text: // 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.
  
  #include "spdy/core/hpack/hpack_decoder_adapter.h"
  
  // Tests of HpackDecoderAdapter.
  
  #include <stdint.h>
  
  #include <string>
  #include <tuple>
  #include <utility>
  #include <vector>
  
  #include "absl/base/macros.h"
  #include "absl/strings/escaping.h"
  #include "http2/hpack/decoder/hpack_decoder_state.h"
  #include "http2/hpack/decoder/hpack_decoder_tables.h"
  #include "http2/hpack/tools/hpack_block_builder.h"
  #include "http2/test_tools/http2_random.h"
  #include "common/platform/api/quiche_logging.h"
  #include "common/platform/api/quiche_test.h"
  #include "spdy/core/hpack/hpack_constants.h"
  #include "spdy/core/hpack/hpack_encoder.h"
  #include "spdy/core/hpack/hpack_output_stream.h"
  #include "spdy/core/recording_headers_handler.h"
  #include "spdy/core/spdy_test_utils.h"
  #include "spdy/platform/api/spdy_string_utils.h"
  
  using ::http2::HpackEntryType;
  using ::http2::HpackStringPair;
  using ::http2::test::HpackBlockBuilder;
  using ::http2::test::HpackDecoderPeer;
  using ::testing::ElementsAre;
  using ::testing::Pair;
  
  namespace http2 {
  namespace test {
  
  class HpackDecoderStatePeer {
   public:
    static HpackDecoderTables* GetDecoderTables(HpackDecoderState* state) {
      return &state->decoder_tables_;
    }
  };
  
  class HpackDecoderPeer {
   public:
    static HpackDecoderState* GetDecoderState(HpackDecoder* decoder) {
      return &decoder->decoder_state_;
    }
    static HpackDecoderTables* GetDecoderTables(HpackDecoder* decoder) {
      return HpackDecoderStatePeer::GetDecoderTables(GetDecoderState(decoder));
    }
  };
  
  }  // namespace test
  }  // namespace http2
  
  namespace spdy {
  namespace test {
  
  class HpackDecoderAdapterPeer {
   public:
    explicit HpackDecoderAdapterPeer(HpackDecoderAdapter* decoder)
        : decoder_(decoder) {}
  
    void HandleHeaderRepresentation(const std::string& name,
                                    const std::string& value) {
      decoder_->listener_adapter_.OnHeader(name, value);
    }
  
    http2::HpackDecoderTables* GetDecoderTables() {
      return HpackDecoderPeer::GetDecoderTables(&decoder_->hpack_decoder_);
    }
  
    const HpackStringPair* GetTableEntry(uint32_t index) {
      return GetDecoderTables()->Lookup(index);
    }
  
    size_t current_header_table_size() {
      return GetDecoderTables()->current_header_table_size();
    }
  
    size_t header_table_size_limit() {
      return GetDecoderTables()->header_table_size_limit();
    }
  
    void set_header_table_size_limit(size_t size) {
      return GetDecoderTables()->DynamicTableSizeUpdate(size);
    }
  
   private:
    HpackDecoderAdapter* decoder_;
  };
  
  class HpackEncoderPeer {
   public:
    static void CookieToCrumbs(const HpackEncoder::Representation& cookie,
                               HpackEncoder::Representations* crumbs_out) {
      HpackEncoder::CookieToCrumbs(cookie, crumbs_out);
    }
  };
  
  namespace {
  
  const bool kNoCheckDecodedSize = false;
  const char* kCookieKey = "cookie";
  
  // Is HandleControlFrameHeadersStart to be called, and with what value?
  enum StartChoice { START_WITH_HANDLER, START_WITHOUT_HANDLER, NO_START };
  
  class HpackDecoderAdapterTest
      : public QuicheTestWithParam<std::tuple<StartChoice, bool>> {
   protected:
    HpackDecoderAdapterTest() : decoder_(), decoder_peer_(&decoder_) {}
  
    void SetUp() override {
      std::tie(start_choice_, randomly_split_input_buffer_) = GetParam();
    }
  
    void HandleControlFrameHeadersStart() {
      bytes_passed_in_ = 0;
      switch (start_choice_) {
        case START_WITH_HANDLER:
          decoder_.HandleControlFrameHeadersStart(&handler_);
          break;
        case START_WITHOUT_HANDLER:
          decoder_.HandleControlFrameHeadersStart(nullptr);
          break;
        case NO_START:
          break;
      }
    }
  
    bool HandleControlFrameHeadersData(absl::string_view str) {
      QUICHE_VLOG(3) << "HandleControlFrameHeadersData:\n" << SpdyHexDump(str);
      bytes_passed_in_ += str.size();
      return decoder_.HandleControlFrameHeadersData(str.data(), str.size());
    }
  
    bool HandleControlFrameHeadersComplete(size_t* size) {
      bool rc = decoder_.HandleControlFrameHeadersComplete(size);
      if (size != nullptr) {
        EXPECT_EQ(*size, bytes_passed_in_);
      }
      return rc;
    }
  
    bool DecodeHeaderBlock(absl::string_view str,
                           bool check_decoded_size = true) {
      // Don't call this again if HandleControlFrameHeadersData failed previously.
      EXPECT_FALSE(decode_has_failed_);
      HandleControlFrameHeadersStart();
      if (randomly_split_input_buffer_) {
        do {
          // Decode some fragment of the remaining bytes.
          size_t bytes = str.size();
          if (!str.empty()) {
            bytes = random_.Uniform(str.size()) + 1;
          }
          EXPECT_LE(bytes, str.size());
          if (!HandleControlFrameHeadersData(str.substr(0, bytes))) {
            decode_has_failed_ = true;
            return false;
          }
          str.remove_prefix(bytes);
        } while (!str.empty());
      } else if (!HandleControlFrameHeadersData(str)) {
        decode_has_failed_ = true;
        return false;
      }
      // Want to get out the number of compressed bytes that were decoded,
      // so pass in a pointer if no handler.
      size_t total_hpack_bytes = 0;
      if (start_choice_ == START_WITH_HANDLER) {
        if (!HandleControlFrameHeadersComplete(nullptr)) {
          decode_has_failed_ = true;
          return false;
        }
        total_hpack_bytes = handler_.compressed_header_bytes();
      } else {
        if (!HandleControlFrameHeadersComplete(&total_hpack_bytes)) {
          decode_has_failed_ = true;
          return false;
        }
      }
      EXPECT_EQ(total_hpack_bytes, bytes_passed_in_);
      if (check_decoded_size && start_choice_ == START_WITH_HANDLER) {
        EXPECT_EQ(handler_.uncompressed_header_bytes(),
                  SizeOfHeaders(decoded_block()));
      }
      return true;
    }
  
