Android Open Source - AndroidShoppingList Work Queue

• Back to App/shopping  ↑

From Project

Back to project page AndroidShoppingList.

License

The source code is released under:

Apache License

Java Source Code

/**
 * Copyright 2012 C. A. Fitzgerald//from w ww. ja v a 2  s.  c om
 *
 *  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.github.riotopsys.shoppinglist.server.work;

import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;

import android.app.AlarmManager;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.util.Log;

import com.github.riotopsys.shoppinglist.AppKeys;
import com.github.riotopsys.shoppinglist.model.Work;
import com.github.riotopsys.shoppinglist.server.ServerInterfaceService;
import com.github.riotopsys.shoppinglist.server.ServerTask;

public class WorkQueue {

  private static class SingletonHolder {
    public static final WorkQueue INSTANCE = new WorkQueue();
  }

  private static final long DELAY = 10000;
  private static final String TAG = null;

  public static WorkQueue getInstance() {
    return SingletonHolder.INSTANCE;
  }

  private LinkedList<Work> queue = new LinkedList<Work>();

  public synchronized void offer(Context ctx, Work w) {
    w.vaildate();
    queue.push(w);
    groomQueue();
    updateTimer(ctx);
  }

  private void updateTimer(Context ctx) {
    Log.i(TAG, "kick");
    AlarmManager mgr = (AlarmManager) ctx.getSystemService(Context.ALARM_SERVICE);
    Intent i = new Intent(ctx, ServerInterfaceService.class);
    i.putExtra(AppKeys.SERVER_TASK_KEY, ServerTask.PUSH_WORK);
    PendingIntent pi = PendingIntent.getService(ctx, 0, i, PendingIntent.FLAG_UPDATE_CURRENT);
    mgr.set(AlarmManager.RTC_WAKEUP, System.currentTimeMillis() + DELAY, pi);
  }

  public synchronized List<Work> getAvailableWork() {
    List<Work> result = new LinkedList<Work>(queue);
    queue.clear();
    return result;
  }

  public synchronized void reintegrateWork(List<Work> work) {
    LinkedList<Work> newWork = new LinkedList<Work>(queue);
    queue.clear();
    queue.addAll(work);
    while (!newWork.isEmpty()) {
      queue.push(newWork.pollLast());
      groomQueue();
    }
  }

  private void groomQueue() {
    Work head = queue.get(0);
    boolean purgeHead = false;

    if (head.operation == Operations.CREATE_ITEM || head.operation == Operations.CREATE_LIST) {
      // noop conditions
      return;
    }

    Iterator<Work> i = queue.iterator();
    i.next(); // skip first
    while (i.hasNext()) {
      Work work = i.next();

      switch (head.operation) {
        case DELETE_ITEM:
          if (work.target == head.target) {
            if (work.operation == Operations.CREATE_ITEM) {
              // this item has only been created locally we can
              // clear the delete as well as it's not gone to the
              // server yet
              purgeHead = true;
            }
            // we've just deleted this item no need to do anything
            // to it
            i.remove();
          }
          break;
        case UNSUBSCRIBE_LIST:
          // purge changes for this list and it's children
          if (work.target == head.target || (work.parent != null && work.parent == head.target)) {
            if (work.operation == Operations.CREATE_LIST) {
              // this item has only been created locally we can
              // clear the delete as well as it's not gone to the
              // server yet
              purgeHead = true;
            }
            // we've just deleted this item no need to do anything
            // to it
            i.remove();
          }
          break;
        case FIELD_UPDATE:
          if (work.target == head.target && work.operation == Operations.FIELD_UPDATE && head.field.equals(work.field)) {
            // redundant changes to this field are removed
            i.remove();
          }
          break;
      }

    }

    if (purgeHead) {
      queue.pop();
    }
  }
}

Java Source Code List

• Back to App/shopping  ↑