Some changes to prepare for endian change for QUIC: 1) Make data reader/write be able to read/write…

net/quic/core/quic_data_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_QUIC_CORE_QUIC_DATA_READER_H_
 #define NET_QUIC_CORE_QUIC_DATA_READER_H_
 
 #include <cstddef>
 #include <cstdint>
 
 #include "base/macros.h"
 #include "net/base/int128.h"
 #include "net/quic/core/quic_types.h"
+#include "net/quic/platform/api/quic_endian.h"
 #include "net/quic/platform/api/quic_export.h"
 #include "net/quic/platform/api/quic_string_piece.h"
 
 namespace net {
 
 // Used for reading QUIC data. Though there isn't really anything terribly
 // QUIC-specific here, it's a helper class that's useful when doing QUIC
 // framing.
 //
 // To use, simply construct a QuicDataReader 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 QuicDataReader 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 QUIC_EXPORT_PRIVATE QuicDataReader {
  public:
   // Caller must provide an underlying buffer to work on.
-  QuicDataReader(const char* data, const size_t len, Perspective perspective);
+  QuicDataReader(const char* data,
+                 const size_t len,
+                 Perspective perspective,
+                 Endianness endianness);
 
   // Empty destructor.
   ~QuicDataReader() {}
 
-  // Reads a 16-bit unsigned integer into the given output parameter.
-  // Forwards the internal iterator on success.
-  // Returns true on success, false otherwise.
+  // Reads an 8/16/32/64-bit unsigned integer into the given output
+  // parameter. Forwards the internal iterator on success. Returns true on
+  // success, false otherwise.
+  bool ReadUInt8(uint8_t* result);
   bool ReadUInt16(uint16_t* result);
+  bool ReadUInt32(uint32_t* result);
+  bool ReadUInt64(uint64_t* result);
 
-  // Reads a 32-bit unsigned integer into the given output parameter.
-  // Forwards the internal iterator on success.
-  // Returns true on success, false otherwise.
-  bool ReadUInt32(uint32_t* result);
-
-  // Reads a 64-bit unsigned integer into the given output parameter.
-  // Forwards the internal iterator on success.
-  // Returns true on success, false otherwise.
-  bool ReadUInt64(uint64_t* result);
+  // Reads |num_bytes| bytes in the correct byte order into least significant
+  // bytes of |result|.
+  bool ReadBytesToUInt64(size_t num_bytes, uint64_t* result);
 
   // Reads a 16-bit unsigned float into the given output parameter.
   // Forwards the internal iterator on success.
   // Returns true on success, false otherwise.
   bool ReadUFloat16(uint64_t* 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!
@@ skipping 74 matching lines @@
   const size_t len_;
 
   // The location of the next read from our data buffer.
   size_t pos_;
 
   // Perspective of this data reader. Please note, although client and server
   // may have different in-memory representation of the same field, the on wire
   // representation must be consistent.
   Perspective perspective_;
 
+  // The endianness to read integers and floating numbers.
+  Endianness endianness_;
+
   DISALLOW_COPY_AND_ASSIGN(QuicDataReader);
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_CORE_QUIC_DATA_READER_H_