    bool EncodeAndDecodeDynamicTableSizeUpdates(size_t first, size_t second) {
      HpackBlockBuilder hbb;
      hbb.AppendDynamicTableSizeUpdate(first);
      if (second != first) {
        hbb.AppendDynamicTableSizeUpdate(second);
      }
      return DecodeHeaderBlock(hbb.buffer());
    }
  
    const SpdyHeaderBlock& decoded_block() const {
      if (start_choice_ == START_WITH_HANDLER) {
        return handler_.decoded_block();
      } else {
        return decoder_.decoded_block();
      }
    }
  
    static size_t SizeOfHeaders(const SpdyHeaderBlock& headers) {
      size_t size = 0;
      for (const auto& kv : headers) {
        if (kv.first == kCookieKey) {
          HpackEncoder::Representations crumbs;
          HpackEncoderPeer::CookieToCrumbs(kv, &crumbs);
          for (const auto& crumb : crumbs) {
            size += crumb.first.size() + crumb.second.size();
          }
        } else {
          size += kv.first.size() + kv.second.size();
        }
      }
      return size;
    }
  
    const SpdyHeaderBlock& DecodeBlockExpectingSuccess(absl::string_view str) {
      EXPECT_TRUE(DecodeHeaderBlock(str));
      return decoded_block();
    }
  
    void expectEntry(size_t index,
                     size_t size,
                     const std::string& name,
                     const std::string& value) {
      const HpackStringPair* entry = decoder_peer_.GetTableEntry(index);
      EXPECT_EQ(name, entry->name) << "index " << index;
      EXPECT_EQ(value, entry->value);
      EXPECT_EQ(size, entry->size());
    }
  
    SpdyHeaderBlock MakeHeaderBlock(
        const std::vector<std::pair<std::string, std::string>>& headers) {
      SpdyHeaderBlock result;
      for (const auto& kv : headers) {
        result.AppendValueOrAddHeader(kv.first, kv.second);
      }
      return result;
    }
  
    http2::test::Http2Random random_;
    HpackDecoderAdapter decoder_;
    test::HpackDecoderAdapterPeer decoder_peer_;
    RecordingHeadersHandler handler_;
    StartChoice start_choice_;
    bool randomly_split_input_buffer_;
    bool decode_has_failed_ = false;
    size_t bytes_passed_in_;
  };
  
  INSTANTIATE_TEST_SUITE_P(
      NoHandler,
      HpackDecoderAdapterTest,
      ::testing::Combine(::testing::Values(START_WITHOUT_HANDLER, NO_START),
                         ::testing::Bool()));
  
  INSTANTIATE_TEST_SUITE_P(
      WithHandler,
      HpackDecoderAdapterTest,
      ::testing::Combine(::testing::Values(START_WITH_HANDLER),
                         ::testing::Bool()));
  
  TEST_P(HpackDecoderAdapterTest,
         AddHeaderDataWithHandleControlFrameHeadersData) {
    // The hpack decode buffer size is limited in size. This test verifies that
    // adding encoded data under that limit is accepted, and data that exceeds the
    // limit is rejected.
    HandleControlFrameHeadersStart();
    const size_t kMaxBufferSizeBytes = 50;
    const std::string a_value = std::string(49, 'x');
    decoder_.set_max_decode_buffer_size_bytes(kMaxBufferSizeBytes);
    HpackBlockBuilder hbb;
    hbb.AppendLiteralNameAndValue(HpackEntryType::kNeverIndexedLiteralHeader,
                                  false, "a", false, a_value);
    const std::string& s = hbb.buffer();
    EXPECT_GT(s.size(), kMaxBufferSizeBytes);
  
    // Any one in input buffer must not exceed kMaxBufferSizeBytes.
    EXPECT_TRUE(HandleControlFrameHeadersData(s.substr(0, s.size() / 2)));
    EXPECT_TRUE(HandleControlFrameHeadersData(s.substr(s.size() / 2)));
  
    EXPECT_FALSE(HandleControlFrameHeadersData(s));
    SpdyHeaderBlock expected_block = MakeHeaderBlock({{"a", a_value}});
    EXPECT_EQ(expected_block, decoded_block());
  }
  
  TEST_P(HpackDecoderAdapterTest, NameTooLong) {
    // Verify that a name longer than the allowed size generates an error.
    const size_t kMaxBufferSizeBytes = 50;
    const std::string name = std::string(2 * kMaxBufferSizeBytes, 'x');
    const std::string value = "abc";
  
    decoder_.set_max_decode_buffer_size_bytes(kMaxBufferSizeBytes);
  
    HpackBlockBuilder hbb;
    hbb.AppendLiteralNameAndValue(HpackEntryType::kNeverIndexedLiteralHeader,
                                  false, name, false, value);
  
    const size_t fragment_size = (3 * kMaxBufferSizeBytes) / 2;
    const std::string fragment = hbb.buffer().substr(0, fragment_size);
  
    HandleControlFrameHeadersStart();
    EXPECT_FALSE(HandleControlFrameHeadersData(fragment));
  }
  
  TEST_P(HpackDecoderAdapterTest, HeaderTooLongToBuffer) {
    // Verify that a header longer than the allowed size generates an error if
    // it isn't all in one input buffer.
    const std::string name = "some-key";
    const std::string value = "some-value";
    const size_t kMaxBufferSizeBytes = name.size() + value.size() - 2;
    decoder_.set_max_decode_buffer_size_bytes(kMaxBufferSizeBytes);
  
