gfe-relnote: Use indexed name if possible when sending Literal Header Field without Indexing instruction. Protected by gfe2_reloadable_flag_spdy_hpack_use_indexed_name.
This CL touches HPACK encoding, which is used over HTTP/2 and Google QUIC.
If compression is enabled and a pseudo-header other than :authority has a
matching name but not matching value in the static table, then before this
change, its name was sent as a string literal; after this change, it is sent
indexed.
Bug: https://crbug.com/983254
PiperOrigin-RevId: 305517407
Change-Id: If6172beacb02efe2465d8753749e6c586688e3c0
diff --git a/spdy/core/hpack/hpack_encoder.cc b/spdy/core/hpack/hpack_encoder.cc
index 3835047..e3bf8f6 100644
--- a/spdy/core/hpack/hpack_encoder.cc
+++ b/spdy/core/hpack/hpack_encoder.cc
@@ -13,6 +13,7 @@
#include "net/third_party/quiche/src/spdy/core/hpack/hpack_huffman_table.h"
#include "net/third_party/quiche/src/spdy/core/hpack/hpack_output_stream.h"
#include "net/third_party/quiche/src/spdy/platform/api/spdy_estimate_memory_usage.h"
+#include "net/third_party/quiche/src/spdy/platform/api/spdy_flags.h"
#include "net/third_party/quiche/src/spdy/platform/api/spdy_logging.h"
namespace spdy {
@@ -146,10 +147,10 @@
} else if (should_index_(header.first, header.second)) {
EmitIndexedLiteral(header);
} else {
- EmitNonIndexedLiteral(header);
+ EmitNonIndexedLiteral(header, enable_compression_);
}
} else {
- EmitNonIndexedLiteral(header);
+ EmitNonIndexedLiteral(header, enable_compression_);
}
}
@@ -170,12 +171,25 @@
header_table_.TryAddEntry(representation.first, representation.second);
}
-void HpackEncoder::EmitNonIndexedLiteral(const Representation& representation) {
+void HpackEncoder::EmitNonIndexedLiteral(const Representation& representation,
+ bool enable_compression) {
SPDY_DVLOG(2) << "Emitting nonindexed literal: (" << representation.first
<< ", " << representation.second << ")";
output_stream_.AppendPrefix(kLiteralNoIndexOpcode);
- output_stream_.AppendUint32(0);
- EmitString(representation.first);
+ if (GetSpdyReloadableFlag(spdy_hpack_use_indexed_name)) {
+ SPDY_CODE_COUNT(spdy_hpack_use_indexed_name);
+ const HpackEntry* name_entry =
+ header_table_.GetByName(representation.first);
+ if (enable_compression && name_entry != nullptr) {
+ output_stream_.AppendUint32(header_table_.IndexOf(name_entry));
+ } else {
+ output_stream_.AppendUint32(0);
+ EmitString(representation.first);
+ }
+ } else {
+ output_stream_.AppendUint32(0);
+ EmitString(representation.first);
+ }
EmitString(representation.second);
}
@@ -347,14 +361,14 @@
std::string* output) {
SPDY_BUG_IF(!has_next_)
<< "Encoderator::Next called with nothing left to encode.";
- const bool use_compression = encoder_->enable_compression_;
+ const bool enable_compression = encoder_->enable_compression_;
// Encode up to max_encoded_bytes of headers.
