1// fstshortestdistance.cc
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: allauzen@google.com (Cyril Allauzen)
17// Modified: jpr@google.com (Jake Ratkiewicz) to use FstClass
18//
19// \file
20// Find shortest distances in an FST.
21
22#include <string>
23#include <vector>
24using std::vector;
25
26#include <fst/script/shortest-distance.h>
27#include <fst/script/text-io.h>
28
29DEFINE_bool(reverse, false, "Perform in the reverse direction");
30DEFINE_double(delta, fst::kDelta, "Comparison/quantization delta");
31DEFINE_int64(nstate, fst::kNoStateId, "State number threhold");
32DEFINE_string(queue_type, "auto", "Queue type: one of: \"auto\", "
33              "\"fifo\", \"lifo\", \"shortest\", \"state\", \"top\"");
34
35int main(int argc, char **argv) {
36  namespace s = fst::script;
37  using fst::script::FstClass;
38
39  string usage = "Finds shortest distance(s) in an FST.\n\n  Usage: ";
40  usage += argv[0];
41  usage += " [in.fst [distance.txt]]\n";
42
43  std::set_new_handler(FailedNewHandler);
44  SET_FLAGS(usage.c_str(), &argc, &argv, true);
45  if (argc > 3) {
46    ShowUsage();
47    return 1;
48  }
49
50  string in_fname = (argc > 1 && (strcmp(argv[1], "-") != 0)) ? argv[1] : "";
51  string out_fname = argc > 2 ? argv[2] : "";
52
53  FstClass *ifst = FstClass::Read(in_fname);
54  if (!ifst) return 1;
55
56  vector<s::WeightClass> distance;
57
58  fst::QueueType qt;
59
60  if (FLAGS_queue_type == "auto") {
61    qt = fst::AUTO_QUEUE;
62  } else if (FLAGS_queue_type == "fifo") {
63    qt = fst::FIFO_QUEUE;
64  } else if (FLAGS_queue_type == "lifo") {
65    qt = fst::LIFO_QUEUE;
66  } else if (FLAGS_queue_type == "shortest") {
67    qt = fst::SHORTEST_FIRST_QUEUE;
68  } else if (FLAGS_queue_type == "state") {
69    qt = fst::STATE_ORDER_QUEUE;
70  } else if (FLAGS_queue_type == "top") {
71    qt = fst::TOP_ORDER_QUEUE;
72  } else {
73    LOG(ERROR) << "Unknown or unsupported queue type: " << FLAGS_queue_type;
74    return 1;
75  }
76
77  if (FLAGS_reverse && qt != fst::AUTO_QUEUE) {
78    LOG(ERROR) << "Specifying a non-default queue with reverse not supported.";
79    return 1;
80  }
81
82  if (FLAGS_reverse) {
83    s::ShortestDistance(*ifst, &distance, FLAGS_reverse, FLAGS_delta);
84  } else {
85    s::ShortestDistanceOptions opts(qt, s::ANY_ARC_FILTER,
86                                    FLAGS_nstate, FLAGS_delta);
87    s::ShortestDistance(*ifst, &distance, opts);
88  }
89
90  s::WritePotentials(out_fname, distance);
91
92  return 0;
93}
94