Add block cache tracer. (#5410)

Summary:
This PR adds a help class block cache tracer to read/write block cache accesses. It uses the trace reader/writer to perform this task.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5410

Differential Revision: D15612843

Pulled By: HaoyuHuang

fbshipit-source-id: f30fd1e1524355ca87db5d533a5c086728b141ea
main
haoyuhuang 6 years ago committed by Facebook Github Bot
parent 340ed4fac7
commit aa71718ac3
  1. 1
      CMakeLists.txt
  2. 4
      Makefile
  3. 2
      src.mk
  4. 218
      trace_replay/block_cache_tracer.cc
  5. 105
      trace_replay/block_cache_tracer.h
  6. 167
      trace_replay/block_cache_tracer_test.cc
  7. 38
      trace_replay/trace_replay.cc
  8. 15
      trace_replay/trace_replay.h

@ -628,6 +628,7 @@ set(SOURCES
tools/sst_dump_tool.cc tools/sst_dump_tool.cc
tools/trace_analyzer_tool.cc tools/trace_analyzer_tool.cc
trace_replay/trace_replay.cc trace_replay/trace_replay.cc
trace_replay/block_cache_tracer.cc
util/bloom.cc util/bloom.cc
util/coding.cc util/coding.cc
util/compaction_job_stats_impl.cc util/compaction_job_stats_impl.cc

@ -561,6 +561,7 @@ TESTS = \
range_del_aggregator_test \ range_del_aggregator_test \
sst_file_reader_test \ sst_file_reader_test \
db_secondary_test \ db_secondary_test \
block_cache_tracer_test \
PARALLEL_TEST = \ PARALLEL_TEST = \
backupable_db_test \ backupable_db_test \
@ -1588,6 +1589,9 @@ sst_file_reader_test: table/sst_file_reader_test.o $(LIBOBJECTS) $(TESTHARNESS)
db_secondary_test: db/db_impl/db_secondary_test.o db/db_test_util.o $(LIBOBJECTS) $(TESTHARNESS) db_secondary_test: db/db_impl/db_secondary_test.o db/db_test_util.o $(LIBOBJECTS) $(TESTHARNESS)
$(AM_LINK) $(AM_LINK)
block_cache_tracer_test: trace_replay/block_cache_tracer_test.o trace_replay/block_cache_tracer.o $(LIBOBJECTS) $(TESTHARNESS)
$(AM_LINK)
#------------------------------------------------- #-------------------------------------------------
# make install related stuff # make install related stuff
INSTALL_PATH ?= /usr/local INSTALL_PATH ?= /usr/local

@ -143,6 +143,7 @@ LIB_SOURCES = \
test_util/transaction_test_util.cc \ test_util/transaction_test_util.cc \
tools/dump/db_dump_tool.cc \ tools/dump/db_dump_tool.cc \
trace_replay/trace_replay.cc \ trace_replay/trace_replay.cc \
trace_replay/block_cache_tracer.cc \
util/bloom.cc \ util/bloom.cc \
util/build_version.cc \ util/build_version.cc \
util/coding.cc \ util/coding.cc \
@ -371,6 +372,7 @@ MAIN_SOURCES = \
tools/reduce_levels_test.cc \ tools/reduce_levels_test.cc \
tools/sst_dump_test.cc \ tools/sst_dump_test.cc \
tools/trace_analyzer_test.cc \ tools/trace_analyzer_test.cc \
trace_replay/block_cache_tracer_test.cc \
util/autovector_test.cc \ util/autovector_test.cc \
util/bloom_test.cc \ util/bloom_test.cc \
util/coding_test.cc \ util/coding_test.cc \

