extract.h revision dfd8b8327b93660601d016cdc6f29f433b45a8d8 
1// extract-main.h
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// Copyright 2005-2010 Google, Inc.
16// Author: riley@google.com (Michael Riley)
17// Modified: jpr@google.com (Jake Ratkiewicz) to use the new arc-dispatch
18
19// \file
20// Extracts component FSTs from an finite-state archive.
21//
22
23#ifndef FST_EXTENSIONS_FAR_EXTRACT_H__
24#define FST_EXTENSIONS_FAR_EXTRACT_H__
25
26#include <string>
27#include <vector>
28using std::vector;
29
30#include <fst/extensions/far/far.h>
31
32namespace fst {
33
34template<class Arc>
35void FarExtract(const vector<string> &ifilenames,
36                const int32 &generate_filenames,
37                const string &begin_key,
38                const string &end_key,
39                const string &filename_prefix,
40                const string &filename_suffix) {
41  FarReader<Arc> *far_reader = FarReader<Arc>::Open(ifilenames);
42  if (!far_reader) return;
43
44  if (!begin_key.empty())
45    far_reader->Find(begin_key);
46
47  string okey;
48  int nrep = 0;
49  for (int i = 1; !far_reader->Done(); far_reader->Next(), ++i) {
50    string key = far_reader->GetKey();
51    if (!end_key.empty() && end_key < key)
52      break;
53    const Fst<Arc> &fst = far_reader->GetFst();
54
55    if (key == okey)
56      ++nrep;
57    else
58      nrep = 0;
59
60    okey = key;
61
62    string ofilename;
63    if (generate_filenames) {
64      ostringstream tmp;
65      tmp.width(generate_filenames);
66      tmp.fill('0');
67      tmp << i;
68      ofilename = tmp.str();
69    } else {
70      if (nrep > 0) {
71        ostringstream tmp;
72        tmp << '.' << nrep;
73        key.append(tmp.str().data(), tmp.str().size());
74      }
75      ofilename = key;
76    }
77    fst.Write(filename_prefix + ofilename + filename_suffix);
78  }
79
80  return;
81}
82
83}  // namespace fst
84
85#endif  // FST_EXTENSIONS_FAR_EXTRACT_H__
86