trunk/src/files.c

/***************************************
 $Header: /home/amb/CVS/routino/src/files.c,v 1.20 2010-07-12 17:59:41 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 <stdio.h>
#include <string.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <sys/types.h>

#include "files.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_RDWR|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);
}


/*++++++++++++++++++++++++++++++++++++++
  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);
}


/*++++++++++++++++++++++++++++++++++++++
  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 1.20 2010-07-12 17:59:41 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 <stdio.h>
28	#include <string.h>
29	#include <fcntl.h>
30	#include <errno.h>
31	#include <sys/stat.h>
32	#include <sys/mman.h>
33	#include <sys/types.h>
34
35	#include "files.h"
36
37
38	/+ A structure to contain the list of memory mapped files. +/
39	struct mmapinfo
40	{
41	const char filename; /+ The name of the file (the index of the list). +*/
42	int fd; /+ The file descriptor used when it was opened. +/
43	void address; /+ The address the file was mapped to. +*/
44	size_t length; /+ The length of the file. +/
45	};
46
47	/+ The list of memory mapped files. +/
48	static struct mmapinfo *mappedfiles;
49
50	/+ The number of mapped files. +/
51	static int nmappedfiles=0;
52
53
54	/*++++++++++++++++++++++++++++++++++++++
55	Return a filename composed of the dirname, prefix and filename.
56
57	char *FileName Returns an allocated filename.
58
59	const char *dirname The directory name.
60
61	const char *prefix The file prefix.
62
63	const char *name The filename.
64	++++++++++++++++++++++++++++++++++++++*/
65
66	char FileName(const char dirname,const char prefix, const char name)
67	{
68	char filename=(char)malloc((dirname?strlen(dirname):0)+1+(prefix?strlen(prefix):0)+1+strlen(name));
69
70	sprintf(filename,"%s%s%s%s%s",dirname?dirname:"",dirname?"/":"",prefix?prefix:"",prefix?"-":"",name);
71
72	return(filename);
73	}
74
75
76	/*++++++++++++++++++++++++++++++++++++++
77	Open a file and map it into memory.
78
79	void *MapFile Returns the address of the file or exits in case of an error.
80
81	const char *filename The name of the file to open.
82	++++++++++++++++++++++++++++++++++++++*/
83
84	void MapFile(const char filename)
85	{
86	int fd;
87	off_t size;
88	void *address;
89
90	/* Open the file and get its size */
91
92	fd=ReOpenFile(filename);
93
94	size=SizeFile(filename);
95
96	/* Map the file */
97
98	address=mmap(NULL,size,PROT_READ,MAP_SHARED,fd,0);
99
100	if(address==MAP_FAILED)
101	{
102	close(fd);
103
104	fprintf(stderr,"Cannot mmap file '%s' [%s].\n",filename,strerror(errno));
105	exit(EXIT_FAILURE);
106	}
107
108	mappedfiles=(struct mmapinfo)realloc((void)mappedfiles,(nmappedfiles+1)*sizeof(struct mmapinfo));
109
110	mappedfiles[nmappedfiles].filename=filename;
111	mappedfiles[nmappedfiles].fd=fd;
112	mappedfiles[nmappedfiles].address=address;
113	mappedfiles[nmappedfiles].length=size;
114
115	nmappedfiles++;
116
117	return(address);
118	}
119
120
121	/*++++++++++++++++++++++++++++++++++++++
122	Unmap a file.
123
124	void *UnmapFile Returns NULL (for similarity to the MapFile function).
125
126	const char *filename The name of the file when it was opened.
127	++++++++++++++++++++++++++++++++++++++*/
128
129	void UnmapFile(const char filename)
130	{
131	int i;
132
133	for(i=0;i<nmappedfiles;i++)
134	if(!strcmp(mappedfiles[i].filename,filename))
135	break;
136
137	if(i==nmappedfiles)
138	{
139	fprintf(stderr,"The file '%s' was not mapped using MapFile().\n",filename);
140	exit(EXIT_FAILURE);
141	}
142
143	/* Close the file */