@ -0,0 +1,218 @@
// 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).
#include "trace_replay/block_cache_tracer.h"
#include "db/db_impl/db_impl.h"
#include "rocksdb/slice.h"
#include "util/coding.h"
#include "util/hash.h"
#include "util/string_util.h"
namespace rocksdb {
namespace {
const unsigned int kCharSize = 1;
bool ShouldTraceReferencedKey(const BlockCacheTraceRecord& record) {
return (record.block_type == TraceType::kBlockTraceDataBlock) &&
(record.caller == BlockCacheLookupCaller::kUserGet ||
record.caller == BlockCacheLookupCaller::kUserMGet);
}
} // namespace
BlockCacheTraceWriter::BlockCacheTraceWriter(
Env* env, const TraceOptions& trace_options,
std::unique_ptr<TraceWriter>&& trace_writer)
: env_(env),
trace_options_(trace_options),
trace_writer_(std::move(trace_writer)) {}
bool BlockCacheTraceWriter::ShouldTrace(
const BlockCacheTraceRecord& record) const {
if (trace_options_.sampling_frequency == 0 ||
trace_options_.sampling_frequency == 1) {
return true;
}
// We use spatial downsampling so that we have a complete access history for a
// block.
const uint64_t hash = GetSliceNPHash64(Slice(record.block_key));
return hash % trace_options_.sampling_frequency == 0;
}
Status BlockCacheTraceWriter::WriteBlockAccess(
const BlockCacheTraceRecord& record) {
uint64_t trace_file_size = trace_writer_->GetFileSize();
if (trace_file_size > trace_options_.max_trace_file_size ||
!ShouldTrace(record)) {
return Status::OK();
}
Trace trace;
trace.ts = record.access_timestamp;
trace.type = record.block_type;
PutLengthPrefixedSlice(&trace.payload, record.block_key);
PutFixed64(&trace.payload, record.block_size);
PutFixed32(&trace.payload, record.cf_id);
PutLengthPrefixedSlice(&trace.payload, record.cf_name);
PutFixed32(&trace.payload, record.level);
PutFixed32(&trace.payload, record.sst_fd_number);
trace.payload.push_back(record.caller);
trace.payload.push_back(record.is_cache_hit);
trace.payload.push_back(record.no_insert);
if (ShouldTraceReferencedKey(record)) {
PutLengthPrefixedSlice(&trace.payload, record.referenced_key);
PutFixed64(&trace.payload, record.num_keys_in_block);
trace.payload.push_back(record.is_referenced_key_exist_in_block);
}
std::string encoded_trace;
TracerHelper::EncodeTrace(trace, &encoded_trace);
InstrumentedMutexLock lock_guard(&trace_writer_mutex_);
return trace_writer_->Write(encoded_trace);
}
Status BlockCacheTraceWriter::WriteHeader() {
Trace trace;
trace.ts = env_->NowMicros();
trace.type = TraceType::kTraceBegin;
PutLengthPrefixedSlice(&trace.payload, kTraceMagic);
PutFixed32(&trace.payload, kMajorVersion);
PutFixed32(&trace.payload, kMinorVersion);
std::string encoded_trace;
TracerHelper::EncodeTrace(trace, &encoded_trace);
InstrumentedMutexLock lock_guard(&trace_writer_mutex_);
return trace_writer_->Write(encoded_trace);
}
BlockCacheTraceReader::BlockCacheTraceReader(
std::unique_ptr<TraceReader>&& reader)
: trace_reader_(std::move(reader)) {}
Status BlockCacheTraceReader::ReadHeader(BlockCacheTraceHeader* header) {
assert(header != nullptr);
std::string encoded_trace;
Status s = trace_reader_->Read(&encoded_trace);
if (!s.ok()) {
return s;
}
Trace trace;
s = TracerHelper::DecodeTrace(encoded_trace, &trace);
if (!s.ok()) {
return s;
}
header->start_time = trace.ts;
Slice enc_slice = Slice(trace.payload);
Slice magnic_number;
if (!GetLengthPrefixedSlice(&enc_slice, &magnic_number)) {
return Status::Corruption(
"Corrupted header in the trace file: Failed to read the magic number.");
}
if (magnic_number.ToString() != kTraceMagic) {
return Status::Corruption(
"Corrupted header in the trace file: Magic number does not match.");
}
if (!GetFixed32(&enc_slice, &header->rocksdb_major_version)) {
return Status::Corruption(
"Corrupted header in the trace file: Failed to read rocksdb major "
"version number.");
}
if (!GetFixed32(&enc_slice, &header->rocksdb_minor_version)) {
return Status::Corruption(
"Corrupted header in the trace file: Failed to read rocksdb minor "
"version number.");
}
// We should have retrieved all information in the header.
if (!enc_slice.empty()) {
return Status::Corruption(
"Corrupted header in the trace file: The length of header is too "
"long.");
}
return Status::OK();
}
Status BlockCacheTraceReader::ReadAccess(BlockCacheTraceRecord* record) {
assert(record);
std::string encoded_trace;
Status s = trace_reader_->Read(&encoded_trace);
if (!s.ok()) {
return s;
}
Trace trace;
s = TracerHelper::DecodeTrace(encoded_trace, &trace);
if (!s.ok()) {
return s;
}
record->access_timestamp = trace.ts;
record->block_type = trace.type;
Slice enc_slice = Slice(trace.payload);
Slice block_key;
if (!GetLengthPrefixedSlice(&enc_slice, &block_key)) {
return Status::Incomplete(
"Incomplete access record: Failed to read block key.");
}
record->block_key = block_key.ToString();
if (!GetFixed64(&enc_slice, &record->block_size)) {
return Status::Incomplete(
"Incomplete access record: Failed to read block size.");
}
if (!GetFixed32(&enc_slice, &record->cf_id)) {
return Status::Incomplete(
"Incomplete access record: Failed to read column family ID.");
}
Slice cf_name;
if (!GetLengthPrefixedSlice(&enc_slice, &cf_name)) {
return Status::Incomplete(
"Incomplete access record: Failed to read column family name.");
}
record->cf_name = cf_name.ToString();
if (!GetFixed32(&enc_slice, &record->level)) {
return Status::Incomplete(
"Incomplete access record: Failed to read level.");
}
if (!GetFixed32(&enc_slice, &record->sst_fd_number)) {
return Status::Incomplete(
"Incomplete access record: Failed to read SST file number.");
}
if (enc_slice.empty()) {
return Status::Incomplete(
"Incomplete access record: Failed to read caller.");
}
record->caller = static_cast<BlockCacheLookupCaller>(enc_slice[0]);
enc_slice.remove_prefix(kCharSize);
if (enc_slice.empty()) {
return Status::Incomplete(
"Incomplete access record: Failed to read is_cache_hit.");
}
record->is_cache_hit = static_cast<Boolean>(enc_slice[0]);
enc_slice.remove_prefix(kCharSize);
if (enc_slice.empty()) {
return Status::Incomplete(
"Incomplete access record: Failed to read no_insert.");
}
record->no_insert = static_cast<Boolean>(enc_slice[0]);
enc_slice.remove_prefix(kCharSize);
if (ShouldTraceReferencedKey(*record)) {
Slice referenced_key;
if (!GetLengthPrefixedSlice(&enc_slice, &referenced_key)) {
return Status::Incomplete(
"Incomplete access record: Failed to read the referenced key.");
}
record->referenced_key = referenced_key.ToString();
if (!GetFixed64(&enc_slice, &record->num_keys_in_block)) {
return Status::Incomplete(
"Incomplete access record: Failed to read the number of keys in the "
"block.");
}
if (enc_slice.empty()) {
return Status::Incomplete(
"Incomplete access record: Failed to read "
"is_referenced_key_exist_in_block.");
}
record->is_referenced_key_exist_in_block =
static_cast<Boolean>(enc_slice[0]);
}
return Status::OK();
}
} // namespace rocksdb