    HpackBlockBuilder hbb;
    hbb.AppendLiteralNameAndValue(HpackEntryType::kNeverIndexedLiteralHeader,
                                  false, name, false, value);
    const size_t fragment_size = hbb.size() - 1;
    const std::string fragment = hbb.buffer().substr(0, fragment_size);
  
    HandleControlFrameHeadersStart();
    EXPECT_FALSE(HandleControlFrameHeadersData(fragment));
  }
  
  // Verify that a header block that exceeds the maximum length is rejected.
  TEST_P(HpackDecoderAdapterTest, HeaderBlockTooLong) {
    const std::string name = "some-key";
    const std::string value = "some-value";
    const size_t kMaxBufferSizeBytes = 1024;
  
    HpackBlockBuilder hbb;
    hbb.AppendLiteralNameAndValue(HpackEntryType::kIndexedLiteralHeader, false,
                                  name, false, value);
    while (hbb.size() < kMaxBufferSizeBytes) {
      hbb.AppendLiteralNameAndValue(HpackEntryType::kIndexedLiteralHeader, false,
                                    "", false, "");
    }
    // With no limit on the maximum header block size, the decoder handles the
    // entire block successfully.
    HandleControlFrameHeadersStart();
    EXPECT_TRUE(HandleControlFrameHeadersData(hbb.buffer()));
    size_t total_bytes;
    EXPECT_TRUE(HandleControlFrameHeadersComplete(&total_bytes));
  
    // When a total byte limit is imposed, the decoder bails before the end of the
    // block.
    decoder_.set_max_header_block_bytes(kMaxBufferSizeBytes);
    HandleControlFrameHeadersStart();
    EXPECT_FALSE(HandleControlFrameHeadersData(hbb.buffer()));
  }
  
  // Decode with incomplete data in buffer.
  TEST_P(HpackDecoderAdapterTest, DecodeWithIncompleteData) {
    HandleControlFrameHeadersStart();
  
    // No need to wait for more data.
    EXPECT_TRUE(HandleControlFrameHeadersData("\x82\x85\x82"));
    std::vector<std::pair<std::string, std::string>> expected_headers = {
        {":method", "GET"}, {":path", "/index.html"}, {":method", "GET"}};
  
    SpdyHeaderBlock expected_block1 = MakeHeaderBlock(expected_headers);
    EXPECT_EQ(expected_block1, decoded_block());
  
    // Full and partial headers, won't add partial to the headers.
    EXPECT_TRUE(
        HandleControlFrameHeadersData("\x40\x03goo"
                                      "\x03gar\xbe\x40\x04spam"));
    expected_headers.push_back({"goo", "gar"});
    expected_headers.push_back({"goo", "gar"});
  
    SpdyHeaderBlock expected_block2 = MakeHeaderBlock(expected_headers);
    EXPECT_EQ(expected_block2, decoded_block());
  
    // Add the needed data.
    EXPECT_TRUE(HandleControlFrameHeadersData("\x04gggs"));
  
    size_t size = 0;
    EXPECT_TRUE(HandleControlFrameHeadersComplete(&size));
    EXPECT_EQ(24u, size);
  
    expected_headers.push_back({"spam", "gggs"});
  
    SpdyHeaderBlock expected_block3 = MakeHeaderBlock(expected_headers);
    EXPECT_EQ(expected_block3, decoded_block());
  }
  
  TEST_P(HpackDecoderAdapterTest, HandleHeaderRepresentation) {
    // Make sure the decoder is properly initialized.
    HandleControlFrameHeadersStart();
    HandleControlFrameHeadersData("");
  
    // All cookie crumbs are joined.
    decoder_peer_.HandleHeaderRepresentation("cookie", " part 1");
    decoder_peer_.HandleHeaderRepresentation("cookie", "part 2 ");
    decoder_peer_.HandleHeaderRepresentation("cookie", "part3");
  
    // Already-delimited headers are passed through.
    decoder_peer_.HandleHeaderRepresentation("passed-through",
                                             std::string("foo\0baz", 7));
  
    // Other headers are joined on \0. Case matters.
    decoder_peer_.HandleHeaderRepresentation("joined", "joined");
    decoder_peer_.HandleHeaderRepresentation("joineD", "value 1");
    decoder_peer_.HandleHeaderRepresentation("joineD", "value 2");
  
    // Empty headers remain empty.
    decoder_peer_.HandleHeaderRepresentation("empty", "");
  
    // Joined empty headers work as expected.
    decoder_peer_.HandleHeaderRepresentation("empty-joined", "");
    decoder_peer_.HandleHeaderRepresentation("empty-joined", "foo");
    decoder_peer_.HandleHeaderRepresentation("empty-joined", "");
    decoder_peer_.HandleHeaderRepresentation("empty-joined", "");
  
    // Non-contiguous cookie crumb.
    decoder_peer_.HandleHeaderRepresentation("cookie", " fin!");
  
    // Finish and emit all headers.
    decoder_.HandleControlFrameHeadersComplete(nullptr);
  
    // Resulting decoded headers are in the same order as the inputs.
    EXPECT_THAT(
        decoded_block(),
        ElementsAre(
            Pair("cookie", " part 1; part 2 ; part3;  fin!"),
            Pair("passed-through", absl::string_view("foo\0baz", 7)),
            Pair("joined", absl::string_view("joined\0value 1\0value 2", 22)),
            Pair("empty", ""),
            Pair("empty-joined", absl::string_view("\0foo\0\0", 6))));
  }
  
  // Decoding indexed static table field should work.
  TEST_P(HpackDecoderAdapterTest, IndexedHeaderStatic) {
    // Reference static table entries #2 and #5.
    const SpdyHeaderBlock& header_set1 = DecodeBlockExpectingSuccess("\x82\x85");
    SpdyHeaderBlock expected_header_set1;
    expected_header_set1[":method"] = "GET";
    expected_header_set1[":path"] = "/index.html";
    EXPECT_EQ(expected_header_set1, header_set1);
  
