Adding upstream version 18.2.2.upstream/18.2.2

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1062 insertions, 0 deletions

diff --git a/src/rocksdb/db/log_test.cc b/src/rocksdb/db/log_test.cc
new file mode 100644
index 000000000..2a43dc152
--- /dev/null
+++ b/src/rocksdb/db/log_test.cc
@@ -0,0 +1,1062 @@
+//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+//
+// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file. See the AUTHORS file for names of contributors.
+
+#include "db/log_reader.h"
+#include "db/log_writer.h"
+#include "file/sequence_file_reader.h"
+#include "file/writable_file_writer.h"
+#include "rocksdb/env.h"
+#include "test_util/testharness.h"
+#include "test_util/testutil.h"
+#include "util/coding.h"
+#include "util/crc32c.h"
+#include "util/random.h"
+#include "utilities/memory_allocators.h"
+
+namespace ROCKSDB_NAMESPACE {
+namespace log {
+
+// Construct a string of the specified length made out of the supplied
+// partial string.
+static std::string BigString(const std::string& partial_string, size_t n) {
+  std::string result;
+  while (result.size() < n) {
+    result.append(partial_string);
+  }
+  result.resize(n);
+  return result;
+}
+
+// Construct a string from a number
+static std::string NumberString(int n) {
+  char buf[50];
+  snprintf(buf, sizeof(buf), "%d.", n);
+  return std::string(buf);
+}
+
+// Return a skewed potentially long string
+static std::string RandomSkewedString(int i, Random* rnd) {
+  return BigString(NumberString(i), rnd->Skewed(17));
+}
+
+// Param type is tuple<int, bool>
+// get<0>(tuple): non-zero if recycling log, zero if regular log
+// get<1>(tuple): true if allow retry after read EOF, false otherwise
+class LogTest
+    : public ::testing::TestWithParam<std::tuple<int, bool, CompressionType>> {
+ private:
+  class StringSource : public FSSequentialFile {
+   public:
+    Slice& contents_;
+    bool force_error_;
+    size_t force_error_position_;
+    bool force_eof_;
+    size_t force_eof_position_;
+    bool returned_partial_;
+    bool fail_after_read_partial_;
+    explicit StringSource(Slice& contents, bool fail_after_read_partial)
+        : contents_(contents),
+          force_error_(false),
+          force_error_position_(0),
+          force_eof_(false),
+          force_eof_position_(0),
+          returned_partial_(false),
+          fail_after_read_partial_(fail_after_read_partial) {}
+
+    IOStatus Read(size_t n, const IOOptions& /*opts*/, Slice* result,
+                  char* scratch, IODebugContext* /*dbg*/) override {
+      if (fail_after_read_partial_) {
+        EXPECT_TRUE(!returned_partial_) << "must not Read() after eof/error";
+      }
+
+      if (force_error_) {
+        if (force_error_position_ >= n) {
+          force_error_position_ -= n;
+        } else {
+          *result = Slice(contents_.data(), force_error_position_);
+          contents_.remove_prefix(force_error_position_);
+          force_error_ = false;
+          returned_partial_ = true;
+          return IOStatus::Corruption("read error");
+        }
+      }
+
+      if (contents_.size() < n) {
+        n = contents_.size();
+        returned_partial_ = true;
+      }
+
+      if (force_eof_) {
+        if (force_eof_position_ >= n) {
+          force_eof_position_ -= n;
+        } else {
+          force_eof_ = false;
+          n = force_eof_position_;
+          returned_partial_ = true;
+        }
+      }
+
+      // By using scratch we ensure that caller has control over the
+      // lifetime of result.data()
+      memcpy(scratch, contents_.data(), n);
+      *result = Slice(scratch, n);
+
+      contents_.remove_prefix(n);
+      return IOStatus::OK();
+    }
+
+    IOStatus Skip(uint64_t n) override {
+      if (n > contents_.size()) {
+        contents_.clear();
+        return IOStatus::NotFound("in-memory file skipepd past end");
+      }
+
+      contents_.remove_prefix(n);
+
+      return IOStatus::OK();
+    }
+  };
+
+  class ReportCollector : public Reader::Reporter {
+   public:
+    size_t dropped_bytes_;
+    std::string message_;
+
+    ReportCollector() : dropped_bytes_(0) {}
+    void Corruption(size_t bytes, const Status& status) override {
+      dropped_bytes_ += bytes;
+      message_.append(status.ToString());
+    }
+  };
+
+  std::string& dest_contents() { return sink_->contents_; }
+
+  const std::string& dest_contents() const { return sink_->contents_; }
+
+  void reset_source_contents() { source_->contents_ = dest_contents(); }
+
+  Slice reader_contents_;
+  test::StringSink* sink_;
+  StringSource* source_;
+  ReportCollector report_;
+
+ protected:
+  std::unique_ptr<Writer> writer_;
+  std::unique_ptr<Reader> reader_;
+  bool allow_retry_read_;
+  CompressionType compression_type_;
+
+ public:
+  LogTest()
+      : reader_contents_(),
+        sink_(new test::StringSink(&reader_contents_)),
+        source_(new StringSource(reader_contents_, !std::get<1>(GetParam()))),
+        allow_retry_read_(std::get<1>(GetParam())),
