com.google.gerrit.client.change.UpdateCheckTimer.java Source code

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Here is the source code for com.google.gerrit.client.change.UpdateCheckTimer.java

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// Copyright (C) 2013 The Android Open Source Project
//
// 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 com.google.gerrit.client.change;

import com.google.gerrit.client.Gerrit;
import com.google.gerrit.client.info.ChangeInfo;
import com.google.gerrit.client.ui.UserActivityMonitor;
import com.google.gwt.event.logical.shared.ValueChangeEvent;
import com.google.gwt.event.logical.shared.ValueChangeHandler;
import com.google.gwt.user.client.Timer;
import com.google.gwt.user.client.rpc.AsyncCallback;

class UpdateCheckTimer extends Timer implements ValueChangeHandler<Boolean> {
    private static final int MAX_PERIOD = 3 * 60 * 1000;
    private static final int IDLE_PERIOD = 2 * 3600 * 1000;
    private static final int POLL_PERIOD = Gerrit.info().change().updateDelay() * 1000;

    private final ChangeScreen screen;
    private int delay;
    private boolean running;

    UpdateCheckTimer(ChangeScreen screen) {
        this.screen = screen;
        this.delay = POLL_PERIOD;
    }

    void schedule() {
        scheduleRepeating(delay);
    }

    @Override
    public void run() {
        if (!screen.isAttached()) {
            // screen should have cancelled this timer.
            cancel();
            return;
        } else if (running) {
            return;
        }

        running = true;
        screen.loadChangeInfo(false, new AsyncCallback<ChangeInfo>() {
            @Override
            public void onSuccess(ChangeInfo info) {
                running = false;
                screen.showUpdates(info);

                int d = UserActivityMonitor.isActive() ? POLL_PERIOD : IDLE_PERIOD;
                if (d != delay) {
                    delay = d;
                    schedule();
                }
            }

            @Override
            public void onFailure(Throwable caught) {
                // On failures increase the delay time and try again,
                // but place an upper bound on the delay.
                running = false;
                delay = (int) Math.max(delay * (1.5 + Math.random()),
                        UserActivityMonitor.isActive() ? MAX_PERIOD : IDLE_PERIOD + MAX_PERIOD);
                schedule();
            }
        });
    }

    @Override
    public void onValueChange(ValueChangeEvent<Boolean> event) {
        if (event.getValue()) {
            delay = POLL_PERIOD;
            run();
        } else {
            delay = IDLE_PERIOD;
        }
        schedule();
    }
}