logd/SerializedLogChunkTest.cpp - LeafOS-Project/android_system_core - Gitiles

 /*
  * Copyright (C) 2020 The Android Open Source Project
  *
  * 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 "SerializedLogChunk.h"

 #include <limits>

 #include <android-base/stringprintf.h>
 #include <android/log.h>
 #include <gtest/gtest.h>

 using android::base::StringPrintf;

 TEST(SerializedLogChunk, smoke) {
     size_t chunk_size = 10 * 4096;
     auto chunk = SerializedLogChunk{chunk_size};
     EXPECT_EQ(chunk_size, chunk.PruneSize());

     static const char log_message[] = "log message";
     size_t expected_total_len = sizeof(SerializedLogEntry) + sizeof(log_message);
     ASSERT_TRUE(chunk.CanLog(expected_total_len));
     EXPECT_TRUE(chunk.CanLog(chunk_size));
     EXPECT_FALSE(chunk.CanLog(chunk_size + 1));

     log_time time(CLOCK_REALTIME);
     auto* entry = chunk.Log(1234, time, 0, 1, 2, log_message, sizeof(log_message));
     ASSERT_NE(nullptr, entry);

     EXPECT_EQ(1234U, entry->sequence());
     EXPECT_EQ(time, entry->realtime());
     EXPECT_EQ(0U, entry->uid());
     EXPECT_EQ(1, entry->pid());
     EXPECT_EQ(2, entry->tid());
     EXPECT_EQ(sizeof(log_message), entry->msg_len());
     EXPECT_STREQ(log_message, entry->msg());
     EXPECT_EQ(expected_total_len, entry->total_len());

     EXPECT_FALSE(chunk.CanLog(chunk_size));
     EXPECT_EQ(static_cast<int>(expected_total_len), chunk.write_offset());
     EXPECT_EQ(1234U, chunk.highest_sequence_number());
 }

 TEST(SerializedLogChunk, fill_log_exactly) {
     static const char log_message[] = "this is a log message";
     size_t individual_message_size = sizeof(SerializedLogEntry) + sizeof(log_message);
     size_t chunk_size = individual_message_size * 3;
     auto chunk = SerializedLogChunk{chunk_size};
     EXPECT_EQ(chunk_size, chunk.PruneSize());

     ASSERT_TRUE(chunk.CanLog(individual_message_size));
     EXPECT_NE(nullptr, chunk.Log(1, log_time(), 1000, 1, 1, log_message, sizeof(log_message)));

     ASSERT_TRUE(chunk.CanLog(individual_message_size));
     EXPECT_NE(nullptr, chunk.Log(2, log_time(), 1000, 2, 1, log_message, sizeof(log_message)));

     ASSERT_TRUE(chunk.CanLog(individual_message_size));
     EXPECT_NE(nullptr, chunk.Log(3, log_time(), 1000, 3, 1, log_message, sizeof(log_message)));

     EXPECT_FALSE(chunk.CanLog(1));
 }

 TEST(SerializedLogChunk, three_logs) {
     size_t chunk_size = 10 * 4096;
     auto chunk = SerializedLogChunk{chunk_size};

     chunk.Log(2, log_time(0x1234, 0x5678), 0x111, 0x222, 0x333, "initial message",
               strlen("initial message"));
     chunk.Log(3, log_time(0x2345, 0x6789), 0x444, 0x555, 0x666, "second message",
               strlen("second message"));
     auto uint64_t_max = std::numeric_limits<uint64_t>::max();
     auto uint32_t_max = std::numeric_limits<uint32_t>::max();
     chunk.Log(uint64_t_max, log_time(uint32_t_max, uint32_t_max), uint32_t_max, uint32_t_max,
               uint32_t_max, "last message", strlen("last message"));

     static const char expected_buffer_data[] =
             "\x11\x01\x00\x00\x22\x02\x00\x00\x33\x03\x00\x00"  // UID PID TID
             "\x02\x00\x00\x00\x00\x00\x00\x00"                  // Sequence
             "\x34\x12\x00\x00\x78\x56\x00\x00"                  // Timestamp
             "\x0F\x00initial message"                           // msg_len + message
             "\x44\x04\x00\x00\x55\x05\x00\x00\x66\x06\x00\x00"  // UID PID TID
             "\x03\x00\x00\x00\x00\x00\x00\x00"                  // Sequence
             "\x45\x23\x00\x00\x89\x67\x00\x00"                  // Timestamp
             "\x0E\x00second message"                            // msg_len + message
             "\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF"  // UID PID TID
             "\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF"                  // Sequence
             "\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF"                  // Timestamp
             "\x0C\x00last message";                             // msg_len + message

