#17825 [Asn->Csd]: problem using chunk_size argument to ob_start()

ID: 17825 Updated by: yohgaki@php.net Reported By: hhr02368@haris.org -Status: Assigned +Status: Closed Bug Type: Output Control Operating System: linux redhat 6.2 PHP Version: 4.3.0-dev Assigned To: yohgaki New Comment: This bug has been fixed in CVS. In case this was a PHP problem, snapshots of the sources are packaged every three hours; this change will be in the next snapshot. You can grab the snapshot at http://snaps.php.net/. In case this was a documentation problem, the fix will show up soon at http://www.php.net/manual/. In case this was a PHP.net website problem, the change will show up on the PHP.net site and on the mirror sites in short time. Thank you for the report, and for helping us make PHP better. It was rather obvious :) Previous Comments: ------------------------------------------------------------------------ [2002-10-01 04:59:17] yohgaki@php.net Found what's wrong. OG(active_ob_buffer).output_handler is destoryed after 1st call for some reason. Fix will be committed in a few days. ------------------------------------------------------------------------ [2002-09-30 17:39:38] sniper@php.net be specific about the version.. ------------------------------------------------------------------------ [2002-09-29 22:40:11] iliaa@php.net verified & bumped version #. ------------------------------------------------------------------------ [2002-06-18 21:35:40] hhr02368@haris.org Test environment: A) apache 1.3.24, PHP 4.2.1 built as apache module B) apache 1.3.23, PHP 4.1.2 built as apache module The following program demonstrates the change in behavior between versions 4.1.2 and 4.2.1: <? function output_handler($buffer, $mode) { static $s_count; $s_count++; error_log("output_handler: s_count=$s_count " . "strlen(buffer)=" . strlen($buffer) . "\n", 3, '/tmp/logfile'); return strtoupper($buffer); } header("Content-Type: text/plain"); ob_start('output_handler', 400); for ($i=0; $i<20; $i++) { echo sprintf("%5d the quick brown fox jumped over the lazy dog\n", $i); } ?> Our expectation is that output_handler() will get called multiple times, every time there are more than 100 bytes of output to process or when explicit ob_flush is called. Running with php 4.2.1 (test environment A) output_handler() is called only once: > cat /tmp/logfile > output_handler: s_count=1 strlen(buffer)=102 The browser displays: > 0 THE QUICK BROWN FOX JUMPED OVER THE LAZY DOG > 1 THE QUICK BROWN FOX JUMPED OVER THE LAZY DOG > 2 the quick brown fox jumped over the lazy dog > 3 the quick brown fox jumped over the lazy dog > 4 the quick brown fox jumped over the lazy dog It appears that after the 1st time, our output is sent to the browser unprocessed. If using ob_gzhandler() the results are more unpleasant as the first buffer is compressed but the rest are sent uncompressed, confusing the browser. If ob_start() is called without the 2nd argument then output_handler() is called once to process the complete output. This results in correct output but is undesirable because for some scripts this buffer can be very large. Running the same program with php 4.1.2 (test environment B) output_handler() is called 3 times: > cat /tmp/logfile > output_handler: s_count=1 strlen(buffer)=102 > output_handler: s_count=2 strlen(buffer)=102 > output_handler: s_count=3 strlen(buffer)=51 The browser displays: > 0 THE QUICK BROWN FOX JUMPED OVER THE LAZY DOG > 1 THE QUICK BROWN FOX JUMPED OVER THE LAZY DOG > 2 THE QUICK BROWN FOX JUMPED OVER THE LAZY DOG > 3 THE QUICK BROWN FOX JUMPED OVER THE LAZY DOG > 4 THE QUICK BROWN FOX JUMPED OVER THE LAZY DOG > 5 THE QUICK BROWN FOX JUMPED OVER THE LAZY DOG ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=17825&edit=1