    // Reference static table entry #2.
    const SpdyHeaderBlock& header_set2 = DecodeBlockExpectingSuccess("\x82");
    SpdyHeaderBlock expected_header_set2;
    expected_header_set2[":method"] = "GET";
    EXPECT_EQ(expected_header_set2, header_set2);
  }
  
  TEST_P(HpackDecoderAdapterTest, IndexedHeaderDynamic) {
    // First header block: add an entry to header table.
    const SpdyHeaderBlock& header_set1 = DecodeBlockExpectingSuccess(
        "\x40\x03"
        "foo"
        "\x03"
        "bar");
    SpdyHeaderBlock expected_header_set1;
    expected_header_set1["foo"] = "bar";
    EXPECT_EQ(expected_header_set1, header_set1);
  
    // Second header block: add another entry to header table.
    const SpdyHeaderBlock& header_set2 = DecodeBlockExpectingSuccess(
        "\xbe\x40\x04"
        "spam"
        "\x04"
        "eggs");
    SpdyHeaderBlock expected_header_set2;
    expected_header_set2["foo"] = "bar";
    expected_header_set2["spam"] = "eggs";
    EXPECT_EQ(expected_header_set2, header_set2);
  
    // Third header block: refer to most recently added entry.
    const SpdyHeaderBlock& header_set3 = DecodeBlockExpectingSuccess("\xbe");
    SpdyHeaderBlock expected_header_set3;
    expected_header_set3["spam"] = "eggs";
    EXPECT_EQ(expected_header_set3, header_set3);
  }
  
  // Test a too-large indexed header.
  TEST_P(HpackDecoderAdapterTest, InvalidIndexedHeader) {
    // High-bit set, and a prefix of one more than the number of static entries.
    EXPECT_FALSE(DecodeHeaderBlock("\xbe"));
  }
  
  TEST_P(HpackDecoderAdapterTest, ContextUpdateMaximumSize) {
    EXPECT_EQ(kDefaultHeaderTableSizeSetting,
              decoder_peer_.header_table_size_limit());
    std::string input;
    {
      // Maximum-size update with size 126. Succeeds.
      HpackOutputStream output_stream;
      output_stream.AppendPrefix(kHeaderTableSizeUpdateOpcode);
      output_stream.AppendUint32(126);
  
      output_stream.TakeString(&input);
      EXPECT_TRUE(DecodeHeaderBlock(absl::string_view(input)));
      EXPECT_EQ(126u, decoder_peer_.header_table_size_limit());
    }
    {
      // Maximum-size update with kDefaultHeaderTableSizeSetting. Succeeds.
      HpackOutputStream output_stream;
      output_stream.AppendPrefix(kHeaderTableSizeUpdateOpcode);
      output_stream.AppendUint32(kDefaultHeaderTableSizeSetting);
  
      output_stream.TakeString(&input);
      EXPECT_TRUE(DecodeHeaderBlock(absl::string_view(input)));
      EXPECT_EQ(kDefaultHeaderTableSizeSetting,
                decoder_peer_.header_table_size_limit());
    }
    {
      // Maximum-size update with kDefaultHeaderTableSizeSetting + 1. Fails.
      HpackOutputStream output_stream;
      output_stream.AppendPrefix(kHeaderTableSizeUpdateOpcode);
      output_stream.AppendUint32(kDefaultHeaderTableSizeSetting + 1);
  
      output_stream.TakeString(&input);
      EXPECT_FALSE(DecodeHeaderBlock(absl::string_view(input)));
      EXPECT_EQ(kDefaultHeaderTableSizeSetting,
                decoder_peer_.header_table_size_limit());
    }
  }
  
  // Two HeaderTableSizeUpdates may appear at the beginning of the block
  TEST_P(HpackDecoderAdapterTest, TwoTableSizeUpdates) {
    std::string input;
    {
      // Should accept two table size updates, update to second one
      HpackOutputStream output_stream;
      output_stream.AppendPrefix(kHeaderTableSizeUpdateOpcode);
      output_stream.AppendUint32(0);
      output_stream.AppendPrefix(kHeaderTableSizeUpdateOpcode);
      output_stream.AppendUint32(122);
  
      output_stream.TakeString(&input);
      EXPECT_TRUE(DecodeHeaderBlock(absl::string_view(input)));
      EXPECT_EQ(122u, decoder_peer_.header_table_size_limit());
    }
  }
  
  // Three HeaderTableSizeUpdates should result in an error
  TEST_P(HpackDecoderAdapterTest, ThreeTableSizeUpdatesError) {
    std::string input;
    {
      // Should reject three table size updates, update to second one
      HpackOutputStream output_stream;
      output_stream.AppendPrefix(kHeaderTableSizeUpdateOpcode);
      output_stream.AppendUint32(5);
      output_stream.AppendPrefix(kHeaderTableSizeUpdateOpcode);
      output_stream.AppendUint32(10);
      output_stream.AppendPrefix(kHeaderTableSizeUpdateOpcode);
      output_stream.AppendUint32(15);
  
      output_stream.TakeString(&input);
  
      EXPECT_FALSE(DecodeHeaderBlock(absl::string_view(input)));
      EXPECT_EQ(10u, decoder_peer_.header_table_size_limit());
    }
  }
  
  // HeaderTableSizeUpdates may only appear at the beginning of the block
  // Any other updates should result in an error
  TEST_P(HpackDecoderAdapterTest, TableSizeUpdateSecondError) {
    std::string input;
    {
      // Should reject a table size update appearing after a different entry
      // The table size should remain as the default
      HpackOutputStream output_stream;
      output_stream.AppendBytes("\x82\x85");
      output_stream.AppendPrefix(kHeaderTableSizeUpdateOpcode);
      output_stream.AppendUint32(123);
  
      output_stream.TakeString(&input);
  
      EXPECT_FALSE(DecodeHeaderBlock(absl::string_view(input)));
      EXPECT_EQ(kDefaultHeaderTableSizeSetting,
                decoder_peer_.header_table_size_limit());
    }
  }
  
