trunk/src/files.c

/***************************************
 $Header: /home/amb/CVS/routino/src/files.c,v 1.15 2010-03-19 19:47:09 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 <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.

  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.

  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,"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);

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

  int AppendFile 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 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' to read and append.\n",filename);
    exit(EXIT_FAILURE);
   }

 return(fd);
}


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

  int ReOpenFile 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.

  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);
}


/*++++++++++++++++++++++++++++++++++++++
  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 1.15 2010-03-19 19:47:09 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 <sys/stat.h>
30	#include <sys/mman.h>
31	#include <sys/types.h>
32
33	#include "functions.h"
34
35
36	/+ A structure to contain the list of memory mapped files. +/
37	struct mmapinfo
38	{
39	const char filename; /+ The name of the file (the index of the list). +*/
40	int fd; /+ The file descriptor used when it was opened. +/
41	void address; /+ The address the file was mapped to. +*/
42	size_t length; /+ The length of the file. +/
43	};
44
45	/+ The list of memory mapped files. +/
46	static struct mmapinfo *mappedfiles;
47
48	/+ The number of mapped files. +/
49	static int nmappedfiles=0;
50
51
52	/*++++++++++++++++++++++++++++++++++++++
53	Return a filename composed of the dirname, prefix and filename.
54
55	char *FileName Returns an allocated filename.
56
57	const char *dirname The directory name.
58
59	const char *prefix The file prefix.
60
61	const char *name The filename.
62	++++++++++++++++++++++++++++++++++++++*/
63
64	char FileName(const char dirname,const char prefix, const char name)
65	{
66	char filename=(char)malloc((dirname?strlen(dirname):0)+1+(prefix?strlen(prefix):0)+1+strlen(name));
67
68	sprintf(filename,"%s%s%s%s%s",dirname?dirname:"",dirname?"/":"",prefix?prefix:"",prefix?"-":"",name);
69
70	return(filename);
71	}
72
73
74	/*++++++++++++++++++++++++++++++++++++++
75	Open a file and map it into memory.
76
77	void *MapFile Returns the address of the file.
78
79	const char *filename The name of the file to open.
80	++++++++++++++++++++++++++++++++++++++*/
81
82	void MapFile(const char filename)
83	{
84	int fd;
85	struct stat buf;
86	void *address;
87
88	/* Open the file */
89
90	fd=open(filename,O_RDONLY);
91
92	if(fd<0)
93	{
94	fprintf(stderr,"Cannot open file '%s' to read.\n",filename);
95	exit(EXIT_FAILURE);
96	}
97
98	/* Get the length of the file */
99
100	if(fstat(fd,&buf))
101	{
102	close(fd);
103
104	fprintf(stderr,"Cannot stat file '%s'.\n",filename);
105	exit(EXIT_FAILURE);
106	}
107
108	/* Map the file */
109
110	address=mmap(NULL,buf.st_size,PROT_READ,MAP_SHARED,fd,0);
111
112	if(address==MAP_FAILED)
113	{
114	close(fd);
115
116	fprintf(stderr,"Cannot mmap file '%s'.\n",filename);
117	exit(EXIT_FAILURE);
118	}
119
120	mappedfiles=(struct mmapinfo)realloc((void)mappedfiles,(nmappedfiles+1)*sizeof(struct mmapinfo));
121
122	mappedfiles[nmappedfiles].filename=filename;
123	mappedfiles[nmappedfiles].fd=fd;
124	mappedfiles[nmappedfiles].address=address;
125	mappedfiles[nmappedfiles].length=buf.st_size;
126
127	nmappedfiles++;
128
129	return(address);
130	}
131
132
133	/*++++++++++++++++++++++++++++++++++++++
134	Unmap a file and optionally delete it.
135
136	void *UnmapFile Returns NULL (for similarity to the MapFile function).
137
138	const char *filename The name of the file when it was opened.
139	++++++++++++++++++++++++++++++++++++++*/
140
141	void UnmapFile(const char filename)
142	{
143	int i;
144
145	for(i=0;i<nmappedfiles;i++)
146	if(!strcmp(mappedfiles[i].filename,filename))
147	break;
148
149	if(i==nmappedfiles)
150	{
151	fprintf(stderr,"Cannot find file '%s' to unmap.\n",filename);
152	exit(EXIT_FAILURE);
153	}
154
155	/* Close the file */
156
157	close(mappedfiles[i].fd);
158
159	/* Unmap the file */
160