     for (size_t i = 0; i < chunk_size; ++i) {
         if (i < sizeof(expected_buffer_data)) {
             EXPECT_EQ(static_cast<uint8_t>(expected_buffer_data[i]), chunk.data()[i])
                     << "position: " << i;
         } else {
             EXPECT_EQ(0, chunk.data()[i]) << "position: " << i;
         }
     }
 }

 // Check that the CHECK() in DecReaderRefCount() if the ref count goes bad is caught.
 TEST(SerializedLogChunk, catch_DecCompressedRef_CHECK) {
     size_t chunk_size = 10 * 4096;
     auto chunk = SerializedLogChunk{chunk_size};
     EXPECT_DEATH({ chunk.DecReaderRefCount(true); }, "");
     EXPECT_DEATH({ chunk.DecReaderRefCount(false); }, "");
 }

 // Check that the CHECK() in ClearUidLogs() if the ref count is greater than 0 is caught.
 TEST(SerializedLogChunk, catch_ClearUidLogs_CHECK) {
     size_t chunk_size = 10 * 4096;
     auto chunk = SerializedLogChunk{chunk_size};
     chunk.IncReaderRefCount();
     EXPECT_DEATH({ chunk.ClearUidLogs(1000, LOG_ID_MAIN, nullptr); }, "");
     chunk.DecReaderRefCount(false);
 }

 class UidClearTest : public testing::TestWithParam<bool> {
   protected:
     template <typename Write, typename Check>
     void Test(const Write& write, const Check& check, bool expected_result) {
         write(chunk_);

         bool finish_writing = GetParam();
         if (finish_writing) {
             chunk_.FinishWriting();
         }
         EXPECT_EQ(expected_result, chunk_.ClearUidLogs(kUidToClear, LOG_ID_MAIN, nullptr));
         if (finish_writing) {
             chunk_.IncReaderRefCount();
         }

         check(chunk_);

         if (finish_writing) {
             chunk_.DecReaderRefCount(false);
         }
     }

     static constexpr size_t kChunkSize = 10 * 4096;
     static constexpr uid_t kUidToClear = 1000;
     static constexpr uid_t kOtherUid = 1234;

     SerializedLogChunk chunk_{kChunkSize};
 };

 // Test that ClearUidLogs() is a no-op if there are no logs of that UID in the buffer.
 TEST_P(UidClearTest, no_logs_in_chunk) {
     auto write = [](SerializedLogChunk&) {};
     auto check = [](SerializedLogChunk&) {};

     Test(write, check, true);
 }

 // Test that ClearUidLogs() is a no-op if there are no logs of that UID in the buffer.
 TEST_P(UidClearTest, no_logs_from_uid) {
     static const char msg[] = "this is a log message";
     auto write = [](SerializedLogChunk& chunk) {
         chunk.Log(1, log_time(), kOtherUid, 1, 2, msg, sizeof(msg));
     };

     auto check = [](SerializedLogChunk& chunk) {
         auto* entry = chunk.log_entry(0);
         EXPECT_STREQ(msg, entry->msg());
     };

     Test(write, check, false);
 }

 // Test that ClearUidLogs() returns true if all logs in a given buffer correspond to the given UID.
 TEST_P(UidClearTest, all_single) {
     static const char msg[] = "this is a log message";
     auto write = [](SerializedLogChunk& chunk) {
         chunk.Log(1, log_time(), kUidToClear, 1, 2, msg, sizeof(msg));
     };
     auto check = [](SerializedLogChunk&) {};

     Test(write, check, true);
 }

 // Test that ClearUidLogs() returns true if all logs in a given buffer correspond to the given UID.
 TEST_P(UidClearTest, all_multiple) {
     static const char msg[] = "this is a log message";
     auto write = [](SerializedLogChunk& chunk) {
         chunk.Log(2, log_time(), kUidToClear, 1, 2, msg, sizeof(msg));
         chunk.Log(3, log_time(), kUidToClear, 1, 2, msg, sizeof(msg));
         chunk.Log(4, log_time(), kUidToClear, 1, 2, msg, sizeof(msg));
     };
     auto check = [](SerializedLogChunk&) {};

