring_buffer);
	constexpr uint8_t a = 0x41;
	EXPECT_THAT(writer.Push(&a, sizeof(a)),
	IsTrue()); // Writes 2 bytes (1 for length)
	constexpr uint8_t b = 0x42;
	EXPECT_THAT(writer.Push(&b, sizeof(b)),
	IsTrue()); // Writes 2 bytes (1 for length)

	LengthDelimitedRingBufferReader reader(ring_buffer);
	std::vector<uint8_t> first;
	EXPECT_THAT(reader.Pop(first), IsTrue());
	const std::vector<uint8_t> expected_first = {0x41};
	EXPECT_THAT(first, Eq(expected_first));

	std::vector<uint8_t> second;
	EXPECT_THAT(reader.Pop(second), IsTrue());
	const std::vector<uint8_t> expected_second = {0x42};
	EXPECT_THAT(second, Eq(expected_second));

	std::vector<uint8_t> empty;
	EXPECT_THAT(reader.Pop(empty), IsFalse());
	}

	TEST(LengthDelimitedRingBufferTest,
	PushThenPopBuffersOfDifferingLengthsShouldReturnBuffers) {
	RingBufferData<5> ring_buffer;
	LengthDelimitedRingBufferWriter writer(ring_buffer);
	constexpr uint8_t ab[2] = {0x41, 0x42};
	EXPECT_THAT(writer.Push(ab, sizeof(ab)),
	IsTrue()); // Writes 3 bytes (1 for length)
	constexpr uint8_t c = 0x43;
	EXPECT_THAT(writer.Push(&c, sizeof(c)),
	IsTrue()); // Writes 2 bytes (1 for length)

	LengthDelimitedRingBufferReader reader(ring_buffer);
	std::vector<uint8_t> first;
	EXPECT_THAT(reader.Pop(first), IsTrue());
	const std::vector<uint8_t> expected_first = {0x41, 0x42};
	EXPECT_THAT(first, Eq(expected_first));

	std::vector<uint8_t> second;
	EXPECT_THAT(reader.Pop(second), IsTrue());
	const std::vector<uint8_t> expected_second = {0x43};
	EXPECT_THAT(second, Eq(expected_second));

	std::vector<uint8_t> empty;
	EXPECT_THAT(reader.Pop(empty), IsFalse());
	}

	TEST(LengthDelimitedRingBufferDataTest, PushOnFullBufferShouldOverwriteOldest) {
	RingBufferData<4> ring_buffer;
	LengthDelimitedRingBufferWriter writer(ring_buffer);
	constexpr uint8_t a = 0x41;
	EXPECT_THAT(writer.Push(&a, sizeof(a)),
	IsTrue()); // Writes 2 bytes (1 for length)
	constexpr uint8_t b = 0x42;
	EXPECT_THAT(writer.Push(&b, sizeof(b)),
	IsTrue()); // Writes 2 bytes (1 for length)
	constexpr uint8_t c = 0x43;
	EXPECT_THAT(writer.Push(&c, sizeof(c)), IsTrue()); // Should overwrite "A"

	LengthDelimitedRingBufferReader reader(ring_buffer);
	std::vector<uint8_t> first;
	EXPECT_THAT(reader.Pop(first), IsTrue());
	const std::vector<uint8_t> expected_first = {uint8_t{0x42}};
	EXPECT_THAT(first, Eq(expected_first));

	std::vector<uint8_t> second;
	EXPECT_THAT(reader.Pop(second), IsTrue());
	const std::vector<uint8_t> expected_second = {uint8_t{0x43}};
	EXPECT_THAT(second, Eq(expected_second));
	}

	TEST(LengthDelimitedRingBufferDataTest,
	PushOnFullBufferShouldOverwriteMultipleOldest) {
	RingBufferData<4> ring_buffer;
	LengthDelimitedRingBufferWriter writer(ring_buffer);
	constexpr uint8_t a = 0x41;
	EXPECT_THAT(writer.Push(&a, sizeof(a)),
	IsTrue()); // Writes 2 bytes (1 for length)
	constexpr uint8_t b = 0x42;
	EXPECT_THAT(writer.Push(&b, sizeof(b)),
	IsTrue()); // Writes 2 bytes (1 for length)
	constexpr uint8_t cd[] = {0x43, 0x44};
	EXPECT_THAT(writer.Push(cd, sizeof(cd)),
	IsTrue()); // Needs 3 bytes; should overwrite "A" and "B"

	LengthDelimitedRingBufferReader reader(ring_buffer);
	std::vector<uint8_t> first;
	EXPECT_THAT(reader.Pop(first), IsTrue());
	const std::vector<uint8_t> expected_first = {0x43, 0x44};
	EXPECT_THAT(first, Eq(expected_first));

	std::vector<uint8_t> empty;
	EXPECT_THAT(reader.Pop(empty), IsFalse());
	}

	TEST(LengthDelimitedRingBufferDataTest, PushThenPopWithLengthVarintTwoBytes) {
	RingBufferData ring_buffer;
	decltype(ring_buffer)::SizeType size = 150;
	std::string s(size, 'X');
	LengthDelimitedRingBufferWriter writer(ring_buffer);
	ASSERT_THAT(writer.Push(reinterpret_cast<const uint8_t*>(s.c_str()), size),
	IsTrue());