161	munmap(mappedfiles[i].address,mappedfiles[i].length);
162
163	/* Shuffle the list of files */
164
165	nmappedfiles--;
166
167	if(nmappedfiles>i)
168	memmove(&mappedfiles[i],&mappedfiles[i+1],(nmappedfiles-i)*sizeof(struct mmapinfo));
169
170	return(NULL);
171	}
172
173
174	/*++++++++++++++++++++++++++++++++++++++
175	Open a new file on disk for writing to.
176
177	int OpenFile Returns the file descriptor if OK or something negative in case of an error.
178
179	const char *filename The name of the file to create.
180	++++++++++++++++++++++++++++++++++++++*/
181
182	int OpenFile(const char *filename)
183	{
184	int fd;
185
186	/* Open the file */
187
188	fd=open(filename,O_WRONLY\|O_CREAT\|O_TRUNC,S_IRUSR\|S_IWUSR\|S_IRGRP\|S_IROTH);
189
190	if(fd<0)
191	{
192	fprintf(stderr,"Cannot open file '%s' to write.\n",filename);
193	exit(EXIT_FAILURE);
194	}
195
196	return(fd);
197	}
198
199
200	/*++++++++++++++++++++++++++++++++++++++
201	Open a new file on disk for reading and appending.
202
203	int AppendFile Returns the file descriptor if OK or something negative in case of an error.
204
205	const char *filename The name of the file to create.
206	++++++++++++++++++++++++++++++++++++++*/
207
208	int AppendFile(const char *filename)
209	{
210	int fd;
211
212	/* Open the file */
213
214	fd=open(filename,O_RDWR\|O_CREAT\|O_APPEND,S_IRUSR\|S_IWUSR\|S_IRGRP\|S_IROTH);
215
216	if(fd<0)
217	{
218	fprintf(stderr,"Cannot open file '%s' to read and append.\n",filename);
219	exit(EXIT_FAILURE);
220	}
221
222	return(fd);
223	}
224
225
226	/*++++++++++++++++++++++++++++++++++++++
227	Open an existing file on disk for reading from.
228
229	int ReOpenFile Returns the file descriptor if OK or something negative in case of an error.
230
231	const char *filename The name of the file to open.
232	++++++++++++++++++++++++++++++++++++++*/
233
234	int ReOpenFile(const char *filename)
235	{
236	int fd;
237
238	/* Open the file */
239
240	fd=open(filename,O_RDONLY);
241
242	if(fd<0)
243	{
244	fprintf(stderr,"Cannot open file '%s' to read.\n",filename);
245	exit(EXIT_FAILURE);
246	}
247
248	return(fd);
249	}
250
251
252	/*++++++++++++++++++++++++++++++++++++++
253	Write data to a file on disk.
254
255	int WriteFile Returns 0 if OK or something else in case of an error.
256
257	int fd The file descriptor to write to.
258
259	const void *address The address of the data to be written from.
260
261	size_t length The length of data to write.
262	++++++++++++++++++++++++++++++++++++++*/
263
264	int WriteFile(int fd,const void *address,size_t length)
265	{
266	/* Write the data */
267
268	if(write(fd,address,length)!=length)
269	return(-1);
270
271	return(0);
272	}
273
274
275	/*++++++++++++++++++++++++++++++++++++++
276	Read data from a file on disk.
277
278	int ReadFile Returns 0 if OK or something else in case of an error.
279
280	int fd The file descriptor to read from.
281
282	void *address The address of the data to be read into.
283
284	size_t length The length of data to read.
285	++++++++++++++++++++++++++++++++++++++*/
286
287	int ReadFile(int fd,void *address,size_t length)
288	{
289	/* Read the data */
290
291	if(read(fd,address,length)!=length)
292	return(-1);
293
294	return(0);
295	}
296
297
298	/*++++++++++++++++++++++++++++++++++++++
299	Seek to a position in a file on disk.
300
301	int SeekFile Returns 0 if OK or something else in case of an error.
302
303	int fd The file descriptor to seek within.
304
305	size_t position The position to seek to.
306	++++++++++++++++++++++++++++++++++++++*/
307
308	int SeekFile(int fd,size_t position)
309	{
310	/* Seek the data */
311
312	if(lseek(fd,position,SEEK_SET)!=position)
313	return(-1);
314
315	return(0);
316	}
317
318
319	/*++++++++++++++++++++++++++++++++++++++
320	Close a file on disk.
321
322	int fd The file descriptor to close.
323	++++++++++++++++++++++++++++++++++++++*/
324
325	void CloseFile(int fd)
326	{
327	close(fd);
328	}
329
330
331	/*++++++++++++++++++++++++++++++++++++++
332	Delete a file from disk.
333
334	int DeleteFile Returns 0 if OK or something else in case of an error.
335
336	char *filename The name of the file to delete.
337	++++++++++++++++++++++++++++++++++++++*/
338
339	int DeleteFile(char *filename)
340	{
341	unlink(filename);
342
343	return(0);
344	}