+        compression_type_(std::get<2>(GetParam())) {
+    std::unique_ptr<FSWritableFile> sink_holder(sink_);
+    std::unique_ptr<WritableFileWriter> file_writer(new WritableFileWriter(
+        std::move(sink_holder), "" /* don't care */, FileOptions()));
+    Writer* writer =
+        new Writer(std::move(file_writer), 123, std::get<0>(GetParam()), false,
+                   compression_type_);
+    writer_.reset(writer);
+    std::unique_ptr<FSSequentialFile> source_holder(source_);
+    std::unique_ptr<SequentialFileReader> file_reader(
+        new SequentialFileReader(std::move(source_holder), "" /* file name */));
+    if (allow_retry_read_) {
+      reader_.reset(new FragmentBufferedReader(nullptr, std::move(file_reader),
+                                               &report_, true /* checksum */,
+                                               123 /* log_number */));
+    } else {
+      reader_.reset(new Reader(nullptr, std::move(file_reader), &report_,
+                               true /* checksum */, 123 /* log_number */));
+    }
+  }
+
+  Slice* get_reader_contents() { return &reader_contents_; }
+
+  void Write(const std::string& msg) {
+    ASSERT_OK(writer_->AddRecord(Slice(msg)));
+  }
+
+  size_t WrittenBytes() const { return dest_contents().size(); }
+
+  std::string Read(const WALRecoveryMode wal_recovery_mode =
+                       WALRecoveryMode::kTolerateCorruptedTailRecords) {
+    std::string scratch;
+    Slice record;
+    bool ret = false;
+    uint64_t record_checksum;
+    ret = reader_->ReadRecord(&record, &scratch, wal_recovery_mode,
+                              &record_checksum);
+    if (ret) {
+      if (!allow_retry_read_) {
+        // allow_retry_read_ means using FragmentBufferedReader which does not
+        // support record checksum yet.
+        uint64_t actual_record_checksum =
+            XXH3_64bits(record.data(), record.size());
+        assert(actual_record_checksum == record_checksum);
+      }
+      return record.ToString();
+    } else {
+      return "EOF";
+    }
+  }
+
+  void IncrementByte(int offset, char delta) {
+    dest_contents()[offset] += delta;
+  }
+
+  void SetByte(int offset, char new_byte) {
+    dest_contents()[offset] = new_byte;
+  }
+
+  void ShrinkSize(int bytes) { sink_->Drop(bytes); }
+
+  void FixChecksum(int header_offset, int len, bool recyclable) {
+    // Compute crc of type/len/data
+    int header_size = recyclable ? kRecyclableHeaderSize : kHeaderSize;
+    uint32_t crc = crc32c::Value(&dest_contents()[header_offset + 6],
+                                 header_size - 6 + len);
+    crc = crc32c::Mask(crc);
+    EncodeFixed32(&dest_contents()[header_offset], crc);
+  }
+
+  void ForceError(size_t position = 0) {
+    source_->force_error_ = true;
+    source_->force_error_position_ = position;
+  }
+
+  size_t DroppedBytes() const { return report_.dropped_bytes_; }
+
+  std::string ReportMessage() const { return report_.message_; }
+
+  void ForceEOF(size_t position = 0) {
+    source_->force_eof_ = true;
+    source_->force_eof_position_ = position;
+  }
+
+  void UnmarkEOF() {
+    source_->returned_partial_ = false;
+    reader_->UnmarkEOF();
+  }
+
+  bool IsEOF() { return reader_->IsEOF(); }
+
+  // Returns OK iff recorded error message contains "msg"
+  std::string MatchError(const std::string& msg) const {
+    if (report_.message_.find(msg) == std::string::npos) {
+      return report_.message_;
+    } else {
+      return "OK";
+    }
+  }
+};
+
+TEST_P(LogTest, Empty) { ASSERT_EQ("EOF", Read()); }
+
+TEST_P(LogTest, ReadWrite) {
+  Write("foo");
+  Write("bar");
+  Write("");
+  Write("xxxx");
+  ASSERT_EQ("foo", Read());
+  ASSERT_EQ("bar", Read());
+  ASSERT_EQ("", Read());
+  ASSERT_EQ("xxxx", Read());
+  ASSERT_EQ("EOF", Read());
+  ASSERT_EQ("EOF", Read());  // Make sure reads at eof work
+}
+
+TEST_P(LogTest, ManyBlocks) {
+  for (int i = 0; i < 100000; i++) {
+    Write(NumberString(i));
+  }
+  for (int i = 0; i < 100000; i++) {
+    ASSERT_EQ(NumberString(i), Read());
+  }
+  ASSERT_EQ("EOF", Read());
+}
+
+TEST_P(LogTest, Fragmentation) {
+  Write("small");
+  Write(BigString("medium", 50000));
+  Write(BigString("large", 100000));
+  ASSERT_EQ("small", Read());
+  ASSERT_EQ(BigString("medium", 50000), Read());
+  ASSERT_EQ(BigString("large", 100000), Read());
+  ASSERT_EQ("EOF", Read());
+}
+
+TEST_P(LogTest, MarginalTrailer) {
+  // Make a trailer that is exactly the same length as an empty record.
+  int header_size =
+      std::get<0>(GetParam()) ? kRecyclableHeaderSize : kHeaderSize;
+  const int n = kBlockSize - 2 * header_size;
+  Write(BigString("foo", n));
+  ASSERT_EQ((unsigned int)(kBlockSize - header_size), WrittenBytes());
+  Write("");
+  Write("bar");
+  ASSERT_EQ(BigString("foo", n), Read());
+  ASSERT_EQ("", Read());
+  ASSERT_EQ("bar", Read());
+  ASSERT_EQ("EOF", Read());
+}
+
+TEST_P(LogTest, MarginalTrailer2) {
+  // Make a trailer that is exactly the same length as an empty record.