	LengthDelimitedRingBufferReader reader(ring_buffer);
	std::vector<uint8_t> first;
	EXPECT_THAT(reader.Pop(first), IsTrue());
	std::string result(reinterpret_cast<const char*>(first.data()), first.size());
	EXPECT_THAT(result, Eq(s));
	}

	TEST(LengthDelimitedRingBufferDataTest, DeserializeFromTooShortShouldFail) {
	RingBufferData<1> ring_buffer;
	EXPECT_THAT(ring_buffer.DeserializeFromBuffer(nullptr, 0), IsFalse());
	}

	TEST(LengthDelimitedRingBufferDataTest, DeserializeFromTooLongShouldFail) {
	RingBufferData<1> ring_buffer;
	// This buffer is size 3; it won't fit in the template arg (size 1).
	EXPECT_THAT(ring_buffer.DeserializeFromBuffer(
	reinterpret_cast<const uint8_t*>(kValidBufferSize3),
	kValidBufferSize3Len),
	IsFalse());
	}

	TEST(LengthDelimitedRingBufferDataTest,
	DeserializeFromInvalidVersionShouldFail) {
	RingBufferData<3> ring_buffer;
	EXPECT_THAT(ring_buffer.DeserializeFromBuffer(
	reinterpret_cast<const uint8_t*>(kInvalidVersionBuffer),
	kInvalidVersionBufferLen),
	IsFalse());
	}

	TEST(LengthDelimitedRingBufferDataTest,
	DeserializeFromInvalidVarintLengthShouldSucceedButPopShouldFail) {
	RingBufferData ring_buffer;
	EXPECT_THAT(ring_buffer.DeserializeFromBuffer(
	reinterpret_cast<const uint8_t*>(kInvalidBase128VarintBuffer),
	kInvalidBase128VarintBufferLen),
	IsTrue());
	LengthDelimitedRingBufferReader reader(ring_buffer);
	std::vector<uint8_t> data;
	EXPECT_THAT(reader.Pop(data), IsFalse());
	}

	TEST(LengthDelimitedRingBufferDataTest,
	DeserializeFromInvalidVarintBitsShouldSucceedButPopShouldFail) {
	RingBufferData ring_buffer;
	EXPECT_THAT(ring_buffer.DeserializeFromBuffer(
	reinterpret_cast<const uint8_t*>(
	kInvalidBase128VarintBits33And34SetBuffer),
	kInvalidBase128VarintBits33And34SetBufferLen),
	IsTrue());
	LengthDelimitedRingBufferReader reader(ring_buffer);
	std::vector<uint8_t> data;
	EXPECT_THAT(reader.Pop(data), IsFalse());
	}

	TEST(LengthDelimitedRingBufferDataTest,
	DeserializeFromInvalidPayloadBufferTooShortShouldSucceedButPopShouldFail) {
	RingBufferData ring_buffer;
	EXPECT_THAT(
	ring_buffer.DeserializeFromBuffer(
	reinterpret_cast<const uint8_t*>(kInvalidPayloadBufferTooShort),
	kInvalidPayloadBufferTooShortLen),
	IsTrue());
	LengthDelimitedRingBufferReader reader(ring_buffer);
	std::vector<uint8_t> data;
	EXPECT_THAT(reader.Pop(data), IsFalse());
	}

	TEST(LengthDelimitedRingBufferDataTest,
	DeserializeFromFullBufferShouldSucceed) {
	RingBufferData<3> ring_buffer;
	EXPECT_THAT(ring_buffer.DeserializeFromBuffer(
	reinterpret_cast<const uint8_t*>(kValidBufferSize3),
	kValidBufferSize3Len),
	IsTrue());
	LengthDelimitedRingBufferReader reader(ring_buffer);
	std::vector<uint8_t> data;
	EXPECT_THAT(reader.Pop(data), IsTrue());
	const std::vector<uint8_t> expected = {0x42, 0x23};
	EXPECT_THAT(data, Eq(expected));
	}

	TEST(LengthDelimitedRingBufferDataTest,
	DeserializeFromMidCrashBufferShouldSucceedButSubsequentPopShouldFail) {
	RingBufferData ring_buffer;
	EXPECT_THAT(ring_buffer.DeserializeFromBuffer(
	reinterpret_cast<const uint8_t*>(kMidCrashBuffer),
	kMidCrashBufferLen),
	IsTrue());
	LengthDelimitedRingBufferReader reader(ring_buffer);
	// Pop should fail since the length was written to be 0.
	std::vector<uint8_t> data;
	EXPECT_THAT(reader.Pop(data), IsFalse());
	}

	} // namespace
	} // namespace test
	} // namespace crashpad