Signal-Android/src/org/thoughtcrime/securesms/camera/OrderEnforcer.java

75 lines
1.8 KiB
Java

package org.thoughtcrime.securesms.camera;
import android.support.annotation.NonNull;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.CopyOnWriteArrayList;
public class OrderEnforcer<E> {
private final E[] stages;
private final Map<E, Integer> stageIndices;
private final Map<E, List<Runnable>> actions;
private final boolean[] completion;
public OrderEnforcer(@NonNull E... stages) {
this.stages = stages;
this.stageIndices = new HashMap<>();
this.actions = new HashMap<>();
this.completion = new boolean[stages.length];
for (int i = 0; i < stages.length; i++) {
stageIndices.put(stages[i], i);
}
}
public synchronized void run(@NonNull E stage, Runnable r) {
if (isCompletedThrough(stage)) {
r.run();
} else {
List<Runnable> stageActions = actions.containsKey(stage) ? actions.get(stage) : new CopyOnWriteArrayList<>();
stageActions.add(r);
actions.put(stage, stageActions);
}
}
public synchronized void markCompleted(@NonNull E stage) {
completion[stageIndices.get(stage)] = true;
int i = 0;
while (i < completion.length && completion[i]) {
List<Runnable> stageActions = actions.get(stages[i]);
if (stageActions != null) {
for (Runnable r : stageActions) {
r.run();
}
stageActions.clear();
}
i++;
}
}
public synchronized void reset() {
for (int i = 0; i < completion.length; i++) {
completion[i] = false;
}
actions.clear();
}
private boolean isCompletedThrough(@NonNull E stage) {
int index = stageIndices.get(stage);
int i = 0;
while (i <= index && i < completion.length) {
if (!completion[i]) {
return false;
}
i++;
}
return true;
}
}