net: Introduce SeekableIOBuffer and clean up HttpStreamParser.

net/base/io_buffer.cc

 // Copyright (c) 2011 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.
 
 #include "net/base/io_buffer.h"
 
 #include "base/logging.h"
 
 namespace net {
 
@@ skipping 65 matching lines @@
   DCHECK_LE(bytes, size_);
   used_ = bytes;
   data_ = base_->data() + used_;
 }
 
 DrainableIOBuffer::~DrainableIOBuffer() {
   // The buffer is owned by the |base_| instance.
   data_ = NULL;
 }
 
+SeekableIOBuffer::SeekableIOBuffer(int size)
+    : IOBuffer(size),
+      begin_(data_),
+      capacity_(size),
+      size_(0),
+      used_(0) {
+}
+
+void SeekableIOBuffer::DidConsume(int bytes) {
+  SetOffset(used_ + bytes);
+}
+
+int SeekableIOBuffer::BytesRemaining() const {
+  return size_ - used_;
+}
+
+int SeekableIOBuffer::BytesConsumed() const {
+  return used_;
+}
+
+void SeekableIOBuffer::SetOffset(int bytes) {
+  DCHECK_GE(bytes, 0);
+  DCHECK_LE(bytes, size_);
+  used_ = bytes;
+  data_ = begin_ + used_;
+}
+
+void SeekableIOBuffer::DidAppend(int bytes) {
+  DCHECK_GE(size_ + bytes, 0);
+  DCHECK_LE(size_ + bytes, capacity_);
+  size_ += bytes;
+}
+
+void SeekableIOBuffer::Clear() {
+  size_ = 0;
+  SetOffset(0);
+}
+
+SeekableIOBuffer::~SeekableIOBuffer() {
+  // data_ will be deleted in IOBuffer::~IOBuffer().
+  data_ = begin_;
+}
+
 GrowableIOBuffer::GrowableIOBuffer()
     : IOBuffer(),
       capacity_(0),
       offset_(0) {
 }
 
 void GrowableIOBuffer::SetCapacity(int capacity) {
   DCHECK_GE(capacity, 0);
   // realloc will crash if it fails.
   real_data_.reset(static_cast<char*>(realloc(real_data_.release(), capacity)));
@@ skipping 33 matching lines @@
 
 WrappedIOBuffer::WrappedIOBuffer(const char* data)
     : IOBuffer(const_cast<char*>(data)) {
 }
 
 WrappedIOBuffer::~WrappedIOBuffer() {
   data_ = NULL;
 }
 
 }  // namespace net