/**
* Copyright 2010 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package org.waveprotocol.wave.client.paging;
import org.waveprotocol.wave.client.paging.Traverser.MoveablePoint;
import java.util.Arrays;
/**
* Helper class for validity checking of paging, and general debug stuff.
*
*/
public final class PagingDebugHelper {
/** Enables/disables aggressive (costly) consistency checking. */
public final static boolean AGGRESSIVE_DEBUG = false;
/** Current stack depth of activation. */
private static int depth;
/** Maximum stack depth of current activation. */
private static int maxDepth;
/** Distribution of maximum depths so far (maps depth to frequency). */
private static int [] depths = new int [20];
private PagingDebugHelper() {
}
/**
* Checks the monotonicity of locations in a block tree.
*/
public static void maybeCheckBlocks(Block root) {
if (AGGRESSIVE_DEBUG) {
assert areBlocksValid(root);
}
}
private static boolean areBlocksValid(Block root) {
MoveablePoint point = SimpleMoveablePoint.startOf(root);
double lastLocation = point.absoluteLocation();
while (point.hasNext()) {
point.next();
double location = point.absoluteLocation();
assert location + 0.01 >= lastLocation : "point backtracks";
lastLocation = location;
}
return true;
}
/**
* Keeps track of the stack depth of recursive activations.
*/
public static void enterActivate() {
if (!AGGRESSIVE_DEBUG) {
return;
}
if (++depth > maxDepth) {
maxDepth = depth;
}
}
/**
* Keeps track of the stack depth of recursive activations.
*/
public static void leaveActivate() {
if (!AGGRESSIVE_DEBUG) {
return;
}
if (--depth == 0) {
depths[maxDepth]++;
maxDepth = 0;
}
}
/**
* Reports the distribution of stack depths for recursive activation.
*/
public static void report() {
int total = 0;
for (int i = 0; i < depths.length; i++) {
total += depths[i];
}
for (int i = 0; i < depths.length; i++) {
int count = depths[i];
int pct = Math.round(count * 100.0f / total);
System.out.println("Depth " + i + ": " + pct + "%");
}
Arrays.fill(depths, 0);
}
}