1 // Copyright (c) 2019 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 #include "quiche/quic/core/qpack/qpack_decoded_headers_accumulator.h"
6 
7 #include "absl/strings/string_view.h"
8 #include "quiche/quic/core/qpack/qpack_decoder.h"
9 #include "quiche/quic/core/qpack/qpack_header_table.h"
10 #include "quiche/quic/platform/api/quic_bug_tracker.h"
11 #include "quiche/quic/platform/api/quic_flags.h"
12 
13 namespace quic {
14 
QpackDecodedHeadersAccumulator(QuicStreamId id,QpackDecoder * qpack_decoder,Visitor * visitor,size_t max_header_list_size)15 QpackDecodedHeadersAccumulator::QpackDecodedHeadersAccumulator(
16     QuicStreamId id, QpackDecoder* qpack_decoder, Visitor* visitor,
17     size_t max_header_list_size)
18     : decoder_(qpack_decoder->CreateProgressiveDecoder(id, this)),
19       visitor_(visitor),
20       max_header_list_size_(max_header_list_size),
21       uncompressed_header_bytes_including_overhead_(0),
22       uncompressed_header_bytes_without_overhead_(0),
23       compressed_header_bytes_(0),
24       header_list_size_limit_exceeded_(false),
25       headers_decoded_(false),
26       error_detected_(false) {
27   quic_header_list_.OnHeaderBlockStart();
28 }
29 
OnHeaderDecoded(absl::string_view name,absl::string_view value)30 void QpackDecodedHeadersAccumulator::OnHeaderDecoded(absl::string_view name,
31                                                      absl::string_view value) {
32   QUICHE_DCHECK(!error_detected_);
33 
34   uncompressed_header_bytes_without_overhead_ += name.size() + value.size();
35 
36   if (header_list_size_limit_exceeded_) {
37     return;
38   }
39 
40   uncompressed_header_bytes_including_overhead_ +=
41       name.size() + value.size() + kQpackEntrySizeOverhead;
42 
43   const size_t uncompressed_header_bytes =
44       GetQuicFlag(quic_header_size_limit_includes_overhead)
45           ? uncompressed_header_bytes_including_overhead_
46           : uncompressed_header_bytes_without_overhead_;
47   if (uncompressed_header_bytes > max_header_list_size_) {
48     header_list_size_limit_exceeded_ = true;
49   }
50   quic_header_list_.OnHeader(name, value);
51 }
52 
OnDecodingCompleted()53 void QpackDecodedHeadersAccumulator::OnDecodingCompleted() {
54   QUICHE_DCHECK(!headers_decoded_);
55   QUICHE_DCHECK(!error_detected_);
56 
57   headers_decoded_ = true;
58 
59   quic_header_list_.OnHeaderBlockEnd(
60       uncompressed_header_bytes_without_overhead_, compressed_header_bytes_);
61 
62   // Might destroy |this|.
63   visitor_->OnHeadersDecoded(std::move(quic_header_list_),
64                              header_list_size_limit_exceeded_);
65 }
66 
OnDecodingErrorDetected(QuicErrorCode error_code,absl::string_view error_message)67 void QpackDecodedHeadersAccumulator::OnDecodingErrorDetected(
68     QuicErrorCode error_code, absl::string_view error_message) {
69   QUICHE_DCHECK(!error_detected_);
70   QUICHE_DCHECK(!headers_decoded_);
71 
72   error_detected_ = true;
73   // Might destroy |this|.
74   visitor_->OnHeaderDecodingError(error_code, error_message);
75 }
76 
Decode(absl::string_view data)77 void QpackDecodedHeadersAccumulator::Decode(absl::string_view data) {
78   QUICHE_DCHECK(!error_detected_);
79 
80   compressed_header_bytes_ += data.size();
81   // Might destroy |this|.
82   decoder_->Decode(data);
83 }
84 
EndHeaderBlock()85 void QpackDecodedHeadersAccumulator::EndHeaderBlock() {
86   QUICHE_DCHECK(!error_detected_);
87   QUICHE_DCHECK(!headers_decoded_);
88 
89   if (!decoder_) {
90     QUIC_BUG(b215142466_EndHeaderBlock);
91     return;
92   }
93 
94   // Might destroy |this|.
95   decoder_->EndHeaderBlock();
96 }
97 
98 }  // namespace quic
99