jpeg_open_backing_store (j_common_ptr cinfo, backing_store_ptr info,
long total_bytes_needed)
{
short tmpRef, vRefNum;
long dirID;
FInfo finderInfo;
FSSpec theSpec;
Str255 fName;
OSErr osErr;
long gestaltResponse = 0;
/* Check that FSSpec calls are available. */
osErr = Gestalt( gestaltFSAttr, &gestaltResponse );
if ( ( osErr != noErr )
|| !( gestaltResponse & (1<<gestaltHasFSSpecCalls) ) )
ERREXITS(cinfo, JERR_TFILE_CREATE, "- System 7.0 or later required");
/* TO DO: add a proper error message to jerror.h. */
/* Check that FindFolder is available. */
osErr = Gestalt( gestaltFindFolderAttr, &gestaltResponse );
if ( ( osErr != noErr )
|| !( gestaltResponse & (1<<gestaltFindFolderPresent) ) )
ERREXITS(cinfo, JERR_TFILE_CREATE, "- System 7.0 or later required.");
/* TO DO: add a proper error message to jerror.h. */
osErr = FindFolder ( kOnSystemDisk, kTemporaryFolderType, kCreateFolder,
&vRefNum, &dirID );
if ( osErr != noErr )
ERREXITS(cinfo, JERR_TFILE_CREATE, "- temporary items folder unavailable");
/* TO DO: Try putting the temp files somewhere else. */
/* Keep generating file names till we find one that's not in use */
for (;;) {
next_file_num++; /* advance counter */
sprintf(info->temp_name, TEMP_FILE_NAME, next_file_num);
strcpy ( (Ptr)fName+1, info->temp_name );
*fName = strlen (info->temp_name);
osErr = FSMakeFSSpec ( vRefNum, dirID, fName, &theSpec );
if ( (osErr = FSpGetFInfo ( &theSpec, &finderInfo ) ) != noErr )
break;
}
osErr = FSpCreate ( &theSpec, '????', '????', smSystemScript );
if ( osErr != noErr )
ERREXITS(cinfo, JERR_TFILE_CREATE, info->temp_name);
osErr = FSpOpenDF ( &theSpec, fsRdWrPerm, &(info->temp_file) );
if ( osErr != noErr )
ERREXITS(cinfo, JERR_TFILE_CREATE, info->temp_name);
info->tempSpec = theSpec;
info->read_backing_store = read_backing_store;
info->write_backing_store = write_backing_store;
info->close_backing_store = close_backing_store;
TRACEMSS(cinfo, 1, JTRC_TFILE_OPEN, info->temp_name);
}
close_backing_store (j_common_ptr cinfo, backing_store_ptr info)
{
fclose(info->temp_file); /* close the file */
unlink(info->temp_name); /* delete the file */
/* If your system doesn't have unlink(), use remove() instead.
* remove() is the ANSI-standard name for this function, but if
* your system was ANSI you'd be using jmemansi.c, right?
*/
TRACEMSS(cinfo, 1, JTRC_TFILE_CLOSE, info->temp_name);
}
close_file_store (j_common_ptr cinfo, backing_store_ptr info)
{
jdos_close(info->handle.file_handle); /* close the file */
remove(info->temp_name); /* delete the file */
/* If your system doesn't have remove(), try unlink() instead.
* remove() is the ANSI-standard name for this function, but
* unlink() was more common in pre-ANSI systems.
*/
TRACEMSS(cinfo, 1, JTRC_TFILE_CLOSE, info->temp_name);
}
GLOBAL void jpeg_open_backing_store(j_common_ptr cinfo, backing_store_ptr info, long total_bytes_needed)
{
select_file_name(info->temp_name);
if((info->temp_file = fopen(info->temp_name, RW_BINARY)) == NULL)
ERREXITS(cinfo, JERR_TFILE_CREATE, info->temp_name);
info->read_backing_store = read_backing_store;
info->write_backing_store = write_backing_store;
info->close_backing_store = close_backing_store;
TRACEMSS(cinfo, 1, JTRC_TFILE_OPEN, info->temp_name);
}
open_file_store (j_common_ptr cinfo, backing_store_ptr info,
long total_bytes_needed)
{
short handle;
select_file_name(info->temp_name);
if (jdos_open((short far *) & handle, (char far *) info->temp_name)) {
/* might as well exit since jpeg_open_backing_store will fail anyway */
ERREXITS(cinfo, JERR_TFILE_CREATE, info->temp_name);
return FALSE;
}
info->handle.file_handle = handle;
info->read_backing_store = read_file_store;
info->write_backing_store = write_file_store;
info->close_backing_store = close_file_store;
TRACEMSS(cinfo, 1, JTRC_TFILE_OPEN, info->temp_name);
return TRUE; /* succeeded */
}
