1
2// Licensed under the Apache License, Version 2.0 (the "License");
3// you may not use this file except in compliance with the License.
4// You may obtain a copy of the License at
5//
6//     http://www.apache.org/licenses/LICENSE-2.0
7//
8// Unless required by applicable law or agreed to in writing, software
9// distributed under the License is distributed on an "AS IS" BASIS,
10// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
11// See the License for the specific language governing permissions and
12// limitations under the License.
13//
14// Copyright 2005-2010 Google, Inc.
15// Author: jpr@google.com (Jake Ratkiewicz)
16
17#include <fst/extensions/far/compile-strings.h>
18#include <iostream>
19#include <fstream>
20
21namespace fst {
22
23// Compute the minimal length required to
24// encode each line number as a decimal number
25int KeySize(const char *filename) {
26  ifstream istrm(filename);
27  istrm.seekg(0);
28  string s;
29  int nline = 0;
30  while (getline(istrm, s))
31    ++nline;
32  istrm.seekg(0);
33  return nline ? ceil(log10(nline + 1)) : 1;
34}
35
36}  // namespace fst
37