// Copyright (c) 2013, Facebook, Inc. All rights reserved.
// This source code is licensed under the BSD-style license found in the
// LICENSE file in the root directory of this source tree. An additional grant
// of patent rights can be found in the PATENTS file in the same 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 "rocksdb/env.h"
#include "util/coding.h"
#include "util/crc32c.h"
#include "util/random.h"
#include "util/testharness.h"
namespace rocksdb {
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));
}
class LogTest {
private:
class StringDest : public WritableFile {
public:
std::string contents_;
explicit StringDest(Slice& reader_contents) :
WritableFile(),
contents_(""),
reader_contents_(reader_contents),
last_flush_(0) {
reader_contents_ = Slice(contents_.data(), 0);
};
virtual Status Close() { return Status::OK(); }
virtual Status Flush() {
ASSERT_TRUE(reader_contents_.size() <= last_flush_);
size_t offset = last_flush_ - reader_contents_.size();
reader_contents_ = Slice(
contents_.data() + offset,
contents_.size() - offset);
last_flush_ = contents_.size();
return Status::OK();
}
virtual Status Sync() { return Status::OK(); }
virtual Status Append(const Slice& slice) {
contents_.append(slice.data(), slice.size());
return Status::OK();
}
void Drop(size_t bytes) {
contents_.resize(contents_.size() - bytes);
reader_contents_ = Slice(
reader_contents_.data(), reader_contents_.size() - bytes);
last_flush_ = contents_.size();
}
private:
Slice& reader_contents_;
size_t last_flush_;
};
class StringSource : public SequentialFile {
public:
Slice& contents_;
bool force_error_;
size_t force_error_position_;
bool force_eof_;
size_t force_eof_position_;
bool returned_partial_;
explicit StringSource(Slice& contents) :
contents_(contents),
force_error_(false),
force_error_position_(0),
force_eof_(false),
force_eof_position_(0),
returned_partial_(false) { }
virtual Status Read(size_t n, Slice* result, char* scratch) {
ASSERT_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 Status::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 Status::OK();
}
virtual Status Skip(uint64_t n) {
if (n > contents_.size()) {
contents_.clear();
return Status::NotFound("in-memory file skipepd past end");
}
contents_.remove_prefix(n);
return Status::OK();
}
};
class ReportCollector : public Reader::Reporter {
public:
size_t dropped_bytes_;
std::string message_;
ReportCollector() : dropped_bytes_(0) { }
virtual void Corruption(size_t bytes, const Status& status) {
dropped_bytes_ += bytes;
message_.append(status.ToString());
}
};
std::string& dest_contents() {
auto dest = dynamic_cast<StringDest*>(writer_.file());
assert(dest);
return dest->contents_;
}
const std::string& dest_contents() const {
auto dest = dynamic_cast<const StringDest*>(writer_.file());
assert(dest);
return dest->contents_;
}
void reset_source_contents() {
auto src = dynamic_cast<StringSource*>(reader_.file());
assert(src);
src->contents_ = dest_contents();
}
Slice reader_contents_;
unique_ptr<StringDest> dest_holder_;
unique_ptr<StringSource> source_holder_;
ReportCollector report_;
Writer writer_;
Reader reader_;
// Record metadata for testing initial offset functionality
static size_t initial_offset_record_sizes_[];
static uint64_t initial_offset_last_record_offsets_[];
public:
LogTest() : reader_contents_(),
dest_holder_(new StringDest(reader_contents_)),
source_holder_(new StringSource(reader_contents_)),
writer_(std::move(dest_holder_)),
reader_(std::move(source_holder_), &report_, true/*checksum*/,
0/*initial_offset*/) {
}
void Write(const std::string& msg) {
writer_.AddRecord(Slice(msg));
}
size_t WrittenBytes() const {
return dest_contents().size();
}
std::string Read() {
std::string scratch;
Slice record;
if (reader_.ReadRecord(&record, &scratch)) {
return record.ToString();
} else {
return "EOF";
}
}
void IncrementByte(int offset, int delta) {
dest_contents()[offset] += delta;
}
void SetByte(int offset, char new_byte) {
dest_contents()[offset] = new_byte;
}
void ShrinkSize(int bytes) {
auto dest = dynamic_cast<StringDest*>(writer_.file());
assert(dest);
dest->Drop(bytes);
}
void FixChecksum(int header_offset, int len) {
// Compute crc of type/len/data
