1 files changed, 135 insertions, 0 deletions
diff --git a/src/nix/dotgraph.cc b/src/nix/dotgraph.cc
new file mode 100644
index 000000000000..36daf7f9966d
--- /dev/null
+++ b/src/nix/dotgraph.cc
@@ -0,0 +1,135 @@
+#include "dotgraph.hh"
+#include "normalise.hh"
+
+
+static string dotQuote(const string & s)
+{
+    return "\"" + s + "\"";
+}
+
+
+static string nextColour()
+{
+    static int n = 0;
+    static string colours[] =
+	{ "black", "red", "green", "blue"
+	, "magenta", "burlywood" };
+    return colours[n++ % (sizeof(colours) / sizeof(string))];
+}
+
+
+static string makeEdge(const string & src, const string & dst)
+{
+    format f = format("%1% -> %2% [color = %3%];\n")
+	% dotQuote(src) % dotQuote(dst) % dotQuote(nextColour());
+    return f.str();
+}
+
+
+static string makeNode(const string & id, const string & label,
+    const string & colour)
+{
+    format f = format("%1% [label = %2%, shape = box, "
+	"style = filled, fillcolor = %3%];\n")
+	% dotQuote(id) % dotQuote(label) % dotQuote(colour);
+    return f.str();
+}
+
+
+static string symbolicName(const string & path)
+{
+    string p = baseNameOf(path);
+    if (isHash(string(p, 0, Hash::hashSize * 2)) && 
+	p[Hash::hashSize * 2] == '-')
+	p = string(p, Hash::hashSize * 2 + 1);
+    return p;
+}
+
+
+string pathLabel(const Path & nePath, const string & elemPath)
+{
+    return (string) nePath + "-" + elemPath;
+}
+
+
+void printClosure(const Path & nePath, const NixExpr & fs)
+{
+    PathSet workList(fs.closure.roots);
+    PathSet doneSet;
+
+    for (PathSet::iterator i = workList.begin(); i != workList.end(); i++) {
+	cout << makeEdge(pathLabel(nePath, *i), nePath);
+    }
+
+    while (!workList.empty()) {
+	Path path = *(workList.begin());
+	workList.erase(path);
+
+	if (doneSet.find(path) == doneSet.end()) {
+	    doneSet.insert(path);
+
+	    ClosureElems::const_iterator elem = fs.closure.elems.find(path);
+	    if (elem == fs.closure.elems.end())
+		throw Error(format("bad closure, missing path `%1%'") % path);
+
+	    for (StringSet::const_iterator i = elem->second.refs.begin();
+		 i != elem->second.refs.end(); i++)
+	    {
+		workList.insert(*i);
+		cout << makeEdge(pathLabel(nePath, *i), pathLabel(nePath, path));
+	    }
+
+	    cout << makeNode(pathLabel(nePath, path), 
+		symbolicName(path), "#ff0000");
+	}
+    }
+}
+
+
+void printDotGraph(const PathSet & roots)
+{
+    PathSet workList(roots);
+    PathSet doneSet;
+            
+    cout << "digraph G {\n";
+
+    while (!workList.empty()) {
+	Path nePath = *(workList.begin());
+	workList.erase(nePath);
+
+	if (doneSet.find(nePath) == doneSet.end()) {
+	    doneSet.insert(nePath);
+
+	    NixExpr ne = exprFromPath(nePath);
+
+	    string label, colour;
+                    
+	    if (ne.type == NixExpr::neDerivation) {
+		for (PathSet::iterator i = ne.derivation.inputs.begin();
+		     i != ne.derivation.inputs.end(); i++)
+		{
+		    workList.insert(*i);
+		    cout << makeEdge(*i, nePath);
+		}
+
+		label = "derivation";
+		colour = "#00ff00";
+		for (StringPairs::iterator i = ne.derivation.env.begin();
+		     i != ne.derivation.env.end(); i++)
+		    if (i->first == "name") label = i->second;
+	    }
+
+	    else if (ne.type == NixExpr::neClosure) {
+		label = "<closure>";
+		colour = "#00ffff";
+		printClosure(nePath, ne);
+	    }
+
+	    else abort();
+
+	    cout << makeNode(nePath, label, colour);
+	}
+    }
+
+    cout << "}\n";
+}