     Test(write, check, true);
 }

 static std::string MakePrintable(const uint8_t* in, size_t length) {
     std::string result;
     for (size_t i = 0; i < length; ++i) {
         uint8_t c = in[i];
         if (isprint(c)) {
             result.push_back(c);
         } else {
             result.append(StringPrintf("\\%02x", static_cast<int>(c) & 0xFF));
         }
     }
     return result;
 }

 // This test clears UID logs at the beginning and end of the buffer, as well as two back to back
 // logs in the interior.
 TEST_P(UidClearTest, clear_beginning_and_end) {
     static const char msg1[] = "this is a log message";
     static const char msg2[] = "non-cleared message";
     static const char msg3[] = "back to back cleared messages";
     static const char msg4[] = "second in a row gone";
     static const char msg5[] = "but we save this one";
     static const char msg6[] = "and this 1!";
     static const char msg7[] = "the last one goes too";
     auto write = [](SerializedLogChunk& chunk) {
         ASSERT_NE(nullptr, chunk.Log(1, log_time(), kUidToClear, 1, 2, msg1, sizeof(msg1)));
         ASSERT_NE(nullptr, chunk.Log(2, log_time(), kOtherUid, 1, 2, msg2, sizeof(msg2)));
         ASSERT_NE(nullptr, chunk.Log(3, log_time(), kUidToClear, 1, 2, msg3, sizeof(msg3)));
         ASSERT_NE(nullptr, chunk.Log(4, log_time(), kUidToClear, 1, 2, msg4, sizeof(msg4)));
         ASSERT_NE(nullptr, chunk.Log(5, log_time(), kOtherUid, 1, 2, msg5, sizeof(msg5)));
         ASSERT_NE(nullptr, chunk.Log(6, log_time(), kOtherUid, 1, 2, msg6, sizeof(msg6)));
         ASSERT_NE(nullptr, chunk.Log(7, log_time(), kUidToClear, 1, 2, msg7, sizeof(msg7)));
     };

     auto check = [](SerializedLogChunk& chunk) {
         size_t read_offset = 0;
         auto* entry = chunk.log_entry(read_offset);
         EXPECT_STREQ(msg2, entry->msg());
         read_offset += entry->total_len();

         entry = chunk.log_entry(read_offset);
         EXPECT_STREQ(msg5, entry->msg());
         read_offset += entry->total_len();

         entry = chunk.log_entry(read_offset);
         EXPECT_STREQ(msg6, entry->msg()) << MakePrintable(chunk.data(), chunk.write_offset());
         read_offset += entry->total_len();

         EXPECT_EQ(static_cast<int>(read_offset), chunk.write_offset());
     };
     Test(write, check, false);
 }

 // This tests the opposite case of beginning_and_end, in which we don't clear the beginning or end
 // logs.  There is a single log pruned in the middle instead of back to back logs.
 TEST_P(UidClearTest, save_beginning_and_end) {
     static const char msg1[] = "saved first message";
     static const char msg2[] = "cleared interior message";
     static const char msg3[] = "last message stays";
     auto write = [](SerializedLogChunk& chunk) {
         ASSERT_NE(nullptr, chunk.Log(1, log_time(), kOtherUid, 1, 2, msg1, sizeof(msg1)));
         ASSERT_NE(nullptr, chunk.Log(2, log_time(), kUidToClear, 1, 2, msg2, sizeof(msg2)));
         ASSERT_NE(nullptr, chunk.Log(3, log_time(), kOtherUid, 1, 2, msg3, sizeof(msg3)));
     };

     auto check = [](SerializedLogChunk& chunk) {
         size_t read_offset = 0;
         auto* entry = chunk.log_entry(read_offset);
         EXPECT_STREQ(msg1, entry->msg());
         read_offset += entry->total_len();

         entry = chunk.log_entry(read_offset);
         EXPECT_STREQ(msg3, entry->msg());
         read_offset += entry->total_len();

         EXPECT_EQ(static_cast<int>(read_offset), chunk.write_offset());
     };
     Test(write, check, false);
 }

