hphp/util/log-file-flusher.h

   1 /*
   2    +----------------------------------------------------------------------+
   3    | HipHop for PHP                                                       |
   4    +----------------------------------------------------------------------+
   5    | Copyright (c) 2010-present 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 #ifndef incl_HPHP_LOG_FILE_FLUSHER_H_
  17 #define incl_HPHP_LOG_FILE_FLUSHER_H_
  18
  19 #include <cstdio>
  20 #include <atomic>
  21
  22 #include "hphp/util/compatibility.h"
  23
  24 #include <folly/portability/Unistd.h>
  25
  26 namespace HPHP {
  27
  28 //////////////////////////////////////////////////////////////////////
  29
  30 struct LogFileFlusher {
  31   LogFileFlusher() {}
  32   virtual ~LogFileFlusher() {}
  33
  34   void recordWriteAndMaybeDropCaches(int fd, int bytes);
  35   inline void recordWriteAndMaybeDropCaches(FILE* f, int bytes) {
  36     recordWriteAndMaybeDropCaches(fileno(f), bytes);
  37   }
  38
  39   enum {
  40     kDropCacheTail = 1 * 1024 * 1024
  41   };
  42
  43   static int DropCacheChunkSize;
  44
  45 private: // For testing
  46   virtual void dropCache(int fd, off_t len) { fadvise_dontneed(fd, len); }
  47
  48 private:
  49   std::atomic<int> m_bytesWritten{0};
  50 };
  51
  52 //////////////////////////////////////////////////////////////////////
  53
  54 }
  55
  56 #endif