mirror of https://github.com/facebook/rocksdb.git
60 lines
1.8 KiB
C++
60 lines
1.8 KiB
C++
// Copyright (c) Meta Platforms, Inc. and affiliates.
|
|
// 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 <memory>
|
|
|
|
#include "memory/memory_allocator_impl.h"
|
|
#include "rocksdb/advanced_cache.h"
|
|
#include "rocksdb/rocksdb_namespace.h"
|
|
#include "rocksdb/slice.h"
|
|
#include "rocksdb/status.h"
|
|
|
|
namespace ROCKSDB_NAMESPACE {
|
|
|
|
// A class representing a single uncompressed value read from a blob file.
|
|
class BlobContents {
|
|
public:
|
|
BlobContents(CacheAllocationPtr&& allocation, size_t size)
|
|
: allocation_(std::move(allocation)), data_(allocation_.get(), size) {}
|
|
|
|
BlobContents(const BlobContents&) = delete;
|
|
BlobContents& operator=(const BlobContents&) = delete;
|
|
|
|
BlobContents(BlobContents&&) = default;
|
|
BlobContents& operator=(BlobContents&&) = default;
|
|
|
|
~BlobContents() = default;
|
|
|
|
const Slice& data() const { return data_; }
|
|
size_t size() const { return data_.size(); }
|
|
|
|
size_t ApproximateMemoryUsage() const;
|
|
|
|
// For TypedCacheInterface
|
|
const Slice& ContentSlice() const { return data_; }
|
|
static constexpr CacheEntryRole kCacheEntryRole = CacheEntryRole::kBlobValue;
|
|
|
|
private:
|
|
CacheAllocationPtr allocation_;
|
|
Slice data_;
|
|
};
|
|
|
|
class BlobContentsCreator : public Cache::CreateContext {
|
|
public:
|
|
static void Create(std::unique_ptr<BlobContents>* out, size_t* out_charge,
|
|
const Slice& contents, MemoryAllocator* alloc) {
|
|
auto raw = new BlobContents(AllocateAndCopyBlock(contents, alloc),
|
|
contents.size());
|
|
out->reset(raw);
|
|
if (out_charge) {
|
|
*out_charge = raw->ApproximateMemoryUsage();
|
|
}
|
|
}
|
|
};
|
|
|
|
} // namespace ROCKSDB_NAMESPACE
|