filter/error.c

   1 /*
   2  * "$Id: error.c 6274 2007-02-13 21:05:28Z mike $"
   3  *
   4  *   Raster error handling for the Common UNIX Printing System (CUPS).
   5  *
   6  *   Copyright 2007 by Easy Software Products.
   7  *
   8  *   These coded instructions, statements, and computer programs are the
   9  *   property of Easy Software Products and are protected by Federal
  10  *   copyright law.  Distribution and use rights are outlined in the file
  11  *   "LICENSE.txt" which should have been included with this file.  If this
  12  *   file is missing or damaged please contact Easy Software Products
  13  *   at:
  14  *
  15  *       Attn: CUPS Licensing Information
  16  *       Easy Software Products
  17  *       44141 Airport View Drive, Suite 204
  18  *       Hollywood, Maryland 20636 USA
  19  *
  20  *       Voice: (301) 373-9600
  21  *       EMail: cups-info@cups.org
  22  *         WWW: http://www.cups.org
  23  *
  24  *   This file is subject to the Apple OS-Developed Software exception.
  25  *
  26  * Contents:
  27  *
  28  *   _cupsRasterAddError()   - Add an error message to the error buffer.
  29  *   _cupsRasterClearError() - Clear the error buffer.
  30  *   cupsRasterErrorString() - Return the last error from a raster function.
  31  *   get_error_buffer()      - Return a pointer to thread local storage.
  32  *   raster_init()           - Initialize error buffer once.
  33  *   raster_destructor()     - Free memory allocated by get_error_buffer().
  34  */
  35
  36 /*
  37  * Include necessary headers...
  38  */
  39
  40 #include "image-private.h"
  41 #include <stdarg.h>
  42
  43
  44 /*
  45  * Local structures...
  46  */
  47
  48 typedef struct _cups_raster_error_s     /**** Error buffer structure ****/
  49 {
  50   char  *start,                         /* Start of buffer */
  51         *current,                       /* Current position in buffer */
  52         *end;                           /* End of buffer */
  53 } _cups_raster_error_t;
  54
  55
  56 /*
  57  * Local functions...
  58  */
  59
  60 static _cups_raster_error_t     *get_error_buffer(void);
  61
  62
  63 /*
  64  * '_cupsRasterAddError()' - Add an error message to the error buffer.
  65  */
  66
  67 void
  68 _cupsRasterAddError(const char *f,      /* I - Printf-style error message */
  69                     ...)                /* I - Additional arguments as needed */
  70 {
  71   _cups_raster_error_t  *buf = get_error_buffer();
  72                                         /* Error buffer */
  73   va_list       ap;                     /* Pointer to additional arguments */
  74   char          s[2048];                /* Message string */
  75   size_t        bytes;                  /* Bytes in message string */
  76
  77
  78   va_start(ap, f);
  79   bytes = vsnprintf(s, sizeof(s), f, ap);
  80   va_end(ap);
  81
  82   if (bytes <= 0)
  83     return;
  84
  85   bytes ++;
  86
  87   if (bytes >= sizeof(s))
  88     return;
  89
  90   if (bytes > (buf->end - buf->current))
  91   {
  92    /*
  93     * Allocate more memory...
  94     */
  95
  96     char        *temp;                  /* New buffer */
  97     size_t      size;                   /* Size of buffer */
  98
  99
 100     size = buf->end - buf->start + 2 * bytes + 1024;
 101
 102     if (buf->start)
 103       temp = realloc(buf->start, size);
 104     else
 105       temp = malloc(size);
 106
 107     if (!temp)
 108       return;
 109
 110    /*
 111     * Update pointers...
 112     */
 113
 114     buf->end     = temp + size;
 115     buf->current = temp + (buf->current - buf->start);
 116     buf->start   = temp;
 117   }
 118
 119  /*
 120   * Append the message to the end of the current string...
 121   */
 122
 123   memcpy(buf->current, s, bytes);
 124   buf->current += bytes - 1;
 125 }
 126
 127
 128 /*
 129  * '_cupsRasterClearError()' - Clear the error buffer.