+  int header_size =
+      std::get<0>(GetParam()) ? kRecyclableHeaderSize : kHeaderSize;
+  const int n = kBlockSize - 2 * header_size;
+  Write(BigString("foo", n));
+  ASSERT_EQ((unsigned int)(kBlockSize - header_size), WrittenBytes());
+  Write("bar");
+  ASSERT_EQ(BigString("foo", n), Read());
+  ASSERT_EQ("bar", Read());
+  ASSERT_EQ("EOF", Read());
+  ASSERT_EQ(0U, DroppedBytes());
+  ASSERT_EQ("", ReportMessage());
+}
+
+TEST_P(LogTest, ShortTrailer) {
+  int header_size =
+      std::get<0>(GetParam()) ? kRecyclableHeaderSize : kHeaderSize;
+  const int n = kBlockSize - 2 * header_size + 4;
+  Write(BigString("foo", n));
+  ASSERT_EQ((unsigned int)(kBlockSize - header_size + 4), WrittenBytes());
+  Write("");
+  Write("bar");
+  ASSERT_EQ(BigString("foo", n), Read());
+  ASSERT_EQ("", Read());
+  ASSERT_EQ("bar", Read());
+  ASSERT_EQ("EOF", Read());
+}
+
+TEST_P(LogTest, AlignedEof) {
+  int header_size =
+      std::get<0>(GetParam()) ? kRecyclableHeaderSize : kHeaderSize;
+  const int n = kBlockSize - 2 * header_size + 4;
+  Write(BigString("foo", n));
+  ASSERT_EQ((unsigned int)(kBlockSize - header_size + 4), WrittenBytes());
+  ASSERT_EQ(BigString("foo", n), Read());
+  ASSERT_EQ("EOF", Read());
+}
+
+TEST_P(LogTest, RandomRead) {
+  const int N = 500;
+  Random write_rnd(301);
+  for (int i = 0; i < N; i++) {
+    Write(RandomSkewedString(i, &write_rnd));
+  }
+  Random read_rnd(301);
+  for (int i = 0; i < N; i++) {
+    ASSERT_EQ(RandomSkewedString(i, &read_rnd), Read());
+  }
+  ASSERT_EQ("EOF", Read());
+}
+
+// Tests of all the error paths in log_reader.cc follow:
+
+TEST_P(LogTest, ReadError) {
+  Write("foo");
+  ForceError();
+  ASSERT_EQ("EOF", Read());
+  ASSERT_EQ((unsigned int)kBlockSize, DroppedBytes());
+  ASSERT_EQ("OK", MatchError("read error"));
+}
+
+TEST_P(LogTest, BadRecordType) {
+  Write("foo");
+  // Type is stored in header[6]
+  IncrementByte(6, 100);
+  FixChecksum(0, 3, false);
+  ASSERT_EQ("EOF", Read());
+  ASSERT_EQ(3U, DroppedBytes());
+  ASSERT_EQ("OK", MatchError("unknown record type"));
+}
+
+TEST_P(LogTest, TruncatedTrailingRecordIsIgnored) {
+  Write("foo");
+  ShrinkSize(4);  // Drop all payload as well as a header byte
+  ASSERT_EQ("EOF", Read());
+  // Truncated last record is ignored, not treated as an error
+  ASSERT_EQ(0U, DroppedBytes());
+  ASSERT_EQ("", ReportMessage());
+}
+
+TEST_P(LogTest, TruncatedTrailingRecordIsNotIgnored) {
+  if (allow_retry_read_) {
+    // If read retry is allowed, then truncated trailing record should not
+    // raise an error.
+    return;
+  }
+  Write("foo");
+  ShrinkSize(4);  // Drop all payload as well as a header byte
+  ASSERT_EQ("EOF", Read(WALRecoveryMode::kAbsoluteConsistency));
+  // Truncated last record is ignored, not treated as an error
+  ASSERT_GT(DroppedBytes(), 0U);
+  ASSERT_EQ("OK", MatchError("Corruption: truncated header"));
+}
+
+TEST_P(LogTest, BadLength) {
+  if (allow_retry_read_) {
+    // If read retry is allowed, then we should not raise an error when the
+    // record length specified in header is longer than data currently
+    // available. It's possible that the body of the record is not written yet.
+    return;
+  }
+  bool recyclable_log = (std::get<0>(GetParam()) != 0);
+  int header_size = recyclable_log ? kRecyclableHeaderSize : kHeaderSize;
+  const int kPayloadSize = kBlockSize - header_size;
+  Write(BigString("bar", kPayloadSize));
+  Write("foo");
+  // Least significant size byte is stored in header[4].
+  IncrementByte(4, 1);
+  if (!recyclable_log) {
+    ASSERT_EQ("foo", Read());
+    ASSERT_EQ(kBlockSize, DroppedBytes());
+    ASSERT_EQ("OK", MatchError("bad record length"));
+  } else {
+    ASSERT_EQ("EOF", Read());
+  }
+}
+
+TEST_P(LogTest, BadLengthAtEndIsIgnored) {
+  if (allow_retry_read_) {
+    // If read retry is allowed, then we should not raise an error when the
+    // record length specified in header is longer than data currently
+    // available. It's possible that the body of the record is not written yet.
