Add API to get current HPACK dynamic table size

doc/Makefile.am

@@ -108,6 +108,8 @@ APIDOCS= \
 	nghttp2_session_find_stream.rst \
 	nghttp2_session_get_effective_local_window_size.rst \
 	nghttp2_session_get_effective_recv_data_length.rst \
+	nghttp2_session_get_hd_deflate_dynamic_table_size.rst \
+	nghttp2_session_get_hd_inflate_dynamic_table_size.rst \
 	nghttp2_session_get_last_proc_stream_id.rst \
 	nghttp2_session_get_local_settings.rst \
 	nghttp2_session_get_local_window_size.rst \

lib/includes/nghttp2/nghttp2.h

@@ -3135,6 +3135,24 @@ NGHTTP2_EXTERN int
 nghttp2_session_get_stream_remote_close(nghttp2_session *session,
                                         int32_t stream_id);
 
+/**
+ * @function
+ *
+ * Returns the current dynamic table size of HPACK inflater, including
+ * the overhead 32 bytes per entry described in RFC 7541.
+ */
+NGHTTP2_EXTERN size_t
+nghttp2_session_get_hd_inflate_dynamic_table_size(nghttp2_session *session);
+
+/**
+ * @function
+ *
+ * Returns the current dynamic table size of HPACK deflater including
+ * the overhead 32 bytes per entry described in RFC 7541.
+ */
+NGHTTP2_EXTERN size_t
+nghttp2_session_get_hd_deflate_dynamic_table_size(nghttp2_session *session);
+
 /**
  * @function
  *

lib/nghttp2_session.c

@@ -7588,3 +7588,13 @@ int nghttp2_session_create_idle_stream(nghttp2_session *session,
      called. */
   return 0;
 }
+
+size_t
+nghttp2_session_get_hd_inflate_dynamic_table_size(nghttp2_session *session) {
+  return nghttp2_hd_inflate_get_dynamic_table_size(&session->hd_inflater);
+}
+
+size_t
+nghttp2_session_get_hd_deflate_dynamic_table_size(nghttp2_session *session) {
+  return nghttp2_hd_deflate_get_dynamic_table_size(&session->hd_deflater);
+}