| // Copyright 2016 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. |
| |
| // HpackDecoderState maintains the HPACK decompressor state; i.e. updates the |
| // HPACK dynamic table according to RFC 7541 as the entries in an HPACK block |
| // are decoded, and reads from the static and dynamic tables in order to build |
| // complete header entries. Calls an HpackDecoderListener with the completely |
| // decoded headers (i.e. after resolving table indices into names or values), |
| // thus translating the decoded HPACK entries into HTTP/2 headers. |
| |
| #ifndef QUICHE_HTTP2_HPACK_DECODER_HPACK_DECODER_STATE_H_ |
| #define QUICHE_HTTP2_HPACK_DECODER_HPACK_DECODER_STATE_H_ |
| |
| #include <stddef.h> |
| |
| #include <cstdint> |
| |
| #include "absl/strings/string_view.h" |
| #include "quiche/http2/hpack/decoder/hpack_decoder_listener.h" |
| #include "quiche/http2/hpack/decoder/hpack_decoder_string_buffer.h" |
| #include "quiche/http2/hpack/decoder/hpack_decoder_tables.h" |
| #include "quiche/http2/hpack/decoder/hpack_decoding_error.h" |
| #include "quiche/http2/hpack/decoder/hpack_whole_entry_listener.h" |
| #include "quiche/http2/hpack/http2_hpack_constants.h" |
| #include "quiche/common/platform/api/quiche_export.h" |
| |
| namespace http2 { |
| namespace test { |
| class HpackDecoderStatePeer; |
| } // namespace test |
| |
| class QUICHE_EXPORT HpackDecoderState : public HpackWholeEntryListener { |
| public: |
| explicit HpackDecoderState(HpackDecoderListener* listener); |
| ~HpackDecoderState() override; |
| |
| HpackDecoderState(const HpackDecoderState&) = delete; |
| HpackDecoderState& operator=(const HpackDecoderState&) = delete; |
| |
| // Set the listener to be notified when a whole entry has been decoded, |
| // including resolving name or name and value references. |
| // The listener may be changed at any time. |
| HpackDecoderListener* listener() const { return listener_; } |
| |
| // ApplyHeaderTableSizeSetting notifies this object that this endpoint has |
| // received a SETTINGS ACK frame acknowledging an earlier SETTINGS frame from |
| // this endpoint specifying a new value for SETTINGS_HEADER_TABLE_SIZE (the |
| // maximum size of the dynamic table that this endpoint will use to decode |
| // HPACK blocks). |
| // Because a SETTINGS frame can contain SETTINGS_HEADER_TABLE_SIZE values, |
| // the caller must keep track of those multiple changes, and make |
| // corresponding calls to this method. In particular, a call must be made |
| // with the lowest value acknowledged by the peer, and a call must be made |
| // with the final value acknowledged, in that order; additional calls may |
| // be made if additional values were sent. These calls must be made between |
| // decoding the SETTINGS ACK, and before the next HPACK block is decoded. |
| void ApplyHeaderTableSizeSetting(uint32_t max_header_table_size); |
| |
| // Returns the most recently applied value of SETTINGS_HEADER_TABLE_SIZE. |
| size_t GetCurrentHeaderTableSizeSetting() const { |
| return final_header_table_size_; |
| } |
| |
| // OnHeaderBlockStart notifies this object that we're starting to decode the |
| // HPACK payload of a HEADERS or PUSH_PROMISE frame. |
| void OnHeaderBlockStart(); |
| |
| // Implement the HpackWholeEntryListener methods, each of which notifies this |
| // object when an entire entry has been decoded. |
| void OnIndexedHeader(size_t index) override; |
| void OnNameIndexAndLiteralValue( |
| HpackEntryType entry_type, size_t name_index, |
| HpackDecoderStringBuffer* value_buffer) override; |
| void OnLiteralNameAndValue(HpackEntryType entry_type, |
| HpackDecoderStringBuffer* name_buffer, |
| HpackDecoderStringBuffer* value_buffer) override; |
| void OnDynamicTableSizeUpdate(size_t size) override; |
| void OnHpackDecodeError(HpackDecodingError error) override; |
| |
| // OnHeaderBlockEnd notifies this object that an entire HPACK block has been |
| // decoded, which might have extended into CONTINUATION blocks. |
| void OnHeaderBlockEnd(); |
| |
| // Returns error code after an error has been detected and reported. |
| // No further callbacks will be made to the listener. |
| HpackDecodingError error() const { return error_; } |
| |
| size_t GetDynamicTableSize() const { |
| return decoder_tables_.current_header_table_size(); |
| } |
| |
| const HpackDecoderTables& decoder_tables_for_test() const { |
| return decoder_tables_; |
| } |
| |
| private: |
| friend class test::HpackDecoderStatePeer; |
| |
| // Reports an error to the listener IF this is the first error detected. |
| void ReportError(HpackDecodingError error); |
| |
| // The static and dynamic HPACK tables. |
| HpackDecoderTables decoder_tables_; |
| |
| // The listener to be notified of headers, the start and end of header |
| // lists, and of errors. |
| HpackDecoderListener* listener_; |
| |
| // The most recent HEADER_TABLE_SIZE setting acknowledged by the peer. |
| uint32_t final_header_table_size_; |
| |
| // The lowest HEADER_TABLE_SIZE setting acknowledged by the peer; valid until |
| // the next HPACK block is decoded. |
| // TODO(jamessynge): Test raising the HEADER_TABLE_SIZE. |
| uint32_t lowest_header_table_size_; |
| |
| // Must the next (first) HPACK entry be a dynamic table size update? |
| bool require_dynamic_table_size_update_; |
| |
| // May the next (first or second) HPACK entry be a dynamic table size update? |
| bool allow_dynamic_table_size_update_; |
| |
| // Have we already seen a dynamic table size update in this HPACK block? |
| bool saw_dynamic_table_size_update_; |
| |
| // Has an error already been detected and reported to the listener? |
| HpackDecodingError error_; |
| }; |
| |
| } // namespace http2 |
| |
| #endif // QUICHE_HTTP2_HPACK_DECODER_HPACK_DECODER_STATE_H_ |