/*
* Copyright 2010, 2011, 2012 mapsforge.org
*
* This program is free software: you can redistribute it and/or modify it under the
* terms of the GNU Lesser General Public License as published by the Free Software
* Foundation, either version 3 of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
* PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License along with
* this program. If not, see <http://www.gnu.org/licenses/>.
*/
package org.mapsforge.map.rendertheme.rule;
import java.util.Stack;
import java.util.logging.Logger;
final class RuleOptimizer {
private static final Logger LOGGER = Logger.getLogger(RuleOptimizer.class.getName());
private static AttributeMatcher optimizeKeyMatcher(AttributeMatcher attributeMatcher, Stack<Rule> ruleStack) {
for (int i = 0, n = ruleStack.size(); i < n; ++i) {
if (ruleStack.get(i) instanceof PositiveRule) {
PositiveRule positiveRule = (PositiveRule) ruleStack.get(i);
if (positiveRule.keyMatcher.isCoveredBy(attributeMatcher)) {
return AnyMatcher.INSTANCE;
}
}
}
return attributeMatcher;
}
private static AttributeMatcher optimizeValueMatcher(AttributeMatcher attributeMatcher, Stack<Rule> ruleStack) {
for (int i = 0, n = ruleStack.size(); i < n; ++i) {
if (ruleStack.get(i) instanceof PositiveRule) {
PositiveRule positiveRule = (PositiveRule) ruleStack.get(i);
if (positiveRule.valueMatcher.isCoveredBy(attributeMatcher)) {
return AnyMatcher.INSTANCE;
}
}
}
return attributeMatcher;
}
static AttributeMatcher optimize(AttributeMatcher attributeMatcher, Stack<Rule> ruleStack) {
if (attributeMatcher instanceof AnyMatcher || attributeMatcher instanceof NegativeMatcher) {
return attributeMatcher;
} else if (attributeMatcher instanceof KeyMatcher) {
return optimizeKeyMatcher(attributeMatcher, ruleStack);
} else if (attributeMatcher instanceof ValueMatcher) {
return optimizeValueMatcher(attributeMatcher, ruleStack);
}
throw new IllegalArgumentException("unknown AttributeMatcher: " + attributeMatcher);
}
static ClosedMatcher optimize(ClosedMatcher closedMatcher, Stack<Rule> ruleStack) {
if (closedMatcher instanceof AnyMatcher) {
return closedMatcher;
}
for (int i = 0, n = ruleStack.size(); i < n; ++i) {
if (ruleStack.get(i).closedMatcher.isCoveredBy(closedMatcher)) {
return AnyMatcher.INSTANCE;
} else if (!closedMatcher.isCoveredBy(ruleStack.get(i).closedMatcher)) {
LOGGER.warning("unreachable rule (closed)");
}
}
return closedMatcher;
}
static ElementMatcher optimize(ElementMatcher elementMatcher, Stack<Rule> ruleStack) {
if (elementMatcher instanceof AnyMatcher) {
return elementMatcher;
}
for (int i = 0, n = ruleStack.size(); i < n; ++i) {
Rule rule = ruleStack.get(i);
if (rule.elementMatcher.isCoveredBy(elementMatcher)) {
return AnyMatcher.INSTANCE;
} else if (!elementMatcher.isCoveredBy(rule.elementMatcher)) {
LOGGER.warning("unreachable rule (e)");
}
}
return elementMatcher;
}
private RuleOptimizer() {
throw new IllegalStateException();
}
}