Adding flushing of files on chromeos, so that when something is downloaded, its written out ot disk shortly after finish downloading.

BUG=chromium-os:2661
TEST=none
Review URL: http://codereview.chromium.org/2770002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@49461 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 41 insertions, 0 deletions

diff --git a/net/base/file_stream.h b/net/base/file_stream.h
index ff9e7a6..a6d5739 100644
--- a/net/base/file_stream.h
+++ b/net/base/file_stream.h
@@ -120,6 +120,15 @@ class FileStream {
   //   platform with this call.
   int64 Truncate(int64 bytes);
 
+  // Forces out a filesystem sync on this file to make sure that the file was
+  // written out to disk and is not currently sitting in the buffer. This does
+  // not have to be called, it just forces one to happen at the time of
+  // calling.
+  //
+  /// Returns an error code if the operation could not be performed.
+  //
+  // This method should not be called if the stream was opened READ_ONLY.
+  int Flush();
  private:
   class AsyncContext;
   friend class AsyncContext;
diff --git a/net/base/file_stream_posix.cc b/net/base/file_stream_posix.cc
index 8a0f2e3..2036260 100644
--- a/net/base/file_stream_posix.cc
+++ b/net/base/file_stream_posix.cc
@@ -70,6 +70,16 @@ int WriteFile(base::PlatformFile file, const char* buf, int buf_len) {
   return res;
 }
 
+// FlushFile() is a simple wrapper around fsync() that handles EINTR signals and
+// calls MapErrorCode() to map errno to net error codes.  It tries to flush to
+// completion.
+int FlushFile(base::PlatformFile file) {
+  ssize_t res = HANDLE_EINTR(fsync(file));
+  if (res == -1)
+    return MapErrorCode(errno);
+  return res;
+}
+
 // BackgroundReadTask is a simple task that reads a file and then runs
 // |callback|.  AsyncContext will post this task to the WorkerPool.
 class BackgroundReadTask : public Task {
@@ -445,6 +455,13 @@ int FileStream::Write(
   }
 }
 
+int FileStream::Flush() {
+  if (!IsOpen())
+    return ERR_UNEXPECTED;
+
+  return FlushFile(file_);
+}
+
 int64 FileStream::Truncate(int64 bytes) {
   if (!IsOpen())
     return ERR_UNEXPECTED;
diff --git a/net/base/file_stream_win.cc b/net/base/file_stream_win.cc
index 6a6db90..8b7f090 100644
--- a/net/base/file_stream_win.cc
+++ b/net/base/file_stream_win.cc
@@ -302,6 +302,21 @@ int FileStream::Write(
   return rv;
 }
 
+int FileStream::Flush() {
+  if (!IsOpen())
+    return ERR_UNEXPECTED;
+
+  DCHECK(open_flags_ & base::PLATFORM_FILE_WRITE);
+  if (FlushFileBuffers(file_)) {
+    return OK;
+  }
+
+  int rv;
+  DWORD error = GetLastError();
+  rv = MapErrorCode(error);
+  return rv;
+}
+
 int64 FileStream::Truncate(int64 bytes) {
   if (!IsOpen())
     return ERR_UNEXPECTED;