1/*
2 * Copyright 2016 Google Inc. All rights reserved.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *     http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include "flatbuffers/util.h"
18
19namespace flatbuffers {
20
21bool FileExistsRaw(const char *name) {
22  std::ifstream ifs(name);
23  return ifs.good();
24}
25
26bool LoadFileRaw(const char *name, bool binary, std::string *buf) {
27  if (DirExists(name)) return false;
28  std::ifstream ifs(name, binary ? std::ifstream::binary : std::ifstream::in);
29  if (!ifs.is_open()) return false;
30  if (binary) {
31    // The fastest way to read a file into a string.
32    ifs.seekg(0, std::ios::end);
33    auto size = ifs.tellg();
34    (*buf).resize(static_cast<size_t>(size));
35    ifs.seekg(0, std::ios::beg);
36    ifs.read(&(*buf)[0], (*buf).size());
37  } else {
38    // This is slower, but works correctly on all platforms for text files.
39    std::ostringstream oss;
40    oss << ifs.rdbuf();
41    *buf = oss.str();
42  }
43  return !ifs.bad();
44}
45
46static LoadFileFunction g_load_file_function = LoadFileRaw;
47static FileExistsFunction g_file_exists_function = FileExistsRaw;
48
49bool LoadFile(const char *name, bool binary, std::string *buf) {
50  assert(g_load_file_function);
51  return g_load_file_function(name, binary, buf);
52}
53
54bool FileExists(const char *name) {
55  assert(g_file_exists_function);
56  return g_file_exists_function(name);
57}
58
59bool DirExists(const char *name) {
60  #ifdef _WIN32
61    #define flatbuffers_stat _stat
62    #define FLATBUFFERS_S_IFDIR _S_IFDIR
63  #else
64    #define flatbuffers_stat stat
65    #define FLATBUFFERS_S_IFDIR S_IFDIR
66  #endif
67  struct flatbuffers_stat file_info;
68  if (flatbuffers_stat(name, &file_info) != 0) return false;
69  return (file_info.st_mode & FLATBUFFERS_S_IFDIR) != 0;
70}
71
72LoadFileFunction SetLoadFileFunction(LoadFileFunction load_file_function) {
73  LoadFileFunction previous_function = g_load_file_function;
74  g_load_file_function = load_file_function ? load_file_function : LoadFileRaw;
75  return previous_function;
76}
77
78FileExistsFunction SetFileExistsFunction(
79    FileExistsFunction file_exists_function) {
80  FileExistsFunction previous_function = g_file_exists_function;
81  g_file_exists_function = file_exists_function ?
82      file_exists_function : FileExistsRaw;
83  return previous_function;
84}
85
86}  // namespace flatbuffers
87