rocksdb/table/persistent_cache_helper.cc
Siying Dong d616ebea23 Add GPLv2 as an alternative license.
Summary: Closes https://github.com/facebook/rocksdb/pull/2226

Differential Revision: D4967547

Pulled By: siying

fbshipit-source-id: dd3b58ae1e7a106ab6bb6f37ab5c88575b125ab4
2017-04-27 18:06:12 -07:00

117 lines
4.5 KiB
C++

// Copyright (c) 2011-present, 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.
// This source code is also licensed under the GPLv2 license found in the
// COPYING file in the root directory of this source tree.
#include "table/persistent_cache_helper.h"
#include "table/block_based_table_reader.h"
#include "table/format.h"
namespace rocksdb {
void PersistentCacheHelper::InsertRawPage(
const PersistentCacheOptions& cache_options, const BlockHandle& handle,
const char* data, const size_t size) {
assert(cache_options.persistent_cache);
assert(cache_options.persistent_cache->IsCompressed());
// construct the page key
char cache_key[BlockBasedTable::kMaxCacheKeyPrefixSize + kMaxVarint64Length];
auto key = BlockBasedTable::GetCacheKey(cache_options.key_prefix.c_str(),
cache_options.key_prefix.size(),
handle, cache_key);
// insert content to cache
cache_options.persistent_cache->Insert(key, data, size);
}
void PersistentCacheHelper::InsertUncompressedPage(
const PersistentCacheOptions& cache_options, const BlockHandle& handle,
const BlockContents& contents) {
assert(cache_options.persistent_cache);
assert(!cache_options.persistent_cache->IsCompressed());
if (!contents.cachable || contents.compression_type != kNoCompression) {
// We shouldn't cache this. Either
// (1) content is not cacheable
// (2) content is compressed
return;
}
// construct the page key
char cache_key[BlockBasedTable::kMaxCacheKeyPrefixSize + kMaxVarint64Length];
auto key = BlockBasedTable::GetCacheKey(cache_options.key_prefix.c_str(),
cache_options.key_prefix.size(),
handle, cache_key);
// insert block contents to page cache
cache_options.persistent_cache->Insert(key, contents.data.data(),
contents.data.size());
}
Status PersistentCacheHelper::LookupRawPage(
const PersistentCacheOptions& cache_options, const BlockHandle& handle,
std::unique_ptr<char[]>* raw_data, const size_t raw_data_size) {
assert(cache_options.persistent_cache);
assert(cache_options.persistent_cache->IsCompressed());
// construct the page key
char cache_key[BlockBasedTable::kMaxCacheKeyPrefixSize + kMaxVarint64Length];
auto key = BlockBasedTable::GetCacheKey(cache_options.key_prefix.c_str(),
cache_options.key_prefix.size(),
handle, cache_key);
// Lookup page
size_t size;
Status s = cache_options.persistent_cache->Lookup(key, raw_data, &size);
if (!s.ok()) {
// cache miss
RecordTick(cache_options.statistics, PERSISTENT_CACHE_MISS);
return s;
}
// cache hit
assert(raw_data_size == handle.size() + kBlockTrailerSize);
assert(size == raw_data_size);
RecordTick(cache_options.statistics, PERSISTENT_CACHE_HIT);
return Status::OK();
}
Status PersistentCacheHelper::LookupUncompressedPage(
const PersistentCacheOptions& cache_options, const BlockHandle& handle,
BlockContents* contents) {
assert(cache_options.persistent_cache);
assert(!cache_options.persistent_cache->IsCompressed());
if (!contents) {
// We shouldn't lookup in the cache. Either
// (1) Nowhere to store
return Status::NotFound();
}
// construct the page key
char cache_key[BlockBasedTable::kMaxCacheKeyPrefixSize + kMaxVarint64Length];
auto key = BlockBasedTable::GetCacheKey(cache_options.key_prefix.c_str(),
cache_options.key_prefix.size(),
handle, cache_key);
// Lookup page
std::unique_ptr<char[]> data;
size_t size;
Status s = cache_options.persistent_cache->Lookup(key, &data, &size);
if (!s.ok()) {
// cache miss
RecordTick(cache_options.statistics, PERSISTENT_CACHE_MISS);
return s;
}
// please note we are potentially comparing compressed data size with
// uncompressed data size
assert(handle.size() <= size);
// update stats
RecordTick(cache_options.statistics, PERSISTENT_CACHE_HIT);
// construct result and return
*contents =
BlockContents(std::move(data), size, false /*cacheable*/, kNoCompression);
return Status::OK();
}
} // namespace rocksdb