filter/error.c

   1 /*
   2  * "$Id: error.c 7460 2008-04-16 02:19:54Z mike $"
   3  *
   4  *   Raster error handling for the Common UNIX Printing System (CUPS).
   5  *
   6  *   Copyright 2007-2008 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 "image-private.h"
  32 #include <stdarg.h>
  33
  34
  35 /*
  36  * Local structures...
  37  */
  38
  39 typedef struct _cups_raster_error_s     /**** Error buffer structure ****/
  40 {
  41   char  *start,                         /* Start of buffer */
  42         *current,                       /* Current position in buffer */
  43         *end;                           /* End of buffer */
  44 } _cups_raster_error_t;
  45
  46
  47 /*
  48  * Local functions...
  49  */
  50
  51 static _cups_raster_error_t     *get_error_buffer(void);
  52
  53
  54 /*
  55  * '_cupsRasterAddError()' - Add an error message to the error buffer.
  56  */
  57
  58 void
  59 _cupsRasterAddError(const char *f,      /* I - Printf-style error message */
  60                     ...)                /* I - Additional arguments as needed */
  61 {
  62   _cups_raster_error_t  *buf = get_error_buffer();
  63                                         /* Error buffer */
  64   va_list       ap;                     /* Pointer to additional arguments */
  65   char          s[2048];                /* Message string */
  66   size_t        bytes;                  /* Bytes in message string */
  67
  68
  69   va_start(ap, f);
  70   bytes = vsnprintf(s, sizeof(s), f, ap);
  71   va_end(ap);
  72
  73   if (bytes <= 0)
  74     return;
  75
  76   bytes ++;
  77
  78   if (bytes >= sizeof(s))
  79     return;
  80
  81   if (bytes > (buf->end - buf->current))
  82   {
  83    /*
  84     * Allocate more memory...
  85     */
  86
  87     char        *temp;                  /* New buffer */
  88     size_t      size;                   /* Size of buffer */
  89
  90
  91     size = buf->end - buf->start + 2 * bytes + 1024;
  92
  93     if (buf->start)
  94       temp = realloc(buf->start, size);
  95     else
  96       temp = malloc(size);
  97
  98     if (!temp)
  99       return;
 100
 101    /*
 102     * Update pointers...
 103     */
 104
 105     buf->end     = temp + size;
 106     buf->current = temp + (buf->current - buf->start);
 107     buf->start   = temp;
 108   }
 109
 110  /*
 111   * Append the message to the end of the current string...
 112   */
 113
 114   memcpy(buf->current, s, bytes);
 115   buf->current += bytes - 1;
 116 }
 117
 118
 119 /*
 120  * '_cupsRasterClearError()' - Clear the error buffer.
 121  */
 122
 123 void
 124 _cupsRasterClearError(void)
 125 {
 126   _cups_raster_error_t  *buf = get_error_buffer();
 127                                         /* Error buffer */
 128
 129
 130   buf->current = buf->start;
 131
 132   if (buf->start)
 133     *(buf->start) = '\0';
 134 }
 135
 136
 137 /*
 138  * 'cupsRasterErrorString()' - Return the last error from a raster function.
 139  *
 140  * If there are no recent errors, NULL is returned.
 141  *
 142  * @since CUPS 1.3/Mac OS X 10.5@
 143  */
 144
 145 const char *                            /* O - Last error */
 146 cupsRasterErrorString(void)
 147 {
 148   _cups_raster_error_t  *buf = get_error_buffer();
 149                                         /* Error buffer */
 150
 151
 152   if (buf->current == buf->start)
 153     return (NULL);
 154   else
 155     return (buf->start);
 156 }
 157
 158
 159 #ifdef HAVE_PTHREAD_H
 160 /*
 161  * Implement per-thread globals...
 162  */
 163
 164 #  include <pthread.h>
 165
 166
 167 /*
 168  * Local globals...
 169  */
 170
 171 static pthread_key_t    raster_key = -1;
 172                                         /* Thread local storage key */
 173 static pthread_once_t   raster_key_once = PTHREAD_ONCE_INIT;
 174                                         /* One-time initialization object */
 175
 176
 177 /*
 178  * Local functions...
 179  */
 180
 181 static void     raster_init(void);
 182 static void     raster_destructor(void *value);
 183
 184
 185 /*
 186  * 'get_error_buffer()' - Return a pointer to thread local storage.
 187  */
 188
 189 _cups_raster_error_t *                  /* O - Pointer to error buffer */
 190 get_error_buffer(void)
 191 {
 192   _cups_raster_error_t *buf;            /* Pointer to error buffer */
 193
 194
 195  /*
 196   * Initialize the global data exactly once...
 197   */
 198
 199   DEBUG_puts("get_error_buffer()");
 200
 201   pthread_once(&raster_key_once, raster_init);
 202
 203  /*
 204   * See if we have allocated the data yet...
 205   */
 206
 207   if ((buf = (_cups_raster_error_t *)pthread_getspecific(raster_key))
 208           == NULL)
 209   {
 210     DEBUG_puts("get_error_buffer: allocating memory for thread...");
 211
 212    /*
 213     * No, allocate memory as set the pointer for the key...
 214     */
 215
 216     buf = calloc(1, sizeof(_cups_raster_error_t));
 217     pthread_setspecific(raster_key, buf);
 218
 219     DEBUG_printf(("    buf=%p\n", buf));
 220   }
 221
 222  /*
 223   * Return the pointer to the data...
 224   */
 225
 226   return (buf);
 227 }
 228
 229
 230 /*
 231  * 'raster_init()' - Initialize error buffer once.
 232  */
 233
 234 static void
 235 raster_init(void)
 236 {
 237   pthread_key_create(&raster_key, raster_destructor);
 238
 239   DEBUG_printf(("raster_init(): raster_key=%x(%u)\n", (unsigned)raster_key,
 240                 (unsigned)raster_key));
 241 }
 242
 243
 244 /*
 245  * 'raster_destructor()' - Free memory allocated by get_error_buffer().
 246  */
 247
 248 static void
 249 raster_destructor(void *value)          /* I - Data to free */
 250 {
 251   _cups_raster_error_t *buf = (_cups_raster_error_t *)value;
 252                                         /* Error buffer */
 253
 254
 255   DEBUG_printf(("raster_destructor(value=%p)\n", value));
 256
 257   if (buf->start)
 258     free(buf->start);
 259
 260   free(value);
 261 }
 262
 263
 264 #else
 265 /*
 266  * Implement static globals...
 267  */
 268
 269 /*
 270  * 'get_error_buffer()' - Return a pointer to thread local storage.
 271  */
 272
 273 _cups_raster_error_t *                  /* O - Pointer to error buffer */
 274 get_error_buffer(void)
 275 {
 276   static _cups_raster_error_t buf = { 0, 0, 0 };
 277                                         /* Error buffer */
 278
 279
 280   return (&buf);
 281 }
 282 #endif /* HAVE_PTHREAD_H */
 283
 284
 285 /*
 286  * End of "$Id: error.c 7460 2008-04-16 02:19:54Z mike $".
 287  */