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							- /*
 -  * jerror.c
 -  *
 -  * Copyright (C) 1991-1998, Thomas G. Lane.
 -  * This file is part of the Independent JPEG Group's software.
 -  * For conditions of distribution and use, see the accompanying README file.
 -  *
 -  * This file contains simple error-reporting and trace-message routines.
 -  * These are suitable for Unix-like systems and others where writing to
 -  * stderr is the right thing to do.  Many applications will want to replace
 -  * some or all of these routines.
 -  *
 -  * If you define USE_WINDOWS_MESSAGEBOX in jconfig.h or in the makefile,
 -  * you get a Windows-specific hack to display error messages in a dialog box.
 -  * It ain't much, but it beats dropping error messages into the bit bucket,
 -  * which is what happens to output to stderr under most Windows C compilers.
 -  *
 -  * These routines are used by both the compression and decompression code.
 -  */
 - 
 - /* this is not a core library module, so it doesn't define JPEG_INTERNALS */
 - #include "jinclude.h"
 - #include "jpeglib.h"
 - #include "jversion.h"
 - #include "jerror.h"
 - 
 - #ifdef USE_WINDOWS_MESSAGEBOX
 - #include <windows.h>
 - #endif
 - 
 - #ifndef EXIT_FAILURE		/* define exit() codes if not provided */
 - #define EXIT_FAILURE  1
 - #endif
 - 
 - 
 - /*
 -  * Create the message string table.
 -  * We do this from the master message list in jerror.h by re-reading
 -  * jerror.h with a suitable definition for macro JMESSAGE.
 -  * The message table is made an external symbol just in case any applications
 -  * want to refer to it directly.
 -  */
 - 
 - #ifdef NEED_SHORT_EXTERNAL_NAMES
 - #define jpeg_std_message_table	jMsgTable
 - #endif
 - 
 - #define JMESSAGE(code,string)	string ,
 - 
 - const char * const jpeg_std_message_table[] = {
 - #include "jerror.h"
 -   NULL
 - };
 - 
 - 
 - /*
 -  * Error exit handler: must not return to caller.
 -  *
 -  * Applications may override this if they want to get control back after
 -  * an error.  Typically one would longjmp somewhere instead of exiting.
 -  * The setjmp buffer can be made a private field within an expanded error
 -  * handler object.  Note that the info needed to generate an error message
 -  * is stored in the error object, so you can generate the message now or
 -  * later, at your convenience.
 -  * You should make sure that the JPEG object is cleaned up (with jpeg_abort
 -  * or jpeg_destroy) at some point.
 -  */
 - 
 - METHODDEF(void)
 - error_exit (j_common_ptr cinfo)
 - {
 -   /* Always display the message */
 -   (*cinfo->err->output_message) (cinfo);
 - 
 -   /* Let the memory manager delete any temp files before we die */
 -   jpeg_destroy(cinfo);
 - 
 -   exit(EXIT_FAILURE);
 - }
 - 
 - 
 - /*
 -  * Actual output of an error or trace message.
 -  * Applications may override this method to send JPEG messages somewhere
 -  * other than stderr.
 -  *
 -  * On Windows, printing to stderr is generally completely useless,
 -  * so we provide optional code to produce an error-dialog popup.
 -  * Most Windows applications will still prefer to override this routine,
 -  * but if they don't, it'll do something at least marginally useful.
 -  *
 -  * NOTE: to use the library in an environment that doesn't support the
 -  * C stdio library, you may have to delete the call to fprintf() entirely,
 -  * not just not use this routine.
 -  */
 - 
 - METHODDEF(void)
 - output_message (j_common_ptr cinfo)
 - {
 -   char buffer[JMSG_LENGTH_MAX];
 - 
 -   /* Create the message */
 -   (*cinfo->err->format_message) (cinfo, buffer);
 - 
 - #ifdef USE_WINDOWS_MESSAGEBOX
 -   /* Display it in a message dialog box */
 -   MessageBox(GetActiveWindow(), buffer, "JPEG Library Error",
 - 	     MB_OK | MB_ICONERROR);
 - #else
 -   /* Send it to stderr, adding a newline */
 -   fprintf(stderr, "%s\n", buffer);
 - #endif
 - }
 - 
 - 
 - /*
 -  * Decide whether to emit a trace or warning message.
 -  * msg_level is one of:
 -  *   -1: recoverable corrupt-data warning, may want to abort.
 -  *    0: important advisory messages (always display to user).
 -  *    1: first level of tracing detail.
 -  *    2,3,...: successively more detailed tracing messages.
 -  * An application might override this method if it wanted to abort on warnings
 -  * or change the policy about which messages to display.
