Bug #10166 Updated: read_exif_data loads whole image into memory

ID: 10166 Updated by: sniper Reported By: vvo@geocities.com Old Status: Feedback Status: Closed Bug Type: *Graphics related Operating System: Linux 2.2 PHP Version: 4.0 Latest CVS (04/04/2001) New Comment: Reopen if this isn't what you wanted. Previous Comments: ------------------------------------------------------------------------ [2001-07-30 13:03:01] sniper@php.net In latest CVS there I have added an optional parameter for read_exif_data(): proto read_exif_data(string filename [, int readall]) By setting 'readall' to 0 you can prevent it from loading all of the file into memory. Please test this. --Jani ------------------------------------------------------------------------ [2001-04-04 13:48:56] vvo@geocities.com Some users observed that read_exif_data is too slow with 1MB image files, which is a typical size for digital camera output. I looked into the implementation (ext/exif/exif.c) and it looks like the whole compressed image data is always read into memory, even though read_exif_data should be concerned with just the file header. Here's a line from function read_exif_data: <PRE> ret = php_read_jpeg_exif(&ImageInfo, (*p_name)->value.str.val,1); </PRE> The last parameter (ReadAll=1), causes the whole image data loaded into memory inside function scan_JPEG_header: <PRE> if (ReadAll) { int cp, ep, size; /* Determine how much file is left. */ cp = ftell(infile); fseek(infile, 0, SEEK_END); ep = ftell(infile); fseek(infile, cp, SEEK_SET); size = ep-cp; Data = (uchar *)malloc(size); if (Data == NULL) { php_error(E_ERROR,"could not allocate data for entire image"); } got = fread(Data, 1, size, infile); if (got != size) { php_error(E_ERROR,"could not read the rest of the image"); } Sections[*SectionsRead].Data = Data; Sections[*SectionsRead].Size = size; Sections[*SectionsRead].Type = PSEUDO_IMAGE_MARKER; (*SectionsRead)++; /* *HaveAll = 1; */ } return TRUE; </PRE> I believe the line above should be changed to feed 0 as value of parameter ReadAll. Thanks. V ------------------------------------------------------------------------ Edit this bug report at http://bugs.php.net/?id=10166&edit=1