1/*
2 * "$Id: error.c 11093 2013-07-03 20:48:42Z msweet $"
3 *
4 *   Raster error handling for CUPS.
5 *
6 *   Copyright 2007-2012 by Apple Inc.
7 *   Copyright 2007 by Easy Software Products.
8 *
9 *   These coded instructions, statements, and computer programs are the
10 *   property of Apple Inc. and are protected by Federal copyright
11 *   law.  Distribution and use rights are outlined in the file "LICENSE.txt"
12 *   which should have been included with this file.  If this file is
13 *   file is missing or damaged, see the license at "http://www.cups.org/".
14 *
15 *   This file is subject to the Apple OS-Developed Software exception.
16 *
17 * Contents:
18 *
19 *   _cupsRasterAddError()   - Add an error message to the error buffer.
20 *   _cupsRasterClearError() - Clear the error buffer.
21 *   cupsRasterErrorString() - Return the last error from a raster function.
22 *   get_error_buffer()      - Return a pointer to thread local storage.
23 *   raster_init()           - Initialize error buffer once.
24 *   raster_destructor()     - Free memory allocated by get_error_buffer().
25 */
26
27/*
28 * Include necessary headers...
29 */
30
31#include <cups/raster-private.h>
32
33
34/*
35 * Local structures...
36 */
37
38typedef struct _cups_raster_error_s	/**** Error buffer structure ****/
39{
40  char	*start,				/* Start of buffer */
41	*current,			/* Current position in buffer */
42	*end;				/* End of buffer */
43} _cups_raster_error_t;
44
45
46/*
47 * Local functions...
48 */
49
50static _cups_raster_error_t	*get_error_buffer(void);
51
52
53/*
54 * '_cupsRasterAddError()' - Add an error message to the error buffer.
55 */
56
57void
58_cupsRasterAddError(const char *f,	/* I - Printf-style error message */
59                    ...)		/* I - Additional arguments as needed */
60{
61  _cups_raster_error_t	*buf = get_error_buffer();
62					/* Error buffer */
63  va_list	ap;			/* Pointer to additional arguments */
64  char		s[2048];		/* Message string */
65  size_t	bytes;			/* Bytes in message string */
66
67
68  va_start(ap, f);
69  bytes = vsnprintf(s, sizeof(s), f, ap);
70  va_end(ap);
71
72  if (bytes <= 0)
73    return;
74
75  bytes ++;
76
77  if (bytes >= sizeof(s))
78    return;
79
80  if (bytes > (size_t)(buf->end - buf->current))
81  {
82   /*
83    * Allocate more memory...
84    */
85
86    char	*temp;			/* New buffer */
87    size_t	size;			/* Size of buffer */
88
89
90    size = buf->end - buf->start + 2 * bytes + 1024;
91
92    if (buf->start)
93      temp = realloc(buf->start, size);
94    else
95      temp = malloc(size);
96
97    if (!temp)
98      return;
99
100   /*
101    * Update pointers...
102    */
103
104    buf->end     = temp + size;
105    buf->current = temp + (buf->current - buf->start);
106    buf->start   = temp;
107  }
108
109 /*
110  * Append the message to the end of the current string...
111  */
112
113  memcpy(buf->current, s, bytes);
114  buf->current += bytes - 1;
115}
116
117
118/*
119 * '_cupsRasterClearError()' - Clear the error buffer.
120 */
121
122void
123_cupsRasterClearError(void)
124{
125  _cups_raster_error_t	*buf = get_error_buffer();
126					/* Error buffer */
127
128
129  buf->current = buf->start;
130
131  if (buf->start)
132    *(buf->start) = '\0';
133}
134
135
136/*
137 * 'cupsRasterErrorString()' - Return the last error from a raster function.
138 *
139 * If there are no recent errors, NULL is returned.
140 *
141 * @since CUPS 1.3/OS X 10.5@
142 */
143
144const char *				/* O - Last error */
145cupsRasterErrorString(void)
146{
147  _cups_raster_error_t	*buf = get_error_buffer();
148					/* Error buffer */
149
150
151  if (buf->current == buf->start)
152    return (NULL);
153  else
154    return (buf->start);
155}
156
157
158#ifdef HAVE_PTHREAD_H
159/*
160 * Implement per-thread globals...
161 */
162
163#  include <pthread.h>
164
165
166/*
167 * Local globals...
168 */
169
170static pthread_key_t	raster_key = -1;
171					/* Thread local storage key */
172static pthread_once_t	raster_key_once = PTHREAD_ONCE_INIT;
173					/* One-time initialization object */
174
175
176/*
177 * Local functions...
178 */
179
180static void	raster_init(void);
181static void	raster_destructor(void *value);
182
183
184/*
185 * 'get_error_buffer()' - Return a pointer to thread local storage.
186 */
187
188_cups_raster_error_t *			/* O - Pointer to error buffer */
189get_error_buffer(void)
190{
191  _cups_raster_error_t *buf;		/* Pointer to error buffer */
192
193
194 /*
195  * Initialize the global data exactly once...
196  */
197
198  DEBUG_puts("get_error_buffer()");
199
200  pthread_once(&raster_key_once, raster_init);
201
202 /*
203  * See if we have allocated the data yet...
204  */
205
206  if ((buf = (_cups_raster_error_t *)pthread_getspecific(raster_key))
207          == NULL)
208  {
209    DEBUG_puts("get_error_buffer: allocating memory for thread...");
210
211   /*
212    * No, allocate memory as set the pointer for the key...
213    */
214
215    buf = calloc(1, sizeof(_cups_raster_error_t));
216    pthread_setspecific(raster_key, buf);
217
218    DEBUG_printf(("    buf=%p\n", buf));
219  }
220
221 /*
222  * Return the pointer to the data...
223  */
224
225  return (buf);
226}
227
228
229/*
230 * 'raster_init()' - Initialize error buffer once.
231 */
232
233static void
234raster_init(void)
235{
236  pthread_key_create(&raster_key, raster_destructor);
237
238  DEBUG_printf(("raster_init(): raster_key=%x(%u)\n", (unsigned)raster_key,
239                (unsigned)raster_key));
240}
241
242
243/*
244 * 'raster_destructor()' - Free memory allocated by get_error_buffer().
245 */
246
247static void
248raster_destructor(void *value)		/* I - Data to free */
249{
250  _cups_raster_error_t *buf = (_cups_raster_error_t *)value;
251					/* Error buffer */
252
253
254  DEBUG_printf(("raster_destructor(value=%p)\n", value));
255
256  if (buf->start)
257    free(buf->start);
258
259  free(value);
260}
261
262
263#else
264/*
265 * Implement static globals...
266 */
267
268/*
269 * 'get_error_buffer()' - Return a pointer to thread local storage.
270 */
271
272_cups_raster_error_t *			/* O - Pointer to error buffer */
273get_error_buffer(void)
274{
275  static _cups_raster_error_t buf = { 0, 0, 0 };
276					/* Error buffer */
277
278
279  return (&buf);
280}
281#endif /* HAVE_PTHREAD_H */
282
283
284/*
285 * End of "$Id: error.c 11093 2013-07-03 20:48:42Z msweet $".
286 */
287