#35090 [NEW]: file i/o is not buffered

From: askalski at gmail dot com Operating system: linux PHP version: 5CVS-2005-11-03 (snap) PHP Bug Type: Filesystem function related Bug description: file i/o is not buffered Description: ------------ The documentation for stream_set_write_buffer() says that fwrite()s are buffered at 8K by default. In reality, it does not buffer at all. Any attempt to call stream_set_write_buffer() on a regular file handle results in failure. Reproduce code: --------------- $fh = fopen("asdf", "w"); // write some data using the default buffering for ($i = 0; $i < 5; $i++) fwrite($fh, "test"); // demonstrate that stream_set_write_buffer fails $n = stream_set_write_buffer($fh, 8192); if ($n != 0) echo "stream_set_write_buffer failed\n"; // write some more data to demonstrate the failure for ($i = 0; $i < 5; $i++) fwrite($fh, "again"); fclose($fh); Expected result: ---------------- PHP should buffer its I/O, and strace should log a single write(). stream_set_write_buffer() should not fail on regular files. Actual result: -------------- Output: stream_set_write_buffer failed Abridged strace output: open("/tmp/php5-200511031730/asdf", O_WRONLY|O_CREAT|O_TRUNC, 0666) = 3 fstat64(3, {st_mode=S_IFREG|0600, st_size=0, ...}) = 0 lseek(3, 0, SEEK_CUR) = 0 write(3, "test", 4) = 4 write(3, "test", 4) = 4 write(3, "test", 4) = 4 write(3, "test", 4) = 4 write(3, "test", 4) = 4 write(1, "stream_set_write_buffer failed\n", 31) = 31 write(3, "again", 5) = 5 write(3, "again", 5) = 5 write(3, "again", 5) = 5 write(3, "again", 5) = 5 write(3, "again", 5) = 5 close(3) = 0 -- Edit bug report at http://bugs.php.net/?id=35090&edit=1 -- Try a CVS snapshot (php4): http://bugs.php.net/fix.php?id=35090&r=trysnapshot4 Try a CVS snapshot (php5.0): http://bugs.php.net/fix.php?id=35090&r=trysnapshot50 Try a CVS snapshot (php5.1): http://bugs.php.net/fix.php?id=35090&r=trysnapshot51 Fixed in CVS: http://bugs.php.net/fix.php?id=35090&r=fixedcvs Fixed in release: http://bugs.php.net/fix.php?id=35090&r=alreadyfixed Need backtrace: http://bugs.php.net/fix.php?id=35090&r=needtrace Need Reproduce Script: http://bugs.php.net/fix.php?id=35090&r=needscript Try newer version: http://bugs.php.net/fix.php?id=35090&r=oldversion Not developer issue: http://bugs.php.net/fix.php?id=35090&r=support Expected behavior: http://bugs.php.net/fix.php?id=35090&r=notwrong Not enough info: http://bugs.php.net/fix.php?id=35090&r=notenoughinfo Submitted twice: http://bugs.php.net/fix.php?id=35090&r=submittedtwice register_globals: http://bugs.php.net/fix.php?id=35090&r=globals PHP 3 support discontinued: http://bugs.php.net/fix.php?id=35090&r=php3 Daylight Savings: http://bugs.php.net/fix.php?id=35090&r=dst IIS Stability: http://bugs.php.net/fix.php?id=35090&r=isapi Install GNU Sed: http://bugs.php.net/fix.php?id=35090&r=gnused Floating point limitations: http://bugs.php.net/fix.php?id=35090&r=float No Zend Extensions: http://bugs.php.net/fix.php?id=35090&r=nozend MySQL Configuration Error: http://bugs.php.net/fix.php?id=35090&r=mysqlcfg