rocksdb/table/block_builder.h
Kai Liu 1f8ade6bd6 Fix a bug in table builder
Summary:
In talbe.cc, when reading the metablock, it uses BytewiseComparator();
However in table_builder.cc, we use r->options.comparator. After tracing
the creation of r->options.comparator, I found this comparator is an
InternalKeyComparator, which wraps the user defined comparator(details
can be found in DBImpl::SanitizeOptions().

I encountered this problem when adding metadata about "bloom filter"
before. With different comparator, we may fail to do the binary sort.

Current code works well since there is only one entry in meta block.

Test Plan:
make all check

I've also tested this change in https://reviews.facebook.net/D8283 before.

Reviewers: dhruba, haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13335
2013-10-07 18:53:19 -07:00

61 lines
1.9 KiB
C++

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