@ -0,0 +1,105 @@
// 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).
#pragma once
#include "monitoring/instrumented_mutex.h"
#include "rocksdb/env.h"
#include "rocksdb/options.h"
#include "rocksdb/trace_reader_writer.h"
#include "trace_replay/trace_replay.h"
namespace rocksdb {
enum BlockCacheLookupCaller : char {
kUserGet = 1,
kUserMGet = 2,
kUserIterator = 3,
kPrefetch = 4,
kCompaction = 5,
// All callers should be added before kMaxBlockCacheLookupCaller.
kMaxBlockCacheLookupCaller
};
enum Boolean : char { kTrue = 1, kFalse = 0 };
struct BlockCacheTraceRecord {
// Required fields for all accesses.
uint64_t access_timestamp;
std::string block_key;
TraceType block_type;
uint64_t block_size;
uint32_t cf_id;
std::string cf_name;
uint32_t level;
uint32_t sst_fd_number;
BlockCacheLookupCaller caller;
Boolean is_cache_hit;
Boolean no_insert;
// Required fields for data block and user Get/Multi-Get only.
std::string referenced_key;
uint64_t num_keys_in_block = 0;
Boolean is_referenced_key_exist_in_block = Boolean::kFalse;
};
struct BlockCacheTraceHeader {
uint64_t start_time;
uint32_t rocksdb_major_version;
uint32_t rocksdb_minor_version;
};
// BlockCacheTraceWriter captures all RocksDB block cache accesses using a
// user-provided TraceWriter. Every RocksDB operation is written as a single
// trace. Each trace will have a timestamp and type, followed by the trace
// payload.
class BlockCacheTraceWriter {
public:
BlockCacheTraceWriter(Env* env, const TraceOptions& trace_options,
std::unique_ptr<TraceWriter>&& trace_writer);
~BlockCacheTraceWriter() = default;
// No copy and move.
BlockCacheTraceWriter(const BlockCacheTraceWriter&) = delete;
BlockCacheTraceWriter& operator=(const BlockCacheTraceWriter&) = delete;
BlockCacheTraceWriter(BlockCacheTraceWriter&&) = delete;
BlockCacheTraceWriter& operator=(BlockCacheTraceWriter&&) = delete;
Status WriteBlockAccess(const BlockCacheTraceRecord& record);
// Write a trace header at the beginning, typically on initiating a trace,
// with some metadata like a magic number and RocksDB version.
Status WriteHeader();
private:
bool ShouldTrace(const BlockCacheTraceRecord& record) const;
Env* env_;
TraceOptions trace_options_;
std::unique_ptr<TraceWriter> trace_writer_;
/*Mutex to protect trace_writer_ */
InstrumentedMutex trace_writer_mutex_;
};
// BlockCacheTraceReader helps read the trace file generated by
// BlockCacheTraceWriter using a user provided TraceReader.
class BlockCacheTraceReader {
public:
BlockCacheTraceReader(std::unique_ptr<TraceReader>&& reader);
~BlockCacheTraceReader() = default;
// No copy and move.
BlockCacheTraceReader(const BlockCacheTraceReader&) = delete;
BlockCacheTraceReader& operator=(const BlockCacheTraceReader&) = delete;
BlockCacheTraceReader(BlockCacheTraceReader&&) = delete;
BlockCacheTraceReader& operator=(BlockCacheTraceReader&&) = delete;
Status ReadHeader(BlockCacheTraceHeader* header);
Status ReadAccess(BlockCacheTraceRecord* record);
private:
std::unique_ptr<TraceReader> trace_reader_;
};
} // namespace rocksdb