 INSTANTIATE_TEST_CASE_P(UidClearTests, UidClearTest, testing::Values(true, false));
	/*
	* Copyright (C) 2020 The Android Open Source Project
	*
	* 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 "SerializedLogChunk.h"

	#include <limits>

	#include <android-base/stringprintf.h>
	#include <android/log.h>
	#include <gtest/gtest.h>

	using android::base::StringPrintf;

	TEST(SerializedLogChunk, smoke) {
	size_t chunk_size = 10 * 4096;
	auto chunk = SerializedLogChunk{chunk_size};
	EXPECT_EQ(chunk_size, chunk.PruneSize());

	static const char log_message[] = "log message";
	size_t expected_total_len = sizeof(SerializedLogEntry) + sizeof(log_message);
	ASSERT_TRUE(chunk.CanLog(expected_total_len));
	EXPECT_TRUE(chunk.CanLog(chunk_size));
	EXPECT_FALSE(chunk.CanLog(chunk_size + 1));

	log_time time(CLOCK_REALTIME);
	auto* entry = chunk.Log(1234, time, 0, 1, 2, log_message, sizeof(log_message));
	ASSERT_NE(nullptr, entry);

	EXPECT_EQ(1234U, entry->sequence());
	EXPECT_EQ(time, entry->realtime());
	EXPECT_EQ(0U, entry->uid());
	EXPECT_EQ(1, entry->pid());
	EXPECT_EQ(2, entry->tid());
	EXPECT_EQ(sizeof(log_message), entry->msg_len());
	EXPECT_STREQ(log_message, entry->msg());
	EXPECT_EQ(expected_total_len, entry->total_len());

	EXPECT_FALSE(chunk.CanLog(chunk_size));
	EXPECT_EQ(static_cast<int>(expected_total_len), chunk.write_offset());
	EXPECT_EQ(1234U, chunk.highest_sequence_number());
	}

	TEST(SerializedLogChunk, fill_log_exactly) {
	static const char log_message[] = "this is a log message";
	size_t individual_message_size = sizeof(SerializedLogEntry) + sizeof(log_message);
	size_t chunk_size = individual_message_size * 3;
	auto chunk = SerializedLogChunk{chunk_size};
	EXPECT_EQ(chunk_size, chunk.PruneSize());

	ASSERT_TRUE(chunk.CanLog(individual_message_size));
	EXPECT_NE(nullptr, chunk.Log(1, log_time(), 1000, 1, 1, log_message, sizeof(log_message)));

	ASSERT_TRUE(chunk.CanLog(individual_message_size));
	EXPECT_NE(nullptr, chunk.Log(2, log_time(), 1000, 2, 1, log_message, sizeof(log_message)));

	ASSERT_TRUE(chunk.CanLog(individual_message_size));
	EXPECT_NE(nullptr, chunk.Log(3, log_time(), 1000, 3, 1, log_message, sizeof(log_message)));

	EXPECT_FALSE(chunk.CanLog(1));
	}

	TEST(SerializedLogChunk, three_logs) {
	size_t chunk_size = 10 * 4096;
	auto chunk = SerializedLogChunk{chunk_size};

	chunk.Log(2, log_time(0x1234, 0x5678), 0x111, 0x222, 0x333, "initial message",
	strlen("initial message"));
	chunk.Log(3, log_time(0x2345, 0x6789), 0x444, 0x555, 0x666, "second message",
	strlen("second message"));
	auto uint64_t_max = std::numeric_limits<uint64_t>::max();
	auto uint32_t_max = std::numeric_limits<uint32_t>::max();
	chunk.Log(uint64_t_max, log_time(uint32_t_max, uint32_t_max), uint32_t_max, uint32_t_max,
	uint32_t_max, "last message", strlen("last message"));

	static const char expected_buffer_data[] =
	"\x11\x01\x00\x00\x22\x02\x00\x00\x33\x03\x00\x00" // UID PID TID
	"\x02\x00\x00\x00\x00\x00\x00\x00" // Sequence
	"\x34\x12\x00\x00\x78\x56\x00\x00" // Timestamp
	"\x0F\x00initial message" // msg_len + message
	"\x44\x04\x00\x00\x55\x05\x00\x00\x66\x06\x00\x00" // UID PID TID
	"\x03\x00\x00\x00\x00\x00\x00\x00" // Sequence
	"\x45\x23\x00\x00\x89\x67\x00\x00" // Timestamp
	"\x0E\x00second message" // msg_len + message
	"\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF" // UID PID TID
	"\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF" // Sequence
	"\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF" // Timestamp
	"\x0C\x00last message"; // msg_len + message

