diff options
Diffstat (limited to 'include/leveldb/table_builder.h')
-rw-r--r-- | include/leveldb/table_builder.h | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/include/leveldb/table_builder.h b/include/leveldb/table_builder.h new file mode 100644 index 0000000000..5fd1dc71f1 --- /dev/null +++ b/include/leveldb/table_builder.h @@ -0,0 +1,92 @@ +// 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. +// +// TableBuilder provides the interface used to build a Table +// (an immutable and sorted map from keys to values). +// +// Multiple threads can invoke const methods on a TableBuilder without +// external synchronization, but if any of the threads may call a +// non-const method, all threads accessing the same TableBuilder must use +// external synchronization. + +#ifndef STORAGE_LEVELDB_INCLUDE_TABLE_BUILDER_H_ +#define STORAGE_LEVELDB_INCLUDE_TABLE_BUILDER_H_ + +#include <stdint.h> +#include "leveldb/options.h" +#include "leveldb/status.h" + +namespace leveldb { + +class BlockBuilder; +class BlockHandle; +class WritableFile; + +class TableBuilder { + public: + // Create a builder that will store the contents of the table it is + // building in *file. Does not close the file. It is up to the + // caller to close the file after calling Finish(). + TableBuilder(const Options& options, WritableFile* file); + + // REQUIRES: Either Finish() or Abandon() has been called. + ~TableBuilder(); + + // Change the options used by this builder. Note: only some of the + // option fields can be changed after construction. If a field is + // not allowed to change dynamically and its value in the structure + // passed to the constructor is different from its value in the + // structure passed to this method, this method will return an error + // without changing any fields. + Status ChangeOptions(const Options& options); + + // Add key,value to the table being constructed. + // REQUIRES: key is after any previously added key according to comparator. + // REQUIRES: Finish(), Abandon() have not been called + void Add(const Slice& key, const Slice& value); + + // Advanced operation: flush any buffered key/value pairs to file. + // Can be used to ensure that two adjacent entries never live in + // the same data block. Most clients should not need to use this method. + // REQUIRES: Finish(), Abandon() have not been called + void Flush(); + + // Return non-ok iff some error has been detected. + Status status() const; + + // Finish building the table. Stops using the file passed to the + // constructor after this function returns. + // REQUIRES: Finish(), Abandon() have not been called + Status Finish(); + + // Indicate that the contents of this builder should be abandoned. Stops + // using the file passed to the constructor after this function returns. + // If the caller is not going to call Finish(), it must call Abandon() + // before destroying this builder. + // REQUIRES: Finish(), Abandon() have not been called + void Abandon(); + + // Number of calls to Add() so far. + uint64_t NumEntries() const; + + // Size of the file generated so far. If invoked after a successful + // Finish() call, returns the size of the final generated file. + uint64_t FileSize() const; + + private: + bool ok() const { return status().ok(); } + void WriteBlock(BlockBuilder* block, BlockHandle* handle); + void WriteRawBlock(const Slice& data, CompressionType, BlockHandle* handle); + + struct Rep; + Rep* rep_; + + // No copying allowed + TableBuilder(const TableBuilder&); + void operator=(const TableBuilder&); +}; + +} // namespace leveldb + +#endif // STORAGE_LEVELDB_INCLUDE_TABLE_BUILDER_H_ |