trunk/src/files.c

/***************************************
 $Header: /home/amb/CVS/routino/src/files.c,v 1.11 2009-09-05 09:36:57 amb Exp $

 Functions to map a file into memory.

 Part of the Routino routing software.
 ******************/ /******************
 This file Copyright 2008,2009 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 <sys/stat.h>
#include <sys/mman.h>
#include <sys/types.h>

#include "functions.h"


struct mmapinfo
{
 const char  *filename;
       int    fd;
       void  *address;
       size_t length;
};

struct mmapinfo *mappedfiles;
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.

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

void *MapFile(const char *filename)
{
 int fd;
 struct stat buf;
 void *address;

 /* Open the file */

 fd=open(filename,O_RDONLY);

 if(fd<0)
   {
    fprintf(stderr,"Cannot open file '%s' to read.\n",filename);
    exit(EXIT_FAILURE);
   }

 /* Get the length of the file */

 if(fstat(fd,&buf))
   {
    close(fd);

    fprintf(stderr,"Cannot stat file '%s'.\n",filename);
    exit(EXIT_FAILURE);
   }

 /* Map the file */

 address=mmap(NULL,buf.st_size,PROT_READ,MAP_SHARED,fd,0);

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

    fprintf(stderr,"Cannot mmap file '%s'.\n",filename);
    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=buf.st_size;

 nmappedfiles++;

 return(address);
}


/*++++++++++++++++++++++++++++++++++++++
  Unmap a file and optionally delete it.

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

  int delete If set then delete the file.
  ++++++++++++++++++++++++++++++++++++++*/

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

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

 if(i==nmappedfiles)
   {
    fprintf(stderr,"Cannot find file '%s' to unmap.\n",filename);
    exit(EXIT_FAILURE);
   }

 /* Close the file */

 close(mappedfiles[i].fd);

 /* Unmap the file */

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

 /* Delete the file */

 if(delete)
    unlink(filename);

 /* Shuffle the list of files */

 nmappedfiles--;

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


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

  int OpenFile Returns the file descriptor if OK or something negative 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' to write.\n",filename);
    exit(EXIT_FAILURE);
   }

 return(fd);
}


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

  int OpenFile Returns the file descriptor if OK or something negative 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' to read.\n",filename);
    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.

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

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

int WriteFile(int fd,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);
}


/*++++++++++++++++++++++++++++++++++++++
  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.

