trunk/src/files.c

/***************************************
 $Header: /home/amb/CVS/routino/src/files.c,v 1.18 2010-03-29 18:20:06 amb Exp $

 Functions to handle files.

 Part of the Routino routing software.
 ******************/ /******************
 This file Copyright 2008-2010 Andrew M. Bishop

 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU Affero General Public License as published by
 the Free Software Foundation, either version 3 of the License, or
 (at your option) any later version.

 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU Affero General Public License for more details.

 You should have received a copy of the GNU Affero General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 ***************************************/


#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <sys/types.h>

#include "functions.h"


/*+ A structure to contain the list of memory mapped files. +*/
struct mmapinfo
{
 const char  *filename;         /*+ The name of the file (the index of the list). +*/
       int    fd;               /*+ The file descriptor used when it was opened. +*/
       void  *address;          /*+ The address the file was mapped to. +*/
       size_t length;           /*+ The length of the file. +*/
};

/*+ The list of memory mapped files. +*/
static struct mmapinfo *mappedfiles;

/*+ The number of mapped files. +*/
static int nmappedfiles=0;


/*++++++++++++++++++++++++++++++++++++++
  Return a filename composed of the dirname, prefix and filename.

  char *FileName Returns an allocated filename.

  const char *dirname The directory name.

  const char *prefix The file prefix.

  const char *name The filename.
  ++++++++++++++++++++++++++++++++++++++*/

char *FileName(const char *dirname,const char *prefix, const char *name)
{
 char *filename=(char*)malloc((dirname?strlen(dirname):0)+1+(prefix?strlen(prefix):0)+1+strlen(name));

 sprintf(filename,"%s%s%s%s%s",dirname?dirname:"",dirname?"/":"",prefix?prefix:"",prefix?"-":"",name);

 return(filename);
}


/*++++++++++++++++++++++++++++++++++++++
  Open a file and map it into memory.

  void *MapFile Returns the address of the file or exits in case of an error.

  const char *filename The name of the file to open.
  ++++++++++++++++++++++++++++++++++++++*/

void *MapFile(const char *filename)
{
 int fd;
 off_t size;
 void *address;

 /* Open the file and get its size */

 fd=ReOpenFile(filename);

 size=SizeFile(filename);

 /* Map the file */

 address=mmap(NULL,size,PROT_READ,MAP_SHARED,fd,0);

 if(address==MAP_FAILED)
   {
    close(fd);

    fprintf(stderr,"Cannot mmap file '%s' [%s].\n",filename,strerror(errno));
    exit(EXIT_FAILURE);
   }

 mappedfiles=(struct mmapinfo*)realloc((void*)mappedfiles,(nmappedfiles+1)*sizeof(struct mmapinfo));

 mappedfiles[nmappedfiles].filename=filename;
 mappedfiles[nmappedfiles].fd=fd;
 mappedfiles[nmappedfiles].address=address;
 mappedfiles[nmappedfiles].length=size;

 nmappedfiles++;

 return(address);
}


/*++++++++++++++++++++++++++++++++++++++
  Unmap a file.

  void *UnmapFile Returns NULL (for similarity to the MapFile function).

  const char *filename The name of the file when it was opened.
  ++++++++++++++++++++++++++++++++++++++*/

void *UnmapFile(const char *filename)
{
 int i;

 for(i=0;i<nmappedfiles;i++)
    if(!strcmp(mappedfiles[i].filename,filename))
       break;

 if(i==nmappedfiles)
   {
    fprintf(stderr,"The file '%s' was not mapped using MapFile().\n",filename);
    exit(EXIT_FAILURE);
   }

 /* Close the file */

 close(mappedfiles[i].fd);

 /* Unmap the file */

 munmap(mappedfiles[i].address,mappedfiles[i].length);

 /* Shuffle the list of files */

 nmappedfiles--;

 if(nmappedfiles>i)
    memmove(&mappedfiles[i],&mappedfiles[i+1],(nmappedfiles-i)*sizeof(struct mmapinfo));

 return(NULL);
}


/*++++++++++++++++++++++++++++++++++++++
  Open a new file on disk for writing to.

  int OpenFile Returns the file descriptor if OK or exits in case of an error.