 -  */
 - 
 - METHODDEF(void)
 - emit_message (j_common_ptr cinfo, int msg_level)
 - {
 -   struct jpeg_error_mgr * err = cinfo->err;
 - 
 -   if (msg_level < 0) {
 -     /* It's a warning message.  Since corrupt files may generate many warnings,
 -      * the policy implemented here is to show only the first warning,
 -      * unless trace_level >= 3.
 -      */
 -     if (err->num_warnings == 0 || err->trace_level >= 3)
 -       (*err->output_message) (cinfo);
 -     /* Always count warnings in num_warnings. */
 -     err->num_warnings++;
 -   } else {
 -     /* It's a trace message.  Show it if trace_level >= msg_level. */
 -     if (err->trace_level >= msg_level)
 -       (*err->output_message) (cinfo);
 -   }
 - }
 - 
 - 
 - /*
 -  * Format a message string for the most recent JPEG error or message.
 -  * The message is stored into buffer, which should be at least JMSG_LENGTH_MAX
 -  * characters.  Note that no '\n' character is added to the string.
 -  * Few applications should need to override this method.
 -  */
 - 
 - METHODDEF(void)
 - format_message (j_common_ptr cinfo, char * buffer)
 - {
 -   struct jpeg_error_mgr * err = cinfo->err;
 -   int msg_code = err->msg_code;
 -   const char * msgtext = NULL;
 -   const char * msgptr;
 -   char ch;
 -   boolean isstring;
 - 
 -   /* Look up message string in proper table */
 -   if (msg_code > 0 && msg_code <= err->last_jpeg_message) {
 -     msgtext = err->jpeg_message_table[msg_code];
 -   } else if (err->addon_message_table != NULL &&
 - 	     msg_code >= err->first_addon_message &&
 - 	     msg_code <= err->last_addon_message) {
 -     msgtext = err->addon_message_table[msg_code - err->first_addon_message];
 -   }
 - 
 -   /* Defend against bogus message number */
 -   if (msgtext == NULL) {
 -     err->msg_parm.i[0] = msg_code;
 -     msgtext = err->jpeg_message_table[0];
 -   }
 - 
 -   /* Check for string parameter, as indicated by %s in the message text */
 -   isstring = FALSE;
 -   msgptr = msgtext;
 -   while ((ch = *msgptr++) != '\0') {
 -     if (ch == '%') {
 -       if (*msgptr == 's') isstring = TRUE;
 -       break;
 -     }
 -   }
 - 
 -   /* Format the message into the passed buffer */
 -   if (isstring)
 -     sprintf(buffer, msgtext, err->msg_parm.s);
 -   else
 -     sprintf(buffer, msgtext,
 - 	    err->msg_parm.i[0], err->msg_parm.i[1],
 - 	    err->msg_parm.i[2], err->msg_parm.i[3],
 - 	    err->msg_parm.i[4], err->msg_parm.i[5],
 - 	    err->msg_parm.i[6], err->msg_parm.i[7]);
 - }
 - 
 - 
 - /*
 -  * Reset error state variables at start of a new image.
 -  * This is called during compression startup to reset trace/error
 -  * processing to default state, without losing any application-specific
 -  * method pointers.  An application might possibly want to override
 -  * this method if it has additional error processing state.
 -  */
 - 
 - METHODDEF(void)
 - reset_error_mgr (j_common_ptr cinfo)
 - {
 -   cinfo->err->num_warnings = 0;
 -   /* trace_level is not reset since it is an application-supplied parameter */
 -   cinfo->err->msg_code = 0;	/* may be useful as a flag for "no error" */
 - }
 - 
 - 
 - /*
 -  * Fill in the standard error-handling methods in a jpeg_error_mgr object.
 -  * Typical call is:
 -  *	struct jpeg_compress_struct cinfo;
 -  *	struct jpeg_error_mgr err;
 -  *
 -  *	cinfo.err = jpeg_std_error(&err);
 -  * after which the application may override some of the methods.
 -  */
 - 
 - GLOBAL(struct jpeg_error_mgr *)
 - jpeg_std_error (struct jpeg_error_mgr * err)
 - {
 -   err->error_exit = error_exit;
 -   err->emit_message = emit_message;
 -   err->output_message = output_message;
 -   err->format_message = format_message;
 -   err->reset_error_mgr = reset_error_mgr;
 - 
 -   err->trace_level = 0;		/* default = no tracing */
 -   err->num_warnings = 0;	/* no warnings emitted yet */
 -   err->msg_code = 0;		/* may be useful as a flag for "no error" */
 - 
 -   /* Initialize message table pointers */
 -   err->jpeg_message_table = jpeg_std_message_table;
 -   err->last_jpeg_message = (int) JMSG_LASTMSGCODE - 1;
 - 
 -   err->addon_message_table = NULL;
 -   err->first_addon_message = 0;	/* for safety */
 -   err->last_addon_message = 0;
 - 
 -   return err;
 - }
 
 
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