trunk/src/files.c

/***************************************
 Functions to handle files.

 Part of the Routino routing software.
 ******************/ /******************
 This file Copyright 2008-2012 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 name.

  char *FileName Returns a pointer to memory allocated to the filename.

  const char *dirname The directory name.

  const char *prefix The file prefix.

  const char *name The main part of the name.
  ++++++++++++++++++++++++++++++++++++++*/

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)+1);

 sprintf(filename,"%s%s%s%s%s",dirname?dirname:"",dirname?"/":"",prefix?prefix:"",prefix?"-":"",name);

 return(filename);
}


/*++++++++++++++++++++++++++++++++++++++
  Open a file read-only 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' for reading [%s].\n",filename,strerror(errno));
    exit(EXIT_FAILURE);
   }

 /* Store the information about the mapped file */

 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);
}


/*++++++++++++++++++++++++++++++++++++++
  Open a file read-write and map it into memory.

  void *MapFileWriteable Returns the address of the file or exits in case of an error.

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

void *MapFileWriteable(const char *filename)
{
 int fd;
 off_t size;
 void *address;

 /* Open the file and get its size */

 fd=ReOpenFileWriteable(filename);

 size=SizeFile(filename);

 /* Map the file */

 address=mmap(NULL,size,PROT_READ|PROT_WRITE,MAP_SHARED,fd,0);

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

    fprintf(stderr,"Cannot mmap file '%s' for reading and writing [%s].\n",filename,strerror(errno));
    exit(EXIT_FAILURE);
   }

 /* Store the information about the mapped file */

 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 and close it.

  void *UnmapFile Returns NULL (for similarity to the MapFile function).

  const void *address The address of the mapped file in memory.
  ++++++++++++++++++++++++++++++++++++++*/

void *UnmapFile(const void *address)
{
 int i;

 for(i=0;i<nmappedfiles;i++)
    if(mappedfiles[i].address==address)
       break;

 if(i==nmappedfiles)
   {
    fprintf(stderr,"The data at address %p was not mapped using MapFile().\n",address);
    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.

  int OpenFileNew Returns the file descriptor if OK or exits in case of an error.

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

int OpenFileNew(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 or existing file on disk for reading and appending.

  int OpenFileAppend Returns the file descriptor if OK or exits in case of an error.

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

int OpenFileAppend(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.

  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);
}


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

  int ReOpenFileWriteable Returns the file descriptor if OK or exits in case of an error.

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

int ReOpenFileWriteable(const char *filename)
{
 int fd;

 /* Open the file */

 fd=open(filename,O_RDWR);

 if(fd<0)
   {
    fprintf(stderr,"Cannot open file '%s' for reading and writing [%s].\n",filename,strerror(errno));
    exit(EXIT_FAILURE);
   }

 return(fd);
}


/*++++++++++++++++++++++++++++++++++++++
  Get the size of a file.

  off_t SizeFile Returns the file size if OK or exits in case of an error.

  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 CloseFile returns -1 (for similarity to the *OpenFile* functions).

  int fd The file descriptor to close.
  ++++++++++++++++++++++++++++++++++++++*/

int CloseFile(int fd)
{
 close(fd);

 return(-1);
}


/*++++++++++++++++++++++++++++++++++++++
  Delete a file from disk.

  int DeleteFile Returns 0 if OK.

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

int DeleteFile(const char *filename)
{
 unlink(filename);

 return(0);
}


/*++++++++++++++++++++++++++++++++++++++
  Rename a file on disk.

  int RenameFile Returns 0 if OK.

  const char *oldfilename The old name of the file before renaming.

  const char *newfilename The new name of the file after renaming.
  ++++++++++++++++++++++++++++++++++++++*/

int RenameFile(const char *oldfilename,const char *newfilename)
{
 rename(oldfilename,newfilename);

