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	amb	2	/***************************************
2	amb	326	$Header: /home/amb/CVS/routino/src/files.c,v 1.15 2010-03-19 19:47:09 amb Exp $
3	amb	2
4	amb	326	Functions to handle files.
5	amb	151
6			Part of the Routino routing software.
7	amb	2	****************/ /****************
8	amb	326	This file Copyright 2008-2010 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	289	/+ A structure to contain the list of memory mapped files. +/
37	amb	248	struct mmapinfo
38			{
39	amb	289	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	amb	248	};
44
45	amb	289	/+ The list of memory mapped files. +/
46			static struct mmapinfo *mappedfiles;
47	amb	248
48	amb	289	/+ The number of mapped files. +/
49			static int nmappedfiles=0;
50	amb	248
51	amb	289
52	amb	2	/*++++++++++++++++++++++++++++++++++++++
53	amb	162	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	amb	250	Open a file and map it into memory.
76	amb	2
77			void *MapFile Returns the address of the file.
78
79			const char *filename The name of the file to open.
80			++++++++++++++++++++++++++++++++++++++*/
81
82	amb	250	void MapFile(const char filename)
83	amb	2	{
84			int fd;
85			struct stat buf;
86			void *address;
87
88			/* Open the file */
89
90			fd=open(filename,O_RDONLY);
91
92	amb	177	if(fd<0)
93			{
94			fprintf(stderr,"Cannot open file '%s' to read.\n",filename);
95			exit(EXIT_FAILURE);
96			}
97	amb	2
98			/* Get the length of the file */
99
100			if(fstat(fd,&buf))
101			{
102			close(fd);
103	amb	177
104			fprintf(stderr,"Cannot stat file '%s'.\n",filename);
105			exit(EXIT_FAILURE);
106	amb	2	}
107
108			/* Map the file */
109
110	amb	248	address=mmap(NULL,buf.st_size,PROT_READ,MAP_SHARED,fd,0);
111	amb	2
112	amb	245	if(address==MAP_FAILED)
113	amb	2	{
114			close(fd);
115	amb	177
116			fprintf(stderr,"Cannot mmap file '%s'.\n",filename);
117			exit(EXIT_FAILURE);
118	amb	2	}
119
120	amb	248	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	amb	2	return(address);
130			}
131
132
133			/*++++++++++++++++++++++++++++++++++++++
134	amb	248	Unmap a file and optionally delete it.
135	amb	2
136	amb	289	void *UnmapFile Returns NULL (for similarity to the MapFile function).
137	amb	255
138	amb	248	const char *filename The name of the file when it was opened.
139			++++++++++++++++++++++++++++++++++++++*/
140
141	amb	255	void UnmapFile(const char filename)
142	amb	248	{
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	amb	255
170			return(NULL);
171	amb	248	}
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	amb	97	const char *filename The name of the file to create.
180	amb	2	++++++++++++++++++++++++++++++++++++++*/
181
182	amb	97	int OpenFile(const char *filename)
183	amb	2	{
184	amb	97	int fd;
185	amb	2
186	amb	97	/* Open the file */
187	amb	2
188	amb	248	fd=open(filename,O_WRONLY\|O_CREAT\|O_TRUNC,S_IRUSR\|S_IWUSR\|S_IRGRP\|S_IROTH);
189	amb	2
190	amb	97	if(fd<0)
191	amb	177	{
192			fprintf(stderr,"Cannot open file '%s' to write.\n",filename);
193			exit(EXIT_FAILURE);
194			}
195	amb	2
196	amb	97	return(fd);
197	amb	2	}
198
199
200			/*++++++++++++++++++++++++++++++++++++++
201	amb	326	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	amb	251	Open an existing file on disk for reading from.
228
229	amb	289	int ReOpenFile Returns the file descriptor if OK or something negative in case of an error.
230	amb	251
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	amb	97	Write data to a file on disk.
254	amb	2
255			int WriteFile Returns 0 if OK or something else in case of an error.
256
257	amb	97	int fd The file descriptor to write to.
258	amb	2
259	amb	259	const void *address The address of the data to be written from.
260	amb	2
261			size_t length The length of data to write.
262			++++++++++++++++++++++++++++++++++++++*/
263
264	amb	259	int WriteFile(int fd,const void *address,size_t length)
265	amb	2	{
266			/* Write the data */
267
268			if(write(fd,address,length)!=length)
269			return(-1);
270
271			return(0);
272			}
273	amb	87
274
275			/*++++++++++++++++++++++++++++++++++++++
276	amb	251	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	amb	97	Close a file on disk.
321	amb	87
322	amb	97	int fd The file descriptor to close.
323	amb	87	++++++++++++++++++++++++++++++++++++++*/
324
325	amb	97	void CloseFile(int fd)
326	amb	87	{
327	amb	97	close(fd);
328	amb	87	}
329	amb	251
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			}