1 files changed, 63 insertions, 0 deletions
diff --git a/chromium/net/disk_cache/blockfile/mapped_file_avoid_mmap_posix.cc b/chromium/net/disk_cache/blockfile/mapped_file_avoid_mmap_posix.cc
new file mode 100644
index 00000000000..3936358236d
--- /dev/null
+++ b/chromium/net/disk_cache/blockfile/mapped_file_avoid_mmap_posix.cc
@@ -0,0 +1,63 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "net/disk_cache/blockfile/mapped_file.h"
+
+#include <stdlib.h>
+
+#include "base/files/file_path.h"
+#include "base/logging.h"
+
+namespace disk_cache {
+
+void* MappedFile::Init(const base::FilePath& name, size_t size) {
+  DCHECK(!init_);
+  if (init_ || !File::Init(name))
+    return NULL;
+
+  if (!size)
+    size = GetLength();
+
+  buffer_ = malloc(size);
+  snapshot_ = malloc(size);
+  if (buffer_ && snapshot_ && Read(buffer_, size, 0)) {
+    memcpy(snapshot_, buffer_, size);
+  } else {
+    free(buffer_);
+    free(snapshot_);
+    buffer_ = snapshot_ = 0;
+  }
+
+  init_ = true;
+  view_size_ = size;
+  return buffer_;
+}
+
+void MappedFile::Flush() {
+  DCHECK(buffer_);
+  DCHECK(snapshot_);
+  const char* buffer_ptr = static_cast<const char*>(buffer_);
+  char* snapshot_ptr = static_cast<char*>(snapshot_);
+  const size_t block_size = 4096;
+  for (size_t offset = 0; offset < view_size_; offset += block_size) {
+    size_t size = std::min(view_size_ - offset, block_size);
+    if (memcmp(snapshot_ptr + offset, buffer_ptr + offset, size)) {
+      memcpy(snapshot_ptr + offset, buffer_ptr + offset, size);
+      Write(snapshot_ptr + offset, size, offset);
+    }
+  }
+}
+
+MappedFile::~MappedFile() {
+  if (!init_)
+    return;
+
+  if (buffer_ && snapshot_) {
+    Flush();
+  }
+  free(buffer_);
+  free(snapshot_);
+}
+
+}  // namespace disk_cache