rocksdb/db/table_cache.cc

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// 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/table_cache.h"
#include "db/filename.h"
#include "db/version_edit.h"
#include "rocksdb/statistics.h"
#include "table/iterator_wrapper.h"
#include "table/table_reader.h"
#include "util/coding.h"
#include "util/stop_watch.h"
namespace rocksdb {
static void DeleteEntry(const Slice& key, void* value) {
TableReader* table_reader = reinterpret_cast<TableReader*>(value);
delete table_reader;
}
static void UnrefEntry(void* arg1, void* arg2) {
Cache* cache = reinterpret_cast<Cache*>(arg1);
Cache::Handle* h = reinterpret_cast<Cache::Handle*>(arg2);
cache->Release(h);
}
static Slice GetSliceForFileNumber(const uint64_t* file_number) {
return Slice(reinterpret_cast<const char*>(file_number),
sizeof(*file_number));
}
TableCache::TableCache(const ImmutableCFOptions& ioptions,
const EnvOptions& env_options, Cache* const cache)
: ioptions_(ioptions),
env_options_(env_options),
cache_(cache) {}
TableCache::~TableCache() {
}
TableReader* TableCache::GetTableReaderFromHandle(Cache::Handle* handle) {
return reinterpret_cast<TableReader*>(cache_->Value(handle));
}
void TableCache::ReleaseHandle(Cache::Handle* handle) {
cache_->Release(handle);
}
Status TableCache::FindTable(const EnvOptions& env_options,
const InternalKeyComparator& internal_comparator,
const FileDescriptor& fd, Cache::Handle** handle,
const bool no_io) {
Status s;
uint64_t number = fd.GetNumber();
Slice key = GetSliceForFileNumber(&number);
*handle = cache_->Lookup(key);
if (*handle == nullptr) {
if (no_io) { // Dont do IO and return a not-found status
return Status::Incomplete("Table not found in table_cache, no_io is set");
}
std::string fname =
TableFileName(ioptions_.db_paths, fd.GetNumber(), fd.GetPathId());
unique_ptr<RandomAccessFile> file;
unique_ptr<TableReader> table_reader;
s = ioptions_.env->NewRandomAccessFile(fname, &file, env_options);
RecordTick(ioptions_.statistics, NO_FILE_OPENS);
if (s.ok()) {
if (ioptions_.advise_random_on_open) {
file->Hint(RandomAccessFile::RANDOM);
}
StopWatch sw(ioptions_.env, ioptions_.statistics, TABLE_OPEN_IO_MICROS);
s = ioptions_.table_factory->NewTableReader(
ioptions_, env_options, internal_comparator, std::move(file),
fd.GetFileSize(), &table_reader);
}
if (!s.ok()) {
assert(table_reader == nullptr);
RecordTick(ioptions_.statistics, NO_FILE_ERRORS);
// We do not cache error results so that if the error is transient,
// or somebody repairs the file, we recover automatically.
} else {
assert(file.get() == nullptr);
*handle = cache_->Insert(key, table_reader.release(), 1, &DeleteEntry);
}
}
return s;
}
Iterator* TableCache::NewIterator(const ReadOptions& options,
const EnvOptions& env_options,
const InternalKeyComparator& icomparator,
const FileDescriptor& fd,
TableReader** table_reader_ptr,
bool for_compaction, Arena* arena) {
if (table_reader_ptr != nullptr) {
*table_reader_ptr = nullptr;
}
TableReader* table_reader = fd.table_reader;
Cache::Handle* handle = nullptr;
Status s;
if (table_reader == nullptr) {
s = FindTable(env_options, icomparator, fd, &handle,
options.read_tier == kBlockCacheTier);
if (!s.ok()) {
return NewErrorIterator(s, arena);
}
table_reader = GetTableReaderFromHandle(handle);
}
Iterator* result = table_reader->NewIterator(options, arena);
if (handle != nullptr) {
result->RegisterCleanup(&UnrefEntry, cache_, handle);
}
if (table_reader_ptr != nullptr) {
*table_reader_ptr = table_reader;
}
if (for_compaction) {
table_reader->SetupForCompaction();
}
return result;
}
Status TableCache::Get(const ReadOptions& options,
const InternalKeyComparator& internal_comparator,
const FileDescriptor& fd, const Slice& k, void* arg,
bool (*saver)(void*, const ParsedInternalKey&,
const Slice&),
void (*mark_key_may_exist)(void*)) {
TableReader* t = fd.table_reader;
Status s;
Cache::Handle* handle = nullptr;
if (!t) {
s = FindTable(env_options_, internal_comparator, fd, &handle,
options.read_tier == kBlockCacheTier);
if (s.ok()) {
t = GetTableReaderFromHandle(handle);
}
}
if (s.ok()) {
s = t->Get(options, k, arg, saver, mark_key_may_exist);
if (handle != nullptr) {
ReleaseHandle(handle);
}
} else if (options.read_tier && s.IsIncomplete()) {
// Couldnt find Table in cache but treat as kFound if no_io set
(*mark_key_may_exist)(arg);
return Status::OK();
}
return s;
}
Status TableCache::GetTableProperties(
const EnvOptions& env_options,
const InternalKeyComparator& internal_comparator, const FileDescriptor& fd,
std::shared_ptr<const TableProperties>* properties, bool no_io) {
Status s;
auto table_reader = fd.table_reader;
// table already been pre-loaded?
if (table_reader) {
*properties = table_reader->GetTableProperties();
return s;
}
Cache::Handle* table_handle = nullptr;
s = FindTable(env_options, internal_comparator, fd, &table_handle, no_io);
if (!s.ok()) {
return s;
}
assert(table_handle);
auto table = GetTableReaderFromHandle(table_handle);
*properties = table->GetTableProperties();
ReleaseHandle(table_handle);
return s;
}
size_t TableCache::GetMemoryUsageByTableReader(
const EnvOptions& env_options,
const InternalKeyComparator& internal_comparator,
const FileDescriptor& fd) {
Status s;
auto table_reader = fd.table_reader;
// table already been pre-loaded?
if (table_reader) {
return table_reader->ApproximateMemoryUsage();
}
Cache::Handle* table_handle = nullptr;
s = FindTable(env_options, internal_comparator, fd, &table_handle, true);
if (!s.ok()) {
return 0;
}
assert(table_handle);
auto table = GetTableReaderFromHandle(table_handle);
auto ret = table->ApproximateMemoryUsage();
ReleaseHandle(table_handle);
return ret;
}
void TableCache::Evict(Cache* cache, uint64_t file_number) {
cache->Erase(GetSliceForFileNumber(&file_number));
}
} // namespace rocksdb