SPDY - integration of spdy/3 code.

net/spdy/spdy_frame_reader.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.
+
+#ifndef NET_SPDY_FRAME_READER_H_
+#define NET_SPDY_FRAME_READER_H_
+#pragma once
+
+#include "base/basictypes.h"
+#include "base/string_piece.h"
+#include "net/base/net_export.h"
+
+namespace spdy {
+
+// Used for reading SPDY frames. Though there isn't really anything terribly
+// SPDY-specific here, it's a helper class that's useful when doing SPDY
+// framing.
+//
+// To use, simply construct a SpdyFramerReader using the underlying buffer that
+// you'd like to read fields from, then call one of the Read*() methods to
+// actually do some reading.
+//
+// This class keeps an internal iterator to keep track of what's already been
+// read and each successive Read*() call automatically increments said iterator
+// on success. On failure, internal state of the SpdyFrameReader should not be
+// trusted and it is up to the caller to throw away the failed instance and
+// handle the error as appropriate. None of the Read*() methods should ever be
+// called after failure, as they will also fail immediately.
+class NET_EXPORT_PRIVATE SpdyFrameReader {
+ public:
+  // Caller must provide an underlying buffer to work on.
+  SpdyFrameReader(const char* data, const size_t len);
+
+  // Empty destructor.
+  ~SpdyFrameReader() {}
+
+  // Reads a 16-bit unsigned integer into the given output parameter.
+  // Forwards the internal iterater on success.
+  // Returns true on success, false otherwise.
+  bool ReadUInt16(uint16* result);
+
+  // Reads a 32-bit unsigned integer into the given output parameter.
+  // Forwards the internal iterater on success.
+  // Returns true on success, false otherwise.
+  bool ReadUInt32(uint32* result);
+
+  // Reads a string prefixed with 16-bit length into the given output parameter.
+  //
+  // NOTE: Does not copy but rather references strings in the underlying buffer.
+  // This should be kept in mind when handling memory management!
+  //
+  // Forwards the internal iterater on success.
+  // Returns true on success, false otherwise.
+  bool ReadStringPiece16(base::StringPiece* result);
+
+  // Reads a string prefixed with 32-bit length into the given output parameter.
+  //
+  // NOTE: Does not copy but rather references strings in the underlying buffer.
+  // This should be kept in mind when handling memory management!
+  //
+  // Forwards the internal iterater on success.
+  // Returns true on success, false otherwise.
+  bool ReadStringPiece32(base::StringPiece* result);
+
+  // Reads a given number of bytes into the given buffer. The buffer
+  // must be of adequate size.
+  // Forwards the internal iterater on success.
+  // Returns true on success, false otherwise.
+  bool ReadBytes(void* result, size_t size);
+
+  // Returns true if the entirety of the underlying buffer has been read via
+  // Read*() calls.
+  bool IsDoneReading() const;
+
+ private:
+  // Returns true if the underlying buffer has enough room to read the given
+  // amount of bytes.
+  bool CanRead(size_t bytes) const;
+
+  // To be called when a read fails for any reason.
+  void OnFailure();
+
+  // The data buffer that we're reading from.
+  const char* data_;
+
+  // The length of the data buffer that we're reading from.
+  const size_t len_;
+
+  // The location of the next read from our data buffer.
+  size_t ofs_;
+};
+
+}  // namespace spdy
+
+#endif  // NET_SPDY_FRAME_READER_H_
+