	for (size_t i = 0; i < chunk_size; ++i) {
	if (i < sizeof(expected_buffer_data)) {
	EXPECT_EQ(static_cast<uint8_t>(expected_buffer_data[i]), chunk.data()[i])
	<< "position: " << i;
	} else {
	EXPECT_EQ(0, chunk.data()[i]) << "position: " << i;
	}
	}
	}

	// Check that the CHECK() in DecReaderRefCount() if the ref count goes bad is caught.
	TEST(SerializedLogChunk, catch_DecCompressedRef_CHECK) {
	size_t chunk_size = 10 * 4096;
	auto chunk = SerializedLogChunk{chunk_size};
	EXPECT_DEATH({ chunk.DecReaderRefCount(true); }, "");
	EXPECT_DEATH({ chunk.DecReaderRefCount(false); }, "");
	}

	// Check that the CHECK() in ClearUidLogs() if the ref count is greater than 0 is caught.
	TEST(SerializedLogChunk, catch_ClearUidLogs_CHECK) {
	size_t chunk_size = 10 * 4096;
	auto chunk = SerializedLogChunk{chunk_size};
	chunk.IncReaderRefCount();
	EXPECT_DEATH({ chunk.ClearUidLogs(1000, LOG_ID_MAIN, nullptr); }, "");
	chunk.DecReaderRefCount(false);
	}

	class UidClearTest : public testing::TestWithParam<bool> {
	protected:
	template <typename Write, typename Check>
	void Test(const Write& write, const Check& check, bool expected_result) {
	write(chunk_);

	bool finish_writing = GetParam();
	if (finish_writing) {
	chunk_.FinishWriting();
	}
	EXPECT_EQ(expected_result, chunk_.ClearUidLogs(kUidToClear, LOG_ID_MAIN, nullptr));
	if (finish_writing) {
	chunk_.IncReaderRefCount();
	}

	check(chunk_);

	if (finish_writing) {
	chunk_.DecReaderRefCount(false);
	}
	}

	static constexpr size_t kChunkSize = 10 * 4096;
	static constexpr uid_t kUidToClear = 1000;
	static constexpr uid_t kOtherUid = 1234;

	SerializedLogChunk chunk_{kChunkSize};
	};

	// Test that ClearUidLogs() is a no-op if there are no logs of that UID in the buffer.
	TEST_P(UidClearTest, no_logs_in_chunk) {
	auto write = [](SerializedLogChunk&) {};
	auto check = [](SerializedLogChunk&) {};

	Test(write, check, true);
	}

	// Test that ClearUidLogs() is a no-op if there are no logs of that UID in the buffer.
	TEST_P(UidClearTest, no_logs_from_uid) {
	static const char msg[] = "this is a log message";
	auto write = [](SerializedLogChunk& chunk) {
	chunk.Log(1, log_time(), kOtherUid, 1, 2, msg, sizeof(msg));
	};

	auto check = [](SerializedLogChunk& chunk) {
	auto* entry = chunk.log_entry(0);
	EXPECT_STREQ(msg, entry->msg());
	};

	Test(write, check, false);
	}

	// Test that ClearUidLogs() returns true if all logs in a given buffer correspond to the given UID.
	TEST_P(UidClearTest, all_single) {
	static const char msg[] = "this is a log message";
	auto write = [](SerializedLogChunk& chunk) {
	chunk.Log(1, log_time(), kUidToClear, 1, 2, msg, sizeof(msg));
	};
	auto check = [](SerializedLogChunk&) {};

	Test(write, check, true);
	}

	// Test that ClearUidLogs() returns true if all logs in a given buffer correspond to the given UID.
	TEST_P(UidClearTest, all_multiple) {
	static const char msg[] = "this is a log message";
	auto write = [](SerializedLogChunk& chunk) {
	chunk.Log(2, log_time(), kUidToClear, 1, 2, msg, sizeof(msg));
	chunk.Log(3, log_time(), kUidToClear, 1, 2, msg, sizeof(msg));
	chunk.Log(4, log_time(), kUidToClear, 1, 2, msg, sizeof(msg));
	};
	auto check = [](SerializedLogChunk&) {};

