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9b083cb11c
Summary: The patch makes sure that the functionality required for the new integrated BlobDB implementation (most importantly, the classes related to reading and writing blob files) is also built in LITE mode by removing the corresponding `#ifndef`s. Pull Request resolved: https://github.com/facebook/rocksdb/pull/7272 Test Plan: Ran `make check` in both regular and LITE mode. Reviewed By: zhichao-cao Differential Revision: D23173280 Pulled By: ltamasi fbshipit-source-id: 1596bd1a76409a8a6d83d8f1dbfe08bfdea7ffe6
78 lines
2.3 KiB
C++
78 lines
2.3 KiB
C++
// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
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// This source code is licensed under both the GPLv2 (found in the
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// COPYING file in the root directory) and Apache 2.0 License
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// (found in the LICENSE.Apache file in the root directory).
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//
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#pragma once
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#include <memory>
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#include <string>
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#include "db/blob/blob_log_format.h"
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#include "file/random_access_file_reader.h"
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#include "rocksdb/env.h"
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#include "rocksdb/slice.h"
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#include "rocksdb/statistics.h"
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#include "rocksdb/status.h"
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namespace ROCKSDB_NAMESPACE {
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class SequentialFileReader;
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class Logger;
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/**
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* BlobLogReader is a general purpose log stream reader implementation. The
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* actual job of reading from the device is implemented by the SequentialFile
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* interface.
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*
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* Please see Writer for details on the file and record layout.
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*/
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class BlobLogReader {
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public:
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enum ReadLevel {
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kReadHeader,
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kReadHeaderKey,
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kReadHeaderKeyBlob,
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};
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// Create a reader that will return log records from "*file".
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// "*file" must remain live while this BlobLogReader is in use.
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BlobLogReader(std::unique_ptr<RandomAccessFileReader>&& file_reader, Env* env,
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Statistics* statistics);
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// No copying allowed
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BlobLogReader(const BlobLogReader&) = delete;
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BlobLogReader& operator=(const BlobLogReader&) = delete;
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~BlobLogReader() = default;
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Status ReadHeader(BlobLogHeader* header);
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// Read the next record into *record. Returns true if read
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// successfully, false if we hit end of the input. May use
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// "*scratch" as temporary storage. The contents filled in *record
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// will only be valid until the next mutating operation on this
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// reader or the next mutation to *scratch.
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// If blob_offset is non-null, return offset of the blob through it.
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Status ReadRecord(BlobLogRecord* record, ReadLevel level = kReadHeader,
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uint64_t* blob_offset = nullptr);
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void ResetNextByte() { next_byte_ = 0; }
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uint64_t GetNextByte() const { return next_byte_; }
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private:
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Status ReadSlice(uint64_t size, Slice* slice, char* buf);
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const std::unique_ptr<RandomAccessFileReader> file_;
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Env* env_;
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Statistics* statistics_;
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Slice buffer_;
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char header_buf_[BlobLogRecord::kHeaderSize];
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// which byte to read next. For asserting proper usage
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uint64_t next_byte_;
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};
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} // namespace ROCKSDB_NAMESPACE
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