  const char *filename The name of the file to create.
  ++++++++++++++++++++++++++++++++++++++*/

int OpenFile(const char *filename)
{
 int fd;

 /* Open the file */

 fd=open(filename,O_WRONLY|O_CREAT|O_TRUNC,S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH);

 if(fd<0)
   {
    fprintf(stderr,"Cannot open file '%s' for writing [%s].\n",filename,strerror(errno));
    exit(EXIT_FAILURE);
   }

 return(fd);
}


/*++++++++++++++++++++++++++++++++++++++
  Open a new file on disk for reading and appending.

  int AppendFile Returns the file descriptor if OK or exits in case of an error.

  const char *filename The name of the file to create.
  ++++++++++++++++++++++++++++++++++++++*/

int AppendFile(const char *filename)
{
 int fd;

 /* Open the file */

 fd=open(filename,O_RDWR|O_CREAT|O_APPEND,S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH);

 if(fd<0)
   {
    fprintf(stderr,"Cannot open file '%s' for appending [%s].\n",filename,strerror(errno));
    exit(EXIT_FAILURE);
   }

 return(fd);
}


/*++++++++++++++++++++++++++++++++++++++
  Open an existing file on disk for reading from.

  int ReOpenFile Returns the file descriptor if OK or exits in case of an error.

  const char *filename The name of the file to open.
  ++++++++++++++++++++++++++++++++++++++*/

int ReOpenFile(const char *filename)
{
 int fd;

 /* Open the file */

 fd=open(filename,O_RDONLY);

 if(fd<0)
   {
    fprintf(stderr,"Cannot open file '%s' for reading [%s].\n",filename,strerror(errno));
    exit(EXIT_FAILURE);
   }

 return(fd);
}


/*++++++++++++++++++++++++++++++++++++++
  Write data to a file on disk.

  int WriteFile Returns 0 if OK or something else in case of an error.

  int fd The file descriptor to write to.

  const void *address The address of the data to be written from.

  size_t length The length of data to write.
  ++++++++++++++++++++++++++++++++++++++*/

int WriteFile(int fd,const void *address,size_t length)
{
 /* Write the data */

 if(write(fd,address,length)!=length)
    return(-1);

 return(0);
}


/*++++++++++++++++++++++++++++++++++++++
  Read data from a file on disk.

  int ReadFile Returns 0 if OK or something else in case of an error.

  int fd The file descriptor to read from.

  void *address The address of the data to be read into.

  size_t length The length of data to read.
  ++++++++++++++++++++++++++++++++++++++*/

int ReadFile(int fd,void *address,size_t length)
{
 /* Read the data */

 if(read(fd,address,length)!=length)
    return(-1);

 return(0);
}


/*++++++++++++++++++++++++++++++++++++++
  Get the size of a file.

  off_t SizeFile Returns the file size.

  const char *filename The name of the file to check.
  ++++++++++++++++++++++++++++++++++++++*/

off_t SizeFile(const char *filename)
{
 struct stat buf;

 if(stat(filename,&buf))
   {
    fprintf(stderr,"Cannot stat file '%s' [%s].\n",filename,strerror(errno));
    exit(EXIT_FAILURE);
   }

 return(buf.st_size);
}


/*++++++++++++++++++++++++++++++++++++++
  Check if a file exists.

  int ExistsFile Returns 1 if the file exists and 0 if not.

  const char *filename The name of the file to check.
  ++++++++++++++++++++++++++++++++++++++*/

int ExistsFile(const char *filename)
{
 struct stat buf;

 if(stat(filename,&buf))
    return(0);
 else
    return(1);
}


/*++++++++++++++++++++++++++++++++++++++
  Seek to a position in a file on disk.

  int SeekFile Returns 0 if OK or something else in case of an error.

  int fd The file descriptor to seek within.

  off_t position The position to seek to.
  ++++++++++++++++++++++++++++++++++++++*/

int SeekFile(int fd,off_t position)
{
 /* Seek the data */

 if(lseek(fd,position,SEEK_SET)!=position)
    return(-1);

 return(0);
}


/*++++++++++++++++++++++++++++++++++++++
  Close a file on disk.