  // HeaderTableSizeUpdates may only appear at the beginning of the block
  // Any other updates should result in an error
  TEST_P(HpackDecoderAdapterTest, TableSizeUpdateFirstThirdError) {
    std::string input;
    {
      // Should reject the second table size update
      // if a different entry appears after the first update
      // The table size should update to the first but not the second
      HpackOutputStream output_stream;
      output_stream.AppendPrefix(kHeaderTableSizeUpdateOpcode);
      output_stream.AppendUint32(60);
      output_stream.AppendBytes("\x82\x85");
      output_stream.AppendPrefix(kHeaderTableSizeUpdateOpcode);
      output_stream.AppendUint32(125);
  
      output_stream.TakeString(&input);
  
      EXPECT_FALSE(DecodeHeaderBlock(absl::string_view(input)));
      EXPECT_EQ(60u, decoder_peer_.header_table_size_limit());
    }
  }
  
  // Decoding two valid encoded literal headers with no indexing should
  // work.
  TEST_P(HpackDecoderAdapterTest, LiteralHeaderNoIndexing) {
    // First header with indexed name, second header with string literal
    // name.
    const char input[] = "\x04\x0c/sample/path\x00\x06:path2\x0e/sample/path/2";
    const SpdyHeaderBlock& header_set = DecodeBlockExpectingSuccess(
        absl::string_view(input, ABSL_ARRAYSIZE(input) - 1));
  
    SpdyHeaderBlock expected_header_set;
    expected_header_set[":path"] = "/sample/path";
    expected_header_set[":path2"] = "/sample/path/2";
    EXPECT_EQ(expected_header_set, header_set);
  }
  
  // Decoding two valid encoded literal headers with incremental
  // indexing and string literal names should work.
  TEST_P(HpackDecoderAdapterTest, LiteralHeaderIncrementalIndexing) {
    const char input[] = "\x44\x0c/sample/path\x40\x06:path2\x0e/sample/path/2";
    const SpdyHeaderBlock& header_set = DecodeBlockExpectingSuccess(
        absl::string_view(input, ABSL_ARRAYSIZE(input) - 1));
  
    SpdyHeaderBlock expected_header_set;
    expected_header_set[":path"] = "/sample/path";
    expected_header_set[":path2"] = "/sample/path/2";
    EXPECT_EQ(expected_header_set, header_set);
  }
  
  TEST_P(HpackDecoderAdapterTest, LiteralHeaderWithIndexingInvalidNameIndex) {
    decoder_.ApplyHeaderTableSizeSetting(0);
    EXPECT_TRUE(EncodeAndDecodeDynamicTableSizeUpdates(0, 0));
  
    // Name is the last static index. Works.
    EXPECT_TRUE(DecodeHeaderBlock(absl::string_view("\x7d\x03ooo")));
    // Name is one beyond the last static index. Fails.
    EXPECT_FALSE(DecodeHeaderBlock(absl::string_view("\x7e\x03ooo")));
  }
  
  TEST_P(HpackDecoderAdapterTest, LiteralHeaderNoIndexingInvalidNameIndex) {
    // Name is the last static index. Works.
    EXPECT_TRUE(DecodeHeaderBlock(absl::string_view("\x0f\x2e\x03ooo")));
    // Name is one beyond the last static index. Fails.
    EXPECT_FALSE(DecodeHeaderBlock(absl::string_view("\x0f\x2f\x03ooo")));
  }
  
  TEST_P(HpackDecoderAdapterTest, LiteralHeaderNeverIndexedInvalidNameIndex) {
    // Name is the last static index. Works.
    EXPECT_TRUE(DecodeHeaderBlock(absl::string_view("\x1f\x2e\x03ooo")));
    // Name is one beyond the last static index. Fails.
    EXPECT_FALSE(DecodeHeaderBlock(absl::string_view("\x1f\x2f\x03ooo")));
  }
  
  TEST_P(HpackDecoderAdapterTest, TruncatedIndex) {
    // Indexed Header, varint for index requires multiple bytes,
    // but only one provided.
    EXPECT_FALSE(DecodeHeaderBlock("\xff"));
  }
  
  TEST_P(HpackDecoderAdapterTest, TruncatedHuffmanLiteral) {
    // Literal value, Huffman encoded, but with the last byte missing (i.e.
    // drop the final ff shown below).
    //
    // 41                                      | == Literal indexed ==
    //                                         |   Indexed name (idx = 1)
    //                                         |     :authority
    // 8c                                      |   Literal value (len = 12)
    //                                         |     Huffman encoded:
    // f1e3 c2e5 f23a 6ba0 ab90 f4ff           | .....:k.....
    //                                         |     Decoded:
    //                                         | www.example.com
    //                                         | -> :authority: www.example.com
  
    std::string first = absl::HexStringToBytes("418cf1e3c2e5f23a6ba0ab90f4ff");
    EXPECT_TRUE(DecodeHeaderBlock(first));
    first.pop_back();
    EXPECT_FALSE(DecodeHeaderBlock(first));
  }
  
  TEST_P(HpackDecoderAdapterTest, HuffmanEOSError) {
    // Literal value, Huffman encoded, but with an additional ff byte at the end
    // of the string, i.e. an EOS that is longer than permitted.
    //
    // 41                                      | == Literal indexed ==
    //                                         |   Indexed name (idx = 1)
    //                                         |     :authority
    // 8d                                      |   Literal value (len = 13)
    //                                         |     Huffman encoded:
    // f1e3 c2e5 f23a 6ba0 ab90 f4ff           | .....:k.....
    //                                         |     Decoded:
    //                                         | www.example.com
    //                                         | -> :authority: www.example.com
  
    std::string first = absl::HexStringToBytes("418cf1e3c2e5f23a6ba0ab90f4ff");
    EXPECT_TRUE(DecodeHeaderBlock(first));
    first = absl::HexStringToBytes("418df1e3c2e5f23a6ba0ab90f4ffff");
    EXPECT_FALSE(DecodeHeaderBlock(first));
  }
  
  // Round-tripping the header set from RFC 7541 C.3.1 should work.
  // http://httpwg.org/specs/rfc7541.html#rfc.section.C.3.1
  TEST_P(HpackDecoderAdapterTest, BasicC31) {
    HpackEncoder encoder;
  
