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57 lines
1.7 KiB
57 lines
1.7 KiB
// Copyright (c) 2011 The LevelDB Authors. All rights reserved. |
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// Use of this source code is governed by a BSD-style license that can be |
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// found in the LICENSE file. See the AUTHORS file for names of contributors. |
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#ifndef STORAGE_LEVELDB_TABLE_BLOCK_BUILDER_H_ |
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#define STORAGE_LEVELDB_TABLE_BLOCK_BUILDER_H_ |
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#include <vector> |
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#include <stdint.h> |
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#include "leveldb/slice.h" |
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namespace leveldb { |
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struct Options; |
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class BlockBuilder { |
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public: |
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explicit BlockBuilder(const Options* options); |
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// Reset the contents as if the BlockBuilder was just constructed. |
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void Reset(); |
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// REQUIRES: Finish() has not been called since the last call to Reset(). |
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// REQUIRES: key is larger than any previously added key |
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void Add(const Slice& key, const Slice& value); |
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// Finish building the block and return a slice that refers to the |
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// block contents. The returned slice will remain valid for the |
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// lifetime of this builder or until Reset() is called. |
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Slice Finish(); |
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// Returns an estimate of the current (uncompressed) size of the block |
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// we are building. |
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size_t CurrentSizeEstimate() const; |
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// Return true iff no entries have been added since the last Reset() |
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bool empty() const { |
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return buffer_.empty(); |
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} |
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private: |
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const Options* options_; |
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std::string buffer_; // Destination buffer |
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std::vector<uint32_t> restarts_; // Restart points |
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int counter_; // Number of entries emitted since restart |
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bool finished_; // Has Finish() been called? |
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std::string last_key_; |
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// No copying allowed |
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BlockBuilder(const BlockBuilder&); |
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void operator=(const BlockBuilder&); |
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}; |
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} // namespace leveldb |
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#endif // STORAGE_LEVELDB_TABLE_BLOCK_BUILDER_H_
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