1 /* Copyright 2015 The TensorFlow Authors. All Rights Reserved. 2 3 Licensed under the Apache License, Version 2.0 (the "License"); 4 you may not use this file except in compliance with the License. 5 You may obtain a copy of the License at 6 7 http://www.apache.org/licenses/LICENSE-2.0 8 9 Unless required by applicable law or agreed to in writing, software 10 distributed under the License is distributed on an "AS IS" BASIS, 11 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 See the License for the specific language governing permissions and 13 limitations under the License. 14 ==============================================================================*/ 15 16 // TableBuilder provides the interface used to build a Table 17 // (an immutable and sorted map from keys to values). 18 // 19 // Multiple threads can invoke const methods on a TableBuilder without 20 // external synchronization, but if any of the threads may call a 21 // non-const method, all threads accessing the same TableBuilder must use 22 // external synchronization. 23 24 #ifndef TENSORFLOW_LIB_IO_TABLE_BUILDER_H_ 25 #define TENSORFLOW_LIB_IO_TABLE_BUILDER_H_ 26 27 #include <stdint.h> 28 #include "tensorflow/core/lib/core/status.h" 29 #include "tensorflow/core/lib/io/table_options.h" 30 31 namespace tensorflow { 32 class WritableFile; 33 namespace table { 34 35 class BlockBuilder; 36 class BlockHandle; 37 38 class TableBuilder { 39 public: 40 // Create a builder that will store the contents of the table it is 41 // building in *file. Does not close the file. It is up to the 42 // caller to close the file after calling Finish(). 43 TableBuilder(const Options& options, WritableFile* file); 44 45 // REQUIRES: Either Finish() or Abandon() has been called. 46 ~TableBuilder(); 47 48 // Add key,value to the table being constructed. 49 // REQUIRES: key is after any previously added key in lexicographic order. 50 // REQUIRES: Finish(), Abandon() have not been called 51 void Add(const StringPiece& key, const StringPiece& value); 52 53 // Advanced operation: writes any buffered key/value pairs to file. 54 // Can be used to ensure that two adjacent entries never live in 55 // the same data block. Most clients should not need to use this method. 56 // Does not flush the file itself. 57 // REQUIRES: Finish(), Abandon() have not been called 58 void Flush(); 59 60 // Return non-ok iff some error has been detected. 61 Status status() const; 62 63 // Finish building the table. Stops using the file passed to the 64 // constructor after this function returns. 65 // REQUIRES: Finish(), Abandon() have not been called 66 Status Finish(); 67 68 // Indicate that the contents of this builder should be abandoned. Stops 69 // using the file passed to the constructor after this function returns. 70 // If the caller is not going to call Finish(), it must call Abandon() 71 // before destroying this builder. 72 // REQUIRES: Finish(), Abandon() have not been called 73 void Abandon(); 74 75 // Number of calls to Add() so far. 76 uint64 NumEntries() const; 77 78 // Size of the file generated so far. If invoked after a successful 79 // Finish() call, returns the size of the final generated file. 80 uint64 FileSize() const; 81 82 private: 83 bool ok() const { return status().ok(); } 84 void WriteBlock(BlockBuilder* block, BlockHandle* handle); 85 void WriteRawBlock(const StringPiece& data, CompressionType, 86 BlockHandle* handle); 87 88 struct Rep; 89 Rep* rep_; 90 91 // No copying allowed 92 TableBuilder(const TableBuilder&); 93 void operator=(const TableBuilder&); 94 }; 95 96 } // namespace table 97 } // namespace tensorflow 98 99 #endif // TENSORFLOW_LIB_IO_TABLE_BUILDER_H_ 100
