rocksdb/db/blob/blob_file_cache.h

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// 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).
#pragma once
#include <cinttypes>
#include "cache/cache_helpers.h"
#include "rocksdb/rocksdb_namespace.h"
#include "util/mutexlock.h"
namespace ROCKSDB_NAMESPACE {
class Cache;
struct ImmutableCFOptions;
struct FileOptions;
class HistogramImpl;
class Status;
class BlobFileReader;
class Slice;
class BlobFileCache {
public:
BlobFileCache(Cache* cache, const ImmutableCFOptions* immutable_cf_options,
const FileOptions* file_options, uint32_t column_family_id,
HistogramImpl* blob_file_read_hist);
BlobFileCache(const BlobFileCache&) = delete;
BlobFileCache& operator=(const BlobFileCache&) = delete;
Status GetBlobFileReader(uint64_t blob_file_number,
CacheHandleGuard<BlobFileReader>* blob_file_reader);
private:
Cache* cache_;
// Note: mutex_ below is used to guard against multiple threads racing to open
// the same file.
Striped<port::Mutex, Slice> mutex_;
const ImmutableCFOptions* immutable_cf_options_;
const FileOptions* file_options_;
uint32_t column_family_id_;
HistogramImpl* blob_file_read_hist_;
static constexpr size_t kNumberOfMutexStripes = 1 << 7;
};
} // namespace ROCKSDB_NAMESPACE