+    return;
+  }
+  Write("foo");
+  ShrinkSize(1);
+  ASSERT_EQ("EOF", Read());
+  ASSERT_EQ(0U, DroppedBytes());
+  ASSERT_EQ("", ReportMessage());
+}
+
+TEST_P(LogTest, BadLengthAtEndIsNotIgnored) {
+  if (allow_retry_read_) {
+    // If read retry is allowed, then we should not raise an error when the
+    // record length specified in header is longer than data currently
+    // available. It's possible that the body of the record is not written yet.
+    return;
+  }
+  Write("foo");
+  ShrinkSize(1);
+  ASSERT_EQ("EOF", Read(WALRecoveryMode::kAbsoluteConsistency));
+  ASSERT_GT(DroppedBytes(), 0U);
+  ASSERT_EQ("OK", MatchError("Corruption: truncated record body"));
+}
+
+TEST_P(LogTest, ChecksumMismatch) {
+  Write("foooooo");
+  IncrementByte(0, 14);
+  ASSERT_EQ("EOF", Read());
+  bool recyclable_log = (std::get<0>(GetParam()) != 0);
+  if (!recyclable_log) {
+    ASSERT_EQ(14U, DroppedBytes());
+    ASSERT_EQ("OK", MatchError("checksum mismatch"));
+  } else {
+    ASSERT_EQ(0U, DroppedBytes());
+    ASSERT_EQ("", ReportMessage());
+  }
+}
+
+TEST_P(LogTest, UnexpectedMiddleType) {
+  Write("foo");
+  bool recyclable_log = (std::get<0>(GetParam()) != 0);
+  SetByte(6, static_cast<char>(recyclable_log ? kRecyclableMiddleType
+                                              : kMiddleType));
+  FixChecksum(0, 3, !!recyclable_log);
+  ASSERT_EQ("EOF", Read());
+  ASSERT_EQ(3U, DroppedBytes());
+  ASSERT_EQ("OK", MatchError("missing start"));
+}
+
+TEST_P(LogTest, UnexpectedLastType) {
+  Write("foo");
+  bool recyclable_log = (std::get<0>(GetParam()) != 0);
+  SetByte(6,
+          static_cast<char>(recyclable_log ? kRecyclableLastType : kLastType));
+  FixChecksum(0, 3, !!recyclable_log);
+  ASSERT_EQ("EOF", Read());
+  ASSERT_EQ(3U, DroppedBytes());
+  ASSERT_EQ("OK", MatchError("missing start"));
+}
+
+TEST_P(LogTest, UnexpectedFullType) {
+  Write("foo");
+  Write("bar");
+  bool recyclable_log = (std::get<0>(GetParam()) != 0);
+  SetByte(
+      6, static_cast<char>(recyclable_log ? kRecyclableFirstType : kFirstType));
+  FixChecksum(0, 3, !!recyclable_log);
+  ASSERT_EQ("bar", Read());
+  ASSERT_EQ("EOF", Read());
+  ASSERT_EQ(3U, DroppedBytes());
+  ASSERT_EQ("OK", MatchError("partial record without end"));
+}
+
+TEST_P(LogTest, UnexpectedFirstType) {
+  Write("foo");
+  Write(BigString("bar", 100000));
+  bool recyclable_log = (std::get<0>(GetParam()) != 0);
+  SetByte(
+      6, static_cast<char>(recyclable_log ? kRecyclableFirstType : kFirstType));
+  FixChecksum(0, 3, !!recyclable_log);
+  ASSERT_EQ(BigString("bar", 100000), Read());
+  ASSERT_EQ("EOF", Read());
+  ASSERT_EQ(3U, DroppedBytes());
+  ASSERT_EQ("OK", MatchError("partial record without end"));
+}
+
+TEST_P(LogTest, MissingLastIsIgnored) {
+  Write(BigString("bar", kBlockSize));
+  // Remove the LAST block, including header.
+  ShrinkSize(14);
+  ASSERT_EQ("EOF", Read());
+  ASSERT_EQ("", ReportMessage());
+  ASSERT_EQ(0U, DroppedBytes());
+}
+
+TEST_P(LogTest, MissingLastIsNotIgnored) {
+  if (allow_retry_read_) {
+    // If read retry is allowed, then truncated trailing record should not
+    // raise an error.
+    return;
+  }
+  Write(BigString("bar", kBlockSize));
+  // Remove the LAST block, including header.
+  ShrinkSize(14);
+  ASSERT_EQ("EOF", Read(WALRecoveryMode::kAbsoluteConsistency));
+  ASSERT_GT(DroppedBytes(), 0U);
+  ASSERT_EQ("OK", MatchError("Corruption: error reading trailing data"));
+}
+
+TEST_P(LogTest, PartialLastIsIgnored) {
+  Write(BigString("bar", kBlockSize));
+  // Cause a bad record length in the LAST block.
+  ShrinkSize(1);
+  ASSERT_EQ("EOF", Read());
+  ASSERT_EQ("", ReportMessage());
+  ASSERT_EQ(0U, DroppedBytes());
+}
+
+TEST_P(LogTest, PartialLastIsNotIgnored) {
+  if (allow_retry_read_) {
+    // If read retry is allowed, then truncated trailing record should not
+    // raise an error.
+    return;
+  }
+  Write(BigString("bar", kBlockSize));
+  // Cause a bad record length in the LAST block.