    SpdyHeaderBlock expected_header_set;
    expected_header_set[":method"] = "GET";
    expected_header_set[":scheme"] = "http";
    expected_header_set[":path"] = "/";
    expected_header_set[":authority"] = "www.example.com";
  
    std::string encoded_header_set;
    EXPECT_TRUE(
        encoder.EncodeHeaderSet(expected_header_set, &encoded_header_set));
  
    EXPECT_TRUE(DecodeHeaderBlock(encoded_header_set));
    EXPECT_EQ(expected_header_set, decoded_block());
  }
  
  // RFC 7541, Section C.4: Request Examples with Huffman Coding
  // http://httpwg.org/specs/rfc7541.html#rfc.section.C.4
  TEST_P(HpackDecoderAdapterTest, SectionC4RequestHuffmanExamples) {
    // TODO(jamessynge): Use http2/hpack/tools/hpack_example.h to parse the
    // example directly, instead of having it as a comment.
    //
    // 82                                      | == Indexed - Add ==
    //                                         |   idx = 2
    //                                         | -> :method: GET
    // 86                                      | == Indexed - Add ==
    //                                         |   idx = 6
    //                                         | -> :scheme: http
    // 84                                      | == Indexed - Add ==
    //                                         |   idx = 4
    //                                         | -> :path: /
    // 41                                      | == Literal indexed ==
    //                                         |   Indexed name (idx = 1)
    //                                         |     :authority
    // 8c                                      |   Literal value (len = 12)
    //                                         |     Huffman encoded:
    // f1e3 c2e5 f23a 6ba0 ab90 f4ff           | .....:k.....
    //                                         |     Decoded:
    //                                         | www.example.com
    //                                         | -> :authority: www.example.com
    std::string first =
        absl::HexStringToBytes("828684418cf1e3c2e5f23a6ba0ab90f4ff");
    const SpdyHeaderBlock& first_header_set = DecodeBlockExpectingSuccess(first);
  
    EXPECT_THAT(first_header_set,
                ElementsAre(
                    // clang-format off
        Pair(":method", "GET"),
        Pair(":scheme", "http"),
        Pair(":path", "/"),
        Pair(":authority", "www.example.com")));
    // clang-format on
  
    expectEntry(62, 57, ":authority", "www.example.com");
    EXPECT_EQ(57u, decoder_peer_.current_header_table_size());
  
    // 82                                      | == Indexed - Add ==
    //                                         |   idx = 2
    //                                         | -> :method: GET
    // 86                                      | == Indexed - Add ==
    //                                         |   idx = 6
    //                                         | -> :scheme: http
    // 84                                      | == Indexed - Add ==
    //                                         |   idx = 4
    //                                         | -> :path: /
    // be                                      | == Indexed - Add ==
    //                                         |   idx = 62
    //                                         | -> :authority: www.example.com
    // 58                                      | == Literal indexed ==
    //                                         |   Indexed name (idx = 24)
    //                                         |     cache-control
    // 86                                      |   Literal value (len = 8)
    //                                         |     Huffman encoded:
    // a8eb 1064 9cbf                          | ...d..
    //                                         |     Decoded:
    //                                         | no-cache
    //                                         | -> cache-control: no-cache
  
    std::string second = absl::HexStringToBytes("828684be5886a8eb10649cbf");
    const SpdyHeaderBlock& second_header_set =
        DecodeBlockExpectingSuccess(second);
  
    EXPECT_THAT(second_header_set,
                ElementsAre(
                    // clang-format off
        Pair(":method", "GET"),
        Pair(":scheme", "http"),
        Pair(":path", "/"),
        Pair(":authority", "www.example.com"),
        Pair("cache-control", "no-cache")));
    // clang-format on
  
    expectEntry(62, 53, "cache-control", "no-cache");
    expectEntry(63, 57, ":authority", "www.example.com");
    EXPECT_EQ(110u, decoder_peer_.current_header_table_size());
  
    // 82                                      | == Indexed - Add ==
    //                                         |   idx = 2
    //                                         | -> :method: GET
    // 87                                      | == Indexed - Add ==
    //                                         |   idx = 7
    //                                         | -> :scheme: https
    // 85                                      | == Indexed - Add ==
    //                                         |   idx = 5
    //                                         | -> :path: /index.html
    // bf                                      | == Indexed - Add ==
    //                                         |   idx = 63
    //                                         | -> :authority: www.example.com
    // 40                                      | == Literal indexed ==
    // 88                                      |   Literal name (len = 10)
    //                                         |     Huffman encoded:
    // 25a8 49e9 5ba9 7d7f                     | %.I.[.}.
    //                                         |     Decoded:
    //                                         | custom-key
    // 89                                      |   Literal value (len = 12)
    //                                         |     Huffman encoded:
    // 25a8 49e9 5bb8 e8b4 bf                  | %.I.[....
    //                                         |     Decoded:
    //                                         | custom-value
    //                                         | -> custom-key: custom-value
    std::string third = absl::HexStringToBytes(
        "828785bf408825a849e95ba97d7f8925a849e95bb8e8b4bf");
    const SpdyHeaderBlock& third_header_set = DecodeBlockExpectingSuccess(third);
  
    EXPECT_THAT(
        third_header_set,
        ElementsAre(
            // clang-format off
        Pair(":method", "GET"),
        Pair(":scheme", "https"),
        Pair(":path", "/index.html"),
        Pair(":authority", "www.example.com"),
        Pair("custom-key", "custom-value")));
    // clang-format on
  
    expectEntry(62, 54, "custom-key", "custom-value");
    expectEntry(63, 53, "cache-control", "no-cache");
    expectEntry(64, 57, ":authority", "www.example.com");
    EXPECT_EQ(164u, decoder_peer_.current_header_table_size());
  }
  
  // RFC 7541, Section C.6: Response Examples with Huffman Coding
  // http://httpwg.org/specs/rfc7541.html#rfc.section.C.6
  TEST_P(HpackDecoderAdapterTest, SectionC6ResponseHuffmanExamples) {
    // The example is based on a maximum dynamic table size of 256,
    // which allows for testing dynamic table evictions.
    decoder_peer_.set_header_table_size_limit(256);
  