while (header_it_->HasNext() &&
encoder_->output_stream_.size() <= max_encoded_bytes) {
const Representation header = header_it_->Next();
encoder_->listener_(header.first, header.second);
- if (use_compression) {
+ if (enable_compression) {
const HpackEntry* entry = encoder_->header_table_.GetByNameAndValue(
header.first, header.second);
if (entry != nullptr) {
@@ -362,10 +376,10 @@
} else if (encoder_->should_index_(header.first, header.second)) {
encoder_->EmitIndexedLiteral(header);
} else {
- encoder_->EmitNonIndexedLiteral(header);
+ encoder_->EmitNonIndexedLiteral(header, enable_compression);
}
} else {
- encoder_->EmitNonIndexedLiteral(header);
+ encoder_->EmitNonIndexedLiteral(header, enable_compression);
}
}
diff --git a/spdy/core/hpack/hpack_encoder.h b/spdy/core/hpack/hpack_encoder.h
index c3d3a19..534b9e6 100644
--- a/spdy/core/hpack/hpack_encoder.h
+++ b/spdy/core/hpack/hpack_encoder.h
@@ -122,7 +122,8 @@
// Emits a literal representation (Section 7.2).
void EmitIndexedLiteral(const Representation& representation);
- void EmitNonIndexedLiteral(const Representation& representation);
+ void EmitNonIndexedLiteral(const Representation& representation,
+ bool enable_compression);
void EmitLiteral(const Representation& representation);
// Emits a Huffman or identity string (whichever is smaller).
diff --git a/spdy/core/hpack/hpack_encoder_test.cc b/spdy/core/hpack/hpack_encoder_test.cc
index 2ac0a5f..2b1efe9 100644
--- a/spdy/core/hpack/hpack_encoder_test.cc
+++ b/spdy/core/hpack/hpack_encoder_test.cc
@@ -11,6 +11,7 @@
#include "net/third_party/quiche/src/common/platform/api/quiche_test.h"
#include "net/third_party/quiche/src/spdy/core/hpack/hpack_huffman_table.h"
#include "net/third_party/quiche/src/spdy/core/spdy_simple_arena.h"
+#include "net/third_party/quiche/src/spdy/platform/api/spdy_flags.h"
namespace spdy {
@@ -182,6 +183,12 @@
ExpectString(&expected_, name);
ExpectString(&expected_, value);
}
+ void ExpectNonIndexedLiteralWithNameIndex(const HpackEntry* key_entry,
+ quiche::QuicheStringPiece value) {
+ expected_.AppendPrefix(kLiteralNoIndexOpcode);
+ expected_.AppendUint32(IndexOf(key_entry));
+ ExpectString(&expected_, value);
+ }
void ExpectString(HpackOutputStream* stream, quiche::QuicheStringPiece str) {
const HpackHuffmanTable& huffman_table = peer_.huffman_table();
size_t encoded_size = peer_.compression_enabled()
@@ -267,7 +274,12 @@
{"accept", "text/html, text/plain,application/xml"},
{"cookie", "val4"},
{"withnul", quiche::QuicheStringPiece("one\0two", 7)}};
- ExpectNonIndexedLiteral(":path", "/home");
+ if (GetSpdyReloadableFlag(spdy_hpack_use_indexed_name)) {
+ ExpectNonIndexedLiteralWithNameIndex(peer_.table()->GetByName(":path"),
+ "/home");
+ } else {
+ ExpectNonIndexedLiteral(":path", "/home");
+ }
ExpectIndexedLiteral(peer_.table()->GetByName("cookie"), "val1");
ExpectIndexedLiteral(peer_.table()->GetByName("cookie"), "val2");
ExpectIndexedLiteral(peer_.table()->GetByName("cookie"), "val3");
@@ -554,7 +566,12 @@
// Headers are indexed in the order in which they were added.
// This entry pushes "cookie: a=bb" back to 63.
- ExpectNonIndexedLiteral(":path", "/spam/eggs.html");
+ if (GetSpdyReloadableFlag(spdy_hpack_use_indexed_name)) {
+ ExpectNonIndexedLiteralWithNameIndex(peer_.table()->GetByName(":path"),
+ "/spam/eggs.html");
+ } else {
+ ExpectNonIndexedLiteral(":path", "/spam/eggs.html");
+ }
ExpectIndexedLiteral(peer_.table()->GetByName(":authority"),
"www.example.com");
ExpectIndexedLiteral("-foo", "bar");
