digraph cache_logic {
  nodesep=1.25;
  center=true;

  node[fontname="Lucida Sans Unicode",labelloc=c,margin=0.10,0.03]
  edge[fontname="Lucida Sans Unicode",fontcolor="#444444",labeldistance=20];

  receive -> pass[label="uncacheable request",color=grey];
  receive -> lookup[label="cacheable request"];

  pass -> deliver[label="",color=grey];

  lookup -> hit[label="fresh"];
  lookup -> fetch[label="stale (needs validation)"];
  lookup -> miss[label="uncached"];

  hit -> deliver[label="sizzling"];
  hit -> pass[label="bailing...",color=grey];

  miss -> fetch[label=""];
  miss -> pass[color=grey];

  fetch -> store[label="cacheable"];
  fetch -> deliver[label="not cacheable",color=grey];

  store -> deliver[label="KTHX"];
}