  int fd The file descriptor to close.
  ++++++++++++++++++++++++++++++++++++++*/

void CloseFile(int fd)
{
 close(fd);
}


/*++++++++++++++++++++++++++++++++++++++
  Delete a file from disk.

  int DeleteFile Returns 0 if OK or something else in case of an error.

  char *filename The name of the file to delete.
  ++++++++++++++++++++++++++++++++++++++*/

int DeleteFile(char *filename)
{
 unlink(filename);

 return(0);
}
1	amb	2	/***************************************
2	amb	341	$Header: /home/amb/CVS/routino/src/files.c,v 1.18 2010-03-29 18:20:06 amb Exp $
3	amb	2
4	amb	326	Functions to handle files.
5	amb	151
6			Part of the Routino routing software.
7	amb	2	****************/ /****************
8	amb	326	This file Copyright 2008-2010 Andrew M. Bishop
9	amb	2
10	amb	151	This program is free software: you can redistribute it and/or modify
11			it under the terms of the GNU Affero General Public License as published by
12			the Free Software Foundation, either version 3 of the License, or
13			(at your option) any later version.
14
15			This program is distributed in the hope that it will be useful,
16			but WITHOUT ANY WARRANTY; without even the implied warranty of
17			MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18			GNU Affero General Public License for more details.
19
20			You should have received a copy of the GNU Affero General Public License
21			along with this program. If not, see <http://www.gnu.org/licenses/>.
22	amb	2	***************************************/
23
24
25			#include <unistd.h>
26			#include <stdlib.h>
27	amb	162	#include <string.h>
28	amb	2	#include <fcntl.h>
29	amb	330	#include <errno.h>
30	amb	2	#include <sys/stat.h>
31			#include <sys/mman.h>
32	amb	251	#include <sys/types.h>
33	amb	2
34			#include "functions.h"
35
36
37	amb	289	/+ A structure to contain the list of memory mapped files. +/
38	amb	248	struct mmapinfo
39			{
40	amb	289	const char filename; /+ The name of the file (the index of the list). +*/
41			int fd; /+ The file descriptor used when it was opened. +/
42			void address; /+ The address the file was mapped to. +*/
43			size_t length; /+ The length of the file. +/
44	amb	248	};
45
46	amb	289	/+ The list of memory mapped files. +/
47			static struct mmapinfo *mappedfiles;
48	amb	248
49	amb	289	/+ The number of mapped files. +/
50			static int nmappedfiles=0;
51	amb	248
52	amb	289
53	amb	2	/*++++++++++++++++++++++++++++++++++++++
54	amb	162	Return a filename composed of the dirname, prefix and filename.
55
56			char *FileName Returns an allocated filename.
57
58			const char *dirname The directory name.
59
60			const char *prefix The file prefix.
61
62			const char *name The filename.
63			++++++++++++++++++++++++++++++++++++++*/
64
65			char FileName(const char dirname,const char prefix, const char name)
66			{
67			char filename=(char)malloc((dirname?strlen(dirname):0)+1+(prefix?strlen(prefix):0)+1+strlen(name));
68
69			sprintf(filename,"%s%s%s%s%s",dirname?dirname:"",dirname?"/":"",prefix?prefix:"",prefix?"-":"",name);
70
71			return(filename);
72			}
73
74
75			/*++++++++++++++++++++++++++++++++++++++
76	amb	250	Open a file and map it into memory.
77	amb	2
78	amb	331	void *MapFile Returns the address of the file or exits in case of an error.
79	amb	2
80			const char *filename The name of the file to open.
81			++++++++++++++++++++++++++++++++++++++*/
82
83	amb	250	void MapFile(const char filename)
84	amb	2	{
85			int fd;
86	amb	331	off_t size;
87	amb	2	void *address;
88
89	amb	331	/* Open the file and get its size */
90	amb	2
91	amb	331	fd=ReOpenFile(filename);
92	amb	2
93	amb	331	size=SizeFile(filename);