 130  */
 131
 132 void
 133 _cupsRasterClearError(void)
 134 {
 135   _cups_raster_error_t  *buf = get_error_buffer();
 136                                         /* Error buffer */
 137
 138
 139   buf->current = buf->start;
 140
 141   if (buf->start)
 142     *(buf->start) = '\0';
 143 }
 144
 145
 146 /*
 147  * 'cupsRasterErrorString()' - Return the last error from a raster function.
 148  *
 149  * If there are no recent errors, NULL is returned.
 150  *
 151  * @since CUPS 1.3@
 152  */
 153
 154 const char *                            /* O - Last error */
 155 cupsRasterErrorString(void)
 156 {
 157   _cups_raster_error_t  *buf = get_error_buffer();
 158                                         /* Error buffer */
 159
 160
 161   if (buf->current == buf->start)
 162     return (NULL);
 163   else
 164     return (buf->start);
 165 }
 166
 167
 168 #ifdef HAVE_PTHREAD_H
 169 /*
 170  * Implement per-thread globals...
 171  */
 172
 173 #  include <pthread.h>
 174
 175
 176 /*
 177  * Local globals...
 178  */
 179
 180 static pthread_key_t    raster_key = -1;
 181                                         /* Thread local storage key */
 182 static pthread_once_t   raster_key_once = PTHREAD_ONCE_INIT;
 183                                         /* One-time initialization object */
 184
 185
 186 /*
 187  * Local functions...
 188  */
 189
 190 static void     raster_init(void);
 191 static void     raster_destructor(void *value);
 192
 193
 194 /*
 195  * 'get_error_buffer()' - Return a pointer to thread local storage.
 196  */
 197
 198 _cups_raster_error_t *                  /* O - Pointer to error buffer */
 199 get_error_buffer(void)
 200 {
 201   _cups_raster_error_t *buf;            /* Pointer to error buffer */
 202
 203
 204  /*
 205   * Initialize the global data exactly once...
 206   */
 207
 208   DEBUG_printf(("get_error_buffer(): raster_key_once=%d\n",
 209                 raster_key_once));
 210
 211   pthread_once(&raster_key_once, raster_init);
 212
 213  /*
 214   * See if we have allocated the data yet...
 215   */
 216
 217   if ((buf = (_cups_raster_error_t *)pthread_getspecific(raster_key))
 218           == NULL)
 219   {
 220     DEBUG_puts("get_error_buffer: allocating memory for thread...");
 221
 222    /*
 223     * No, allocate memory as set the pointer for the key...
 224     */
 225
 226     buf = calloc(1, sizeof(_cups_raster_error_t));
 227     pthread_setspecific(raster_key, buf);
 228
 229     DEBUG_printf(("    buf=%p\n", buf));
 230   }
 231
 232  /*
 233   * Return the pointer to the data...
 234   */
 235
 236   return (buf);
 237 }
 238
 239
 240 /*
 241  * 'raster_init()' - Initialize error buffer once.
 242  */
 243
 244 static void
 245 raster_init(void)
 246 {
 247   pthread_key_create(&raster_key, raster_destructor);
 248
 249   DEBUG_printf(("raster_init(): raster_key=%x(%u)\n", raster_key,
 250                 raster_key));
 251 }
 252
 253
 254 /*
 255  * 'raster_destructor()' - Free memory allocated by get_error_buffer().
 256  */
 257
 258 static void
 259 raster_destructor(void *value)          /* I - Data to free */
 260 {
 261   _cups_raster_error_t *buf = (_cups_raster_error_t *)value;
 262                                         /* Error buffer */
 263
 264
 265   DEBUG_printf(("raster_destructor(value=%p)\n", value));
 266
 267   if (buf->start)
 268     free(buf->start);
 269
 270   free(value);
 271 }
 272
 273
 274 #else
 275 /*
 276  * Implement static globals...
 277  */
 278
 279 /*
 280  * 'get_error_buffer()' - Return a pointer to thread local storage.
 281  */
 282
 283 _cups_raster_error_t *                  /* O - Pointer to error buffer */
 284 get_error_buffer(void)
 285 {
 286   static _cups_raster_error_t buf = { 0, 0, 0 };
 287                                         /* Error buffer */
 288
 289
 290   return (&buf);
 291 }
 292 #endif /* HAVE_PTHREAD_H */
 293
 294
 295 /*
 296  * End of "$Id: error.c 6274 2007-02-13 21:05:28Z mike $".
 297  */