android_webview/browser/input_stream.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef ANDROID_WEBVIEW_BROWSER_INPUT_STREAM_H_
   6 #define ANDROID_WEBVIEW_BROWSER_INPUT_STREAM_H_
   7
   8 #include "base/basictypes.h"
   9
  10 namespace net {
  11 class IOBuffer;
  12 }
  13
  14 namespace android_webview {
  15
  16 // Abstract wrapper used to access the InputStream Java class.
  17 // This class is safe to pass around between threads (the destructor,
  18 // constructor and methods can be called on different threads) but calling
  19 // methods concurrently might have undefined results.
  20 class InputStream {
  21  public:
  22   virtual ~InputStream() {}
  23
  24   // Sets |bytes_available| to the number of bytes that can be read (or skipped
  25   // over) from this input stream without blocking by the next caller of a
  26   // method for this input stream.
  27   // Returns true if completed successfully or false if an exception was
  28   // thrown.
  29   virtual bool BytesAvailable(int* bytes_available) const = 0;
  30
  31   // Skips over and discards |n| bytes of data from this input stream. Sets
  32   // |bytes_skipped| to the number of of bytes skipped.
  33   // Returns true if completed successfully or false if an exception was
  34   // thrown.
  35   virtual bool Skip(int64_t n, int64_t* bytes_skipped) = 0;
  36
  37   // Reads at most |length| bytes into |dest|. Sets |bytes_read| to the total
  38   // number of bytes read into |dest| or 0 if there is no more data because the
  39   // end of the stream was reached.
  40   // |dest| must be at least |length| in size.
  41   // Returns true if completed successfully or false if an exception was
  42   // thrown.
  43   virtual bool Read(net::IOBuffer* dest, int length, int* bytes_read) = 0;
  44
  45  protected:
  46   InputStream() {}
  47 };
  48
  49 } // namespace android_webview
  50
  51 #endif //  ANDROID_WEBVIEW_BROWSER_INPUT_STREAM_H_