Bug Report #1258

Kohana flushes its output buffer during `shutdown()` rather than `close_buffers()`

Added by Chris Bandy almost 3 years ago. Updated over 2 years ago.

Status:Closed Start date:
Priority:High Due date:
Assignee:- % Done:

0%
Category:Core
Target version:2.3.3
Resolution:fixed Points:

Description

Output buffering is A Good Thing, but disabling output_buffering in php.ini (or htaccess) allows streaming. Kohana's internal output buffering handles this configuration, but not when a Controller tries to stream. This affects downloads as evidenced in #1107.

I'm not sure how Kohana is expected to behave, but here is a test case and results with output compression disabled.

A_Controller::index() {
    echo Kohana::debug('Before: '. ob_get_level());
    Kohana::close_buffers();
    echo Kohana::debug('After: '. ob_get_level());

    echo "first content\n";
    flush();
    sleep(2);
    echo "second content\n";
}

Kohana::close_buffers() {
    echo Kohana::debug('close_buffers: '. ob_get_level() .':'. self::$buffer_level);
    ...
}

Current Results

PHP Output Buffering = 4096 (Large buffer)

Delay precedes all output. Not all content is shown.

(string) Before: 2
(string) close_buffers: 2:2

PHP Output Buffering = 2 (Small buffer)

Delay follows "first content". Kohana buffer is flushed late.

(string) After: 1
first content
second content
(string) close_buffers: 1:1
(string) Before: 2
(string) close_buffers: 2:2

PHP Output Buffering = 0 (Off)

Delay follows "first content". Kohana buffer is flushed late.

(string) After: 0
first content
second content
(string) close_buffers: 0:0

<!-- E_NOTICE Stack trace -->
>system/core/Kohana.php r674:
ob_end_clean() [ref.outcontrol]: failed to delete buffer. No buffer to delete.
...
<!-- End Stack trace -->

(string) close_buffers: 0:0

Notice: ob_end_clean() [ref.outcontrol]: failed to delete buffer. No buffer to delete. in /home/cbandy/projects/kohana/system/core/Kohana.php on line 674

(string) Before: 1
(string) close_buffers: 1:1

0001-Allow-close_buffer-to-be-called-regardless-of-PHP.patch - against trunk (1.8 kB) Chris Bandy, 05/12/2009 08:42 pm

Related issues

blocks Kohana v2.x - Bug Report #1107: download helper causes an error 2.4 Closed

History

#1
Updated by Chris Bandy over 2 years ago

Upon further investigation, it is unreasonable for an application to flush the Kohana buffer since this buffer is passed to the system.display event during shutdown. To clear the buffer, one should call

Kohana::close_buffers(FALSE);
Kohana::$output = '';

The ob_end_clean() error reported above occurs any time close_buffers() is called more than the number of buffer levels.

The attached patch fixes this error, clarifies comments surrounding output buffering, and makes output consistent for different PHP configurations.

Results after patch

PHP Output Buffering = 4096 (Large buffer)

Delay precedes all output. All content is shown.

(string) After: 1
first content second content
(string) close_buffers: 1:2
(string) Before: 2
(string) close_buffers: 2:2

PHP Output Buffering = 2 (Small buffer)

Delay follows "first content". All content is shown.

(string) After: 1
first content second content
(string) close_buffers: 1:2
(string) Before: 2
(string) close_buffers: 2:2

PHP Output Buffering = 0 (Off)

Delay follows "first content". All content is shown.

(string) After: 0
first content second content
(string) close_buffers: 0:1
(string) Before: 1
(string) close_buffers: 1:1

#2
Updated by Parnell Springmeyer over 2 years ago

  • Status changed from New to Closed
  • Resolution set to fixed

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