- Notifications
You must be signed in to change notification settings - Fork8k
Description
Description
Problem
Files
fileecho.php
<?php$fsize =1000;$chunksize =99;$chunks =floor($fsize /$chunksize);// 10 chunks * 99 bytes$lastchunksize =$fsize -$chunksize *$chunks;// 1 chunk * 10 bytesheader("Content-length:" .$fsize);flush();for ($chunk =1;$chunk <=$chunks;$chunk++) {echostr_repeat('x',$chunksize); @ob_flush();usleep(50 *1000);}echostr_repeat('x',$lastchunksize);
filetest.php
<?php$context =stream_context_create(['http' => ['ignore_errors' =>true,]]);$lastBytesTransferred =0;stream_context_set_params($context, ['notification' =>function ($code,$s,$m,$mc,$bytes_transferred,$bytes_max)use (&$lastBytesTransferred) {$progress =$bytes_max ?$bytes_transferred /$bytes_max *100 :0;$chunksize =$bytes_transferred -$lastBytesTransferred;if ($code ===STREAM_NOTIFY_PROGRESS)echo"\nprogress:$progress% ($bytes_transferred/$bytes_max b) (chunksize=$chunksize)";if ($code ===STREAM_NOTIFY_FILE_SIZE_IS)echo"\nexpected filesize=$bytes_max";if ($code ===STREAM_NOTIFY_COMPLETED)echo"\nSTREAM_NOTIFY_COMPLETED";$lastBytesTransferred =$bytes_transferred; @ob_flush();}]);$get =file_get_contents('http://localhost:8000/echo.php',false,$context);if (!$get)die("\nERROR during file_get_contents. is the local server running? ( php -\"dxdebug.mode\"=off -S localhost:8000 )\n");echo"\ngot filesize=" .strlen($get) .PHP_EOL;
CLI commands:
# to start local serverphp -S localhost:8000# to run the testphp test.php
Wrong output (happens irregularly):
> php .\src\test.phpexpected filesize= 1000progress: 0% (0/1000 b) (chunksize=0)progress: 9.9% (99/1000 b) (chunksize=99)progress: 19.8% (198/1000 b) (chunksize=99)progress: 29.7% (297/1000 b) (chunksize=99)progress: 39.6% (396/1000 b) (chunksize=99)progress: 49.5% (495/1000 b) (chunksize=99)progress: 59.4% (594/1000 b) (chunksize=99)progress: 69.3% (693/1000 b) (chunksize=99)progress: 79.2% (792/1000 b) (chunksize=99)progress: 89.1% (891/1000 b) (chunksize=99)progress: 90.1% (901/1000 b) (chunksize=10)got filesize=1000Correct output:
> php .\src\test.phpexpected filesize= 1000progress: 0% (0/1000 b) (chunksize=0)progress: 9.9% (99/1000 b) (chunksize=99)progress: 19.8% (198/1000 b) (chunksize=99)progress: 29.7% (297/1000 b) (chunksize=99)progress: 39.6% (396/1000 b) (chunksize=99)progress: 49.5% (495/1000 b) (chunksize=99)progress: 59.4% (594/1000 b) (chunksize=99)progress: 69.3% (693/1000 b) (chunksize=99)progress: 79.2% (792/1000 b) (chunksize=99)progress: 89.1% (891/1000 b) (chunksize=99)progress: 99% (990/1000 b) (chunksize=99)progress: 100% (1000/1000 b) (chunksize=10)got filesize=1000Description
The fileecho.php generates a series of 1000 consecutive"x"s. The data is emitted with intervals of 50ms (usleep(50 * 1000)), in 10 chunks sized 99bytes, plus one final chunk of 10bytes (99*10 + 10 = 1000).
The scripttest.php fetches the data from the url/echo.php of the local web server.file_get_contents is passed a context with anotification callback. This callback prints the download progress: percentage, bytes transferred, total bytes, current chunk size. The chunk size is calculated by subtracting theprevious$bytes_transferred from the current$bytes_transferred.
If you runphp test.php multiple times, you will see thatsometimes the event last 1/2STREAM_NOTIFY_PROGRESS events are not emitted correctly.
The last events shouldalways be:
progress: 89.1% (891/1000 b) (chunksize=99)= chunk 9progress: 99% (**990**/1000 b) (chunksize=**99**)= chunk 10progress: 100% (**1000**/1000 b) (chunksize=**10**)= chunk 11
Instead, sometimes the last chunks are messed up:
progress: 89.1% (891/1000 b) (chunksize=99)= chunk 9progress: 90.1% (**901**/1000 b) (chunksize=**10**)= chunk 10. This line here is the culprit. This chunk has the correct size of the last chunk (10 bytes), but it's reported as being the 10th! In reality, the 10th chunk is still 99bytes large, and the 11th is the 10bytes one.
When this problem occurs, 100% progress is never emitted (as the 10th chunk is mistaken for the 11th).
I don't think this is a problem in the communication betweenphp and the web server. Any possible delay in the communication shouldn't interfere with how the chunks are passed to the notification callback. I tried runningcurl -#O multiple times to see howcurl receives the data. This is the command line i used (powershell):1..10 | % { curl -#LO http://localhost:8000/echo.php *>&1 | php -r "preg_match_all('/[0-9\.]+/m', stream_get_contents(STDIN), `$m);echo implode(', ', `$m[0]).PHP_EOL;" ;}. For each iteration (1..10), this prints every progress percentage reported bycurl.
It prints something like this:
19.8, 39.6, 49.5, 59.4, 69.3, 79.2, 99.0, 100.019.8, 29.7, 39.6, 49.5, 59.4, 69.3, 79.2, 89.1, 99.0, 100.019.8, 29.7, 39.6, 49.5, 59.4, 69.3, 89.1, 99.0, 100.019.8, 39.6, 49.5, 59.4, 69.3, 79.2, 89.1, 99.0, 100.019.8, 29.7, 39.6, 49.5, 59.4, 69.3, 79.2, 99.0, 100.019.8, 29.7, 39.6, 59.4, 69.3, 79.2, 89.1, 99.0, 100.019.8, 29.7, 39.6, 49.5, 59.4, 79.2, 89.1, 99.0, 100.019.8, 29.7, 39.6, 49.5, 59.4, 69.3, 79.2, 89.1, 99.0, 100.019.8, 39.6, 49.5, 59.4, 69.3, 79.2, 89.1, 99.0, 100.019.8, 29.7, 39.6, 49.5, 59.4, 69.3, 79.2, 89.1, 99.0, 100.0As you can see,curl doesn't always report its progress, but even though it skips some reporting, it always has the correct progress percentages. It always ends with89.1,99.0,100.0, which is the correct sequence.
php on the other hand sometimes ends with89.1,90.1.
In conclusion, at the moment theSTREAM_NOTIFY_PROGRESS event is not reliable.
I cannot determinewhy this problem occures only sometimes. I really can't. This appearsextremely frequently when the chunks are transferred with varying sizes (eg if the php script on the server callsreadfile(), and/or if the connection to the server is not stable).
PHP Version
PHP 8.1.12
Operating System
Windows 11 (10.0.22621.819)