jerror.cpp

来自「Windows 图形编程 书籍」· C++ 代码 · 共 326 行

//-------------------------------------------------------------------------//
//          Windows Graphics Programming: Win32 GDI and DirectDraw         //
//                        ISBN  0-13-086985-6                              //
//                                                                         //
//  Modified by: Yuan, Feng                             www.fengyuan.com   //
//  Changes    : C++, exception, in-memory source, BGR byte order          //
//  Version    : 1.00.000, May 31, 2000                                    //
//-------------------------------------------------------------------------//

/*
 * 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.
 */

jpeg_error_mgr::~jpeg_error_mgr()
{
}

void jpeg_error_mgr::error_exit(j_common_ptr cinfo)
{
	/* Always display the message */
	output_message();

	/* Let the memory manager delete any temp files before we die */
	// cinfo->jpeg_destroy();

	throw msg_code; // C++ exception
}


/*
 * 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.
 */

void jpeg_error_mgr::output_message(void)
{
	char buffer[JMSG_LENGTH_MAX];

	// Create the message
	format_message(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.
 */

void jpeg_error_mgr::emit_message(int msg_level)
{
	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 (num_warnings == 0 || trace_level >= 3)
			output_message();
		/* Always count warnings in num_warnings. */
		num_warnings++;
	} 
	else 
	{
		/* It's a trace message.  Show it if trace_level >= msg_level. */
		if (trace_level >= msg_level)
			output_message();
	}
}


/*
 * 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.
 */

void jpeg_error_mgr::format_message (char * buffer)
{
	const char * msgtext = NULL;
	const char * msgptr;
	char ch;
	boolean isstring;

	/* Look up message string in proper table */
	if (msg_code > 0 && msg_code <= last_jpeg_message) {
		msgtext = jpeg_message_table[msg_code];
	} 
	else if (addon_message_table != NULL &&
	     msg_code >= first_addon_message &&
	     msg_code <= last_addon_message) 
	{
		msgtext = addon_message_table[msg_code - first_addon_message];
	}

	/* Defend against bogus message number */
	if (msgtext == NULL) 
	{
		msg_parm.i[0] = msg_code;
		msgtext = 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, msg_parm.s);
	else
		sprintf(buffer, msgtext,
			msg_parm.i[0], msg_parm.i[1],
			msg_parm.i[2], msg_parm.i[3],
			msg_parm.i[4], msg_parm.i[5],
			msg_parm.i[6], 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.
 */

void jpeg_error_mgr::reset_error_mgr(void)
{
	num_warnings = 0;
					/* trace_level is not reset since it is an application-supplied parameter */
	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.
 */

// constructor
jpeg_error_mgr::jpeg_error_mgr(void)
{
	trace_level  = 0;	/* default = no tracing */
	num_warnings = 0;	/* no warnings emitted yet */
	msg_code     = 0;	/* may be useful as a flag for "no error" */

	/* Initialize message table pointers */
	jpeg_message_table = jpeg_std_message_table;
	last_jpeg_message = (int) JMSG_LASTMSGCODE - 1;

	addon_message_table = NULL;
	first_addon_message = 0;	/* for safety */
	last_addon_message = 0;
}

void jpeg_common_struct::ERREXIT(int code)
{
	err->msg_code = code;
	err->error_exit(this);
}

void jpeg_common_struct::ERREXIT1(int code, int p1)
{
	err->msg_code      = code;
	err->msg_parm.i[0] = p1;
    err->error_exit(this);
}

void jpeg_common_struct::ERREXIT2(int code, int p1, int p2)
{
	err->msg_code      = code;
	err->msg_parm.i[0] = p1;
	err->msg_parm.i[1] = p2;
    err->error_exit(this);
}

void jpeg_common_struct::ERREXIT3(int code, int p1, int p2, int p3)
{
	err->msg_code      = code;
	err->msg_parm.i[0] = p1;
	err->msg_parm.i[1] = p2;
	err->msg_parm.i[2] = p3;
    err->error_exit(this);
}

void jpeg_common_struct::ERREXIT4(int code, int p1, int p2, int p3, int p4)
{
	err->msg_code      = code;
	err->msg_parm.i[0] = p1;
	err->msg_parm.i[1] = p2;
	err->msg_parm.i[2] = p3;
	err->msg_parm.i[3] = p4;
    err->error_exit(this);
}

void jpeg_common_struct::ERREXITS(int code, const char * msg)
{
	err->msg_code = code;
	strncpy(err->msg_parm.s, msg, JMSG_STR_PARM_MAX);
	err->error_exit(this);
}

void jpeg_common_struct::WARNMS(int code)
{
	err->msg_code = code;
	
	err->emit_message(-1);
}

void jpeg_common_struct::WARNMS1(int code, int p1)
{
	err->msg_code      = code;
	err->msg_parm.i[0] = p1;
	
	err->emit_message(-1);
}

void jpeg_common_struct::WARNMS2(int code, int p1, int p2)
{
	err->msg_code      = code;
	err->msg_parm.i[0] = p1;
	err->msg_parm.i[1] = p2;
	
	err->emit_message(-1);
}