net: Implement canceling of all async operations in FileStream.

Canceling of async operations allows to not wait for their completion
in FileStream's destructor. Other related changes include:

- Got rid of FileStream::Close() and FileStream::CloseSync() methods because
reuse of FileStream object doesn't make much sense, it should be destroyed
instead.

- Changed FileStream to always acquire ownership of the PlatformFile it was
given. Fixed usages of FileStream where no ownership was assumed, introduced
new helper functions in base/platform_file.h on the way.

- FileStream's destructor now always closes the file. If file was opened with
PLATFORM_FILE_ASYNC then actual closing is done asynchronously, destructor
doesn't wait for that and returns immediately. When file was opened without
PLATFORM_FILE_ASYNC closing is done synchronously and the thread doing that
should be allowed to do IO operations.

- Implementation of FileStream is refactored. FileStream is now just a wrapper
around internal object that does all actual work and that can be easily
orphaned in the destructor to not block on the actual file descriptor closing.
All platform-independent code is extracted into a special file and amount of
platform-dependent code is minimized.


BUG=115067, 112474
TEST=net_unittests

Review URL: https://chromiumcodereview.appspot.com/10701050

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@166091 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 25 insertions, 0 deletions

diff --git a/base/platform_file_win.cc b/base/platform_file_win.cc
index b7861e6..92f1c1f 100644
--- a/base/platform_file_win.cc
+++ b/base/platform_file_win.cc
@@ -115,6 +115,21 @@ bool ClosePlatformFile(PlatformFile file) {
   return (CloseHandle(file) != 0);
 }
 
+int64 SeekPlatformFile(PlatformFile file,
+                       PlatformFileWhence whence,
+                       int64 offset) {
+  base::ThreadRestrictions::AssertIOAllowed();
+  if (file < 0 || offset < 0)
+    return -1;
+
+  LARGE_INTEGER distance, res;
+  distance.QuadPart = offset;
+  DWORD move_method = static_cast<DWORD>(whence);
+  if (!SetFilePointerEx(file, distance, &res, move_method))
+    return -1;
+  return res.QuadPart;
+}
+
 int ReadPlatformFile(PlatformFile file, int64 offset, char* data, int size) {
   base::ThreadRestrictions::AssertIOAllowed();
   if (file == kInvalidPlatformFileValue)
@@ -145,6 +160,11 @@ int ReadPlatformFileNoBestEffort(PlatformFile file, int64 offset, char* data,
   return ReadPlatformFile(file, offset, data, size);
 }
 
+int ReadPlatformFileCurPosNoBestEffort(PlatformFile file,
+                                       char* data, int size) {
+  return ReadPlatformFile(file, 0, data, size);
+}
+
 int WritePlatformFile(PlatformFile file, int64 offset,
                       const char* data, int size) {
   base::ThreadRestrictions::AssertIOAllowed();
@@ -170,6 +190,11 @@ int WritePlatformFileAtCurrentPos(PlatformFile file, const char* data,
   return WritePlatformFile(file, 0, data, size);
 }
 
+int WritePlatformFileCurPosNoBestEffort(PlatformFile file,
+                                        const char* data, int size) {
+  return WritePlatformFile(file, 0, data, size);
+}
+
 bool TruncatePlatformFile(PlatformFile file, int64 length) {
   base::ThreadRestrictions::AssertIOAllowed();
   if (file == kInvalidPlatformFileValue)