    // 48                                      | == Literal indexed ==
    //                                         |   Indexed name (idx = 8)
    //                                         |     :status
    // 82                                      |   Literal value (len = 3)
    //                                         |     Huffman encoded:
    // 6402                                    | d.
    //                                         |     Decoded:
    //                                         | 302
    //                                         | -> :status: 302
    // 58                                      | == Literal indexed ==
    //                                         |   Indexed name (idx = 24)
    //                                         |     cache-control
    // 85                                      |   Literal value (len = 7)
    //                                         |     Huffman encoded:
    // aec3 771a 4b                            | ..w.K
    //                                         |     Decoded:
    //                                         | private
    //                                         | -> cache-control: private
    // 61                                      | == Literal indexed ==
    //                                         |   Indexed name (idx = 33)
    //                                         |     date
    // 96                                      |   Literal value (len = 29)
    //                                         |     Huffman encoded:
    // d07a be94 1054 d444 a820 0595 040b 8166 | .z...T.D. .....f
    // e082 a62d 1bff                          | ...-..
    //                                         |     Decoded:
    //                                         | Mon, 21 Oct 2013 20:13:21
    //                                         | GMT
    //                                         | -> date: Mon, 21 Oct 2013
    //                                         |   20:13:21 GMT
    // 6e                                      | == Literal indexed ==
    //                                         |   Indexed name (idx = 46)
    //                                         |     location
    // 91                                      |   Literal value (len = 23)
    //                                         |     Huffman encoded:
    // 9d29 ad17 1863 c78f 0b97 c8e9 ae82 ae43 | .)...c.........C
    // d3                                      | .
    //                                         |     Decoded:
    //                                         | https://www.example.com
    //                                         | -> location: https://www.e
    //                                         |    xample.com
  
    std::string first = absl::HexStringToBytes(
        "488264025885aec3771a4b6196d07abe"
        "941054d444a8200595040b8166e082a6"
        "2d1bff6e919d29ad171863c78f0b97c8"
        "e9ae82ae43d3");
    const SpdyHeaderBlock& first_header_set = DecodeBlockExpectingSuccess(first);
  
    EXPECT_THAT(first_header_set,
                ElementsAre(
                    // clang-format off
        Pair(":status", "302"),
        Pair("cache-control", "private"),
        Pair("date", "Mon, 21 Oct 2013 20:13:21 GMT"),
        Pair("location", "https://www.example.com")));
    // clang-format on
  
    expectEntry(62, 63, "location", "https://www.example.com");
    expectEntry(63, 65, "date", "Mon, 21 Oct 2013 20:13:21 GMT");
    expectEntry(64, 52, "cache-control", "private");
    expectEntry(65, 42, ":status", "302");
    EXPECT_EQ(222u, decoder_peer_.current_header_table_size());
  
    // 48                                      | == Literal indexed ==
    //                                         |   Indexed name (idx = 8)
    //                                         |     :status
    // 83                                      |   Literal value (len = 3)
    //                                         |     Huffman encoded:
    // 640e ff                                 | d..
    //                                         |     Decoded:
    //                                         | 307
    //                                         | - evict: :status: 302
    //                                         | -> :status: 307
    // c1                                      | == Indexed - Add ==
    //                                         |   idx = 65
    //                                         | -> cache-control: private
    // c0                                      | == Indexed - Add ==
    //                                         |   idx = 64
    //                                         | -> date: Mon, 21 Oct 2013
    //                                         |   20:13:21 GMT
    // bf                                      | == Indexed - Add ==
    //                                         |   idx = 63
    //                                         | -> location:
    //                                         |   https://www.example.com
    std::string second = absl::HexStringToBytes("4883640effc1c0bf");
    const SpdyHeaderBlock& second_header_set =
        DecodeBlockExpectingSuccess(second);
  
    EXPECT_THAT(second_header_set,
                ElementsAre(
                    // clang-format off
        Pair(":status", "307"),
        Pair("cache-control", "private"),
        Pair("date", "Mon, 21 Oct 2013 20:13:21 GMT"),
        Pair("location", "https://www.example.com")));
    // clang-format on
  
    expectEntry(62, 42, ":status", "307");
    expectEntry(63, 63, "location", "https://www.example.com");
    expectEntry(64, 65, "date", "Mon, 21 Oct 2013 20:13:21 GMT");
    expectEntry(65, 52, "cache-control", "private");
    EXPECT_EQ(222u, decoder_peer_.current_header_table_size());
  
    // 88                                      | == Indexed - Add ==
    //                                         |   idx = 8
    //                                         | -> :status: 200
    // c1                                      | == Indexed - Add ==
    //                                         |   idx = 65
    //                                         | -> cache-control: private
    // 61                                      | == Literal indexed ==
    //                                         |   Indexed name (idx = 33)
    //                                         |     date
    // 96                                      |   Literal value (len = 22)
    //                                         |     Huffman encoded:
    // d07a be94 1054 d444 a820 0595 040b 8166 | .z...T.D. .....f
    // e084 a62d 1bff                          | ...-..
    //                                         |     Decoded:
    //                                         | Mon, 21 Oct 2013 20:13:22
    //                                         | GMT
    //                                         | - evict: cache-control:
    //                                         |   private
    //                                         | -> date: Mon, 21 Oct 2013
    //                                         |   20:13:22 GMT
    // c0                                      | == Indexed - Add ==
    //                                         |   idx = 64
    //                                         | -> location:
    //                                         |    https://www.example.com
    // 5a                                      | == Literal indexed ==
    //                                         |   Indexed name (idx = 26)
    //                                         |     content-encoding
    // 83                                      |   Literal value (len = 3)
    //                                         |     Huffman encoded:
    // 9bd9 ab                                 | ...
    //                                         |     Decoded:
    //                                         | gzip
    //                                         | - evict: date: Mon, 21 Oct
    //                                         |    2013 20:13:21 GMT
    //                                         | -> content-encoding: gzip
    // 77                                      | == Literal indexed ==
    //                                         |   Indexed name (idx = 55)
    //                                         |     set-cookie
    // ad                                      |   Literal value (len = 45)
    //                                         |     Huffman encoded:
    // 94e7 821d d7f2 e6c7 b335 dfdf cd5b 3960 | .........5...[9`
    // d5af 2708 7f36 72c1 ab27 0fb5 291f 9587 | ..'..6r..'..)...
    // 3160 65c0 03ed 4ee5 b106 3d50 07        | 1`e...N...=P.
    //                                         |     Decoded:
    //                                         | foo=ASDJKHQKBZXOQWEOPIUAXQ
    //                                         | WEOIU; max-age=3600; versi
    //                                         | on=1
    //                                         | - evict: location:
    //                                         |   https://www.example.com
    //                                         | - evict: :status: 307
    //                                         | -> set-cookie: foo=ASDJKHQ
    //                                         |   KBZXOQWEOPIUAXQWEOIU;
    //                                         |   max-age=3600; version=1
    std::string third = absl::HexStringToBytes(
        "88c16196d07abe941054d444a8200595"
        "040b8166e084a62d1bffc05a839bd9ab"
        "77ad94e7821dd7f2e6c7b335dfdfcd5b"
        "3960d5af27087f3672c1ab270fb5291f"
        "9587316065c003ed4ee5b1063d5007");
    const SpdyHeaderBlock& third_header_set = DecodeBlockExpectingSuccess(third);
  
