#33070 [NEW]: bzdecompress inefficient

From: lindsay at bitleap dot com Operating system: Linux 2.6.10 kernel PHP version: 5.0.3 PHP Bug Type: Performance problem Bug description: bzdecompress inefficient Description: ------------ I found bug #13860 regarding bzdecompress speeds on 4.2.x. The bug suggests its fixed for 4.2.0 but I see slowness in 5.0.3. On 5.0.3, bzdecompress seems to get exponentionally slower as data sizes increase. I timed the length of decompression on increasing file sizes containing compressed random data: file length 256K ran in: 2 seconds file length 512K ran in: 10 seconds file length 1M ran in: 41 seconds file length 2M ran in: 135 seconds file length 3M ran in: 278 seconds file length 4M ran in: 476 seconds I'm not a c coder but the do while loop at line 472 of: http://cvs.php.net/co.php/php-src/ext/bz2/bz2.c?r=1.9 seems to decompress the string over and over. Each iteration attempts a decompress w/ a buffer size based on the iteration count. If the decompress fails, a larger buffer is tried. If I'm reading this correctly, the same data could be decompressed hundreds of times until the buffer gets large enough. -- Edit bug report at http://bugs.php.net/?id=33070&edit=1 -- Try a CVS snapshot (php4): http://bugs.php.net/fix.php?id=33070&r=trysnapshot4 Try a CVS snapshot (php5.0): http://bugs.php.net/fix.php?id=33070&r=trysnapshot50 Try a CVS snapshot (php5.1): http://bugs.php.net/fix.php?id=33070&r=trysnapshot51 Fixed in CVS: http://bugs.php.net/fix.php?id=33070&r=fixedcvs Fixed in release: http://bugs.php.net/fix.php?id=33070&r=alreadyfixed Need backtrace: http://bugs.php.net/fix.php?id=33070&r=needtrace Need Reproduce Script: http://bugs.php.net/fix.php?id=33070&r=needscript Try newer version: http://bugs.php.net/fix.php?id=33070&r=oldversion Not developer issue: http://bugs.php.net/fix.php?id=33070&r=support Expected behavior: http://bugs.php.net/fix.php?id=33070&r=notwrong Not enough info: http://bugs.php.net/fix.php?id=33070&r=notenoughinfo Submitted twice: http://bugs.php.net/fix.php?id=33070&r=submittedtwice register_globals: http://bugs.php.net/fix.php?id=33070&r=globals PHP 3 support discontinued: http://bugs.php.net/fix.php?id=33070&r=php3 Daylight Savings: http://bugs.php.net/fix.php?id=33070&r=dst IIS Stability: http://bugs.php.net/fix.php?id=33070&r=isapi Install GNU Sed: http://bugs.php.net/fix.php?id=33070&r=gnused Floating point limitations: http://bugs.php.net/fix.php?id=33070&r=float No Zend Extensions: http://bugs.php.net/fix.php?id=33070&r=nozend MySQL Configuration Error: http://bugs.php.net/fix.php?id=33070&r=mysqlcfg