| // Copyright 2014 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_ENCODER_H_ |
| #define QUICHE_SPDY_CORE_HPACK_HPACK_ENCODER_H_ |
| |
| #include <stddef.h> |
| |
| #include <functional> |
| #include <map> |
| #include <memory> |
| #include <utility> |
| #include <vector> |
| |
| #include "base/macros.h" |
| #include "net/third_party/quiche/src/spdy/core/hpack/hpack_header_table.h" |
| #include "net/third_party/quiche/src/spdy/core/hpack/hpack_output_stream.h" |
| #include "net/third_party/quiche/src/spdy/core/spdy_protocol.h" |
| #include "net/third_party/quiche/src/spdy/platform/api/spdy_export.h" |
| #include "net/third_party/quiche/src/spdy/platform/api/spdy_string.h" |
| #include "net/third_party/quiche/src/spdy/platform/api/spdy_string_piece.h" |
| |
| // An HpackEncoder encodes header sets as outlined in |
| // http://tools.ietf.org/html/rfc7541. |
| |
| namespace spdy { |
| |
| class HpackHuffmanTable; |
| |
| namespace test { |
| class HpackEncoderPeer; |
| } // namespace test |
| |
| class SPDY_EXPORT_PRIVATE HpackEncoder { |
| public: |
| using Representation = std::pair<SpdyStringPiece, SpdyStringPiece>; |
| using Representations = std::vector<Representation>; |
| |
| // Callers may provide a HeaderListener to be informed of header name-value |
| // pairs processed by this encoder. |
| using HeaderListener = std::function<void(SpdyStringPiece, SpdyStringPiece)>; |
| |
| // An indexing policy should return true if the provided header name-value |
| // pair should be inserted into the HPACK dynamic table. |
| using IndexingPolicy = std::function<bool(SpdyStringPiece, SpdyStringPiece)>; |
| |
| // |table| is an initialized HPACK Huffman table, having an |
| // externally-managed lifetime which spans beyond HpackEncoder. |
| explicit HpackEncoder(const HpackHuffmanTable& table); |
| HpackEncoder(const HpackEncoder&) = delete; |
| HpackEncoder& operator=(const HpackEncoder&) = delete; |
| ~HpackEncoder(); |
| |
| // Encodes the given header set into the given string. Returns |
| // whether or not the encoding was successful. |
| bool EncodeHeaderSet(const SpdyHeaderBlock& header_set, SpdyString* output); |
| |
| class SPDY_EXPORT_PRIVATE ProgressiveEncoder { |
| public: |
| virtual ~ProgressiveEncoder() {} |
| |
| // Returns true iff more remains to encode. |
| virtual bool HasNext() const = 0; |
| |
| // Encodes up to max_encoded_bytes of the current header block into the |
| // given output string. |
| virtual void Next(size_t max_encoded_bytes, SpdyString* output) = 0; |
| }; |
| |
| // Returns a ProgressiveEncoder which must be outlived by both the given |
| // SpdyHeaderBlock and this object. |
| std::unique_ptr<ProgressiveEncoder> EncodeHeaderSet( |
| const SpdyHeaderBlock& header_set); |
| |
| // Called upon a change to SETTINGS_HEADER_TABLE_SIZE. Specifically, this |
| // is to be called after receiving (and sending an acknowledgement for) a |
| // SETTINGS_HEADER_TABLE_SIZE update from the remote decoding endpoint. |
| void ApplyHeaderTableSizeSetting(size_t size_setting); |
| |
| size_t CurrentHeaderTableSizeSetting() const { |
| return header_table_.settings_size_bound(); |
| } |
| |
| // This HpackEncoder will use |policy| to determine whether to insert header |
| // name-value pairs into the dynamic table. |
| void SetIndexingPolicy(IndexingPolicy policy) { should_index_ = policy; } |
| |
| // |listener| will be invoked for each header name-value pair processed by |
| // this encoder. |
| void SetHeaderListener(HeaderListener listener) { listener_ = listener; } |
| |
| void SetHeaderTableDebugVisitor( |
| std::unique_ptr<HpackHeaderTable::DebugVisitorInterface> visitor) { |
| header_table_.set_debug_visitor(std::move(visitor)); |
| } |
| |
| void DisableCompression() { enable_compression_ = false; } |
| |
| // Returns the estimate of dynamically allocated memory in bytes. |
| size_t EstimateMemoryUsage() const; |
| |
| private: |
| friend class test::HpackEncoderPeer; |
| |
| class RepresentationIterator; |
| class Encoderator; |
| |
| // Encodes a sequence of header name-value pairs as a single header block. |
| void EncodeRepresentations(RepresentationIterator* iter, SpdyString* output); |
| |
| // Emits a static/dynamic indexed representation (Section 7.1). |
| void EmitIndex(const HpackEntry* entry); |
| |
| // Emits a literal representation (Section 7.2). |
| void EmitIndexedLiteral(const Representation& representation); |
| void EmitNonIndexedLiteral(const Representation& representation); |
| void EmitLiteral(const Representation& representation); |
| |
| // Emits a Huffman or identity string (whichever is smaller). |
| void EmitString(SpdyStringPiece str); |
| |
| // Emits the current dynamic table size if the table size was recently |
| // updated and we have not yet emitted it (Section 6.3). |
| void MaybeEmitTableSize(); |
| |
| // Crumbles a cookie header into ";" delimited crumbs. |
| static void CookieToCrumbs(const Representation& cookie, |
| Representations* crumbs_out); |
| |
| // Crumbles other header field values at \0 delimiters. |
| static void DecomposeRepresentation(const Representation& header_field, |
| Representations* out); |
| |
| // Gathers headers without crumbling. Used when compression is not enabled. |
| static void GatherRepresentation(const Representation& header_field, |
| Representations* out); |
| |
| HpackHeaderTable header_table_; |
| HpackOutputStream output_stream_; |
| |
| const HpackHuffmanTable& huffman_table_; |
| size_t min_table_size_setting_received_; |
| HeaderListener listener_; |
| IndexingPolicy should_index_; |
| bool enable_compression_; |
| bool should_emit_table_size_; |
| }; |
| |
| } // namespace spdy |
| |
| #endif // QUICHE_SPDY_CORE_HPACK_HPACK_ENCODER_H_ |