+  ShrinkSize(1);
+  ASSERT_EQ("EOF", Read(WALRecoveryMode::kAbsoluteConsistency));
+  ASSERT_GT(DroppedBytes(), 0U);
+  ASSERT_EQ("OK", MatchError("Corruption: truncated record body"));
+}
+
+TEST_P(LogTest, ErrorJoinsRecords) {
+  // Consider two fragmented records:
+  //    first(R1) last(R1) first(R2) last(R2)
+  // where the middle two fragments disappear.  We do not want
+  // first(R1),last(R2) to get joined and returned as a valid record.
+
+  // Write records that span two blocks
+  Write(BigString("foo", kBlockSize));
+  Write(BigString("bar", kBlockSize));
+  Write("correct");
+
+  // Wipe the middle block
+  for (unsigned int offset = kBlockSize; offset < 2 * kBlockSize; offset++) {
+    SetByte(offset, 'x');
+  }
+
+  bool recyclable_log = (std::get<0>(GetParam()) != 0);
+  if (!recyclable_log) {
+    ASSERT_EQ("correct", Read());
+    ASSERT_EQ("EOF", Read());
+    size_t dropped = DroppedBytes();
+    ASSERT_LE(dropped, 2 * kBlockSize + 100);
+    ASSERT_GE(dropped, 2 * kBlockSize);
+  } else {
+    ASSERT_EQ("EOF", Read());
+  }
+}
+
+TEST_P(LogTest, ClearEofSingleBlock) {
+  Write("foo");
+  Write("bar");
+  bool recyclable_log = (std::get<0>(GetParam()) != 0);
+  int header_size = recyclable_log ? kRecyclableHeaderSize : kHeaderSize;
+  ForceEOF(3 + header_size + 2);
+  ASSERT_EQ("foo", Read());
+  UnmarkEOF();
+  ASSERT_EQ("bar", Read());
+  ASSERT_TRUE(IsEOF());
+  ASSERT_EQ("EOF", Read());
+  Write("xxx");
+  UnmarkEOF();
+  ASSERT_EQ("xxx", Read());
+  ASSERT_TRUE(IsEOF());
+}
+
+TEST_P(LogTest, ClearEofMultiBlock) {
+  size_t num_full_blocks = 5;
+  bool recyclable_log = (std::get<0>(GetParam()) != 0);
+  int header_size = recyclable_log ? kRecyclableHeaderSize : kHeaderSize;
+  size_t n = (kBlockSize - header_size) * num_full_blocks + 25;
+  Write(BigString("foo", n));
+  Write(BigString("bar", n));
+  ForceEOF(n + num_full_blocks * header_size + header_size + 3);
+  ASSERT_EQ(BigString("foo", n), Read());
+  ASSERT_TRUE(IsEOF());
+  UnmarkEOF();
+  ASSERT_EQ(BigString("bar", n), Read());
+  ASSERT_TRUE(IsEOF());
+  Write(BigString("xxx", n));
+  UnmarkEOF();
+  ASSERT_EQ(BigString("xxx", n), Read());
+  ASSERT_TRUE(IsEOF());
+}
+
+TEST_P(LogTest, ClearEofError) {
+  // If an error occurs during Read() in UnmarkEOF(), the records contained
+  // in the buffer should be returned on subsequent calls of ReadRecord()
+  // until no more full records are left, whereafter ReadRecord() should return
+  // false to indicate that it cannot read any further.
+
+  Write("foo");
+  Write("bar");
+  UnmarkEOF();
+  ASSERT_EQ("foo", Read());
+  ASSERT_TRUE(IsEOF());
+  Write("xxx");
+  ForceError(0);
+  UnmarkEOF();
+  ASSERT_EQ("bar", Read());
+  ASSERT_EQ("EOF", Read());
+}
+
+TEST_P(LogTest, ClearEofError2) {
+  Write("foo");
+  Write("bar");
+  UnmarkEOF();
+  ASSERT_EQ("foo", Read());
+  Write("xxx");
+  ForceError(3);
+  UnmarkEOF();
+  ASSERT_EQ("bar", Read());
+  ASSERT_EQ("EOF", Read());
+  ASSERT_EQ(3U, DroppedBytes());
+  ASSERT_EQ("OK", MatchError("read error"));
+}
+
+TEST_P(LogTest, Recycle) {
+  bool recyclable_log = (std::get<0>(GetParam()) != 0);
+  if (!recyclable_log) {
+    return;  // test is only valid for recycled logs
+  }
+  Write("foo");
+  Write("bar");
+  Write("baz");
+  Write("bif");
+  Write("blitz");
+  while (get_reader_contents()->size() < log::kBlockSize * 2) {
+    Write("xxxxxxxxxxxxxxxx");
+  }
+  std::unique_ptr<FSWritableFile> sink(
+      new test::OverwritingStringSink(get_reader_contents()));
+  std::unique_ptr<WritableFileWriter> dest_holder(new WritableFileWriter(
+      std::move(sink), "" /* don't care */, FileOptions()));
+  Writer recycle_writer(std::move(dest_holder), 123, true);
+  ASSERT_OK(recycle_writer.AddRecord(Slice("foooo")));
+  ASSERT_OK(recycle_writer.AddRecord(Slice("bar")));
+  ASSERT_GE(get_reader_contents()->size(), log::kBlockSize * 2);
+  ASSERT_EQ("foooo", Read());
+  ASSERT_EQ("bar", Read());
+  ASSERT_EQ("EOF", Read());
+}
+
+// Do NOT enable compression for this instantiation.
