/**
* Depth-first search on the dependency graph. The correctness of this algorithm follows from the
* invariant that a function is only added to the output after all its dependencies have been
* added.
*
* @param n name of the function to be visited
* @param refs adjacency map
* @param marked already visited nodes
* @param stack stack of current nodes
* @param out output list
* @param equiv equivalence classes
*/
private void visit(
final Name n,
final Map<Name, Set<Name>> refs,
final Set<Name> marked,
final Stack<Name> stack,
final List<Name> out,
final Map<Name, Set<Name>> equiv) {
if (marked.add(n)) { // name wasn't marked
stack.push(n);
for (final Name name : refs.get(n)) {
visit(name, refs, marked, stack, out, equiv);
}
out.add(stack.pop());
} else {
final int pos = stack.lastIndexOf(n);
if (pos >= 0) {
final Set<Name> eqClass = new HashSet<Name>();
for (final Name eq : stack.subList(pos, stack.size())) {
eqClass.add(eq);
final Set<Name> old = equiv.get(eq);
if (old != null) {
eqClass.addAll(old);
}
}
for (final Name nm : eqClass) {
equiv.put(nm, eqClass);
}
}
}
}
public String expand(String str, Stack<String> seenStack) {
if (str == null) {
return str;
}
if (str.indexOf("${") < 0) {
// Contains no potential expressions.
return str;
}
Matcher mat = __propertyPattern.matcher(str);
StringBuilder expanded = new StringBuilder();
int offset = 0;
String property;
String value;
while (mat.find(offset)) {
property = mat.group(1);
// Loop detection
if (seenStack.contains(property)) {
StringBuilder err = new StringBuilder();
err.append("Property expansion loop detected: ");
int idx = seenStack.lastIndexOf(property);
for (int i = idx; i < seenStack.size(); i++) {
err.append(seenStack.get(i));
err.append(" -> ");
}
err.append(property);
throw new RuntimeException(err.toString());
}
seenStack.push(property);
// find property name
expanded.append(str.subSequence(offset, mat.start()));
// get property value
value = getString(property);
if (value == null) {
if (LOG.isDebugEnabled()) LOG.debug("Unable to expand: {}", property);
expanded.append(mat.group());
} else {
// recursively expand
value = expand(value, seenStack);
expanded.append(value);
}
// update offset
offset = mat.end();
}
// leftover
expanded.append(str.substring(offset));
// special case for "$$"
if (expanded.indexOf("$$") >= 0) {
return expanded.toString().replaceAll("\\$\\$", "\\$");
}
return expanded.toString();
}
