1 /*
2 * Copyright 2014-2019 Max Kellermann <max.kellermann@gmail.com>
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 *
8 * - Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 *
11 * - Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the
14 * distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
19 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
20 * FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
22 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
23 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
25 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
27 * OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30 #include "FileReader.hxx"
31 #include "fs/FileInfo.hxx"
32 #include "system/Error.hxx"
33 #include "io/Open.hxx"
34
35 #include <cassert>
36
37 #ifdef _WIN32
38
FileReader(Path _path)39 FileReader::FileReader(Path _path)
40 :path(_path),
41 handle(CreateFile(path.c_str(), GENERIC_READ, FILE_SHARE_READ,
42 nullptr, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL,
43 nullptr))
44 {
45 if (handle == INVALID_HANDLE_VALUE)
46 throw FormatLastError("Failed to open %s", path.ToUTF8().c_str());
47 }
48
49 FileInfo
GetFileInfo() const50 FileReader::GetFileInfo() const
51 {
52 assert(IsDefined());
53
54 return FileInfo(path);
55 }
56
57 size_t
Read(void * data,size_t size)58 FileReader::Read(void *data, size_t size)
59 {
60 assert(IsDefined());
61
62 DWORD nbytes;
63 if (!ReadFile(handle, data, size, &nbytes, nullptr))
64 throw FormatLastError("Failed to read from %s",
65 path.ToUTF8().c_str());
66
67 return nbytes;
68 }
69
70 void
Seek(off_t offset)71 FileReader::Seek(off_t offset)
72 {
73 assert(IsDefined());
74
75 auto result = SetFilePointer(handle, offset, nullptr, FILE_BEGIN);
76 if (result == INVALID_SET_FILE_POINTER)
77 throw MakeLastError("Failed to seek");
78 }
79
80 void
Skip(off_t offset)81 FileReader::Skip(off_t offset)
82 {
83 assert(IsDefined());
84
85 auto result = SetFilePointer(handle, offset, nullptr, FILE_CURRENT);
86 if (result == INVALID_SET_FILE_POINTER)
87 throw MakeLastError("Failed to seek");
88 }
89
90 void
Close()91 FileReader::Close() noexcept
92 {
93 assert(IsDefined());
94
95 CloseHandle(handle);
96 }
97
98 #else
99
FileReader(Path _path)100 FileReader::FileReader(Path _path)
101 :path(_path), fd(OpenReadOnly(path.c_str()))
102 {
103 }
104
105 FileInfo
GetFileInfo() const106 FileReader::GetFileInfo() const
107 {
108 assert(IsDefined());
109
110 FileInfo info;
111 const bool success = fstat(fd.Get(), &info.st) == 0;
112 if (!success)
113 throw FormatErrno("Failed to access %s",
114 path.ToUTF8().c_str());
115
116 return info;
117 }
118
119 size_t
Read(void * data,size_t size)120 FileReader::Read(void *data, size_t size)
121 {
122 assert(IsDefined());
123
124 ssize_t nbytes = fd.Read(data, size);
125 if (nbytes < 0)
126 throw FormatErrno("Failed to read from %s", path.ToUTF8().c_str());
127
128 return nbytes;
129 }
130
131 void
Seek(off_t offset)132 FileReader::Seek(off_t offset)
133 {
134 assert(IsDefined());
135
136 auto result = fd.Seek(offset);
137 const bool success = result >= 0;
138 if (!success)
139 throw MakeErrno("Failed to seek");
140 }
141
142 void
Skip(off_t offset)143 FileReader::Skip(off_t offset)
144 {
145 assert(IsDefined());
146
147 auto result = fd.Skip(offset);
148 const bool success = result >= 0;
149 if (!success)
150 throw MakeErrno("Failed to seek");
151 }
152
153 void
Close()154 FileReader::Close() noexcept
155 {
156 assert(IsDefined());
157
158 fd.Close();
159 }
160
161 #endif
162