+INSTANTIATE_TEST_CASE_P(
+    Log, LogTest,
+    ::testing::Combine(::testing::Values(0, 1), ::testing::Bool(),
+                       ::testing::Values(CompressionType::kNoCompression)));
+
+class RetriableLogTest : public ::testing::TestWithParam<int> {
+ private:
+  class ReportCollector : public Reader::Reporter {
+   public:
+    size_t dropped_bytes_;
+    std::string message_;
+
+    ReportCollector() : dropped_bytes_(0) {}
+    void Corruption(size_t bytes, const Status& status) override {
+      dropped_bytes_ += bytes;
+      message_.append(status.ToString());
+    }
+  };
+
+  Slice contents_;
+  test::StringSink* sink_;
+  std::unique_ptr<Writer> log_writer_;
+  Env* env_;
+  const std::string test_dir_;
+  const std::string log_file_;
+  std::unique_ptr<WritableFileWriter> writer_;
+  std::unique_ptr<SequentialFileReader> reader_;
+  ReportCollector report_;
+  std::unique_ptr<FragmentBufferedReader> log_reader_;
+
+ public:
+  RetriableLogTest()
+      : contents_(),
+        sink_(new test::StringSink(&contents_)),
+        log_writer_(nullptr),
+        env_(Env::Default()),
+        test_dir_(test::PerThreadDBPath("retriable_log_test")),
+        log_file_(test_dir_ + "/log"),
+        writer_(nullptr),
+        reader_(nullptr),
+        log_reader_(nullptr) {
+    std::unique_ptr<FSWritableFile> sink_holder(sink_);
+    std::unique_ptr<WritableFileWriter> wfw(new WritableFileWriter(
+        std::move(sink_holder), "" /* file name */, FileOptions()));
+    log_writer_.reset(new Writer(std::move(wfw), 123, GetParam()));
+  }
+
+  Status SetupTestEnv() {
+    Status s;
+    FileOptions fopts;
+    auto fs = env_->GetFileSystem();
+    s = fs->CreateDirIfMissing(test_dir_, IOOptions(), nullptr);
+    std::unique_ptr<FSWritableFile> writable_file;
+    if (s.ok()) {
+      s = fs->NewWritableFile(log_file_, fopts, &writable_file, nullptr);
+    }
+    if (s.ok()) {
+      writer_.reset(
+          new WritableFileWriter(std::move(writable_file), log_file_, fopts));
+      EXPECT_NE(writer_, nullptr);
+    }
+    std::unique_ptr<FSSequentialFile> seq_file;
+    if (s.ok()) {
+      s = fs->NewSequentialFile(log_file_, fopts, &seq_file, nullptr);
+    }
+    if (s.ok()) {
+      reader_.reset(new SequentialFileReader(std::move(seq_file), log_file_));
+      EXPECT_NE(reader_, nullptr);
+      log_reader_.reset(new FragmentBufferedReader(
+          nullptr, std::move(reader_), &report_, true /* checksum */,
+          123 /* log_number */));
+      EXPECT_NE(log_reader_, nullptr);
+    }
+    return s;
+  }
+
+  std::string contents() { return sink_->contents_; }
+
+  void Encode(const std::string& msg) {
+    ASSERT_OK(log_writer_->AddRecord(Slice(msg)));
+  }
+
+  void Write(const Slice& data) {
+    ASSERT_OK(writer_->Append(data));
+    ASSERT_OK(writer_->Sync(true));
+  }
+
+  bool TryRead(std::string* result) {
+    assert(result != nullptr);
+    result->clear();
+    std::string scratch;
+    Slice record;
+    bool r = log_reader_->ReadRecord(&record, &scratch);
+    if (r) {
+      result->assign(record.data(), record.size());
+      return true;
+    } else {
+      return false;
+    }
+  }
+};
+
+TEST_P(RetriableLogTest, TailLog_PartialHeader) {
+  ASSERT_OK(SetupTestEnv());
+  std::vector<int> remaining_bytes_in_last_record;
+  size_t header_size = GetParam() ? kRecyclableHeaderSize : kHeaderSize;
+  bool eof = false;
+  SyncPoint::GetInstance()->DisableProcessing();
+  SyncPoint::GetInstance()->LoadDependency(
+      {{"RetriableLogTest::TailLog:AfterPart1",
+        "RetriableLogTest::TailLog:BeforeReadRecord"},
+       {"FragmentBufferedLogReader::TryReadMore:FirstEOF",
+        "RetriableLogTest::TailLog:BeforePart2"}});
+  SyncPoint::GetInstance()->ClearAllCallBacks();
+  SyncPoint::GetInstance()->SetCallBack(
+      "FragmentBufferedLogReader::TryReadMore:FirstEOF",
+      [&](void* /*arg*/) { eof = true; });
+  SyncPoint::GetInstance()->EnableProcessing();
+
+  size_t delta = header_size - 1;
+  port::Thread log_writer_thread([&]() {
+    size_t old_sz = contents().size();
+    Encode("foo");
+    size_t new_sz = contents().size();
+    std::string part1 = contents().substr(old_sz, delta);
+    std::string part2 =
+        contents().substr(old_sz + delta, new_sz - old_sz - delta);
+    Write(Slice(part1));
+    TEST_SYNC_POINT("RetriableLogTest::TailLog:AfterPart1");
+    TEST_SYNC_POINT("RetriableLogTest::TailLog:BeforePart2");
+    Write(Slice(part2));
+  });
+
+  std::string record;
