net: FileStream cleanup

net/base/file_stream_context.h

 // 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.
 
 // This file defines FileStream::Context class.
 // The general design of FileStream is as follows: file_stream.h defines
 // FileStream class which basically is just an "wrapper" not containing any
 // specific implementation details. It re-routes all its method calls to
 // the instance of FileStream::Context (FileStream holds a scoped_ptr to
 // FileStream::Context instance). Context was extracted into a different class
@@ skipping 15 matching lines @@
 
 #ifndef NET_BASE_FILE_STREAM_CONTEXT_H_
 #define NET_BASE_FILE_STREAM_CONTEXT_H_
 
 #include "base/files/file.h"
 #include "base/message_loop/message_loop.h"
 #include "base/move.h"
 #include "base/task_runner.h"
 #include "net/base/completion_callback.h"
 #include "net/base/file_stream.h"
-#include "net/base/file_stream_whence.h"
 
 #if defined(OS_POSIX)
 #include <errno.h>
 #endif
 
 namespace base {
 class FilePath;
 }
 
 namespace net {
 
 class IOBuffer;
 
 #if defined(OS_WIN)
 class FileStream::Context : public base::MessageLoopForIO::IOHandler {
 #elif defined(OS_POSIX)
-class FileStream::Context {
+class FileStream::Context : public base::MessageLoopForIO::Watcher {
 #endif
  public:
   ////////////////////////////////////////////////////////////////////////////
   // Platform-dependent methods implemented in
   // file_stream_context_{win,posix}.cc.
   ////////////////////////////////////////////////////////////////////////////
 
   explicit Context(const scoped_refptr<base::TaskRunner>& task_runner);
   Context(base::File file, const scoped_refptr<base::TaskRunner>& task_runner);
-#if defined(OS_WIN)
   virtual ~Context();
-#elif defined(OS_POSIX)
-  ~Context();
-#endif
 
-  int ReadAsync(IOBuffer* buf,
-                int buf_len,
-                const CompletionCallback& callback);
+  int Read(IOBuffer* buf,
+           int buf_len,
+           const CompletionCallback& callback);
 
-  int WriteAsync(IOBuffer* buf,
-                 int buf_len,
-                 const CompletionCallback& callback);
+  int ReadNonBlocking(IOBuffer* buf,
+                      int buf_len,
+                      const CompletionCallback& callback);
 
-  ////////////////////////////////////////////////////////////////////////////
-  // Inline methods.
-  ////////////////////////////////////////////////////////////////////////////
+  int Write(IOBuffer* buf,
+            int buf_len,
+            const CompletionCallback& callback);
+
+  int WriteNonBlocking(IOBuffer* buf,
+                       int buf_len,
+                       const CompletionCallback& callback);
 
   const base::File& file() const { return file_; }
   bool async_in_progress() const { return async_in_progress_; }
 
   ////////////////////////////////////////////////////////////////////////////
   // Platform-independent methods implemented in file_stream_context.cc.
   ////////////////////////////////////////////////////////////////////////////
 
   // Destroys the context. It can be deleted in the method or deletion can be
   // deferred if some asynchronous operation is now in progress or if file is
   // not closed yet.
   void Orphan();
 
-  void OpenAsync(const base::FilePath& path,
-                 int open_flags,
-                 const CompletionCallback& callback);
+  void Open(const base::FilePath& path,
+            int open_flags,
+            const CompletionCallback& callback);
 
-  void CloseAsync(const CompletionCallback& callback);
+  void Close(const CompletionCallback& callback);
 
-  void SeekAsync(Whence whence,
-                 int64 offset,
-                 const Int64CompletionCallback& callback);
+  void Seek(base::File::Whence whence,
+            int64 offset,
+            const Int64CompletionCallback& callback);
 
-  void FlushAsync(const CompletionCallback& callback);
+  void Flush(const CompletionCallback& callback);
 
  private:
-  ////////////////////////////////////////////////////////////////////////////
-  // Platform-independent methods implemented in file_stream_context.cc.
-  ////////////////////////////////////////////////////////////////////////////
-
   struct IOResult {
     IOResult();
     IOResult(int64 result, int os_error);
     static IOResult FromOSError(int64 os_error);
 
     int64 result;
     int os_error;  // Set only when result < 0.
   };
 
   struct OpenResult {
     MOVE_ONLY_TYPE_FOR_CPP_03(OpenResult, RValue)
    public:
     OpenResult();
     OpenResult(base::File file, IOResult error_code);
     // C++03 move emulation of this type.
     OpenResult(RValue other);
     OpenResult& operator=(RValue other);
 
     base::File file;
     IOResult error_code;
   };
 