94	amb	2
95			/* Map the file */
96
97	amb	331	address=mmap(NULL,size,PROT_READ,MAP_SHARED,fd,0);
98	amb	2
99	amb	245	if(address==MAP_FAILED)
100	amb	2	{
101			close(fd);
102	amb	177
103	amb	330	fprintf(stderr,"Cannot mmap file '%s' [%s].\n",filename,strerror(errno));
104	amb	177	exit(EXIT_FAILURE);
105	amb	2	}
106
107	amb	248	mappedfiles=(struct mmapinfo)realloc((void)mappedfiles,(nmappedfiles+1)*sizeof(struct mmapinfo));
108
109			mappedfiles[nmappedfiles].filename=filename;
110			mappedfiles[nmappedfiles].fd=fd;
111			mappedfiles[nmappedfiles].address=address;
112	amb	331	mappedfiles[nmappedfiles].length=size;
113	amb	248
114			nmappedfiles++;
115
116	amb	2	return(address);
117			}
118
119
120			/*++++++++++++++++++++++++++++++++++++++
121	amb	331	Unmap a file.
122	amb	2
123	amb	289	void *UnmapFile Returns NULL (for similarity to the MapFile function).
124	amb	255
125	amb	248	const char *filename The name of the file when it was opened.
126			++++++++++++++++++++++++++++++++++++++*/
127
128	amb	255	void UnmapFile(const char filename)
129	amb	248	{
130			int i;
131
132			for(i=0;i<nmappedfiles;i++)
133			if(!strcmp(mappedfiles[i].filename,filename))
134			break;
135
136			if(i==nmappedfiles)
137			{
138	amb	330	fprintf(stderr,"The file '%s' was not mapped using MapFile().\n",filename);
139	amb	248	exit(EXIT_FAILURE);
140			}
141
142			/* Close the file */
143
144			close(mappedfiles[i].fd);
145
146			/* Unmap the file */
147
148			munmap(mappedfiles[i].address,mappedfiles[i].length);
149
150			/* Shuffle the list of files */
151
152			nmappedfiles--;
153
154			if(nmappedfiles>i)
155			memmove(&mappedfiles[i],&mappedfiles[i+1],(nmappedfiles-i)*sizeof(struct mmapinfo));
156	amb	255
157			return(NULL);
158	amb	248	}
159
160
161			/*++++++++++++++++++++++++++++++++++++++
162			Open a new file on disk for writing to.
163
164	amb	331	int OpenFile Returns the file descriptor if OK or exits in case of an error.
165	amb	248
166	amb	97	const char *filename The name of the file to create.
167	amb	2	++++++++++++++++++++++++++++++++++++++*/
168
169	amb	97	int OpenFile(const char *filename)
170	amb	2	{
171	amb	97	int fd;
172	amb	2
173	amb	97	/* Open the file */
174	amb	2
175	amb	248	fd=open(filename,O_WRONLY\|O_CREAT\|O_TRUNC,S_IRUSR\|S_IWUSR\|S_IRGRP\|S_IROTH);
176	amb	2
177	amb	97	if(fd<0)
178	amb	177	{
179	amb	330	fprintf(stderr,"Cannot open file '%s' for writing [%s].\n",filename,strerror(errno));
180	amb	177	exit(EXIT_FAILURE);
181			}
182	amb	2
183	amb	97	return(fd);
184	amb	2	}
185
186
187			/*++++++++++++++++++++++++++++++++++++++
188	amb	326	Open a new file on disk for reading and appending.
189
190	amb	331	int AppendFile Returns the file descriptor if OK or exits in case of an error.
191	amb	326
192			const char *filename The name of the file to create.
193			++++++++++++++++++++++++++++++++++++++*/
194
195			int AppendFile(const char *filename)
196			{
197			int fd;
198
199			/* Open the file */
200
201			fd=open(filename,O_RDWR\|O_CREAT\|O_APPEND,S_IRUSR\|S_IWUSR\|S_IRGRP\|S_IROTH);
202
203			if(fd<0)
204			{
205	amb	330	fprintf(stderr,"Cannot open file '%s' for appending [%s].\n",filename,strerror(errno));
206	amb	326	exit(EXIT_FAILURE);
207			}
208
209			return(fd);
210			}
211
212
213			/*++++++++++++++++++++++++++++++++++++++
214	amb	251	Open an existing file on disk for reading from.
215
216	amb	331	int ReOpenFile Returns the file descriptor if OK or exits in case of an error.
217	amb	251
218			const char *filename The name of the file to open.
219			++++++++++++++++++++++++++++++++++++++*/
220
221			int ReOpenFile(const char *filename)
222			{
223			int fd;
224
