| // 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 QUICHE_SPDY_CORE_SPDY_FRAME_BUILDER_H_ |
| #define QUICHE_SPDY_CORE_SPDY_FRAME_BUILDER_H_ |
| |
| #include <cstddef> |
| #include <cstdint> |
| #include <memory> |
| |
| #include "absl/strings/string_view.h" |
| #include "quiche/common/platform/api/quiche_bug_tracker.h" |
| #include "quiche/common/platform/api/quiche_export.h" |
| #include "quiche/common/quiche_endian.h" |
| #include "quiche/spdy/core/spdy_protocol.h" |
| #include "quiche/spdy/core/zero_copy_output_buffer.h" |
| |
| namespace spdy { |
| |
| namespace test { |
| class SpdyFrameBuilderPeer; |
| } // namespace test |
| |
| // This class provides facilities for basic binary value packing |
| // into Spdy frames. |
| // |
| // The SpdyFrameBuilder supports appending primitive values (int, string, etc) |
| // to a frame instance. The SpdyFrameBuilder grows its internal memory buffer |
| // dynamically to hold the sequence of primitive values. The internal memory |
| // buffer is exposed as the "data" of the SpdyFrameBuilder. |
| class QUICHE_EXPORT SpdyFrameBuilder { |
| public: |
| // Initializes a SpdyFrameBuilder with a buffer of given size |
| explicit SpdyFrameBuilder(size_t size); |
| // Doesn't take ownership of output. |
| SpdyFrameBuilder(size_t size, ZeroCopyOutputBuffer* output); |
| |
| ~SpdyFrameBuilder(); |
| |
| // Returns the total size of the SpdyFrameBuilder's data, which may include |
| // multiple frames. |
| size_t length() const { return offset_ + length_; } |
| |
| // Seeks forward by the given number of bytes. Useful in conjunction with |
| // GetWriteableBuffer() above. |
| bool Seek(size_t length); |
| |
| // Populates this frame with a HTTP2 frame prefix using length information |
| // from |capacity_|. The given type must be a control frame type. |
| bool BeginNewFrame(SpdyFrameType type, uint8_t flags, SpdyStreamId stream_id); |
| |
| // Populates this frame with a HTTP2 frame prefix with type and length |
| // information. |type| must be a defined frame type. |
| bool BeginNewFrame(SpdyFrameType type, uint8_t flags, SpdyStreamId stream_id, |
| size_t length); |
| |
| // Populates this frame with a HTTP2 frame prefix with type and length |
| // information. |raw_frame_type| may be a defined or undefined frame type. |
| bool BeginNewUncheckedFrame(uint8_t raw_frame_type, uint8_t flags, |
| SpdyStreamId stream_id, size_t length); |
| |
| // Takes the buffer from the SpdyFrameBuilder. |
| SpdySerializedFrame take() { |
| QUICHE_BUG_IF(spdy_bug_39_1, output_ != nullptr) |
| << "ZeroCopyOutputBuffer is used to build " |
| << "frames. take() shouldn't be called"; |
| QUICHE_BUG_IF(spdy_bug_39_2, kMaxFrameSizeLimit < length_) |
| << "Frame length " << length_ |
| << " is longer than the maximum possible allowed length."; |
| SpdySerializedFrame rv(std::move(buffer_), length()); |
| capacity_ = 0; |
| length_ = 0; |
| offset_ = 0; |
| return rv; |
| } |
| |
| // Methods for adding to the payload. These values are appended to the end |
| // of the SpdyFrameBuilder payload. Note - binary integers are converted from |
| // host to network form. |
| bool WriteUInt8(uint8_t value) { return WriteBytes(&value, sizeof(value)); } |
| bool WriteUInt16(uint16_t value) { |
| value = quiche::QuicheEndian::HostToNet16(value); |
| return WriteBytes(&value, sizeof(value)); |
| } |
| bool WriteUInt24(uint32_t value) { |
| value = quiche::QuicheEndian::HostToNet32(value); |
| return WriteBytes(reinterpret_cast<char*>(&value) + 1, sizeof(value) - 1); |
| } |
| bool WriteUInt32(uint32_t value) { |
| value = quiche::QuicheEndian::HostToNet32(value); |
| return WriteBytes(&value, sizeof(value)); |
| } |
| bool WriteUInt64(uint64_t value) { |
| uint32_t upper = |
| quiche::QuicheEndian::HostToNet32(static_cast<uint32_t>(value >> 32)); |
| uint32_t lower = |
| quiche::QuicheEndian::HostToNet32(static_cast<uint32_t>(value)); |
| return (WriteBytes(&upper, sizeof(upper)) && |
| WriteBytes(&lower, sizeof(lower))); |
| } |
| bool WriteStringPiece32(const absl::string_view value); |
| bool WriteBytes(const void* data, uint32_t data_len); |
| |
| private: |
| friend class test::SpdyFrameBuilderPeer; |
| |
| // Populates this frame with a HTTP2 frame prefix with type and length |
| // information. |
| bool BeginNewFrameInternal(uint8_t raw_frame_type, uint8_t flags, |
| SpdyStreamId stream_id, size_t length); |
| |
| // Returns a writeable buffer of given size in bytes, to be appended to the |
| // currently written frame. Does bounds checking on length but does not |
| // increment the underlying iterator. To do so, consumers should subsequently |
| // call Seek(). |
| // In general, consumers should use Write*() calls instead of this. |
| // Returns NULL on failure. |
| char* GetWritableBuffer(size_t length); |
| char* GetWritableOutput(size_t desired_length, size_t* actual_length); |
| |
| // Checks to make sure that there is an appropriate amount of space for a |
| // write of given size, in bytes. |
| bool CanWrite(size_t length) const; |
| |
| // A buffer to be created whenever a new frame needs to be written. Used only |
| // if |output_| is nullptr. |
| std::unique_ptr<char[]> buffer_; |
| // A pre-allocated buffer. If not-null, serialized frame data is written to |
| // this buffer. |
| ZeroCopyOutputBuffer* output_ = nullptr; // Does not own. |
| |
| size_t capacity_; // Allocation size of payload, set by constructor. |
| size_t length_; // Length of the latest frame in the buffer. |
| size_t offset_; // Position at which the latest frame begins. |
| }; |
| |
| } // namespace spdy |
| |
| #endif // QUICHE_SPDY_CORE_SPDY_FRAME_BUILDER_H_ |