hphp/util/log-file-flusher.cpp

   1 /*
   2    +----------------------------------------------------------------------+
   3    | HipHop for PHP                                                       |
   4    +----------------------------------------------------------------------+
   5    | Copyright (c) 2010-2015 Facebook, Inc. (http://www.facebook.com)     |
   6    +----------------------------------------------------------------------+
   7    | This source file is subject to version 3.01 of the PHP license,      |
   8    | that is bundled with this package in the file LICENSE, and is        |
   9    | available through the world-wide-web at the following url:           |
  10    | http://www.php.net/license/3_01.txt                                  |
  11    | If you did not receive a copy of the PHP license and are unable to   |
  12    | obtain it through the world-wide-web, please send a note to          |
  13    | license@php.net so we can mail you a copy immediately.               |
  14    +----------------------------------------------------------------------+
  15 */
  16 #include "hphp/util/log-file-flusher.h"
  17
  18 #include <sys/types.h>
  19 #include <unistd.h>
  20
  21 namespace HPHP {
  22
  23 //////////////////////////////////////////////////////////////////////
  24
  25 int LogFileFlusher::DropCacheChunkSize = 1 << 20;
  26
  27 void LogFileFlusher::recordWriteAndMaybeDropCaches(int fd, int bytes) {
  28   int oldBytesWritten = m_bytesWritten.fetch_add(bytes);
  29   int newBytesWritten = oldBytesWritten + bytes;
  30
  31   if (!(newBytesWritten > DropCacheChunkSize &&
  32         oldBytesWritten <= DropCacheChunkSize)) {
  33     return;
  34   }
  35
  36   off_t offset = lseek(fd, 0, SEEK_CUR);
  37   if (offset > kDropCacheTail) {
  38     dropCache(fd, offset - kDropCacheTail);
  39   }
  40
  41   m_bytesWritten = 0;
  42 }
  43
  44 //////////////////////////////////////////////////////////////////////
  45
  46 }