Fix net::FileStream to handle POSIX errors correctly.

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 98 matching lines @@
   void SeekAsync(Whence whence,
                  int64 offset,
                  const Int64CompletionCallback& callback);
   int64 SeekSync(Whence whence, int64 offset);
 
   void FlushAsync(const CompletionCallback& callback);
   int FlushSync();
 
  private:
   ////////////////////////////////////////////////////////////////////////////
-  // Error code that is platform-dependent but is used in the platform-
-  // independent code implemented in file_stream_context.cc.
-  ////////////////////////////////////////////////////////////////////////////
-  enum {
-#if defined(OS_WIN)
-    ERROR_BAD_FILE = ERROR_INVALID_HANDLE
-#elif defined(OS_POSIX)
-    ERROR_BAD_FILE = EBADF
-#endif
-  };
-
-  ////////////////////////////////////////////////////////////////////////////
   // Platform-independent methods implemented in file_stream_context.cc.
   ////////////////////////////////////////////////////////////////////////////
 
-  struct OpenResult {
-    base::PlatformFile file;
-    int error_code;
+  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.
   };
 
-  // Map system error into network error code and log it with |bound_net_log_|.
-  int RecordAndMapError(int error, FileErrorSource source) const;
+  struct OpenResult {
+    OpenResult();
+    OpenResult(base::PlatformFile file, IOResult error_code);
+    base::PlatformFile file;
+    IOResult error_code;
+  };
+
+  // Log the error from |result| to |bound_net_log_|.
+  void RecordError(const IOResult& result, FileErrorSource source) const;
 
   void BeginOpenEvent(const base::FilePath& path);
 
   OpenResult OpenFileImpl(const base::FilePath& path, int open_flags);
 
-  int ProcessOpenError(int error_code);
-  void OnOpenCompleted(const CompletionCallback& callback, OpenResult result);
+  void ProcessOpenError(const IOResult& result);
+  void OnOpenCompleted(const CompletionCallback& callback,
+                       OpenResult open_result);
 
   void CloseAndDelete();
   void OnCloseCompleted();
 
   Int64CompletionCallback IntToInt64(const CompletionCallback& callback);
 
-  // Checks for IO error that probably happened in async methods.
-  // If there was error reports it.
-  void CheckForIOError(int64* result, FileErrorSource source);
-
   // Called when asynchronous Seek() is completed.
   // Reports error if needed and calls callback.
   void ProcessAsyncResult(const Int64CompletionCallback& callback,
                           FileErrorSource source,
-                          int64 result);
+                          const IOResult& result);
 
   // Called when asynchronous Open() or Seek()
   // is completed. |result| contains the result or a network error code.
   void OnAsyncCompleted(const Int64CompletionCallback& callback, int64 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.
-  int64 SeekFileImpl(Whence whence, int64 offset);
+  IOResult SeekFileImpl(Whence whence, int64 offset);
 
   // Flushes all data written to the stream.
-  int64 FlushFileImpl();
+  IOResult FlushFileImpl();
 
 #if defined(OS_WIN)
   void IOCompletionIsPending(const CompletionCallback& callback, IOBuffer* buf);
 
-  // Implementation of MessageLoopForIO::IOHandler
+  // Implementation of MessageLoopForIO::IOHandler.
   virtual void OnIOCompleted(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.
-  int64 ReadFileImpl(scoped_refptr<IOBuffer> buf, int buf_len);
+  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.
-  int64 WriteFileImpl(scoped_refptr<IOBuffer> buf, int buf_len);
+  IOResult WriteFileImpl(scoped_refptr<IOBuffer> buf, int buf_len);
 #endif
 
   base::PlatformFile file_;
   bool record_uma_;
   bool async_in_progress_;
   bool orphaned_;
   BoundNetLog bound_net_log_;
 
 #if defined(OS_WIN)
   MessageLoopForIO::IOContext io_context_;
   CompletionCallback callback_;
   scoped_refptr<IOBuffer> in_flight_buf_;
   FileErrorSource error_source_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(Context);
 };
 
 }  // namespace net
 
 #endif  // NET_BASE_FILE_STREAM_CONTEXT_H_