@ -0,0 +1,167 @@
// 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).
#include "trace_replay/block_cache_tracer.h"
#include "rocksdb/env.h"
#include "rocksdb/status.h"
#include "rocksdb/trace_reader_writer.h"
#include "test_util/testharness.h"
#include "test_util/testutil.h"
namespace rocksdb {
namespace {
const uint64_t kBlockSize = 1024;
const std::string kBlockKeyPrefix = "test-block-";
const uint32_t kCFId = 0;
const uint32_t kLevel = 1;
const uint64_t kSSTFDNumber = 100;
const std::string kRefKeyPrefix = "test-get-";
const uint64_t kNumKeysInBlock = 1024;
} // namespace
class BlockCacheTracerTest : public testing::Test {
public:
BlockCacheTracerTest() {
test_path_ = test::PerThreadDBPath("block_cache_tracer_test");
env_ = rocksdb::Env::Default();
EXPECT_OK(env_->CreateDir(test_path_));
trace_file_path_ = test_path_ + "/block_cache_trace";
}
~BlockCacheTracerTest() override {
EXPECT_OK(env_->DeleteFile(trace_file_path_));
EXPECT_OK(env_->DeleteDir(test_path_));
}
BlockCacheLookupCaller GetCaller(uint32_t key_id) {
uint32_t n = key_id % 5;
switch (n) {
case 0:
return BlockCacheLookupCaller::kPrefetch;
case 1:
return BlockCacheLookupCaller::kCompaction;
case 2:
return BlockCacheLookupCaller::kUserGet;
case 3:
return BlockCacheLookupCaller::kUserMGet;
case 4:
return BlockCacheLookupCaller::kUserIterator;
}
assert(false);
}
void WriteBlockAccess(BlockCacheTraceWriter* writer, uint32_t from_key_id,
TraceType block_type, uint32_t nblocks) {
assert(writer);
for (uint32_t i = 0; i < nblocks; i++) {
uint32_t key_id = from_key_id + i;
BlockCacheTraceRecord record;
record.block_type = block_type;
record.block_size = kBlockSize + key_id;
record.block_key = kBlockKeyPrefix + std::to_string(key_id);
record.access_timestamp = env_->NowMicros();
record.cf_id = kCFId;
record.cf_name = kDefaultColumnFamilyName;
record.caller = GetCaller(key_id);
record.level = kLevel;
record.sst_fd_number = kSSTFDNumber + key_id;
record.is_cache_hit = Boolean::kFalse;
record.no_insert = Boolean::kFalse;
// Provide these fields for all block types.
// The writer should only write these fields for data blocks and the
// caller is either GET or MGET.
record.referenced_key = kRefKeyPrefix + std::to_string(key_id);
record.is_referenced_key_exist_in_block = Boolean::kTrue;
record.num_keys_in_block = kNumKeysInBlock;
ASSERT_OK(writer->WriteBlockAccess(record));
}
}
void VerifyAccess(BlockCacheTraceReader* reader, uint32_t from_key_id,
TraceType block_type, uint32_t nblocks) {
assert(reader);
for (uint32_t i = 0; i < nblocks; i++) {
uint32_t key_id = from_key_id + i;
BlockCacheTraceRecord record;
ASSERT_OK(reader->ReadAccess(&record));
ASSERT_EQ(block_type, record.block_type);
ASSERT_EQ(kBlockSize + key_id, record.block_size);
ASSERT_EQ(kBlockKeyPrefix + std::to_string(key_id), record.block_key);
ASSERT_EQ(kCFId, record.cf_id);
ASSERT_EQ(kDefaultColumnFamilyName, record.cf_name);
ASSERT_EQ(GetCaller(key_id), record.caller);
ASSERT_EQ(kLevel, record.level);
ASSERT_EQ(kSSTFDNumber + key_id, record.sst_fd_number);
ASSERT_EQ(Boolean::kFalse, record.is_cache_hit);
ASSERT_EQ(Boolean::kFalse, record.no_insert);
if (block_type == TraceType::kBlockTraceDataBlock &&
(record.caller == BlockCacheLookupCaller::kUserGet ||
record.caller == BlockCacheLookupCaller::kUserMGet)) {
ASSERT_EQ(kRefKeyPrefix + std::to_string(key_id),
record.referenced_key);
ASSERT_EQ(Boolean::kTrue, record.is_referenced_key_exist_in_block);
ASSERT_EQ(kNumKeysInBlock, record.num_keys_in_block);
continue;
}
ASSERT_EQ("", record.referenced_key);
ASSERT_EQ(Boolean::kFalse, record.is_referenced_key_exist_in_block);
ASSERT_EQ(0, record.num_keys_in_block);
}
}
Env* env_;
EnvOptions env_options_;
std::string trace_file_path_;
std::string test_path_;
};
TEST_F(BlockCacheTracerTest, MixedBlocks) {
{
// Generate a trace file containing a mix of blocks.
TraceOptions trace_opt;
std::unique_ptr<TraceWriter> trace_writer;
ASSERT_OK(NewFileTraceWriter(env_, env_options_, trace_file_path_,
&trace_writer));
BlockCacheTraceWriter writer(env_, trace_opt, std::move(trace_writer));
ASSERT_OK(writer.WriteHeader());
// Write blocks of different types.
WriteBlockAccess(&writer, 0, TraceType::kBlockTraceUncompressionDictBlock,
10);
WriteBlockAccess(&writer, 10, TraceType::kBlockTraceDataBlock, 10);
WriteBlockAccess(&writer, 20, TraceType::kBlockTraceFilterBlock, 10);
WriteBlockAccess(&writer, 30, TraceType::kBlockTraceIndexBlock, 10);
WriteBlockAccess(&writer, 40, TraceType::kBlockTraceRangeDeletionBlock, 10);
ASSERT_OK(env_->FileExists(trace_file_path_));
}
{
// Verify trace file is generated correctly.
std::unique_ptr<TraceReader> trace_reader;
ASSERT_OK(NewFileTraceReader(env_, env_options_, trace_file_path_,
&trace_reader));
BlockCacheTraceReader reader(std::move(trace_reader));
BlockCacheTraceHeader header;
ASSERT_OK(reader.ReadHeader(&header));
ASSERT_EQ(kMajorVersion, header.rocksdb_major_version);
ASSERT_EQ(kMinorVersion, header.rocksdb_minor_version);
// Read blocks.
VerifyAccess(&reader, 0, TraceType::kBlockTraceUncompressionDictBlock, 10);
VerifyAccess(&reader, 10, TraceType::kBlockTraceDataBlock, 10);
VerifyAccess(&reader, 20, TraceType::kBlockTraceFilterBlock, 10);
VerifyAccess(&reader, 30, TraceType::kBlockTraceIndexBlock, 10);
VerifyAccess(&reader, 40, TraceType::kBlockTraceRangeDeletionBlock, 10);
// Read one more record should report an error.
BlockCacheTraceRecord record;
ASSERT_NOK(reader.ReadAccess(&record));
}
}
} // namespace rocksdb
int main(int argc, char** argv) {
::testing::InitGoogleTest(&argc, argv);
return RUN_ALL_TESTS();
}

