diff options
Diffstat (limited to 'db/log_test.cc')
| -rw-r--r-- | db/log_test.cc | 500 |
1 files changed, 500 insertions, 0 deletions
diff --git a/db/log_test.cc b/db/log_test.cc new file mode 100644 index 0000000..4c5cf87 --- /dev/null +++ b/db/log_test.cc @@ -0,0 +1,500 @@ +// 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 "leveldb/env.h" +#include "util/coding.h" +#include "util/crc32c.h" +#include "util/random.h" +#include "util/testharness.h" + +namespace leveldb { +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_; + + virtual Status Close() { return Status::OK(); } + virtual Status Flush() { return Status::OK(); } + virtual Status Sync() { return Status::OK(); } + virtual Status Append(const Slice& slice) { + contents_.append(slice.data(), slice.size()); + return Status::OK(); + } + }; + + class StringSource : public SequentialFile { + public: + Slice contents_; + bool force_error_; + bool returned_partial_; + StringSource() : force_error_(false), 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_) { + force_error_ = false; + returned_partial_ = true; + return Status::Corruption("read error"); + } + + if (contents_.size() < n) { + n = contents_.size(); + returned_partial_ = true; + } + *result = Slice(contents_.data(), 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()); + } + }; + + StringDest dest_; + StringSource source_; + ReportCollector report_; + bool reading_; + 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() : reading_(false), + writer_(&dest_), + reader_(&source_, &report_, true/*checksum*/, + 0/*initial_offset*/) { + } + + void Write(const std::string& msg) { + ASSERT_TRUE(!reading_) << "Write() after starting to read"; + writer_.AddRecord(Slice(msg)); + } + + size_t WrittenBytes() const { + return dest_.contents_.size(); + } + + std::string Read() { + if (!reading_) { + reading_ = true; + source_.contents_ = Slice(dest_.contents_); + } + 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) { + dest_.contents_.resize(dest_.contents_.size() - 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() { + source_.force_error_ = true; + } + + size_t DroppedBytes() const { + return report_.dropped_bytes_; + } + + std::string ReportMessage() const { + return report_.message_; + } + + // 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(); + reading_ = true; + source_.contents_ = Slice(dest_.contents_); + Reader* offset_reader = new Reader(&source_, &report_, true/*checksum*/, + WrittenBytes() + offset_past_end); + Slice record; + std::string scratch; + ASSERT_TRUE(!offset_reader->ReadRecord(&record, &scratch)); + delete offset_reader; + } + + void CheckInitialOffsetRecord(uint64_t initial_offset, + int expected_record_offset) { + WriteInitialOffsetLog(); + reading_ = true; + source_.contents_ = Slice(dest_.contents_); + Reader* offset_reader = new Reader(&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]); + delete offset_reader; + } + +}; + +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(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(kBlockSize - kHeaderSize, WrittenBytes()); + Write("bar"); + ASSERT_EQ(BigString("foo", n), Read()); + ASSERT_EQ("bar", Read()); + ASSERT_EQ("EOF", Read()); + ASSERT_EQ(0, DroppedBytes()); + ASSERT_EQ("", ReportMessage()); +} + +TEST(LogTest, ShortTrailer) { + const int n = kBlockSize - 2*kHeaderSize + 4; + Write(BigString("foo", n)); + ASSERT_EQ(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(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(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(3, DroppedBytes()); + ASSERT_EQ("OK", MatchError("unknown record type")); +} + +TEST(LogTest, TruncatedTrailingRecord) { + Write("foo"); + ShrinkSize(4); // Drop all payload as well as a header byte + ASSERT_EQ("EOF", Read()); + ASSERT_EQ(kHeaderSize - 1, DroppedBytes()); + ASSERT_EQ("OK", MatchError("truncated record at end of file")); +} + +TEST(LogTest, BadLength) { + Write("foo"); + ShrinkSize(1); + ASSERT_EQ("EOF", Read()); + ASSERT_EQ(kHeaderSize + 2, DroppedBytes()); + ASSERT_EQ("OK", MatchError("bad record length")); +} + +TEST(LogTest, ChecksumMismatch) { + Write("foo"); + IncrementByte(0, 10); + ASSERT_EQ("EOF", Read()); + ASSERT_EQ(10, DroppedBytes()); + ASSERT_EQ("OK", MatchError("checksum mismatch")); +} + +TEST(LogTest, UnexpectedMiddleType) { + Write("foo"); + SetByte(6, kMiddleType); + FixChecksum(0, 3); + ASSERT_EQ("EOF", Read()); + ASSERT_EQ(3, DroppedBytes()); + ASSERT_EQ("OK", MatchError("missing start")); +} + +TEST(LogTest, UnexpectedLastType) { + Write("foo"); + SetByte(6, kLastType); + FixChecksum(0, 3); + ASSERT_EQ("EOF", Read()); + ASSERT_EQ(3, 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(3, 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(3, DroppedBytes()); + ASSERT_EQ("OK", MatchError("partial record without end")); +} + +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 (int offset = kBlockSize; offset < 2*kBlockSize; offset++) { + SetByte(offset, 'x'); + } + + ASSERT_EQ("correct", Read()); + ASSERT_EQ("EOF", Read()); + const 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); +} + +} // namespace log +} // namespace leveldb + +int main(int argc, char** argv) { + return leveldb::test::RunAllTests(); +} |