base/files/memory_mapped_file_posix.cc

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/files/memory_mapped_file.h"
   6
   7 #include <sys/mman.h>
   8 #include <sys/stat.h>
   9 #include <unistd.h>
  10
  11 #include "base/logging.h"
  12 #include "base/threading/thread_restrictions.h"
  13
  14 namespace base {
  15
  16 MemoryMappedFile::MemoryMappedFile() : data_(NULL), length_(0) {
  17 }
  18
  19 bool MemoryMappedFile::MapFileToMemory() {
  20   ThreadRestrictions::AssertIOAllowed();
  21
  22   struct stat file_stat;
  23   if (fstat(file_.GetPlatformFile(), &file_stat) == -1 ) {
  24     DPLOG(ERROR) << "fstat " << file_.GetPlatformFile();
  25     return false;
  26   }
  27   length_ = file_stat.st_size;
  28
  29   data_ = static_cast<uint8*>(
  30       mmap(NULL, length_, PROT_READ, MAP_SHARED, file_.GetPlatformFile(), 0));
  31   if (data_ == MAP_FAILED)
  32     DPLOG(ERROR) << "mmap " << file_.GetPlatformFile();
  33
  34   return data_ != MAP_FAILED;
  35 }
  36
  37 void MemoryMappedFile::CloseHandles() {
  38   ThreadRestrictions::AssertIOAllowed();
  39
  40   if (data_ != NULL)
  41     munmap(data_, length_);
  42   file_.Close();
  43
  44   data_ = NULL;
  45   length_ = 0;
  46 }
  47
  48 }  // namespace base