+  port::Thread log_reader_thread([&]() {
+    TEST_SYNC_POINT("RetriableLogTest::TailLog:BeforeReadRecord");
+    while (!TryRead(&record)) {
+    }
+  });
+  log_reader_thread.join();
+  log_writer_thread.join();
+  ASSERT_EQ("foo", record);
+  ASSERT_TRUE(eof);
+}
+
+TEST_P(RetriableLogTest, TailLog_FullHeader) {
+  ASSERT_OK(SetupTestEnv());
+  std::vector<int> remaining_bytes_in_last_record;
+  size_t header_size = GetParam() ? kRecyclableHeaderSize : kHeaderSize;
+  bool eof = false;
+  SyncPoint::GetInstance()->DisableProcessing();
+  SyncPoint::GetInstance()->LoadDependency(
+      {{"RetriableLogTest::TailLog:AfterPart1",
+        "RetriableLogTest::TailLog:BeforeReadRecord"},
+       {"FragmentBufferedLogReader::TryReadMore:FirstEOF",
+        "RetriableLogTest::TailLog:BeforePart2"}});
+  SyncPoint::GetInstance()->ClearAllCallBacks();
+  SyncPoint::GetInstance()->SetCallBack(
+      "FragmentBufferedLogReader::TryReadMore:FirstEOF",
+      [&](void* /*arg*/) { eof = true; });
+  SyncPoint::GetInstance()->EnableProcessing();
+
+  size_t delta = header_size + 1;
+  port::Thread log_writer_thread([&]() {
+    size_t old_sz = contents().size();
+    Encode("foo");
+    size_t new_sz = contents().size();
+    std::string part1 = contents().substr(old_sz, delta);
+    std::string part2 =
+        contents().substr(old_sz + delta, new_sz - old_sz - delta);
+    Write(Slice(part1));
+    TEST_SYNC_POINT("RetriableLogTest::TailLog:AfterPart1");
+    TEST_SYNC_POINT("RetriableLogTest::TailLog:BeforePart2");
+    Write(Slice(part2));
+    ASSERT_TRUE(eof);
+  });
+
+  std::string record;
+  port::Thread log_reader_thread([&]() {
+    TEST_SYNC_POINT("RetriableLogTest::TailLog:BeforeReadRecord");
+    while (!TryRead(&record)) {
+    }
+  });
+  log_reader_thread.join();
+  log_writer_thread.join();
+  ASSERT_EQ("foo", record);
+}
+
+TEST_P(RetriableLogTest, NonBlockingReadFullRecord) {
+  // Clear all sync point callbacks even if this test does not use sync point.
+  // It is necessary, otherwise the execute of this test may hit a sync point
+  // with which a callback is registered. The registered callback may access
+  // some dead variable, causing segfault.
+  SyncPoint::GetInstance()->DisableProcessing();
+  SyncPoint::GetInstance()->ClearAllCallBacks();
+  ASSERT_OK(SetupTestEnv());
+  size_t header_size = GetParam() ? kRecyclableHeaderSize : kHeaderSize;
+  size_t delta = header_size - 1;
+  size_t old_sz = contents().size();
+  Encode("foo-bar");
+  size_t new_sz = contents().size();
+  std::string part1 = contents().substr(old_sz, delta);
+  std::string part2 =
+      contents().substr(old_sz + delta, new_sz - old_sz - delta);
+  Write(Slice(part1));
+  std::string record;
+  ASSERT_FALSE(TryRead(&record));
+  ASSERT_TRUE(record.empty());
+  Write(Slice(part2));
+  ASSERT_TRUE(TryRead(&record));
+  ASSERT_EQ("foo-bar", record);
+}
+
+INSTANTIATE_TEST_CASE_P(bool, RetriableLogTest, ::testing::Values(0, 2));
+
+class CompressionLogTest : public LogTest {
+ public:
+  Status SetupTestEnv() { return writer_->AddCompressionTypeRecord(); }
+};
+
+TEST_P(CompressionLogTest, Empty) {
+  CompressionType compression_type = std::get<2>(GetParam());
+  if (!StreamingCompressionTypeSupported(compression_type)) {
+    ROCKSDB_GTEST_SKIP("Test requires support for compression type");
+    return;
+  }
+  ASSERT_OK(SetupTestEnv());
+  const bool compression_enabled =
+      std::get<2>(GetParam()) == kNoCompression ? false : true;
+  // If WAL compression is enabled, a record is added for the compression type
+  const int compression_record_size = compression_enabled ? kHeaderSize + 4 : 0;
+  ASSERT_EQ(compression_record_size, WrittenBytes());
+  ASSERT_EQ("EOF", Read());
+}
+
+TEST_P(CompressionLogTest, ReadWrite) {
+  CompressionType compression_type = std::get<2>(GetParam());
+  if (!StreamingCompressionTypeSupported(compression_type)) {
+    ROCKSDB_GTEST_SKIP("Test requires support for compression type");
+    return;
+  }
+  ASSERT_OK(SetupTestEnv());
+  Write("foo");
+  Write("bar");
+  Write("");
+  Write("xxxx");
+  ASSERT_EQ("foo", Read());
+  ASSERT_EQ("bar", Read());
+  ASSERT_EQ("", Read());
+  ASSERT_EQ("xxxx", Read());
+  ASSERT_EQ("EOF", Read());
+  ASSERT_EQ("EOF", Read());  // Make sure reads at eof work
+}
+
+TEST_P(CompressionLogTest, ManyBlocks) {
+  CompressionType compression_type = std::get<2>(GetParam());
+  if (!StreamingCompressionTypeSupported(compression_type)) {