@ -8,7 +8,6 @@
#include <chrono> #include <chrono>
#include <sstream> #include <sstream>
#include <thread> #include <thread>
#include "db/db_impl/db_impl.h" #include "db/db_impl/db_impl.h"
#include "rocksdb/slice.h" #include "rocksdb/slice.h"
#include "rocksdb/write_batch.h" #include "rocksdb/write_batch.h"
@ -32,6 +31,30 @@ void DecodeCFAndKey(std::string& buffer, uint32_t* cf_id, Slice* key) {
} }
} // namespace } // namespace
void TracerHelper::EncodeTrace(const Trace& trace, std::string* encoded_trace) {
assert(encoded_trace);
PutFixed64(encoded_trace, trace.ts);
encoded_trace->push_back(trace.type);
PutFixed32(encoded_trace, static_cast<uint32_t>(trace.payload.size()));
encoded_trace->append(trace.payload);
}
Status TracerHelper::DecodeTrace(const std::string& encoded_trace,
Trace* trace) {
assert(trace != nullptr);
Slice enc_slice = Slice(encoded_trace);
if (!GetFixed64(&enc_slice, &trace->ts)) {
return Status::Incomplete("Decode trace string failed");
}
if (enc_slice.size() < kTraceTypeSize + kTracePayloadLengthSize) {
return Status::Incomplete("Decode trace string failed");
}
trace->type = static_cast<TraceType>(enc_slice[0]);
enc_slice.remove_prefix(kTraceTypeSize + kTracePayloadLengthSize);
trace->payload = enc_slice.ToString();
return Status::OK();
}
Tracer::Tracer(Env* env, const TraceOptions& trace_options, Tracer::Tracer(Env* env, const TraceOptions& trace_options,
std::unique_ptr<TraceWriter>&& trace_writer) std::unique_ptr<TraceWriter>&& trace_writer)
: env_(env), : env_(env),
@ -139,10 +162,7 @@ Status Tracer::WriteFooter() {
Status Tracer::WriteTrace(const Trace& trace) { Status Tracer::WriteTrace(const Trace& trace) {
std::string encoded_trace; std::string encoded_trace;
PutFixed64(&encoded_trace, trace.ts); TracerHelper::EncodeTrace(trace, &encoded_trace);
encoded_trace.push_back(trace.type);
PutFixed32(&encoded_trace, static_cast<uint32_t>(trace.payload.size()));
encoded_trace.append(trace.payload);
return trace_writer_->Write(Slice(encoded_trace)); return trace_writer_->Write(Slice(encoded_trace));
} }
@ -302,13 +322,7 @@ Status Replayer::ReadTrace(Trace* trace) {
if (!s.ok()) { if (!s.ok()) {
return s; return s;
} }
return TracerHelper::DecodeTrace(encoded_trace, trace);
Slice enc_slice = Slice(encoded_trace);
GetFixed64(&enc_slice, &trace->ts);
trace->type = static_cast<TraceType>(enc_slice[0]);
enc_slice.remove_prefix(kTraceTypeSize + kTracePayloadLengthSize);
trace->payload = enc_slice.ToString();
return s;
} }
} // namespace rocksdb } // namespace rocksdb