    EXPECT_THAT(third_header_set,
                ElementsAre(
                    // clang-format off
        Pair(":status", "200"),
        Pair("cache-control", "private"),
        Pair("date", "Mon, 21 Oct 2013 20:13:22 GMT"),
        Pair("location", "https://www.example.com"),
        Pair("content-encoding", "gzip"),
        Pair("set-cookie", "foo=ASDJKHQKBZXOQWEOPIUAXQWEOIU;"
             " max-age=3600; version=1")));
    // clang-format on
  
    expectEntry(62, 98, "set-cookie",
                "foo=ASDJKHQKBZXOQWEOPIUAXQWEOIU;"
                " max-age=3600; version=1");
    expectEntry(63, 52, "content-encoding", "gzip");
    expectEntry(64, 65, "date", "Mon, 21 Oct 2013 20:13:22 GMT");
    EXPECT_EQ(215u, decoder_peer_.current_header_table_size());
  }
  
  // Regression test: Found that entries with dynamic indexed names and literal
  // values caused "use after free" MSAN failures if the name was evicted as it
  // was being re-used.
  TEST_P(HpackDecoderAdapterTest, ReuseNameOfEvictedEntry) {
    // Each entry is measured as 32 bytes plus the sum of the lengths of the name
    // and the value. Set the size big enough for at most one entry, and a fairly
    // small one at that (31 ASCII characters).
    decoder_.ApplyHeaderTableSizeSetting(63);
  
    HpackBlockBuilder hbb;
    hbb.AppendDynamicTableSizeUpdate(0);
    hbb.AppendDynamicTableSizeUpdate(63);
  
    const absl::string_view name("some-name");
    const absl::string_view value1("some-value");
    const absl::string_view value2("another-value");
    const absl::string_view value3("yet-another-value");
  
    // Add an entry that will become the first in the dynamic table, entry 62.
    hbb.AppendLiteralNameAndValue(HpackEntryType::kIndexedLiteralHeader, false,
                                  name, false, value1);
  
    // Confirm that entry has been added by re-using it.
    hbb.AppendIndexedHeader(62);
  
    // Add another entry referring to the name of the first. This will evict the
    // first.
    hbb.AppendNameIndexAndLiteralValue(HpackEntryType::kIndexedLiteralHeader, 62,
                                       false, value2);
  
    // Confirm that entry has been added by re-using it.
    hbb.AppendIndexedHeader(62);
  
    // Add another entry referring to the name of the second. This will evict the
    // second.
    hbb.AppendNameIndexAndLiteralValue(HpackEntryType::kIndexedLiteralHeader, 62,
                                       false, value3);
  
    // Confirm that entry has been added by re-using it.
    hbb.AppendIndexedHeader(62);
  
    // Can't have DecodeHeaderBlock do the default check for size of the decoded
    // data because SpdyHeaderBlock will join multiple headers with the same
    // name into a single entry, thus we won't see repeated occurrences of the
    // name, instead seeing separators between values.
    EXPECT_TRUE(DecodeHeaderBlock(hbb.buffer(), kNoCheckDecodedSize));
  
    SpdyHeaderBlock expected_header_set;
    expected_header_set.AppendValueOrAddHeader(name, value1);
    expected_header_set.AppendValueOrAddHeader(name, value1);
    expected_header_set.AppendValueOrAddHeader(name, value2);
    expected_header_set.AppendValueOrAddHeader(name, value2);
    expected_header_set.AppendValueOrAddHeader(name, value3);
    expected_header_set.AppendValueOrAddHeader(name, value3);
  
    // SpdyHeaderBlock stores these 6 strings as '\0' separated values.
    // Make sure that is what happened.
    std::string joined_values = expected_header_set[name].as_string();
    EXPECT_EQ(joined_values.size(),
              2 * value1.size() + 2 * value2.size() + 2 * value3.size() + 5);
  
    EXPECT_EQ(expected_header_set, decoded_block());
  
    if (start_choice_ == START_WITH_HANDLER) {
      EXPECT_EQ(handler_.uncompressed_header_bytes(),
                6 * name.size() + 2 * value1.size() + 2 * value2.size() +
                    2 * value3.size());
    }
  }
  
  // Regression test for https://crbug.com/747395.
  TEST_P(HpackDecoderAdapterTest, Cookies) {
    SpdyHeaderBlock expected_header_set;
    expected_header_set["cookie"] = "foo; bar";
  
    EXPECT_TRUE(DecodeHeaderBlock(absl::HexStringToBytes("608294e76003626172")));
    EXPECT_EQ(expected_header_set, decoded_block());
  }
  
  }  // namespace
  }  // namespace test
  }  // namespace spdy
  