Lazily alloc/init the HPACK encoder/decoder.

net/spdy/spdy_framer.cc

Index: net/spdy/spdy_framer.cc
diff --git a/net/spdy/spdy_framer.cc b/net/spdy/spdy_framer.cc
index 73aa53299ce8bc418cd8a4f8909e7e4d861217ee..a1287bd9b7f711ee3eb5f043fe1f473ed61bcea6 100644
--- a/net/spdy/spdy_framer.cc
+++ b/net/spdy/spdy_framer.cc
@@ -134,12 +134,6 @@ SpdyFramer::SpdyFramer(SpdyMajorVersion version)
   DCHECK_GE(spdy_version_, SPDY_MIN_VERSION);
   DCHECK_LE(spdy_version_, SPDY_MAX_VERSION);
   Reset();
-
-  // SPDY4 and up use HPACK. Allocate instances for these protocol versions.
-  if (spdy_version_ > SPDY3) {
-    hpack_encoder_.reset(new HpackEncoder(ObtainHpackHuffmanTable()));
-    hpack_decoder_.reset(new HpackDecoder(ObtainHpackHuffmanTable()));
-  }
 }
 
 SpdyFramer::~SpdyFramer() {
@@ -1481,9 +1475,8 @@ size_t SpdyFramer::ProcessControlFrameHeaderBlock(const char* data,
   }
   size_t process_bytes = std::min(data_len, remaining_data_length_);
   if (is_hpack_header_block) {
-    if (!hpack_decoder_->HandleControlFrameHeadersData(current_frame_stream_id_,
-                                                       data,
-                                                       process_bytes)) {
+    if (!GetHpackDecoder()->HandleControlFrameHeadersData(
+            current_frame_stream_id_, data, process_bytes)) {
       // TODO(jgraettinger): Finer-grained HPACK error codes.
       set_error(SPDY_DECOMPRESS_FAILURE);
       processed_successfully = false;
@@ -1503,8 +1496,8 @@ size_t SpdyFramer::ProcessControlFrameHeaderBlock(const char* data,
   if (remaining_data_length_ == 0 && processed_successfully) {
     if (expect_continuation_ == 0) {
       if (is_hpack_header_block) {
-        if (!hpack_decoder_->HandleControlFrameHeadersComplete(
-            current_frame_stream_id_)) {
+        if (!GetHpackDecoder()->HandleControlFrameHeadersComplete(
+                current_frame_stream_id_)) {
           set_error(SPDY_DECOMPRESS_FAILURE);
           processed_successfully = false;
         } else {
@@ -1599,7 +1592,7 @@ void SpdyFramer::DeliverHpackBlockAsSpdy3Block() {
   DCHECK_LT(SPDY3, protocol_version());
   DCHECK_EQ(0u, remaining_data_length_);
 
-  const SpdyNameValueBlock& block = hpack_decoder_->decoded_block();
+  const SpdyNameValueBlock& block = GetHpackDecoder()->decoded_block();
   if (block.empty()) {
     // Special-case this to make tests happy.
     ProcessControlFrameHeaderBlock(NULL, 0, false);
@@ -2148,10 +2141,10 @@ SpdySerializedFrame* SpdyFramer::SerializeSynStream(
   string hpack_encoding;
   if (protocol_version() > SPDY3) {
     if (enable_compression_) {
-      hpack_encoder_->EncodeHeaderSet(
+      GetHpackEncoder()->EncodeHeaderSet(
           syn_stream.name_value_block(), &hpack_encoding);
     } else {
-      hpack_encoder_->EncodeHeaderSetWithoutCompression(
+      GetHpackEncoder()->EncodeHeaderSetWithoutCompression(
           syn_stream.name_value_block(), &hpack_encoding);
     }
     size += hpack_encoding.size();
@@ -2213,10 +2206,10 @@ SpdySerializedFrame* SpdyFramer::SerializeSynReply(
   string hpack_encoding;
   if (protocol_version() > SPDY3) {
     if (enable_compression_) {
-      hpack_encoder_->EncodeHeaderSet(
+      GetHpackEncoder()->EncodeHeaderSet(
           syn_reply.name_value_block(), &hpack_encoding);
     } else {
-      hpack_encoder_->EncodeHeaderSetWithoutCompression(
+      GetHpackEncoder()->EncodeHeaderSetWithoutCompression(
           syn_reply.name_value_block(), &hpack_encoding);
     }
     size += hpack_encoding.size();
@@ -2433,10 +2426,10 @@ SpdySerializedFrame* SpdyFramer::SerializeHeaders(
   string hpack_encoding;
   if (protocol_version() > SPDY3) {
     if (enable_compression_) {
-      hpack_encoder_->EncodeHeaderSet(
+      GetHpackEncoder()->EncodeHeaderSet(
           headers.name_value_block(), &hpack_encoding);
     } else {
-      hpack_encoder_->EncodeHeaderSetWithoutCompression(
+      GetHpackEncoder()->EncodeHeaderSetWithoutCompression(
           headers.name_value_block(), &hpack_encoding);
     }
     size += hpack_encoding.size();
@@ -2526,10 +2519,10 @@ SpdyFrame* SpdyFramer::SerializePushPromise(
   string hpack_encoding;
   if (protocol_version() > SPDY3) {
     if (enable_compression_) {
-      hpack_encoder_->EncodeHeaderSet(
+      GetHpackEncoder()->EncodeHeaderSet(
           push_promise.name_value_block(), &hpack_encoding);
     } else {
-      hpack_encoder_->EncodeHeaderSetWithoutCompression(
+      GetHpackEncoder()->EncodeHeaderSetWithoutCompression(
           push_promise.name_value_block(), &hpack_encoding);
     }
     size += hpack_encoding.size();
@@ -2586,10 +2579,10 @@ SpdyFrame* SpdyFramer::SerializeContinuation(
   size_t size = GetContinuationMinimumSize();
   string hpack_encoding;
   if (enable_compression_) {
-    hpack_encoder_->EncodeHeaderSet(
+    GetHpackEncoder()->EncodeHeaderSet(
         continuation.name_value_block(), &hpack_encoding);
   } else {
-    hpack_encoder_->EncodeHeaderSetWithoutCompression(
+    GetHpackEncoder()->EncodeHeaderSetWithoutCompression(
         continuation.name_value_block(), &hpack_encoding);
   }
   size += hpack_encoding.size();
@@ -2808,6 +2801,22 @@ z_stream* SpdyFramer::GetHeaderDecompressor() {
   return header_decompressor_.get();
 }
 
+HpackEncoder* SpdyFramer::GetHpackEncoder() {
+  DCHECK_LT(SPDY3, spdy_version_);
+  if (hpack_encoder_.get() == NULL) {
+    hpack_encoder_.reset(new HpackEncoder(ObtainHpackHuffmanTable()));
+  }
+  return hpack_encoder_.get();
+}
+
+HpackDecoder* SpdyFramer::GetHpackDecoder() {
+  DCHECK_LT(SPDY3, spdy_version_);
+  if (hpack_decoder_.get() == NULL) {
+    hpack_decoder_.reset(new HpackDecoder(ObtainHpackHuffmanTable()));
+  }
+  return hpack_decoder_.get();
+}
+
 // Incrementally decompress the control frame's header block, feeding the
 // result to the visitor in chunks. Continue this until the visitor
 // indicates that it cannot process any more data, or (more commonly) we