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	/***************************************
2	$Header: /home/amb/CVS/routino/src/files.c,v 1.18 2010-03-29 18:20:06 amb Exp $
3
4	Functions to handle files.
5
6	Part of the Routino routing software.
7	****************/ /****************
8	This file Copyright 2008-2010 Andrew M. Bishop
9
10	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	***************************************/
23
24
25	#include <unistd.h>
26	#include <stdlib.h>
27	#include <string.h>
28	#include <fcntl.h>
29	#include <errno.h>
30	#include <sys/stat.h>
31	#include <sys/mman.h>
32	#include <sys/types.h>
33
34	#include "functions.h"
35
36
37	/+ A structure to contain the list of memory mapped files. +/
38	struct mmapinfo
39	{
40	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	};
45
46	/+ The list of memory mapped files. +/
47	static struct mmapinfo *mappedfiles;
48
49	/+ The number of mapped files. +/
50	static int nmappedfiles=0;
51
52
53	/*++++++++++++++++++++++++++++++++++++++
54	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	Open a file and map it into memory.
77
78	void *MapFile Returns the address of the file or exits in case of an error.
79
80	const char *filename The name of the file to open.
81	++++++++++++++++++++++++++++++++++++++*/
82
83	void MapFile(const char filename)
84	{
85	int fd;
86	off_t size;
87	void *address;
88
89	/* Open the file and get its size */
90
91	fd=ReOpenFile(filename);
92
93	size=SizeFile(filename);
94
95	/* Map the file */
96
97	address=mmap(NULL,size,PROT_READ,MAP_SHARED,fd,0);
98
99	if(address==MAP_FAILED)
100	{
101	close(fd);
102
103	fprintf(stderr,"Cannot mmap file '%s' [%s].\n",filename,strerror(errno));
104	exit(EXIT_FAILURE);
105	}
106
107	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	mappedfiles[nmappedfiles].length=size;
113
114	nmappedfiles++;
115
116	return(address);
117	}
118
119
120	/*++++++++++++++++++++++++++++++++++++++
121	Unmap a file.
122
123	void *UnmapFile Returns NULL (for similarity to the MapFile function).
124
125	const char *filename The name of the file when it was opened.
126	++++++++++++++++++++++++++++++++++++++*/
127
128	void UnmapFile(const char filename)
129	{
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	fprintf(stderr,"The file '%s' was not mapped using MapFile().\n",filename);
139	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
157	return(NULL);
158	}
159
160
161	/*++++++++++++++++++++++++++++++++++++++
162	Open a new file on disk for writing to.
163
164	int OpenFile Returns the file descriptor if OK or exits in case of an error.
165
166	const char *filename The name of the file to create.
167	++++++++++++++++++++++++++++++++++++++*/
168
169	int OpenFile(const char *filename)
170	{
171	int fd;
172
173	/* Open the file */
174
175	fd=open(filename,O_WRONLY\|O_CREAT\|O_TRUNC,S_IRUSR\|S_IWUSR\|S_IRGRP\|S_IROTH);
176
177	if(fd<0)
178	{
179	fprintf(stderr,"Cannot open file '%s' for writing [%s].\n",filename,strerror(errno));
180	exit(EXIT_FAILURE);
181	}
182
183	return(fd);
184	}
185
186
187	/*++++++++++++++++++++++++++++++++++++++
188	Open a new file on disk for reading and appending.
189
190	int AppendFile Returns the file descriptor if OK or exits in case of an error.
191
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	fprintf(stderr,"Cannot open file '%s' for appending [%s].\n",filename,strerror(errno));
206	exit(EXIT_FAILURE);
207	}
208
209	return(fd);
210	}
211
212
213	/*++++++++++++++++++++++++++++++++++++++
214	Open an existing file on disk for reading from.
215
216	int ReOpenFile Returns the file descriptor if OK or exits in case of an error.
217
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	fprintf(stderr,"Cannot open file '%s' for reading [%s].\n",filename,strerror(errno));
232	exit(EXIT_FAILURE);
233	}
234
235	return(fd);
236	}
237
238
239	/*++++++++++++++++++++++++++++++++++++++
240	Write data to a file on disk.
241
242	int WriteFile Returns 0 if OK or something else in case of an error.
243
244	int fd The file descriptor to write to.
245
246	const void *address The address of the data to be written from.
247
248	size_t length The length of data to write.
249	++++++++++++++++++++++++++++++++++++++*/
250
251	int WriteFile(int fd,const void *address,size_t length)
252	{
253	/* Write the data */
254
255	if(write(fd,address,length)!=length)
256	return(-1);
257
258	return(0);
259	}
260
261
262	/*++++++++++++++++++++++++++++++++++++++
263	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	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	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	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	off_t position The position to seek to.
334	++++++++++++++++++++++++++++++++++++++*/
335
336	int SeekFile(int fd,off_t position)
337	{
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	Close a file on disk.
349
350	int fd The file descriptor to close.
351	++++++++++++++++++++++++++++++++++++++*/
352
353	void CloseFile(int fd)
354	{
355	close(fd);
356	}
357
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	}