Implement decoding of literal headers with incremental indexing for HPACK

This lands server change 60592123 by akalin.

BUG=339578

Review URL: https://codereview.chromium.org/154293002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@249196 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 70 insertions, 7 deletions

diff --git a/net/spdy/hpack_constants.h b/net/spdy/hpack_constants.h
index e3da0f1..79aa06b 100644
--- a/net/spdy/hpack_constants.h
+++ b/net/spdy/hpack_constants.h
@@ -31,6 +31,10 @@ const HpackPrefix kIndexedOpcode = { 0x1, 1 };
 // 4.3.1).
 const HpackPrefix kLiteralNoIndexOpcode = { 0x01, 2 };
 
+// The opcode for a literal header field with incremental indexing
+// (from 4.3.2).
+const HpackPrefix kLiteralIncrementalIndexOpcode = { 0x00, 2 };
+
 }  // namespace net
 
 #endif  // NET_SPDY_HPACK_CONSTANTS_H_
diff --git a/net/spdy/hpack_decoder.cc b/net/spdy/hpack_decoder.cc
index e85e6ff..7826ddd 100644
--- a/net/spdy/hpack_decoder.cc
+++ b/net/spdy/hpack_decoder.cc
@@ -92,6 +92,30 @@ bool HpackDecoder::ProcessNextHeaderRepresentation(
     return true;
   }
 
+  // Implements 4.3.2. Literal Header Field with Incremental Indexing.
+  if (input_stream->MatchPrefixAndConsume(kLiteralIncrementalIndexOpcode)) {
+    StringPiece name;
+    if (!DecodeNextName(input_stream, &name))
+      return false;
+
+    StringPiece value;
+    if (!DecodeNextValue(input_stream, &value))
+      return false;
+
+    header_list->push_back(
+        HpackHeaderPair(name.as_string(), value.as_string()));
+
+    uint32 new_index = 0;
+    std::vector<uint32> removed_referenced_indices;
+    context_.ProcessLiteralHeaderWithIncrementalIndexing(
+        name, value, &new_index, &removed_referenced_indices);
+
+    if (new_index > 0)
+      context_.AddTouchesAt(new_index, 0);
+
+    return true;
+  }
+
   return false;
 }
 
diff --git a/net/spdy/hpack_decoder_test.cc b/net/spdy/hpack_decoder_test.cc
index a444bed..5fa7377 100644
--- a/net/spdy/hpack_decoder_test.cc
+++ b/net/spdy/hpack_decoder_test.cc
@@ -117,10 +117,9 @@ TEST(HpackDecoderTest, LiteralHeaderNoIndexing) {
   HpackHeaderPairVector header_list;
   // First header with indexed name, second header with string literal
   // name.
-  EXPECT_TRUE(decoder.DecodeHeaderSet(
-      "\x44\x0c/sample/path\x40\x06:path2\x0e/sample/path/2",
-      &header_list));
-  std::map<string, string> header_set(header_list.begin(), header_list.end());
+  std::map<string, string> header_set =
+      DecodeUniqueHeaderSet(
+          &decoder, "\x44\x0c/sample/path\x40\x06:path2\x0e/sample/path/2");
 
   std::map<string, string> expected_header_set;
   expected_header_set[":path"] = "/sample/path";
@@ -128,6 +127,45 @@ TEST(HpackDecoderTest, LiteralHeaderNoIndexing) {
   EXPECT_EQ(expected_header_set, header_set);
 }
 
+// Decoding two valid encoded literal headers with incremental
+// indexing and string literal names should work and add the headers
+// to the reference set.
+TEST(HpackDecoderTest, LiteralHeaderIncrementalIndexing) {
+  HpackDecoder decoder(kuint32max);
+  std::map<string, string> header_set = DecodeUniqueHeaderSet(
+      &decoder,
+      StringPiece("\x04\x0c/sample/path\x00\x06:path2\x0e/sample/path/2", 37));
+
+  std::map<string, string> expected_header_set;
+  expected_header_set[":path"] = "/sample/path";
+  expected_header_set[":path2"] = "/sample/path/2";
+  EXPECT_EQ(expected_header_set, header_set);
+
+  // Decoding an empty string should just return the reference set.
+  std::map<string, string> header_set2 = DecodeUniqueHeaderSet(&decoder, "");
+  EXPECT_EQ(expected_header_set, header_set2);
+}
+
+// Decoding literal headers with invalid indices should fail
+// gracefully.
+TEST(HpackDecoderTest, LiteralHeaderInvalidIndices) {
+  HpackDecoder decoder(kuint32max);
+
+  HpackHeaderPairVector header_list;
+
+  // No indexing.
+
+  // One more than the number of static table entries.
+  EXPECT_FALSE(decoder.DecodeHeaderSet(StringPiece("\x7d", 1), &header_list));
+  EXPECT_FALSE(decoder.DecodeHeaderSet(StringPiece("\x40", 1), &header_list));
+
+  // Incremental indexing.
+
+  // One more than the number of static table entries.
+  EXPECT_FALSE(decoder.DecodeHeaderSet(StringPiece("\x3d", 1), &header_list));
+  EXPECT_FALSE(decoder.DecodeHeaderSet(StringPiece("\x00", 1), &header_list));
+}
+
 // Round-tripping the header set from E.2.1 should work.
 TEST(HpackDecoderTest, BasicE21) {
   HpackEncoder encoder(kuint32max);
@@ -149,9 +187,6 @@ TEST(HpackDecoderTest, BasicE21) {
   EXPECT_EQ(expected_header_set, header_set);
 }
 
-// TODO(akalin): Add test to exercise emission of the reference set
-// once we can decode opcodes that add to the reference set.
-
 }  // namespace
 
 }  // namespace net