doq_stream_cmp
rbtree_init(&conn->stream_tree, &doq_stream_cmp);
int doq_stream_cmp(const void* key1, const void* key2);
else if(fptr == &doq_stream_cmp) return 1;
rbtree_init(&conn->stream_tree, &doq_stream_cmp);
int doq_stream_cmp(const void* key1, const void* key2);
else if(fptr == &doq_stream_cmp) return 1;