uint32_t crc = crc32c::Value(&dest_contents()[header_offset+6], 1 + len);
crc = crc32c::Mask(crc);
EncodeFixed32(&dest_contents()[header_offset], crc);
}
void ForceError(size_t position = 0) {
auto src = dynamic_cast<StringSource*>(reader_.file());
src->force_error_ = true;
src->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) {
auto src = dynamic_cast<StringSource*>(reader_.file());
src->force_eof_ = true;
src->force_eof_position_ = position;
}
void UnmarkEOF() {
auto src = dynamic_cast<StringSource*>(reader_.file());
src->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";
}
}
void WriteInitialOffsetLog() {
for (int i = 0; i < 4; i++) {
std::string record(initial_offset_record_sizes_[i],
static_cast<char>('a' + i));
Write(record);
}
}
void CheckOffsetPastEndReturnsNoRecords(uint64_t offset_past_end) {
WriteInitialOffsetLog();
unique_ptr<StringSource> source(new StringSource(reader_contents_));
unique_ptr<Reader> offset_reader(
new Reader(std::move(source), &report_, true/*checksum*/,
WrittenBytes() + offset_past_end));
Slice record;
std::string scratch;
ASSERT_TRUE(!offset_reader->ReadRecord(&record, &scratch));
}
void CheckInitialOffsetRecord(uint64_t initial_offset,
int expected_record_offset) {
WriteInitialOffsetLog();
unique_ptr<StringSource> source(new StringSource(reader_contents_));
unique_ptr<Reader> offset_reader(
new Reader(std::move(source), &report_, true/*checksum*/,
initial_offset));
Slice record;
std::string scratch;
ASSERT_TRUE(offset_reader->ReadRecord(&record, &scratch));
ASSERT_EQ(initial_offset_record_sizes_[expected_record_offset],
record.size());
ASSERT_EQ(initial_offset_last_record_offsets_[expected_record_offset],
offset_reader->LastRecordOffset());
ASSERT_EQ((char)('a' + expected_record_offset), record.data()[0]);
}
};
size_t LogTest::initial_offset_record_sizes_[] =
{10000, // Two sizable records in first block
10000,
2 * log::kBlockSize - 1000, // Span three blocks
1};
uint64_t LogTest::initial_offset_last_record_offsets_[] =
{0,
kHeaderSize + 10000,
2 * (kHeaderSize + 10000),
2 * (kHeaderSize + 10000) +
(2 * log::kBlockSize - 1000) + 3 * kHeaderSize};
TEST(LogTest, Empty) {
ASSERT_EQ("EOF", Read());
}
TEST(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(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(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(LogTest, MarginalTrailer) {
// Make a trailer that is exactly the same length as an empty record.
const int n = kBlockSize - 2*kHeaderSize;
Write(BigString("foo", n));
ASSERT_EQ((unsigned int)(kBlockSize - kHeaderSize), WrittenBytes());
Write("");
Write("bar");
ASSERT_EQ(BigString("foo", n), Read());
ASSERT_EQ("", Read());
ASSERT_EQ("bar", Read());
ASSERT_EQ("EOF", Read());
}
TEST(LogTest, MarginalTrailer2) {
// Make a trailer that is exactly the same length as an empty record.
const int n = kBlockSize - 2*kHeaderSize;
Write(BigString("foo", n));
ASSERT_EQ((unsigned int)(kBlockSize - kHeaderSize), 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(LogTest, ShortTrailer) {
const int n = kBlockSize - 2*kHeaderSize + 4;
Write(BigString("foo", n));
ASSERT_EQ((unsigned int)(kBlockSize - kHeaderSize + 4), WrittenBytes());
Write("");
Write("bar");
ASSERT_EQ(BigString("foo", n), Read());
ASSERT_EQ("", Read());
ASSERT_EQ("bar", Read());
ASSERT_EQ("EOF", Read());
}
TEST(LogTest, AlignedEof) {
const int n = kBlockSize - 2*kHeaderSize + 4;
Write(BigString("foo", n));
ASSERT_EQ((unsigned int)(kBlockSize - kHeaderSize + 4), WrittenBytes());
ASSERT_EQ(BigString("foo", n), Read());
ASSERT_EQ("EOF", Read());
}
TEST(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(LogTest, ReadError) {
Write("foo");
ForceError();
ASSERT_EQ("EOF", Read());
ASSERT_EQ((unsigned int)kBlockSize, DroppedBytes());
ASSERT_EQ("OK", MatchError("read error"));
}
TEST(LogTest, BadRecordType) {
Write("foo");
// Type is stored in header[6]
IncrementByte(6, 100);
FixChecksum(0, 3);
ASSERT_EQ("EOF", Read());
ASSERT_EQ(3U, DroppedBytes());
ASSERT_EQ("OK", MatchError("unknown record type"));
}
TEST(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(LogTest, BadLength) {
const int kPayloadSize = kBlockSize - kHeaderSize;
Write(BigString("bar", kPayloadSize));
Write("foo");
// Least significant size byte is stored in header[4].