 return(0);
}
1	/***************************************
2	Functions to handle files.
3
4	Part of the Routino routing software.
5	****************/ /****************
6	This file Copyright 2008-2012 Andrew M. Bishop
7
8	This program is free software: you can redistribute it and/or modify
9	it under the terms of the GNU Affero General Public License as published by
10	the Free Software Foundation, either version 3 of the License, or
11	(at your option) any later version.
12
13	This program is distributed in the hope that it will be useful,
14	but WITHOUT ANY WARRANTY; without even the implied warranty of
15	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16	GNU Affero General Public License for more details.
17
18	You should have received a copy of the GNU Affero General Public License
19	along with this program. If not, see <http://www.gnu.org/licenses/>.
20	***************************************/
21
22
23	#include <unistd.h>
24	#include <stdlib.h>
25	#include <stdio.h>
26	#include <string.h>
27	#include <fcntl.h>
28	#include <errno.h>
29	#include <sys/stat.h>
30	#include <sys/mman.h>
31	#include <sys/types.h>
32
33	#include "files.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 name.
54
55	char *FileName Returns a pointer to memory allocated to the filename.
56
57	const char *dirname The directory name.
58
59	const char *prefix The file prefix.
60
61	const char *name The main part of the name.
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)+1);
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 read-only and map it into memory.
76
77	void *MapFile Returns the address of the file or exits in case of an error.
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	off_t size;
86	void *address;
87
88	/* Open the file and get its size */
89
90	fd=ReOpenFile(filename);
91
92	size=SizeFile(filename);
93
94	/* Map the file */
95
96	address=mmap(NULL,size,PROT_READ,MAP_SHARED,fd,0);
97
98	if(address==MAP_FAILED)
99	{
100	close(fd);
101
102	fprintf(stderr,"Cannot mmap file '%s' for reading [%s].\n",filename,strerror(errno));
103	exit(EXIT_FAILURE);
104	}
105
106	/* Store the information about the mapped file */
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	Open a file read-write and map it into memory.
123
124	void *MapFileWriteable Returns the address of the file or exits in case of an error.
125
126	const char *filename The name of the file to open.
127	++++++++++++++++++++++++++++++++++++++*/
128
129	void MapFileWriteable(const char filename)
130	{
131	int fd;
132	off_t size;
133	void *address;
134
135	/* Open the file and get its size */
136
137	fd=ReOpenFileWriteable(filename);
138
139	size=SizeFile(filename);
140
141	/* Map the file */
142
143	address=mmap(NULL,size,PROT_READ\|PROT_WRITE,MAP_SHARED,fd,0);
144
145	if(address==MAP_FAILED)
146	{
147	close(fd);
148
149	fprintf(stderr,"Cannot mmap file '%s' for reading and writing [%s].\n",filename,strerror(errno));
150	exit(EXIT_FAILURE);
151	}
152
153	/* Store the information about the mapped file */
154
155	mappedfiles=(struct mmapinfo)realloc((void)mappedfiles,(nmappedfiles+1)*sizeof(struct mmapinfo));
156
157	mappedfiles[nmappedfiles].filename=filename;
158	mappedfiles[nmappedfiles].fd=fd;
159	mappedfiles[nmappedfiles].address=address;
160	mappedfiles[nmappedfiles].length=size;
161
162	nmappedfiles++;
163
164	return(address);
165	}
166
167
168	/*++++++++++++++++++++++++++++++++++++++
169	Unmap a file and close it.
170
171	void *UnmapFile Returns NULL (for similarity to the MapFile function).
172
173	const void *address The address of the mapped file in memory.
174	++++++++++++++++++++++++++++++++++++++*/
175
176	void UnmapFile(const void address)
177	{
178	int i;
179
180	for(i=0;i<nmappedfiles;i++)
181	if(mappedfiles[i].address==address)
182	break;
183
184	if(i==nmappedfiles)
185	{
186	fprintf(stderr,"The data at address %p was not mapped using MapFile().\n",address);
187	exit(EXIT_FAILURE);
188	}
189
190	/* Close the file */
191
192	close(mappedfiles[i].fd);
193
194	/* Unmap the file */
195
196	munmap(mappedfiles[i].address,mappedfiles[i].length);
197
198	/* Shuffle the list of files */
199
200	nmappedfiles--;
201
202	if(nmappedfiles>i)
203	memmove(&mappedfiles[i],&mappedfiles[i+1],(nmappedfiles-i)*sizeof(struct mmapinfo));
204
205	return(NULL);
206	}
207
208
209	/*++++++++++++++++++++++++++++++++++++++
210	Open a new file on disk for writing.
211
