rocksdb/db/table_cache.cc
Abhishek Kona 63f216ee0a memory manage statistics
Summary:
Earlier Statistics object was a raw pointer. This meant the user had to clear up
the Statistics object after creating the database. In most use cases the database is created in a function and the statistics pointer is out of scope. Hence the statistics object would never be deleted.
Now Using a shared_ptr to manage this.

Want this in before the next release.

Test Plan: make all check.

Reviewers: dhruba, emayanke

Reviewed By: emayanke

CC: leveldb

Differential Revision: https://reviews.facebook.net/D9735
2013-03-27 11:27:39 -07:00

131 lines
4.0 KiB
C++

// 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 "leveldb/table.h"
#include "leveldb/statistics.h"
#include "util/coding.h"
namespace leveldb {
struct TableAndFile {
unique_ptr<Table> table;
};
static void DeleteEntry(const Slice& key, void* value) {
TableAndFile* tf = reinterpret_cast<TableAndFile*>(value);
delete tf;
}
static void UnrefEntry(void* arg1, void* arg2) {
Cache* cache = reinterpret_cast<Cache*>(arg1);
Cache::Handle* h = reinterpret_cast<Cache::Handle*>(arg2);
cache->Release(h);
}
TableCache::TableCache(const std::string& dbname,
const Options* options,
const StorageOptions& storage_options,
int entries)
: env_(options->env),
dbname_(dbname),
options_(options),
storage_options_(storage_options),
cache_(NewLRUCache(entries, options->table_cache_numshardbits)) {}
TableCache::~TableCache() {
}
Status TableCache::FindTable(const EnvOptions& toptions,
uint64_t file_number, uint64_t file_size,
Cache::Handle** handle, bool* tableIO) {
Status s;
char buf[sizeof(file_number)];
EncodeFixed64(buf, file_number);
Slice key(buf, sizeof(buf));
*handle = cache_->Lookup(key);
if (*handle == nullptr) {
if (tableIO != nullptr) {
*tableIO = true; // we had to do IO from storage
}
std::string fname = TableFileName(dbname_, file_number);
unique_ptr<RandomAccessFile> file;
unique_ptr<Table> table;
s = env_->NewRandomAccessFile(fname, &file, toptions);
RecordTick(options_->statistics, NO_FILE_OPENS);
if (s.ok()) {
s = Table::Open(*options_, toptions, std::move(file), file_size, &table);
}
if (!s.ok()) {
assert(table == nullptr);
RecordTick(options_->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 {
TableAndFile* tf = new TableAndFile;
tf->table = std::move(table);
assert(file.get() == nullptr);
*handle = cache_->Insert(key, tf, 1, &DeleteEntry);
}
}
return s;
}
Iterator* TableCache::NewIterator(const ReadOptions& options,
const EnvOptions& toptions,
uint64_t file_number,
uint64_t file_size,
Table** tableptr) {
if (tableptr != nullptr) {
*tableptr = nullptr;
}
Cache::Handle* handle = nullptr;
Status s = FindTable(toptions, file_number, file_size, &handle);
if (!s.ok()) {
return NewErrorIterator(s);
}
Table* table =
reinterpret_cast<TableAndFile*>(cache_->Value(handle))->table.get();
Iterator* result = table->NewIterator(options);
result->RegisterCleanup(&UnrefEntry, cache_.get(), handle);
if (tableptr != nullptr) {
*tableptr = table;
}
return result;
}
Status TableCache::Get(const ReadOptions& options,
uint64_t file_number,
uint64_t file_size,
const Slice& k,
void* arg,
void (*saver)(void*, const Slice&, const Slice&, bool),
bool* tableIO) {
Cache::Handle* handle = nullptr;
Status s = FindTable(storage_options_, file_number, file_size,
&handle, tableIO);
if (s.ok()) {
Table* t =
reinterpret_cast<TableAndFile*>(cache_->Value(handle))->table.get();
s = t->InternalGet(options, k, arg, saver);
cache_->Release(handle);
}
return s;
}
void TableCache::Evict(uint64_t file_number) {
char buf[sizeof(file_number)];
EncodeFixed64(buf, file_number);
cache_->Erase(Slice(buf, sizeof(buf)));
}
} // namespace leveldb