IncrementByte(4, 1);
ASSERT_EQ("foo", Read());
ASSERT_EQ(kBlockSize, DroppedBytes());
ASSERT_EQ("OK", MatchError("bad record length"));
}
TEST(LogTest, BadLengthAtEndIsIgnored) {
Write("foo");
ShrinkSize(1);
ASSERT_EQ("EOF", Read());
ASSERT_EQ(0U, DroppedBytes());
ASSERT_EQ("", ReportMessage());
}
TEST(LogTest, ChecksumMismatch) {
Write("foo");
IncrementByte(0, 10);
ASSERT_EQ("EOF", Read());
ASSERT_EQ(10U, DroppedBytes());
ASSERT_EQ("OK", MatchError("checksum mismatch"));
}
TEST(LogTest, UnexpectedMiddleType) {
Write("foo");
SetByte(6, kMiddleType);
FixChecksum(0, 3);
ASSERT_EQ("EOF", Read());
ASSERT_EQ(3U, DroppedBytes());
ASSERT_EQ("OK", MatchError("missing start"));
}
TEST(LogTest, UnexpectedLastType) {
Write("foo");
SetByte(6, kLastType);
FixChecksum(0, 3);
ASSERT_EQ("EOF", Read());
ASSERT_EQ(3U, DroppedBytes());
ASSERT_EQ("OK", MatchError("missing start"));
}
TEST(LogTest, UnexpectedFullType) {
Write("foo");
Write("bar");
SetByte(6, kFirstType);
FixChecksum(0, 3);
ASSERT_EQ("bar", Read());
ASSERT_EQ("EOF", Read());
ASSERT_EQ(3U, DroppedBytes());
ASSERT_EQ("OK", MatchError("partial record without end"));
}
TEST(LogTest, UnexpectedFirstType) {
Write("foo");
Write(BigString("bar", 100000));
SetByte(6, kFirstType);
FixChecksum(0, 3);
ASSERT_EQ(BigString("bar", 100000), Read());
ASSERT_EQ("EOF", Read());
ASSERT_EQ(3U, DroppedBytes());
ASSERT_EQ("OK", MatchError("partial record without end"));
}
TEST(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(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(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');
}
ASSERT_EQ("correct", Read());
ASSERT_EQ("EOF", Read());
const unsigned int dropped = DroppedBytes();
ASSERT_LE(dropped, 2*kBlockSize + 100);
ASSERT_GE(dropped, 2*kBlockSize);
}
TEST(LogTest, ReadStart) {
CheckInitialOffsetRecord(0, 0);
}
TEST(LogTest, ReadSecondOneOff) {
CheckInitialOffsetRecord(1, 1);
}
TEST(LogTest, ReadSecondTenThousand) {
CheckInitialOffsetRecord(10000, 1);
}
TEST(LogTest, ReadSecondStart) {
CheckInitialOffsetRecord(10007, 1);
}
TEST(LogTest, ReadThirdOneOff) {
CheckInitialOffsetRecord(10008, 2);
}
TEST(LogTest, ReadThirdStart) {
CheckInitialOffsetRecord(20014, 2);
}
TEST(LogTest, ReadFourthOneOff) {
CheckInitialOffsetRecord(20015, 3);
}
TEST(LogTest, ReadFourthFirstBlockTrailer) {
CheckInitialOffsetRecord(log::kBlockSize - 4, 3);
}
TEST(LogTest, ReadFourthMiddleBlock) {
CheckInitialOffsetRecord(log::kBlockSize + 1, 3);
}
TEST(LogTest, ReadFourthLastBlock) {
CheckInitialOffsetRecord(2 * log::kBlockSize + 1, 3);
}
TEST(LogTest, ReadFourthStart) {
CheckInitialOffsetRecord(
2 * (kHeaderSize + 1000) + (2 * log::kBlockSize - 1000) + 3 * kHeaderSize,
3);
}
TEST(LogTest, ReadEnd) {
CheckOffsetPastEndReturnsNoRecords(0);
}
TEST(LogTest, ReadPastEnd) {
CheckOffsetPastEndReturnsNoRecords(5);
}
TEST(LogTest, ClearEofSingleBlock) {
Write("foo");
Write("bar");
ForceEOF(3 + kHeaderSize + 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(LogTest, ClearEofMultiBlock) {
size_t num_full_blocks = 5;
size_t n = (kBlockSize - kHeaderSize) * num_full_blocks + 25;
Write(BigString("foo", n));
Write(BigString("bar", n));
ForceEOF(n + num_full_blocks * kHeaderSize + 10);
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(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(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"));
}
} // namespace log
} // namespace rocksdb
int main(int argc, char** argv) {
return rocksdb::test::RunAllTests();
}