| // Copyright 2017 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_HPACK_HPACK_DECODER_ADAPTER_H_ |
| #define QUICHE_SPDY_CORE_HPACK_HPACK_DECODER_ADAPTER_H_ |
| |
| // HpackDecoderAdapter uses http2::HpackDecoder to decode HPACK blocks into |
| // HTTP/2 header lists as outlined in http://tools.ietf.org/html/rfc7541. |
| |
| #include <stddef.h> |
| |
| #include <cstdint> |
| #include <memory> |
| |
| #include "absl/strings/string_view.h" |
| #include "http2/hpack/decoder/hpack_decoder.h" |
| #include "http2/hpack/decoder/hpack_decoder_listener.h" |
| #include "http2/hpack/decoder/hpack_decoder_tables.h" |
| #include "http2/hpack/http2_hpack_constants.h" |
| #include "common/platform/api/quiche_export.h" |
| #include "spdy/core/hpack/hpack_header_table.h" |
| #include "spdy/core/spdy_header_block.h" |
| #include "spdy/core/spdy_headers_handler_interface.h" |
| |
| namespace spdy { |
| namespace test { |
| class HpackDecoderAdapterPeer; |
| } // namespace test |
| |
| class QUICHE_EXPORT_PRIVATE HpackDecoderAdapter { |
| public: |
| friend test::HpackDecoderAdapterPeer; |
| HpackDecoderAdapter(); |
| HpackDecoderAdapter(const HpackDecoderAdapter&) = delete; |
| HpackDecoderAdapter& operator=(const HpackDecoderAdapter&) = delete; |
| ~HpackDecoderAdapter(); |
| |
| // Called upon acknowledgement of SETTINGS_HEADER_TABLE_SIZE. |
| void ApplyHeaderTableSizeSetting(size_t size_setting); |
| |
| // Returns the most recently applied value of SETTINGS_HEADER_TABLE_SIZE. |
| size_t GetCurrentHeaderTableSizeSetting() const; |
| |
| // If a SpdyHeadersHandlerInterface is provided, the decoder will emit |
| // headers to it rather than accumulating them in a SpdyHeaderBlock. |
| // Does not take ownership of the handler, but does use the pointer until |
| // the current HPACK block is completely decoded. |
| void HandleControlFrameHeadersStart(SpdyHeadersHandlerInterface* handler); |
| |
| // Called as HPACK block fragments arrive. Returns false if an error occurred |
| // while decoding the block. Does not take ownership of headers_data. |
| bool HandleControlFrameHeadersData(const char* headers_data, |
| size_t headers_data_length); |
| |
| // Called after a HPACK block has been completely delivered via |
| // HandleControlFrameHeadersData(). Returns false if an error occurred. |
| // |compressed_len| if non-null will be set to the size of the encoded |
| // buffered block that was accumulated in HandleControlFrameHeadersData(), |
| // to support subsequent calculation of compression percentage. |
| // Discards the handler supplied at the start of decoding the block. |
| bool HandleControlFrameHeadersComplete(); |
| |
| // Accessor for the most recently decoded headers block. Valid until the next |
| // call to HandleControlFrameHeadersData(). |
| // TODO(birenroy): Remove this method when all users of HpackDecoder specify |
| // a SpdyHeadersHandlerInterface. |
| const SpdyHeaderBlock& decoded_block() const; |
| |
| // Returns the current dynamic table size, including the 32 bytes per entry |
| // overhead mentioned in RFC 7541 section 4.1. |
| size_t GetDynamicTableSize() const { |
| return hpack_decoder_.GetDynamicTableSize(); |
| } |
| |
| // Set how much encoded data this decoder is willing to buffer. |
| // TODO(jamessynge): Resolve definition of this value, as it is currently |
| // too tied to a single implementation. We probably want to limit one or more |
| // of these: individual name or value strings, header entries, the entire |
| // header list, or the HPACK block; we probably shouldn't care about the size |
| // of individual transport buffers. |
| void set_max_decode_buffer_size_bytes(size_t max_decode_buffer_size_bytes); |
| |
| // Specifies the maximum size of an on-the-wire header block that will be |
| // accepted. |
| void set_max_header_block_bytes(size_t max_header_block_bytes); |
| |
| // Error code if an error has occurred, Error::kOk otherwise. |
| http2::HpackDecodingError error() const { return error_; } |
| |
| std::string detailed_error() const { return detailed_error_; } |
| |
| private: |
| class QUICHE_EXPORT_PRIVATE ListenerAdapter |
| : public http2::HpackDecoderListener { |
| public: |
| ListenerAdapter(); |
| ~ListenerAdapter() override; |
| |
| // If a SpdyHeadersHandlerInterface is provided, the decoder will emit |
| // headers to it rather than accumulating them in a SpdyHeaderBlock. |
| // Does not take ownership of the handler, but does use the pointer until |
| // the current HPACK block is completely decoded. |
| void set_handler(SpdyHeadersHandlerInterface* handler); |
| const SpdyHeaderBlock& decoded_block() const { return decoded_block_; } |
| |
| // Override the HpackDecoderListener methods: |
| void OnHeaderListStart() override; |
| void OnHeader(const std::string& name, const std::string& value) override; |
| void OnHeaderListEnd() override; |
| void OnHeaderErrorDetected(absl::string_view error_message) override; |
| |
| void AddToTotalHpackBytes(size_t delta) { total_hpack_bytes_ += delta; } |
| size_t total_hpack_bytes() const { return total_hpack_bytes_; } |
| |
| private: |
| // If the caller doesn't provide a handler, the header list is stored in |
| // this SpdyHeaderBlock. |
| SpdyHeaderBlock decoded_block_; |
| |
| // If non-NULL, handles decoded headers. Not owned. |
| SpdyHeadersHandlerInterface* handler_; |
| |
| // Total bytes that have been received as input (i.e. HPACK encoded) |
| // in the current HPACK block. |
| size_t total_hpack_bytes_; |
| |
| // Total bytes of the name and value strings in the current HPACK block. |
| size_t total_uncompressed_bytes_; |
| }; |
| |
| // Converts calls to HpackDecoderListener into calls to |
| // SpdyHeadersHandlerInterface. |
| ListenerAdapter listener_adapter_; |
| |
| // The actual decoder. |
| http2::HpackDecoder hpack_decoder_; |
| |
| // How much encoded data this decoder is willing to buffer. |
| size_t max_decode_buffer_size_bytes_; |
| |
| // How much encoded data this decoder is willing to process. |
| size_t max_header_block_bytes_; |
| |
| // Flag to keep track of having seen the header block start. Needed at the |
| // moment because HandleControlFrameHeadersStart won't be called if a handler |
| // is not being provided by the caller. |
| bool header_block_started_; |
| |
| // Error code if an error has occurred, Error::kOk otherwise. |
| http2::HpackDecodingError error_; |
| std::string detailed_error_; |
| }; |
| |
| } // namespace spdy |
| |
| #endif // QUICHE_SPDY_CORE_HPACK_HPACK_DECODER_ADAPTER_H_ |