Home | History | Annotate | Download | only in spdy 
      1 // Copyright (c) 2013 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 #include "net/spdy/spdy_buffer.h"
      6 
      7 #include <cstring>
      8 
      9 #include "base/callback.h"
     10 #include "base/logging.h"
     11 #include "net/base/io_buffer.h"
     12 #include "net/spdy/spdy_protocol.h"
     13 
     14 namespace net {
     15 
     16 namespace {
     17 
     18 // Bound on largest frame any SPDY version has allowed.
     19 const size_t kMaxSpdyFrameSize = 0x00ffffff;
     20 
     21 // Makes a SpdyFrame with |size| bytes of data copied from
     22 // |data|. |data| must be non-NULL and |size| must be positive.
     23 scoped_ptr<SpdyFrame> MakeSpdyFrame(const char* data, size_t size) {
     24   DCHECK(data);
     25   CHECK_GT(size, 0u);
     26   CHECK_LE(size, kMaxSpdyFrameSize);
     27   scoped_ptr<char[]> frame_data(new char[size]);
     28   std::memcpy(frame_data.get(), data, size);
     29   scoped_ptr<SpdyFrame> frame(
     30       new SpdyFrame(frame_data.release(), size, true /* owns_buffer */));
     31   return frame.Pass();
     32 }
     33 
     34 }  // namespace
     35 
     36 // This class is an IOBuffer implementation that simply holds a
     37 // reference to a SharedFrame object and a fixed offset. Used by
     38 // SpdyBuffer::GetIOBufferForRemainingData().
     39 class SpdyBuffer::SharedFrameIOBuffer : public IOBuffer {
     40  public:
     41   SharedFrameIOBuffer(const scoped_refptr<SharedFrame>& shared_frame,
     42                       size_t offset)
     43       : IOBuffer(shared_frame->data->data() + offset),
     44         shared_frame_(shared_frame),
     45         offset_(offset) {}
     46 
     47  private:
     48   virtual ~SharedFrameIOBuffer() {
     49     // Prevent ~IOBuffer() from trying to delete |data_|.
     50     data_ = NULL;
     51   }
     52 
     53   const scoped_refptr<SharedFrame> shared_frame_;
     54   const size_t offset_;
     55 
     56   DISALLOW_COPY_AND_ASSIGN(SharedFrameIOBuffer);
     57 };
     58 
     59 SpdyBuffer::SpdyBuffer(scoped_ptr<SpdyFrame> frame)
     60     : shared_frame_(new SharedFrame()),
     61       offset_(0) {
     62   shared_frame_->data = frame.Pass();
     63 }
     64 
     65 // The given data may not be strictly a SPDY frame; we (ab)use
     66 // |frame_| just as a container.
     67 SpdyBuffer::SpdyBuffer(const char* data, size_t size) :
     68     shared_frame_(new SharedFrame()),
     69     offset_(0) {
     70   CHECK_GT(size, 0u);
     71   CHECK_LE(size, kMaxSpdyFrameSize);
     72   shared_frame_->data = MakeSpdyFrame(data, size);
     73 }
     74 
     75 SpdyBuffer::~SpdyBuffer() {
     76   if (GetRemainingSize() > 0)
     77     ConsumeHelper(GetRemainingSize(), DISCARD);
     78 }
     79 
     80 const char* SpdyBuffer::GetRemainingData() const {
     81   return shared_frame_->data->data() + offset_;
     82 }
     83 
     84 size_t SpdyBuffer::GetRemainingSize() const {
     85   return shared_frame_->data->size() - offset_;
     86 }
     87 
     88 void SpdyBuffer::AddConsumeCallback(const ConsumeCallback& consume_callback) {
     89   consume_callbacks_.push_back(consume_callback);
     90 }
     91 
     92 void SpdyBuffer::Consume(size_t consume_size) {
     93   ConsumeHelper(consume_size, CONSUME);
     94 };
     95 
     96 IOBuffer* SpdyBuffer::GetIOBufferForRemainingData() {
     97   return new SharedFrameIOBuffer(shared_frame_, offset_);
     98 }
     99 
    100 void SpdyBuffer::ConsumeHelper(size_t consume_size,
    101                                ConsumeSource consume_source) {
    102   DCHECK_GE(consume_size, 1u);
    103   DCHECK_LE(consume_size, GetRemainingSize());
    104   offset_ += consume_size;
    105   for (std::vector<ConsumeCallback>::const_iterator it =
    106            consume_callbacks_.begin(); it != consume_callbacks_.end(); ++it) {
    107     it->Run(consume_size, consume_source);
    108   }
    109 };
    110 
    111 }  // namespace net
    112