digraph tree {
	subgraph cluster_compiling {
		label="compiling";
		php_compile;
		php_store;
		entry_store;
	}
	error [color=red];
	origin_compile [color=red]

	begin -> origin_compile [label="compiling", color=red];

	begin -> entry_init_key -> entry_lookup;
	edge [label=hit, color=blue]
	entry_lookup -> restore;
	php_lookup -> entry_store;
	edge [label=miss, color=green]
	entry_lookup -> md5_init;
	md5_init -> php_lookup;
	php_lookup -> php_compile;

	edge [label="", color=""]
	php_lookup -> origin_compile [label="miss but compiling", color=red];
	php_compile -> php_store -> entry_store -> restore;

	edge [color=red];
	md5_init -> error;
	php_compile -> error;
	php_store -> error;
	entry_store -> error;
}