@ -40,6 +40,12 @@ enum TraceType : char {
kTraceGet = 4, kTraceGet = 4,
kTraceIteratorSeek = 5, kTraceIteratorSeek = 5,
kTraceIteratorSeekForPrev = 6, kTraceIteratorSeekForPrev = 6,
// Block cache related types.
kBlockTraceIndexBlock = 7,
kBlockTraceFilterBlock = 8,
kBlockTraceDataBlock = 9,
kBlockTraceUncompressionDictBlock = 10,
kBlockTraceRangeDeletionBlock = 11,
// All trace types should be added before kTraceMax // All trace types should be added before kTraceMax
kTraceMax, kTraceMax,
}; };
@ -60,6 +66,15 @@ struct Trace {
} }
}; };
class TracerHelper {
public:
// Encode a trace object into the given string.
static void EncodeTrace(const Trace& trace, std::string* encoded_trace);
// Decode a string into the given trace object.
static Status DecodeTrace(const std::string& encoded_trace, Trace* trace);
};
// Tracer captures all RocksDB operations using a user-provided TraceWriter. // Tracer captures all RocksDB operations using a user-provided TraceWriter.
// Every RocksDB operation is written as a single trace. Each trace will have a // Every RocksDB operation is written as a single trace. Each trace will have a
// timestamp and type, followed by the trace payload. // timestamp and type, followed by the trace payload.

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