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

int SeekFile(int fd,size_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 1.11 2009-09-05 09:36:57 amb Exp $
3
4	Functions to map a file into memory.
5
6	Part of the Routino routing software.
7	****************/ /****************
8	This file Copyright 2008,2009 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 <sys/stat.h>
30	#include <sys/mman.h>
31	#include <sys/types.h>
32
33	#include "functions.h"
34
35
36	struct mmapinfo
37	{
38	const char *filename;
39	int fd;
40	void *address;
41	size_t length;
42	};
43
44	struct mmapinfo *mappedfiles;
45	int nmappedfiles=0;
46
47
48	/*++++++++++++++++++++++++++++++++++++++
49	Return a filename composed of the dirname, prefix and filename.
50
51	char *FileName Returns an allocated filename.
52
53	const char *dirname The directory name.
54
55	const char *prefix The file prefix.
56
57	const char *name The filename.
58	++++++++++++++++++++++++++++++++++++++*/
59
60	char FileName(const char dirname,const char prefix, const char name)
61	{
62	char filename=(char)malloc((dirname?strlen(dirname):0)+1+(prefix?strlen(prefix):0)+1+strlen(name));
63
64	sprintf(filename,"%s%s%s%s%s",dirname?dirname:"",dirname?"/":"",prefix?prefix:"",prefix?"-":"",name);
65
66	return(filename);
67	}
68
69
70	/*++++++++++++++++++++++++++++++++++++++
71	Open a file and map it into memory.
72
73	void *MapFile Returns the address of the file.
74
75	const char *filename The name of the file to open.
76	++++++++++++++++++++++++++++++++++++++*/
77
78	void MapFile(const char filename)
79	{
80	int fd;
81	struct stat buf;
82	void *address;
83
84	/* Open the file */
85
86	fd=open(filename,O_RDONLY);
87
88	if(fd<0)
89	{
90	fprintf(stderr,"Cannot open file '%s' to read.\n",filename);
91	exit(EXIT_FAILURE);
92	}
93
94	/* Get the length of the file */
95
96	if(fstat(fd,&buf))
97	{
98	close(fd);
99
100	fprintf(stderr,"Cannot stat file '%s'.\n",filename);
101	exit(EXIT_FAILURE);
102	}
103
104	/* Map the file */
105
106	address=mmap(NULL,buf.st_size,PROT_READ,MAP_SHARED,fd,0);
107
108	if(address==MAP_FAILED)
109	{
110	close(fd);
111
112	fprintf(stderr,"Cannot mmap file '%s'.\n",filename);
113	exit(EXIT_FAILURE);
114	}
115
116	mappedfiles=(struct mmapinfo)realloc((void)mappedfiles,(nmappedfiles+1)*sizeof(struct mmapinfo));
117
118	mappedfiles[nmappedfiles].filename=filename;
119	mappedfiles[nmappedfiles].fd=fd;
120	mappedfiles[nmappedfiles].address=address;
121	mappedfiles[nmappedfiles].length=buf.st_size;
122
123	nmappedfiles++;
124
125	return(address);
126	}
127
128
129	/*++++++++++++++++++++++++++++++++++++++
130	Unmap a file and optionally delete it.
131
132	const char *filename The name of the file when it was opened.
133
134	int delete If set then delete the file.
135	++++++++++++++++++++++++++++++++++++++*/
136
137	void UnmapFile(const char *filename,int delete)
138	{
139	int i;
140
141	for(i=0;i<nmappedfiles;i++)
142	if(!strcmp(mappedfiles[i].filename,filename))
143	break;
144
145	if(i==nmappedfiles)
146	{
147	fprintf(stderr,"Cannot find file '%s' to unmap.\n",filename);
148	exit(EXIT_FAILURE);
149	}
150
151	/* Close the file */
152
153	close(mappedfiles[i].fd);
154
155	/* Unmap the file */
156
157	munmap(mappedfiles[i].address,mappedfiles[i].length);
158
159	/* Delete the file */
160
161	if(delete)
162	unlink(filename);
163
164	/* Shuffle the list of files */
165
166	nmappedfiles--;
167
168	if(nmappedfiles>i)
169	memmove(&mappedfiles[i],&mappedfiles[i+1],(nmappedfiles-i)*sizeof(struct mmapinfo));
170	}
171
172
173	/*++++++++++++++++++++++++++++++++++++++
174	Open a new file on disk for writing to.
175
176	int OpenFile Returns the file descriptor if OK or something negative in case of an error.
177
178	const char *filename The name of the file to create.
179	++++++++++++++++++++++++++++++++++++++*/
180
181	int OpenFile(const char *filename)
182	{
183	int fd;
184
185	/* Open the file */
186
187	fd=open(filename,O_WRONLY\|O_CREAT\|O_TRUNC,S_IRUSR\|S_IWUSR\|S_IRGRP\|S_IROTH);
188
189	if(fd<0)
190	{
191	fprintf(stderr,"Cannot open file '%s' to write.\n",filename);
192	exit(EXIT_FAILURE);
193	}
194
195	return(fd);
196	}
197
198
199	/*++++++++++++++++++++++++++++++++++++++
200	Open an existing file on disk for reading from.
201
202	int OpenFile Returns the file descriptor if OK or something negative in case of an error.
203
204	const char *filename The name of the file to open.
205	++++++++++++++++++++++++++++++++++++++*/
206
207	int ReOpenFile(const char *filename)
208	{
209	int fd;
210
211	/* Open the file */
212
213	fd=open(filename,O_RDONLY);
214
215	if(fd<0)
216	{
217	fprintf(stderr,"Cannot open file '%s' to read.\n",filename);
218	exit(EXIT_FAILURE);
219	}
220
221	return(fd);
222	}
223
224
225	/*++++++++++++++++++++++++++++++++++++++
226	Write data to a file on disk.
227
228	int WriteFile Returns 0 if OK or something else in case of an error.
229
230	int fd The file descriptor to write to.
231
232	void *address The address of the data to be written from.
233
234	size_t length The length of data to write.
235	++++++++++++++++++++++++++++++++++++++*/
236
237	int WriteFile(int fd,void *address,size_t length)
238	{
239	/* Write the data */
240
241	if(write(fd,address,length)!=length)
242	return(-1);
243
244	return(0);
245	}
246
247
248	/*++++++++++++++++++++++++++++++++++++++
249	Read data from a file on disk.
250
251	int ReadFile Returns 0 if OK or something else in case of an error.
252
253	int fd The file descriptor to read from.
254
255	void *address The address of the data to be read into.
256
257	size_t length The length of data to read.
258	++++++++++++++++++++++++++++++++++++++*/
259
260	int ReadFile(int fd,void *address,size_t length)
261	{
262	/* Read the data */
263
264	if(read(fd,address,length)!=length)
265	return(-1);
266
267	return(0);
268	}
269
270
271	/*++++++++++++++++++++++++++++++++++++++
272	Seek to a position in a file on disk.
273
274	int SeekFile Returns 0 if OK or something else in case of an error.
275
276	int fd The file descriptor to seek within.
277
278	size_t position The position to seek to.
279	++++++++++++++++++++++++++++++++++++++*/
280
281	int SeekFile(int fd,size_t position)
282	{
283	/* Seek the data */
284
285	if(lseek(fd,position,SEEK_SET)!=position)
286	return(-1);
287
288	return(0);
289	}
290
291
292	/*++++++++++++++++++++++++++++++++++++++
293	Close a file on disk.
294
295	int fd The file descriptor to close.
296	++++++++++++++++++++++++++++++++++++++*/
297
298	void CloseFile(int fd)
299	{
300	close(fd);
301	}
302
303
304	/*++++++++++++++++++++++++++++++++++++++
305	Delete a file from disk.
306
307	int DeleteFile Returns 0 if OK or something else in case of an error.
308
309	char *filename The name of the file to delete.
310	++++++++++++++++++++++++++++++++++++++*/
311
312	int DeleteFile(char *filename)
313	{
314	unlink(filename);
315
316	return(0);
317	}