Adds a modified copy of talk/base to webrtc/base. It is the first step in
migrating talk/base to webrtc/base.

BUG=N/A
R=niklas.enbom@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/17479005

git-svn-id: http://webrtc.googlecode.com/svn/trunk@6129 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/webrtc/base/bytebuffer.cc b/webrtc/base/bytebuffer.cc
new file mode 100644
index 0000000..6133759
--- /dev/null
+++ b/webrtc/base/bytebuffer.cc
@@ -0,0 +1,234 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/base/bytebuffer.h"
+
+#include <assert.h>
+#include <string.h>
+
+#include <algorithm>
+
+#include "webrtc/base/basictypes.h"
+#include "webrtc/base/byteorder.h"
+
+namespace rtc {
+
+static const int DEFAULT_SIZE = 4096;
+
+ByteBuffer::ByteBuffer() {
+  Construct(NULL, DEFAULT_SIZE, ORDER_NETWORK);
+}
+
+ByteBuffer::ByteBuffer(ByteOrder byte_order) {
+  Construct(NULL, DEFAULT_SIZE, byte_order);
+}
+
+ByteBuffer::ByteBuffer(const char* bytes, size_t len) {
+  Construct(bytes, len, ORDER_NETWORK);
+}
+
+ByteBuffer::ByteBuffer(const char* bytes, size_t len, ByteOrder byte_order) {
+  Construct(bytes, len, byte_order);
+}
+
+ByteBuffer::ByteBuffer(const char* bytes) {
+  Construct(bytes, strlen(bytes), ORDER_NETWORK);
+}
+
+void ByteBuffer::Construct(const char* bytes, size_t len,
+                           ByteOrder byte_order) {
+  version_ = 0;
+  start_ = 0;
+  size_ = len;
+  byte_order_ = byte_order;
+  bytes_ = new char[size_];
+
+  if (bytes) {
+    end_ = len;
+    memcpy(bytes_, bytes, end_);
+  } else {
+    end_ = 0;
+  }
+}
+
+ByteBuffer::~ByteBuffer() {
+  delete[] bytes_;
+}
+
+bool ByteBuffer::ReadUInt8(uint8* val) {
+  if (!val) return false;
+
+  return ReadBytes(reinterpret_cast<char*>(val), 1);
+}
+
+bool ByteBuffer::ReadUInt16(uint16* val) {
+  if (!val) return false;
+
+  uint16 v;
+  if (!ReadBytes(reinterpret_cast<char*>(&v), 2)) {
+    return false;
+  } else {
+    *val = (byte_order_ == ORDER_NETWORK) ? NetworkToHost16(v) : v;
+    return true;
+  }
+}
+
+bool ByteBuffer::ReadUInt24(uint32* val) {
+  if (!val) return false;
+
+  uint32 v = 0;
+  char* read_into = reinterpret_cast<char*>(&v);
+  if (byte_order_ == ORDER_NETWORK || IsHostBigEndian()) {
+    ++read_into;
+  }
+
+  if (!ReadBytes(read_into, 3)) {
+    return false;
+  } else {
+    *val = (byte_order_ == ORDER_NETWORK) ? NetworkToHost32(v) : v;
+    return true;
+  }
+}
+
+bool ByteBuffer::ReadUInt32(uint32* val) {
+  if (!val) return false;
+
+  uint32 v;
+  if (!ReadBytes(reinterpret_cast<char*>(&v), 4)) {
+    return false;
+  } else {
+    *val = (byte_order_ == ORDER_NETWORK) ? NetworkToHost32(v) : v;
+    return true;
+  }
+}
+
+bool ByteBuffer::ReadUInt64(uint64* val) {
+  if (!val) return false;
+
+  uint64 v;
+  if (!ReadBytes(reinterpret_cast<char*>(&v), 8)) {
+    return false;
+  } else {
+    *val = (byte_order_ == ORDER_NETWORK) ? NetworkToHost64(v) : v;
+    return true;
+  }
+}
+
+bool ByteBuffer::ReadString(std::string* val, size_t len) {
+  if (!val) return false;
+
+  if (len > Length()) {
+    return false;
+  } else {
+    val->append(bytes_ + start_, len);
+    start_ += len;
+    return true;
+  }
+}
+
+bool ByteBuffer::ReadBytes(char* val, size_t len) {
+  if (len > Length()) {
+    return false;
+  } else {
+    memcpy(val, bytes_ + start_, len);
+    start_ += len;
+    return true;
+  }
+}
+
+void ByteBuffer::WriteUInt8(uint8 val) {
+  WriteBytes(reinterpret_cast<const char*>(&val), 1);
+}
+
+void ByteBuffer::WriteUInt16(uint16 val) {
+  uint16 v = (byte_order_ == ORDER_NETWORK) ? HostToNetwork16(val) : val;
+  WriteBytes(reinterpret_cast<const char*>(&v), 2);
+}
+
+void ByteBuffer::WriteUInt24(uint32 val) {
+  uint32 v = (byte_order_ == ORDER_NETWORK) ? HostToNetwork32(val) : val;
+  char* start = reinterpret_cast<char*>(&v);
+  if (byte_order_ == ORDER_NETWORK || IsHostBigEndian()) {
+    ++start;
+  }
+  WriteBytes(start, 3);
+}
+
+void ByteBuffer::WriteUInt32(uint32 val) {
+  uint32 v = (byte_order_ == ORDER_NETWORK) ? HostToNetwork32(val) : val;
+  WriteBytes(reinterpret_cast<const char*>(&v), 4);
+}
+
+void ByteBuffer::WriteUInt64(uint64 val) {
+  uint64 v = (byte_order_ == ORDER_NETWORK) ? HostToNetwork64(val) : val;
+  WriteBytes(reinterpret_cast<const char*>(&v), 8);
+}
+
+void ByteBuffer::WriteString(const std::string& val) {
+  WriteBytes(val.c_str(), val.size());
+}
+
+void ByteBuffer::WriteBytes(const char* val, size_t len) {
+  memcpy(ReserveWriteBuffer(len), val, len);
+}
+
+char* ByteBuffer::ReserveWriteBuffer(size_t len) {
+  if (Length() + len > Capacity())
+    Resize(Length() + len);
+
+  char* start = bytes_ + end_;
+  end_ += len;
+  return start;
+}
+
+void ByteBuffer::Resize(size_t size) {
+  size_t len = _min(end_ - start_, size);
+  if (size <= size_) {
+    // Don't reallocate, just move data backwards
+    memmove(bytes_, bytes_ + start_, len);
+  } else {
+    // Reallocate a larger buffer.
+    size_ = _max(size, 3 * size_ / 2);
+    char* new_bytes = new char[size_];
+    memcpy(new_bytes, bytes_ + start_, len);
+    delete [] bytes_;
+    bytes_ = new_bytes;
+  }
+  start_ = 0;
+  end_ = len;
+  ++version_;
+}
+
+bool ByteBuffer::Consume(size_t size) {
+  if (size > Length())
+    return false;
+  start_ += size;
+  return true;
+}
+
+ByteBuffer::ReadPosition ByteBuffer::GetReadPosition() const {
+  return ReadPosition(start_, version_);
+}
+
+bool ByteBuffer::SetReadPosition(const ReadPosition &position) {
+  if (position.version_ != version_) {
+    return false;
+  }
+  start_ = position.start_;
+  return true;
+}
+
+void ByteBuffer::Clear() {
+  memset(bytes_, 0, size_);
+  start_ = end_ = 0;
+  ++version_;
+}
+
+}  // namespace rtc