1 // Copyright 2016 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 #ifndef QUICHE_HTTP2_DECODER_PAYLOAD_DECODERS_HEADERS_PAYLOAD_DECODER_H_ 6 #define QUICHE_HTTP2_DECODER_PAYLOAD_DECODERS_HEADERS_PAYLOAD_DECODER_H_ 7 8 // Decodes the payload of a HEADERS frame. 9 10 #include "quiche/http2/decoder/decode_buffer.h" 11 #include "quiche/http2/decoder/decode_status.h" 12 #include "quiche/http2/decoder/frame_decoder_state.h" 13 #include "quiche/http2/http2_structures.h" 14 #include "quiche/common/platform/api/quiche_export.h" 15 16 namespace http2 { 17 namespace test { 18 class HeadersPayloadDecoderPeer; 19 } // namespace test 20 21 class QUICHE_EXPORT HeadersPayloadDecoder { 22 public: 23 // States during decoding of a HEADERS frame, unless the fast path kicks 24 // in, in which case the state machine will be bypassed. 25 enum class PayloadState { 26 // The PADDED flag is set, and we now need to read the Pad Length field 27 // (the first byte of the payload, after the common frame header). 28 kReadPadLength, 29 30 // The PRIORITY flag is set, and we now need to read the fixed size priority 31 // fields (E, Stream Dependency, Weight) into priority_fields_. Calls on 32 // OnHeadersPriority if completely decodes those fields. 33 kStartDecodingPriorityFields, 34 35 // The decoder passes the non-padding portion of the remaining payload 36 // (i.e. the HPACK block fragment) to the listener's OnHpackFragment method. 37 kReadPayload, 38 39 // The decoder has finished with the HPACK block fragment, and is now 40 // ready to skip the trailing padding, if the frame has any. 41 kSkipPadding, 42 43 // The fixed size fields weren't all available when the decoder first tried 44 // to decode them (state kStartDecodingPriorityFields); this state resumes 45 // the decoding when ResumeDecodingPayload is called later. 46 kResumeDecodingPriorityFields, 47 }; 48 49 // Starts the decoding of a HEADERS frame's payload, and completes it if 50 // the entire payload is in the provided decode buffer. 51 DecodeStatus StartDecodingPayload(FrameDecoderState* state, DecodeBuffer* db); 52 53 // Resumes decoding a HEADERS frame's payload that has been split across 54 // decode buffers. 55 DecodeStatus ResumeDecodingPayload(FrameDecoderState* state, 56 DecodeBuffer* db); 57 58 private: 59 friend class test::HeadersPayloadDecoderPeer; 60 61 PayloadState payload_state_; 62 Http2PriorityFields priority_fields_; 63 }; 64 65 } // namespace http2 66 67 #endif // QUICHE_HTTP2_DECODER_PAYLOAD_DECODERS_HEADERS_PAYLOAD_DECODER_H_ 68