144
145	close(mappedfiles[i].fd);
146
147	/* Unmap the file */
148
149	munmap(mappedfiles[i].address,mappedfiles[i].length);
150
151	/* Shuffle the list of files */
152
153	nmappedfiles--;
154
155	if(nmappedfiles>i)
156	memmove(&mappedfiles[i],&mappedfiles[i+1],(nmappedfiles-i)*sizeof(struct mmapinfo));
157
158	return(NULL);
159	}
160
161
162	/*++++++++++++++++++++++++++++++++++++++
163	Open a new file on disk for writing to.
164
165	int OpenFile Returns the file descriptor if OK or exits in case of an error.
166
167	const char *filename The name of the file to create.
168	++++++++++++++++++++++++++++++++++++++*/
169
170	int OpenFile(const char *filename)
171	{
172	int fd;
173
174	/* Open the file */
175
176	fd=open(filename,O_RDWR\|O_CREAT\|O_TRUNC,S_IRUSR\|S_IWUSR\|S_IRGRP\|S_IROTH);
177
178	if(fd<0)
179	{
180	fprintf(stderr,"Cannot open file '%s' for writing [%s].\n",filename,strerror(errno));
181	exit(EXIT_FAILURE);
182	}
183
184	return(fd);
185	}
186
187
188	/*++++++++++++++++++++++++++++++++++++++
189	Open a new file on disk for reading and appending.
190
191	int AppendFile Returns the file descriptor if OK or exits in case of an error.
192
193	const char *filename The name of the file to create.
194	++++++++++++++++++++++++++++++++++++++*/
195
196	int AppendFile(const char *filename)
197	{
198	int fd;
199
200	/* Open the file */
201
202	fd=open(filename,O_RDWR\|O_CREAT\|O_APPEND,S_IRUSR\|S_IWUSR\|S_IRGRP\|S_IROTH);
203
204	if(fd<0)
205	{
206	fprintf(stderr,"Cannot open file '%s' for appending [%s].\n",filename,strerror(errno));
207	exit(EXIT_FAILURE);
208	}
209
210	return(fd);
211	}
212
213
214	/*++++++++++++++++++++++++++++++++++++++
215	Open an existing file on disk for reading from.
216
217	int ReOpenFile Returns the file descriptor if OK or exits in case of an error.
218
219	const char *filename The name of the file to open.
220	++++++++++++++++++++++++++++++++++++++*/
221
222	int ReOpenFile(const char *filename)
223	{
224	int fd;
225
226	/* Open the file */
227
228	fd=open(filename,O_RDONLY);
229
230	if(fd<0)
231	{
232	fprintf(stderr,"Cannot open file '%s' for reading [%s].\n",filename,strerror(errno));
233	exit(EXIT_FAILURE);
234	}
235
236	return(fd);
237	}
238
239
240	/*++++++++++++++++++++++++++++++++++++++
241	Get the size of a file.
242
243	off_t SizeFile Returns the file size.
244
245	const char *filename The name of the file to check.
246	++++++++++++++++++++++++++++++++++++++*/
247
248	off_t SizeFile(const char *filename)
249	{
250	struct stat buf;
251
252	if(stat(filename,&buf))
253	{
254	fprintf(stderr,"Cannot stat file '%s' [%s].\n",filename,strerror(errno));
255	exit(EXIT_FAILURE);
256	}
257
258	return(buf.st_size);
259	}
260
261
262	/*++++++++++++++++++++++++++++++++++++++
263	Check if a file exists.
264
265	int ExistsFile Returns 1 if the file exists and 0 if not.
266
267	const char *filename The name of the file to check.
268	++++++++++++++++++++++++++++++++++++++*/
269
270	int ExistsFile(const char *filename)
271	{
272	struct stat buf;
273
274	if(stat(filename,&buf))
275	return(0);
276	else
277	return(1);
278	}
279
280
281	/*++++++++++++++++++++++++++++++++++++++
282	Close a file on disk.
283
284	int fd The file descriptor to close.
285	++++++++++++++++++++++++++++++++++++++*/
286
287	void CloseFile(int fd)
288	{
289	close(fd);
290	}
291
292
293	/*++++++++++++++++++++++++++++++++++++++
294	Delete a file from disk.
295
296	int DeleteFile Returns 0 if OK or something else in case of an error.
297
298	char *filename The name of the file to delete.
299	++++++++++++++++++++++++++++++++++++++*/
300
301	int DeleteFile(char *filename)
302	{
303	unlink(filename);
304
305	return(0);
306	}