Bug #55781 [NEW]: exif_read_file assumes only stdio supports stat(), performs slow seek to end

From: Operating system: All PHP version: 5.3.8 Package: EXIF related Bug Type: Bug Bug description:exif_read_file assumes only stdio supports stat(), performs slow seek to end Description: ------------ Per Twitter exchange with @pierrejoye The exif_read_file function checks whether the file is accessed over stdio. If it is accessed over stdio, VCWD_STAT() is used to get the size of the file efficiently. If it is accessed by any other means, this pattern is used: php_stream_seek(ImageInfo->infile, 0, SEEK_END); ImageInfo->FileSize = php_stream_tell(ImageInfo- >infile); php_stream_seek(ImageInfo->infile, 0, SEEK_SET); Moving the seek pointer to the end can trigger slow, bandwidth-hungry network operations for remote stream wrappers, such as S3 wrappers. Please test whether the stream implements the stat operation and, if so, use it to avoid this performance hit. I was able to work around the problem by teaching my stream wrapper to specifically tolerate the "seek to the end / ftell / seek to the start" pattern and return cached data. -- Edit bug report at https://bugs.php.net/bug.php?id=55781&edit=1 -- Try a snapshot (PHP 5.4): https://bugs.php.net/fix.php?id=55781&r=trysnapshot54 Try a snapshot (PHP 5.3): https://bugs.php.net/fix.php?id=55781&r=trysnapshot53 Try a snapshot (trunk): https://bugs.php.net/fix.php?id=55781&r=trysnapshottrunk Fixed in SVN: https://bugs.php.net/fix.php?id=55781&r=fixed Fixed in SVN and need be documented: https://bugs.php.net/fix.php?id=55781&r=needdocs Fixed in release: https://bugs.php.net/fix.php?id=55781&r=alreadyfixed Need backtrace: https://bugs.php.net/fix.php?id=55781&r=needtrace Need Reproduce Script: https://bugs.php.net/fix.php?id=55781&r=needscript Try newer version: https://bugs.php.net/fix.php?id=55781&r=oldversion Not developer issue: https://bugs.php.net/fix.php?id=55781&r=support Expected behavior: https://bugs.php.net/fix.php?id=55781&r=notwrong Not enough info: https://bugs.php.net/fix.php?id=55781&r=notenoughinfo Submitted twice: https://bugs.php.net/fix.php?id=55781&r=submittedtwice register_globals: https://bugs.php.net/fix.php?id=55781&r=globals PHP 4 support discontinued: https://bugs.php.net/fix.php?id=55781&r=php4 Daylight Savings: https://bugs.php.net/fix.php?id=55781&r=dst IIS Stability: https://bugs.php.net/fix.php?id=55781&r=isapi Install GNU Sed: https://bugs.php.net/fix.php?id=55781&r=gnused Floating point limitations: https://bugs.php.net/fix.php?id=55781&r=float No Zend Extensions: https://bugs.php.net/fix.php?id=55781&r=nozend MySQL Configuration Error: https://bugs.php.net/fix.php?id=55781&r=mysqlcfg