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rocksdb/table/persistent_cache_helper.cc

111 lines
3.5 KiB

// 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 {
const PersistentCacheOptions PersistentCacheOptions::kEmpty;
void PersistentCacheHelper::InsertSerialized(
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());
CacheKey key =
BlockBasedTable::GetCacheKey(cache_options.base_cache_key, handle);
cache_options.persistent_cache->Insert(key.AsSlice(), data, size)
.PermitUncheckedError();
}
void PersistentCacheHelper::InsertUncompressed(
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
CacheKey key =
BlockBasedTable::GetCacheKey(cache_options.base_cache_key, handle);
cache_options.persistent_cache
->Insert(key.AsSlice(), contents.data.data(), contents.data.size())
.PermitUncheckedError();
;
}
Status PersistentCacheHelper::LookupSerialized(
const PersistentCacheOptions& cache_options, const BlockHandle& handle,
std::unique_ptr<char[]>* out_data, const size_t expected_data_size) {
#ifdef NDEBUG
(void)expected_data_size;
#endif
assert(cache_options.persistent_cache);
assert(cache_options.persistent_cache->IsCompressed());
CacheKey key =
BlockBasedTable::GetCacheKey(cache_options.base_cache_key, handle);
size_t size;
Status s =
cache_options.persistent_cache->Lookup(key.AsSlice(), out_data, &size);
if (!s.ok()) {
// cache miss
RecordTick(cache_options.statistics, PERSISTENT_CACHE_MISS);
return s;
}
// cache hit
// Block-based table is assumed
assert(expected_data_size ==
handle.size() + BlockBasedTable::kBlockTrailerSize);
assert(size == expected_data_size);
RecordTick(cache_options.statistics, PERSISTENT_CACHE_HIT);
return Status::OK();
}
Status PersistentCacheHelper::LookupUncompressed(
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();
}
CacheKey key =
BlockBasedTable::GetCacheKey(cache_options.base_cache_key, handle);
std::unique_ptr<char[]> data;
size_t size;
Status s =
cache_options.persistent_cache->Lookup(key.AsSlice(), &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