+    ROCKSDB_GTEST_SKIP("Test requires support for compression type");
+    return;
+  }
+  ASSERT_OK(SetupTestEnv());
+  for (int i = 0; i < 100000; i++) {
+    Write(NumberString(i));
+  }
+  for (int i = 0; i < 100000; i++) {
+    ASSERT_EQ(NumberString(i), Read());
+  }
+  ASSERT_EQ("EOF", Read());
+}
+
+TEST_P(CompressionLogTest, Fragmentation) {
+  CompressionType compression_type = std::get<2>(GetParam());
+  if (!StreamingCompressionTypeSupported(compression_type)) {
+    ROCKSDB_GTEST_SKIP("Test requires support for compression type");
+    return;
+  }
+  ASSERT_OK(SetupTestEnv());
+  Random rnd(301);
+  const std::vector<std::string> wal_entries = {
+      "small",
+      rnd.RandomBinaryString(3 * kBlockSize / 2),  // Spans into block 2
+      rnd.RandomBinaryString(3 * kBlockSize),      // Spans into block 5
+  };
+  for (const std::string& wal_entry : wal_entries) {
+    Write(wal_entry);
+  }
+
+  for (const std::string& wal_entry : wal_entries) {
+    ASSERT_EQ(wal_entry, Read());
+  }
+  ASSERT_EQ("EOF", Read());
+}
+
+INSTANTIATE_TEST_CASE_P(
+    Compression, CompressionLogTest,
+    ::testing::Combine(::testing::Values(0, 1), ::testing::Bool(),
+                       ::testing::Values(CompressionType::kNoCompression,
+                                         CompressionType::kZSTD)));
+
+class StreamingCompressionTest
+    : public ::testing::TestWithParam<std::tuple<int, CompressionType>> {};
+
+TEST_P(StreamingCompressionTest, Basic) {
+  size_t input_size = std::get<0>(GetParam());
+  CompressionType compression_type = std::get<1>(GetParam());
+  if (!StreamingCompressionTypeSupported(compression_type)) {
+    ROCKSDB_GTEST_SKIP("Test requires support for compression type");
+    return;
+  }
+  CompressionOptions opts;
+  constexpr uint32_t compression_format_version = 2;
+  StreamingCompress* compress = StreamingCompress::Create(
+      compression_type, opts, compression_format_version, kBlockSize);
+  StreamingUncompress* uncompress = StreamingUncompress::Create(
+      compression_type, compression_format_version, kBlockSize);
+  MemoryAllocator* allocator = new DefaultMemoryAllocator();
+  std::string input_buffer = BigString("abc", input_size);
+  std::vector<std::string> compressed_buffers;
+  size_t remaining;
+  // Call compress till the entire input is consumed
+  do {
+    char* output_buffer = (char*)allocator->Allocate(kBlockSize);
+    size_t output_pos;
+    remaining = compress->Compress(input_buffer.c_str(), input_size,
+                                   output_buffer, &output_pos);
+    if (output_pos > 0) {
+      std::string compressed_buffer;
+      compressed_buffer.assign(output_buffer, output_pos);
+      compressed_buffers.emplace_back(std::move(compressed_buffer));
+    }
+    allocator->Deallocate((void*)output_buffer);
+  } while (remaining > 0);
+  std::string uncompressed_buffer = "";
+  int ret_val = 0;
+  size_t output_pos;
+  char* uncompressed_output_buffer = (char*)allocator->Allocate(kBlockSize);
+  // Uncompress the fragments and concatenate them.
+  for (int i = 0; i < (int)compressed_buffers.size(); i++) {
+    // Call uncompress till either the entire input is consumed or the output
+    // buffer size is equal to the allocated output buffer size.
+    do {
+      ret_val = uncompress->Uncompress(compressed_buffers[i].c_str(),
+                                       compressed_buffers[i].size(),
+                                       uncompressed_output_buffer, &output_pos);
+      if (output_pos > 0) {
+        std::string uncompressed_fragment;
+        uncompressed_fragment.assign(uncompressed_output_buffer, output_pos);
+        uncompressed_buffer += uncompressed_fragment;
+      }
+    } while (ret_val > 0 || output_pos == kBlockSize);
+  }
+  allocator->Deallocate((void*)uncompressed_output_buffer);
+  delete allocator;
+  delete compress;
+  delete uncompress;
+  // The final return value from uncompress() should be 0.
+  ASSERT_EQ(ret_val, 0);
+  ASSERT_EQ(input_buffer, uncompressed_buffer);
+}
+
+INSTANTIATE_TEST_CASE_P(
+    StreamingCompression, StreamingCompressionTest,
+    ::testing::Combine(::testing::Values(10, 100, 1000, kBlockSize,
+                                         kBlockSize * 2),
+                       ::testing::Values(CompressionType::kZSTD)));
+
+}  // namespace log
+}  // namespace ROCKSDB_NAMESPACE
+
+int main(int argc, char** argv) {
+  ROCKSDB_NAMESPACE::port::InstallStackTraceHandler();
+  ::testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}