trunk/src/files.c

/***************************************
 $Header: /home/amb/CVS/routino/src/files.c,v 1.12 2009-09-06 15:50:15 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.

  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 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	amb	2	/***************************************
2	amb	255	$Header: /home/amb/CVS/routino/src/files.c,v 1.12 2009-09-06 15:50:15 amb Exp $
3	amb	2
4			Functions to map a file into memory.
5	amb	151
6			Part of the Routino routing software.
7	amb	2	****************/ /****************
8	amb	151	This file Copyright 2008,2009 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			#include <sys/stat.h>
30			#include <sys/mman.h>
31	amb	251	#include <sys/types.h>
32	amb	2
33			#include "functions.h"
34
35
36	amb	248	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	amb	2	/*++++++++++++++++++++++++++++++++++++++
49	amb	162	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	amb	250	Open a file and map it into memory.
72	amb	2
73			void *MapFile Returns the address of the file.
74
75			const char *filename The name of the file to open.
76			++++++++++++++++++++++++++++++++++++++*/
77
78	amb	250	void MapFile(const char filename)
79	amb	2	{
80			int fd;
81			struct stat buf;
82			void *address;
83
84			/* Open the file */
85
86			fd=open(filename,O_RDONLY);
87
88	amb	177	if(fd<0)
89			{
90			fprintf(stderr,"Cannot open file '%s' to read.\n",filename);
91			exit(EXIT_FAILURE);
92			}
93	amb	2
94			/* Get the length of the file */
95
96			if(fstat(fd,&buf))
97			{
98			close(fd);
99	amb	177
100			fprintf(stderr,"Cannot stat file '%s'.\n",filename);
101			exit(EXIT_FAILURE);
102	amb	2	}
103
104			/* Map the file */
105
106	amb	248	address=mmap(NULL,buf.st_size,PROT_READ,MAP_SHARED,fd,0);
107	amb	2
108	amb	245	if(address==MAP_FAILED)
109	amb	2	{
110			close(fd);
111	amb	177
112			fprintf(stderr,"Cannot mmap file '%s'.\n",filename);
113			exit(EXIT_FAILURE);
114	amb	2	}
115
116	amb	248	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	amb	2	return(address);
126			}
127
128
129			/*++++++++++++++++++++++++++++++++++++++
130	amb	248	Unmap a file and optionally delete it.
131	amb	2
132	amb	255	Returns NULL (for similarity to the MapFile function).
133
134	amb	248	const char *filename The name of the file when it was opened.
135			++++++++++++++++++++++++++++++++++++++*/
136
137	amb	255	void UnmapFile(const char filename)
138	amb	248	{
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			/* Shuffle the list of files */
160
161			nmappedfiles--;
162
163			if(nmappedfiles>i)
164			memmove(&mappedfiles[i],&mappedfiles[i+1],(nmappedfiles-i)*sizeof(struct mmapinfo));
165	amb	255
166			return(NULL);
167	amb	248	}
168
169
170			/*++++++++++++++++++++++++++++++++++++++
171			Open a new file on disk for writing to.
172
173			int OpenFile Returns the file descriptor if OK or something negative in case of an error.
174
175	amb	97	const char *filename The name of the file to create.
176	amb	2	++++++++++++++++++++++++++++++++++++++*/
177
178	amb	97	int OpenFile(const char *filename)
179	amb	2	{
180	amb	97	int fd;
181	amb	2
182	amb	97	/* Open the file */
183	amb	2
184	amb	248	fd=open(filename,O_WRONLY\|O_CREAT\|O_TRUNC,S_IRUSR\|S_IWUSR\|S_IRGRP\|S_IROTH);
185	amb	2
186	amb	97	if(fd<0)
187	amb	177	{
188			fprintf(stderr,"Cannot open file '%s' to write.\n",filename);
189			exit(EXIT_FAILURE);
190			}
191	amb	2
192	amb	97	return(fd);
193	amb	2	}
194
195
196			/*++++++++++++++++++++++++++++++++++++++
197	amb	251	Open an existing file on disk for reading from.
198
199			int OpenFile Returns the file descriptor if OK or something negative in case of an error.
200
201			const char *filename The name of the file to open.
202			++++++++++++++++++++++++++++++++++++++*/
203
204			int ReOpenFile(const char *filename)
205			{
206			int fd;
207
208			/* Open the file */
209
210			fd=open(filename,O_RDONLY);
211
212			if(fd<0)
213			{
214			fprintf(stderr,"Cannot open file '%s' to read.\n",filename);
215			exit(EXIT_FAILURE);
216			}
217
218			return(fd);
219			}
220
221
222			/*++++++++++++++++++++++++++++++++++++++
223	amb	97	Write data to a file on disk.
224	amb	2
225			int WriteFile Returns 0 if OK or something else in case of an error.
226
227	amb	97	int fd The file descriptor to write to.
228	amb	2
229	amb	251	void *address The address of the data to be written from.
230	amb	2
231			size_t length The length of data to write.
232			++++++++++++++++++++++++++++++++++++++*/
233
234	amb	97	int WriteFile(int fd,void *address,size_t length)
235	amb	2	{
236			/* Write the data */
237
238			if(write(fd,address,length)!=length)
239			return(-1);
240
241			return(0);
242			}
243	amb	87
244
245			/*++++++++++++++++++++++++++++++++++++++
246	amb	251	Read data from a file on disk.
247
248			int ReadFile Returns 0 if OK or something else in case of an error.
249
250			int fd The file descriptor to read from.
251
252			void *address The address of the data to be read into.
253
254			size_t length The length of data to read.
255			++++++++++++++++++++++++++++++++++++++*/
256
257			int ReadFile(int fd,void *address,size_t length)
258			{
259			/* Read the data */
260
261			if(read(fd,address,length)!=length)
262			return(-1);
263
264			return(0);
265			}
266
267
268			/*++++++++++++++++++++++++++++++++++++++
269			Seek to a position in a file on disk.
270
271			int SeekFile Returns 0 if OK or something else in case of an error.
272
273			int fd The file descriptor to seek within.
274
275			size_t position The position to seek to.
276			++++++++++++++++++++++++++++++++++++++*/
277
278			int SeekFile(int fd,size_t position)
279			{
280			/* Seek the data */
281
282			if(lseek(fd,position,SEEK_SET)!=position)
283			return(-1);
284
285			return(0);
286			}
287
288
289			/*++++++++++++++++++++++++++++++++++++++
290	amb	97	Close a file on disk.
291	amb	87
292	amb	97	int fd The file descriptor to close.
293	amb	87	++++++++++++++++++++++++++++++++++++++*/
294
295	amb	97	void CloseFile(int fd)
296	amb	87	{
297	amb	97	close(fd);
298	amb	87	}
299	amb	251
300
301			/*++++++++++++++++++++++++++++++++++++++
302			Delete a file from disk.
303
304			int DeleteFile Returns 0 if OK or something else in case of an error.
305
306			char *filename The name of the file to delete.
307			++++++++++++++++++++++++++++++++++++++*/
308
309			int DeleteFile(char *filename)
310			{
311			unlink(filename);
312
313			return(0);
314			}