3 This file is part of libmspio
4 Copyright © 2007 Mikko Rasa, Mikkosoft Productions
5 Distributed under the LGPL
12 #include <msp/strings/formatter.h>
22 Creates a new file object and opens it. If the
23 create flag is true and write access is requested and the file does exist, it
24 is created. Otherwise a missing file is an error.
26 @param fn Name of the file to open
28 @param cm Flags controlling creation of a new file
30 File::File(const string &fn, Mode m, CreateMode cm)
33 throw InvalidParameterValue("Invalid read/write mode");
34 if(cm&~(C_CREATE|C_TRUNCATE))
35 throw InvalidParameterValue("Invalid create mode");
41 int create_flags=OPEN_EXISTING;
49 switch(static_cast<int>(cm))
51 case C_NONE: create_flags=OPEN_EXISTING; break;
52 case C_CREATE: create_flags=OPEN_ALWAYS; break;
53 case C_TRUNCATE: create_flags=TRUNCATE_EXISTING; break;
54 case C_CREATE+C_TRUNCATE: create_flags=CREATE_ALWAYS; break;
58 handle=CreateFile(fn.c_str(), flags, 0, 0, create_flags, FILE_ATTRIBUTE_NORMAL, 0);
59 if(handle==INVALID_HANDLE_VALUE)
60 throw SystemError(format("Can't open file '%s'", fn), GetLastError());
65 case M_READ: flags|=O_RDONLY; break;
66 case M_WRITE: flags|=O_WRONLY; break;
67 case M_RDWR: flags|=O_RDWR; break;
83 handle=::open(fn.c_str(), flags, 0666);
88 throw FileNotFound("Can't find file "+fn, fn);
90 throw SystemError(format("Can't open file '%s'", fn), err);
98 Closes the file. Any attempt to access the file after this will cause an
99 exception to be thrown.
103 if(handle==MSP_IO_INVALID_HANDLE)
108 signal_closing.emit();
116 handle=MSP_IO_INVALID_HANDLE;
117 signal_closed.emit();
121 Sets the blocking state of the file. If blocking is disabled, all operations
122 will return immediately, even if they can't be fully completed.
124 void File::set_block(bool b)
126 check_access(M_NONE);
128 mode=(mode&~M_NONBLOCK);
130 mode=(mode|M_NONBLOCK);
132 int flags=fcntl(handle, F_GETFD);
133 fcntl(handle, F_SETFL, (flags&O_NONBLOCK)|(b?0:O_NONBLOCK));
138 Seeks the file to the given byte offset.
140 @param off Offset in bytes
143 @return The resulting offset
145 int File::seek(int off, SeekType st)
147 check_access(M_NONE);
149 int type=sys_seek_type(st);
151 DWORD ret=SetFilePointer(handle, off, 0, type);
152 if(ret==INVALID_SET_FILE_POINTER)
153 throw SystemError("Seek failed", GetLastError());
155 int ret=lseek(handle, off, type);
157 throw SystemError("Seek failed", errno);
166 Returns the current read/write offset of the file.
168 int File::tell() const
170 check_access(M_NONE);
173 DWORD ret=SetFilePointer(handle, 0, 0, FILE_CURRENT);
174 if(ret==INVALID_SET_FILE_POINTER)
175 throw SystemError("Tell failed", GetLastError());
177 int ret=lseek(handle, 0, SEEK_CUR);
179 throw SystemError("Tell failed", errno);
190 void File::check_access(Mode m) const
192 if(handle==MSP_IO_INVALID_HANDLE)
193 throw InvalidState("File is not open");
194 if(m==M_READ && !(mode&M_READ))
195 throw InvalidState("File is not readable");
196 if(m==M_WRITE && !(mode&M_WRITE))
197 throw InvalidState("File is not writable");
201 Writes data from a buffer to the file.
203 @param buf Buffer to write from.
204 @param size Length of data to write.
206 @return The number of bytes written
208 unsigned File::do_write(const char *buf, unsigned size)
210 check_access(M_WRITE);
219 if(WriteFile(handle, buf, size, &ret, 0)==0)
220 throw SystemError("Writing to file failed", GetLastError());
222 int ret=::write(handle, buf, size);
228 throw SystemError("Writing to file failed", errno);
243 Reads data from the file.
245 @param buf Buffer to read data into.
246 @param size Maximum size of data to read.
248 @return The number of bytes read, possibly zero
250 unsigned File::do_read(char *buf, unsigned size)
252 check_access(M_READ);
259 if(ReadFile(handle, buf, size, &ret, 0)==0)
260 throw SystemError("Reading from file failed", GetLastError());
262 int ret=::read(handle, buf, size);
268 throw SystemError("Reading from file failed", errno);
275 signal_end_of_file.emit();