Deletes a stream entry from CallbackVisitor's stream map in OnCloseStream().

This should fix the memory consumption bug reported in Envoy:
  https://github.com/envoyproxy/envoy/issues/19761

PiperOrigin-RevId: 425673006

http2/adapter/callback_visitor.cc

diff --git a/http2/adapter/callback_visitor.cc b/http2/adapter/callback_visitor.cc
index 1dd082e..7d59c6d 100644
--- a/http2/adapter/callback_visitor.cc
+++ b/http2/adapter/callback_visitor.cc
@@ -262,6 +262,7 @@
     callbacks_->on_stream_close_callback(
         nullptr, stream_id, static_cast<uint32_t>(error_code), user_data_);
   }
+  stream_map_.erase(stream_id);
 }
 
 void CallbackVisitor::OnPriorityForStream(Http2StreamId /*stream_id*/,

http2/adapter/callback_visitor.h

diff --git a/http2/adapter/callback_visitor.h b/http2/adapter/callback_visitor.h
index fa0c770..1f7452b 100644
--- a/http2/adapter/callback_visitor.h
+++ b/http2/adapter/callback_visitor.h
@@ -69,6 +69,8 @@
   bool OnMetadataEndForStream(Http2StreamId stream_id) override;
   void OnErrorDebug(absl::string_view message) override;
 
+  size_t stream_map_size() const { return stream_map_.size(); }
+
  private:
   struct QUICHE_EXPORT_PRIVATE StreamInfo {
     bool before_sent_headers = false;
@@ -82,9 +84,12 @@
   void PopulateFrame(nghttp2_frame& frame, uint8_t frame_type,
                      Http2StreamId stream_id, size_t length, uint8_t flags,
                      uint32_t error_code, bool sent_headers);
+
   // Creates the StreamInfoMap entry if it doesn't exist.
   StreamInfoMap::iterator GetStreamInfo(Http2StreamId stream_id);
 
+  StreamInfoMap stream_map_;
+
   Perspective perspective_;
   nghttp2_session_callbacks_unique_ptr callbacks_;
   void* user_data_;
@@ -92,8 +97,6 @@
   nghttp2_frame current_frame_;
   std::vector<nghttp2_settings_entry> settings_;
   size_t remaining_data_ = 0;
-
-  StreamInfoMap stream_map_;
 };
 
 }  // namespace adapter

http2/adapter/callback_visitor_test.cc

diff --git a/http2/adapter/callback_visitor_test.cc b/http2/adapter/callback_visitor_test.cc
index 9ed28f0..8f83da5 100644
--- a/http2/adapter/callback_visitor_test.cc
+++ b/http2/adapter/callback_visitor_test.cc
@@ -70,6 +70,8 @@
   EXPECT_CALL(callbacks, OnFrameRecv(IsGoAway(5, NGHTTP2_ENHANCE_YOUR_CALM,
                                               "calm down!!")));
   visitor.OnGoAway(5, Http2ErrorCode::ENHANCE_YOUR_CALM, "calm down!!");
+
+  EXPECT_EQ(visitor.stream_map_size(), 0);
 }
 
 TEST(ClientCallbackVisitorUnitTest, StreamFrames) {
@@ -79,6 +81,8 @@
 
   testing::InSequence seq;
 
+  EXPECT_EQ(visitor.stream_map_size(), 0);
+
   // HEADERS on stream 1
   EXPECT_CALL(callbacks, OnBeginFrame(HasFrameHeader(1, HEADERS, _)));
   visitor.OnFrameHeader(1, 23, HEADERS, 4);
@@ -87,6 +91,8 @@
               OnBeginHeaders(IsHeaders(1, _, NGHTTP2_HCAT_RESPONSE)));
   visitor.OnBeginHeadersForStream(1);
 
+  EXPECT_EQ(visitor.stream_map_size(), 1);
+
   EXPECT_CALL(callbacks, OnHeader(_, ":status", "200", _));
   visitor.OnHeaderForStream(1, ":status", "200");
 
@@ -129,6 +135,9 @@
   EXPECT_CALL(callbacks, OnBeginFrame(HasFrameHeader(3, RST_STREAM, 0)));
   visitor.OnFrameHeader(3, 4, RST_STREAM, 0);
 
+  // No change in stream map size.
+  EXPECT_EQ(visitor.stream_map_size(), 1);
+
   EXPECT_CALL(callbacks, OnFrameRecv(IsRstStream(3, NGHTTP2_INTERNAL_ERROR)));
   visitor.OnRstStream(3, Http2ErrorCode::INTERNAL_ERROR);
 
@@ -147,6 +156,9 @@
   EXPECT_CALL(callbacks, OnStreamClose(1, NGHTTP2_NO_ERROR));
   visitor.OnCloseStream(1, Http2ErrorCode::HTTP2_NO_ERROR);
 
+  // Stream map is empty again.
+  EXPECT_EQ(visitor.stream_map_size(), 0);
+
   EXPECT_CALL(callbacks, OnBeginFrame(HasFrameHeader(5, RST_STREAM, _)));
   visitor.OnFrameHeader(5, 4, RST_STREAM, 0);
 
@@ -155,6 +167,8 @@
 
   EXPECT_CALL(callbacks, OnStreamClose(5, NGHTTP2_REFUSED_STREAM));
   visitor.OnCloseStream(5, Http2ErrorCode::REFUSED_STREAM);
+
+  EXPECT_EQ(visitor.stream_map_size(), 0);
 }
 
 TEST(ClientCallbackVisitorUnitTest, HeadersWithContinuation) {
@@ -228,6 +242,8 @@
 
   EXPECT_CALL(callbacks, OnFrameRecv(IsPingAck(247)));
   visitor.OnPing(247, true);
+
+  EXPECT_EQ(visitor.stream_map_size(), 0);
 }
 
 TEST(ServerCallbackVisitorUnitTest, StreamFrames) {
@@ -246,6 +262,8 @@
                                                   NGHTTP2_HCAT_REQUEST)));
   visitor.OnBeginHeadersForStream(1);
 
+  EXPECT_EQ(visitor.stream_map_size(), 1);
+
   EXPECT_CALL(callbacks, OnHeader(_, ":method", "POST", _));
   visitor.OnHeaderForStream(1, ":method", "POST");
 
@@ -280,6 +298,8 @@
   EXPECT_CALL(callbacks, OnStreamClose(1, NGHTTP2_NO_ERROR));
   visitor.OnCloseStream(1, Http2ErrorCode::HTTP2_NO_ERROR);
 
+  EXPECT_EQ(visitor.stream_map_size(), 0);
+
   // RST_STREAM on stream 3
   EXPECT_CALL(callbacks, OnBeginFrame(HasFrameHeader(3, RST_STREAM, 0)));
   visitor.OnFrameHeader(3, 4, RST_STREAM, 0);
@@ -289,6 +309,8 @@
 
   EXPECT_CALL(callbacks, OnStreamClose(3, NGHTTP2_INTERNAL_ERROR));
   visitor.OnCloseStream(3, Http2ErrorCode::INTERNAL_ERROR);
+
+  EXPECT_EQ(visitor.stream_map_size(), 0);
 }
 
 TEST(ServerCallbackVisitorUnitTest, DataWithPadding) {