	Test(write, check, true);
	}

	static std::string MakePrintable(const uint8_t* in, size_t length) {
	std::string result;
	for (size_t i = 0; i < length; ++i) {
	uint8_t c = in[i];
	if (isprint(c)) {
	result.push_back(c);
	} else {
	result.append(StringPrintf("\\%02x", static_cast<int>(c) & 0xFF));
	}
	}
	return result;
	}

	// This test clears UID logs at the beginning and end of the buffer, as well as two back to back
	// logs in the interior.
	TEST_P(UidClearTest, clear_beginning_and_end) {
	static const char msg1[] = "this is a log message";
	static const char msg2[] = "non-cleared message";
	static const char msg3[] = "back to back cleared messages";
	static const char msg4[] = "second in a row gone";
	static const char msg5[] = "but we save this one";
	static const char msg6[] = "and this 1!";
	static const char msg7[] = "the last one goes too";
	auto write = [](SerializedLogChunk& chunk) {
	ASSERT_NE(nullptr, chunk.Log(1, log_time(), kUidToClear, 1, 2, msg1, sizeof(msg1)));
	ASSERT_NE(nullptr, chunk.Log(2, log_time(), kOtherUid, 1, 2, msg2, sizeof(msg2)));
	ASSERT_NE(nullptr, chunk.Log(3, log_time(), kUidToClear, 1, 2, msg3, sizeof(msg3)));
	ASSERT_NE(nullptr, chunk.Log(4, log_time(), kUidToClear, 1, 2, msg4, sizeof(msg4)));
	ASSERT_NE(nullptr, chunk.Log(5, log_time(), kOtherUid, 1, 2, msg5, sizeof(msg5)));
	ASSERT_NE(nullptr, chunk.Log(6, log_time(), kOtherUid, 1, 2, msg6, sizeof(msg6)));
	ASSERT_NE(nullptr, chunk.Log(7, log_time(), kUidToClear, 1, 2, msg7, sizeof(msg7)));
	};

	auto check = [](SerializedLogChunk& chunk) {
	size_t read_offset = 0;
	auto* entry = chunk.log_entry(read_offset);
	EXPECT_STREQ(msg2, entry->msg());
	read_offset += entry->total_len();

	entry = chunk.log_entry(read_offset);
	EXPECT_STREQ(msg5, entry->msg());
	read_offset += entry->total_len();

	entry = chunk.log_entry(read_offset);
	EXPECT_STREQ(msg6, entry->msg()) << MakePrintable(chunk.data(), chunk.write_offset());
	read_offset += entry->total_len();

	EXPECT_EQ(static_cast<int>(read_offset), chunk.write_offset());
	};
	Test(write, check, false);
	}

	// This tests the opposite case of beginning_and_end, in which we don't clear the beginning or end
	// logs. There is a single log pruned in the middle instead of back to back logs.
	TEST_P(UidClearTest, save_beginning_and_end) {
	static const char msg1[] = "saved first message";
	static const char msg2[] = "cleared interior message";
	static const char msg3[] = "last message stays";
	auto write = [](SerializedLogChunk& chunk) {
	ASSERT_NE(nullptr, chunk.Log(1, log_time(), kOtherUid, 1, 2, msg1, sizeof(msg1)));
	ASSERT_NE(nullptr, chunk.Log(2, log_time(), kUidToClear, 1, 2, msg2, sizeof(msg2)));
	ASSERT_NE(nullptr, chunk.Log(3, log_time(), kOtherUid, 1, 2, msg3, sizeof(msg3)));
	};

	auto check = [](SerializedLogChunk& chunk) {
	size_t read_offset = 0;
	auto* entry = chunk.log_entry(read_offset);
	EXPECT_STREQ(msg1, entry->msg());
	read_offset += entry->total_len();

	entry = chunk.log_entry(read_offset);
	EXPECT_STREQ(msg3, entry->msg());
	read_offset += entry->total_len();

	EXPECT_EQ(static_cast<int>(read_offset), chunk.write_offset());
	};
	Test(write, check, false);
	}

	INSTANTIATE_TEST_CASE_P(UidClearTests, UidClearTest, testing::Values(true, false));