225			/* Open the file */
226
227			fd=open(filename,O_RDONLY);
228
229			if(fd<0)
230			{
231	amb	330	fprintf(stderr,"Cannot open file '%s' for reading [%s].\n",filename,strerror(errno));
232	amb	251	exit(EXIT_FAILURE);
233			}
234
235			return(fd);
236			}
237
238
239			/*++++++++++++++++++++++++++++++++++++++
240	amb	97	Write data to a file on disk.
241	amb	2
242			int WriteFile Returns 0 if OK or something else in case of an error.
243
244	amb	97	int fd The file descriptor to write to.
245	amb	2
246	amb	259	const void *address The address of the data to be written from.
247	amb	2
248			size_t length The length of data to write.
249			++++++++++++++++++++++++++++++++++++++*/
250
251	amb	259	int WriteFile(int fd,const void *address,size_t length)
252	amb	2	{
253			/* Write the data */
254
255			if(write(fd,address,length)!=length)
256			return(-1);
257
258			return(0);
259			}
260	amb	87
261
262			/*++++++++++++++++++++++++++++++++++++++
263	amb	251	Read data from a file on disk.
264
265			int ReadFile Returns 0 if OK or something else in case of an error.
266
267			int fd The file descriptor to read from.
268
269			void *address The address of the data to be read into.
270
271			size_t length The length of data to read.
272			++++++++++++++++++++++++++++++++++++++*/
273
274			int ReadFile(int fd,void *address,size_t length)
275			{
276			/* Read the data */
277
278			if(read(fd,address,length)!=length)
279			return(-1);
280
281			return(0);
282			}
283
284
285			/*++++++++++++++++++++++++++++++++++++++
286	amb	331	Get the size of a file.
287
288			off_t SizeFile Returns the file size.
289
290			const char *filename The name of the file to check.
291			++++++++++++++++++++++++++++++++++++++*/
292
293			off_t SizeFile(const char *filename)
294			{
295			struct stat buf;
296
297			if(stat(filename,&buf))
298			{
299			fprintf(stderr,"Cannot stat file '%s' [%s].\n",filename,strerror(errno));
300			exit(EXIT_FAILURE);
301			}
302
303			return(buf.st_size);
304			}
305
306
307			/*++++++++++++++++++++++++++++++++++++++
308	amb	341	Check if a file exists.
309
310			int ExistsFile Returns 1 if the file exists and 0 if not.
311
312			const char *filename The name of the file to check.
313			++++++++++++++++++++++++++++++++++++++*/
314
315			int ExistsFile(const char *filename)
316			{
317			struct stat buf;
318
319			if(stat(filename,&buf))
320			return(0);
321			else
322			return(1);
323			}
324
325
326			/*++++++++++++++++++++++++++++++++++++++
327	amb	251	Seek to a position in a file on disk.
328
329			int SeekFile Returns 0 if OK or something else in case of an error.
330
331			int fd The file descriptor to seek within.
332
333	amb	331	off_t position The position to seek to.
334	amb	251	++++++++++++++++++++++++++++++++++++++*/
335
336	amb	331	int SeekFile(int fd,off_t position)
337	amb	251	{
338			/* Seek the data */
339
340			if(lseek(fd,position,SEEK_SET)!=position)
341			return(-1);
342
343			return(0);
344			}
345
346
347			/*++++++++++++++++++++++++++++++++++++++
348	amb	97	Close a file on disk.
349	amb	87
350	amb	97	int fd The file descriptor to close.
351	amb	87	++++++++++++++++++++++++++++++++++++++*/
352
353	amb	97	void CloseFile(int fd)
354	amb	87	{
355	amb	97	close(fd);
356	amb	87	}
357	amb	251
358
359			/*++++++++++++++++++++++++++++++++++++++
360			Delete a file from disk.
361
362			int DeleteFile Returns 0 if OK or something else in case of an error.
363
364			char *filename The name of the file to delete.
365			++++++++++++++++++++++++++++++++++++++*/
366
367			int DeleteFile(char *filename)
368			{
369			unlink(filename);
370
371			return(0);
372			}