212	int OpenFileNew Returns the file descriptor if OK or exits in case of an error.
213
214	const char *filename The name of the file to create.
215	++++++++++++++++++++++++++++++++++++++*/
216
217	int OpenFileNew(const char *filename)
218	{
219	int fd;
220
221	/* Open the file */
222
223	fd=open(filename,O_RDWR\|O_CREAT\|O_TRUNC,S_IRUSR\|S_IWUSR\|S_IRGRP\|S_IROTH);
224
225	if(fd<0)
226	{
227	fprintf(stderr,"Cannot open file '%s' for writing [%s].\n",filename,strerror(errno));
228	exit(EXIT_FAILURE);
229	}
230
231	return(fd);
232	}
233
234
235	/*++++++++++++++++++++++++++++++++++++++
236	Open a new or existing file on disk for reading and appending.
237
238	int OpenFileAppend Returns the file descriptor if OK or exits in case of an error.
239
240	const char *filename The name of the file to create or open.
241	++++++++++++++++++++++++++++++++++++++*/
242
243	int OpenFileAppend(const char *filename)
244	{
245	int fd;
246
247	/* Open the file */
248
249	fd=open(filename,O_RDWR\|O_CREAT\|O_APPEND,S_IRUSR\|S_IWUSR\|S_IRGRP\|S_IROTH);
250
251	if(fd<0)
252	{
253	fprintf(stderr,"Cannot open file '%s' for appending [%s].\n",filename,strerror(errno));
254	exit(EXIT_FAILURE);
255	}
256
257	return(fd);
258	}
259
260
261	/*++++++++++++++++++++++++++++++++++++++
262	Open an existing file on disk for reading.
263
264	int ReOpenFile Returns the file descriptor if OK or exits in case of an error.
265
266	const char *filename The name of the file to open.
267	++++++++++++++++++++++++++++++++++++++*/
268
269	int ReOpenFile(const char *filename)
270	{
271	int fd;
272
273	/* Open the file */
274
275	fd=open(filename,O_RDONLY);
276
277	if(fd<0)
278	{
279	fprintf(stderr,"Cannot open file '%s' for reading [%s].\n",filename,strerror(errno));
280	exit(EXIT_FAILURE);
281	}
282
283	return(fd);
284	}
285
286
287	/*++++++++++++++++++++++++++++++++++++++
288	Open an existing file on disk for reading or writing.
289
290	int ReOpenFileWriteable Returns the file descriptor if OK or exits in case of an error.
291
292	const char *filename The name of the file to open.
293	++++++++++++++++++++++++++++++++++++++*/
294
295	int ReOpenFileWriteable(const char *filename)
296	{
297	int fd;
298
299	/* Open the file */
300
301	fd=open(filename,O_RDWR);
302
303	if(fd<0)
304	{
305	fprintf(stderr,"Cannot open file '%s' for reading and writing [%s].\n",filename,strerror(errno));
306	exit(EXIT_FAILURE);
307	}
308
309	return(fd);
310	}
311
312
313	/*++++++++++++++++++++++++++++++++++++++
314	Get the size of a file.
315
316	off_t SizeFile Returns the file size if OK or exits in case of an error.
317
318	const char *filename The name of the file to check.
319	++++++++++++++++++++++++++++++++++++++*/
320
321	off_t SizeFile(const char *filename)
322	{
323	struct stat buf;
324
325	if(stat(filename,&buf))
326	{
327	fprintf(stderr,"Cannot stat file '%s' [%s].\n",filename,strerror(errno));
328	exit(EXIT_FAILURE);
329	}
330
331	return(buf.st_size);
332	}
333
334
335	/*++++++++++++++++++++++++++++++++++++++
336	Check if a file exists.
337
338	int ExistsFile Returns 1 if the file exists and 0 if not.
339
340	const char *filename The name of the file to check.
341	++++++++++++++++++++++++++++++++++++++*/
342
343	int ExistsFile(const char *filename)
344	{
345	struct stat buf;
346
347	if(stat(filename,&buf))
348	return(0);
349	else
350	return(1);
351	}
352
353
354	/*++++++++++++++++++++++++++++++++++++++
355	Close a file on disk.
356
357	int CloseFile returns -1 (for similarity to the OpenFile functions).
358
359	int fd The file descriptor to close.
360	++++++++++++++++++++++++++++++++++++++*/
361
362	int CloseFile(int fd)
363	{
364	close(fd);
365
366	return(-1);
367	}
368
369
370	/*++++++++++++++++++++++++++++++++++++++
371	Delete a file from disk.
372
373	int DeleteFile Returns 0 if OK.
374
375	const char *filename The name of the file to delete.
376	++++++++++++++++++++++++++++++++++++++*/
377
378	int DeleteFile(const char *filename)
379	{
380	unlink(filename);
381
382	return(0);
383	}
384
385
386	/*++++++++++++++++++++++++++++++++++++++
387	Rename a file on disk.
388
389	int RenameFile Returns 0 if OK.
390
391	const char *oldfilename The old name of the file before renaming.
392
393	const char *newfilename The new name of the file after renaming.
394	++++++++++++++++++++++++++++++++++++++*/
395
396	int RenameFile(const char oldfilename,const char newfilename)
397	{
398	rename(oldfilename,newfilename);
399
400	return(0);
401	}