rocksdb/table/persistent_cache_helper.cc

114 lines
4.2 KiB
C++

// 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 "table/persistent_cache_helper.h"
#include "table/block_based/block_based_table_reader.h"
#include "table/format.h"
namespace ROCKSDB_NAMESPACE {
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());
// Precondition:
// (1) content is cacheable
// (2) content is not compressed
// 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) {
#ifdef NDEBUG
(void)raw_data_size;
#endif
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);
return Status::OK();
}
} // namespace ROCKSDB_NAMESPACE