1 // See www.openfst.org for extensive documentation on this weighted
2 // finite-state transducer library.
4 // Extracts component FSTs from an finite-state archive.
6 #ifndef FST_EXTENSIONS_FAR_EXTRACT_H_
7 #define FST_EXTENSIONS_FAR_EXTRACT_H_
13 #include <fst/extensions/far/far.h>
18 inline void FarWriteFst(const Fst<Arc> *fst, string key, string *okey,
19 int *nrep, int32 generate_filenames, int i,
20 const string &filename_prefix,
21 const string &filename_suffix) {
29 if (generate_filenames) {
30 std::ostringstream tmp;
31 tmp.width(generate_filenames);
34 ofilename = tmp.str();
37 std::ostringstream tmp;
39 key.append(tmp.str().data(), tmp.str().size());
43 fst->Write(filename_prefix + ofilename + filename_suffix);
47 void FarExtract(const std::vector<string> &ifilenames, int32 generate_filenames,
48 const string &keys, const string &key_separator,
49 const string &range_delimiter, const string &filename_prefix,
50 const string &filename_suffix) {
51 std::unique_ptr<FarReader<Arc>> far_reader(
52 FarReader<Arc>::Open(ifilenames));
53 if (!far_reader) return;
56 std::vector<char *> key_vector;
57 // User has specified a set of FSTs to extract, where some of these may in
60 auto *keys_cstr = new char[keys.size() + 1];
61 strcpy(keys_cstr, keys.c_str());
62 SplitToVector(keys_cstr, key_separator.c_str(), &key_vector, true);
64 for (size_t k = 0; k < key_vector.size(); ++k, ++i) {
65 string key = key_vector[k];
66 auto *key_cstr = new char[key.size() + 1];
67 strcpy(key_cstr, key.c_str());
68 std::vector<char *> range_vector;
69 SplitToVector(key_cstr, range_delimiter.c_str(), &range_vector, false);
70 if (range_vector.size() == 1) { // Not a range
71 if (!far_reader->Find(key)) {
72 LOG(ERROR) << "FarExtract: Cannot find key " << key;
75 const auto *fst = far_reader->GetFst();
76 FarWriteFst(fst, key, &okey, &nrep, generate_filenames, i,
77 filename_prefix, filename_suffix);
78 } else if (range_vector.size() == 2) { // A legal range
79 string begin_key = range_vector[0];
80 string end_key = range_vector[1];
81 if (begin_key.empty() || end_key.empty()) {
82 LOG(ERROR) << "FarExtract: Illegal range specification " << key;
85 if (!far_reader->Find(begin_key)) {
86 LOG(ERROR) << "FarExtract: Cannot find key " << begin_key;
89 for (; !far_reader->Done(); far_reader->Next(), ++i) {
90 const auto &ikey = far_reader->GetKey();
91 if (end_key < ikey) break;
92 const auto *fst = far_reader->GetFst();
93 FarWriteFst(fst, ikey, &okey, &nrep, generate_filenames, i,
94 filename_prefix, filename_suffix);
97 LOG(ERROR) << "FarExtract: Illegal range specification " << key;
105 // Nothing specified, so just extracts everything.
106 for (size_t i = 1; !far_reader->Done(); far_reader->Next(), ++i) {
107 const auto &key = far_reader->GetKey();
108 const auto *fst = far_reader->GetFst();
109 FarWriteFst(fst, key, &okey, &nrep, generate_filenames, i, filename_prefix,
117 #endif // FST_EXTENSIONS_FAR_EXTRACT_H_