+  ////////////////////////////////////////////////////////////////////////////
+  // Platform-independent methods implemented in file_stream_context.cc.
+  ////////////////////////////////////////////////////////////////////////////
+
   OpenResult OpenFileImpl(const base::FilePath& path, int open_flags);
 
   IOResult CloseFileImpl();
 
+  IOResult FlushFileImpl();
+
   void OnOpenCompleted(const CompletionCallback& callback,
                        OpenResult open_result);
 
   void CloseAndDelete();
 
   Int64CompletionCallback IntToInt64(const CompletionCallback& callback);
 
-  // Called when asynchronous Open() or Seek()
-  // is completed. |result| contains the result or a network error code.
+  // Called when Open() or Seek() completes. |result| contains the result or a
+  // network error code.
   void OnAsyncCompleted(const Int64CompletionCallback& callback,
                         const IOResult& result);
 
   ////////////////////////////////////////////////////////////////////////////
-  // Helper stuff which is platform-dependent but is used in the platform-
-  // independent code implemented in file_stream_context.cc. These helpers were
-  // introduced solely to implement as much of the Context methods as
-  // possible independently from platform.
-  ////////////////////////////////////////////////////////////////////////////
-
-#if defined(OS_WIN)
-  int GetLastErrno() { return GetLastError(); }
-  void OnAsyncFileOpened();
-#elif defined(OS_POSIX)
-  int GetLastErrno() { return errno; }
-  void OnAsyncFileOpened() {}
-  void CancelIo(base::PlatformFile) {}
-#endif
-
-  ////////////////////////////////////////////////////////////////////////////
   // Platform-dependent methods implemented in
   // file_stream_context_{win,posix}.cc.
   ////////////////////////////////////////////////////////////////////////////
 
   // Adjusts the position from where the data is read.
-  IOResult SeekFileImpl(Whence whence, int64 offset);
+  IOResult SeekFileImpl(base::File::Whence whence, int64 offset);
 
-  // Flushes all data written to the stream.

[wtc, 2014/06/16 23:01:44]

Should we preserve this comment in the new code?

[rvargas (doing something else), 2014/06/18 01:36:38]

Looks kind of an empty comment to me, especially given that this is a private
method and is now declared among other self descriptive methods.

-  IOResult FlushFileImpl();
+  void OnFileOpened();
+
+  // The stream is going away.
+  void CancelIO();
 
 #if defined(OS_WIN)
   void IOCompletionIsPending(const CompletionCallback& callback, IOBuffer* buf);
 
   // Implementation of MessageLoopForIO::IOHandler.
   virtual void OnIOCompleted(base::MessageLoopForIO::IOContext* context,
                              DWORD bytes_read,
                              DWORD error) OVERRIDE;
 #elif defined(OS_POSIX)
   // ReadFileImpl() is a simple wrapper around read() that handles EINTR
   // signals and calls RecordAndMapError() to map errno to net error codes.
   IOResult ReadFileImpl(scoped_refptr<IOBuffer> buf, int buf_len);
 
   // WriteFileImpl() is a simple wrapper around write() that handles EINTR
   // signals and calls MapSystemError() to map errno to net error codes.
   // It tries to write to completion.
   IOResult WriteFileImpl(scoped_refptr<IOBuffer> buf, int buf_len);
+
+  // MessageLoopForIO::Watcher interface
+  virtual void OnFileCanReadWithoutBlocking(int fd) OVERRIDE;
+  virtual void OnFileCanWriteWithoutBlocking(int fd) OVERRIDE;
 #endif
 
   base::File file_;
   bool async_in_progress_;
   bool orphaned_;
   scoped_refptr<base::TaskRunner> task_runner_;
+  CompletionCallback callback_;
+  scoped_refptr<IOBuffer> in_flight_buf_;
 
 #if defined(OS_WIN)
   base::MessageLoopForIO::IOContext io_context_;
-  CompletionCallback callback_;
-  scoped_refptr<IOBuffer> in_flight_buf_;
+#elif defined(OS_POSIX)
+  base::MessageLoopForIO::FileDescriptorWatcher file_watcher_;
+  int buf_len_;

[wtc, 2014/06/16 23:01:44]

Document this member. I found that it is used in conjunction with
in_flight_buf_, so we can also just rename it in_flight_buf_len_.

[rvargas (doing something else), 2014/06/18 01:36:38]

removed

 #endif
 
   DISALLOW_COPY_AND_ASSIGN(Context);
 };
 
 }  // namespace net
 
 #endif  // NET_BASE_FILE_STREAM_CONTEXT_H_