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      1 /*
      2  * Copyright (C) 2011 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.android.providers.downloads;
     18 
     19 import android.content.res.Resources;
     20 import android.util.Log;
     21 
     22 import java.util.ArrayList;
     23 import java.util.HashMap;
     24 import java.util.Iterator;
     25 import java.util.LinkedHashMap;
     26 
     27 public class DownloadHandler {
     28 
     29     private static final String TAG = "DownloadHandler";
     30     private final LinkedHashMap<Long, DownloadInfo> mDownloadsQueue =
     31             new LinkedHashMap<Long, DownloadInfo>();
     32     private final HashMap<Long, DownloadInfo> mDownloadsInProgress =
     33             new HashMap<Long, DownloadInfo>();
     34     private static final DownloadHandler mDownloadHandler = new DownloadHandler();
     35     private final int mMaxConcurrentDownloadsAllowed = Resources.getSystem().getInteger(
     36             com.android.internal.R.integer.config_MaxConcurrentDownloadsAllowed);
     37 
     38     static DownloadHandler getInstance() {
     39         return mDownloadHandler;
     40     }
     41 
     42     synchronized void enqueueDownload(DownloadInfo info) {
     43         if (!mDownloadsQueue.containsKey(info.mId)) {
     44             if (Constants.LOGV) {
     45                 Log.i(TAG, "enqueued download. id: " + info.mId + ", uri: " + info.mUri);
     46             }
     47             mDownloadsQueue.put(info.mId, info);
     48             startDownloadThread();
     49         }
     50     }
     51 
     52     private synchronized void startDownloadThread() {
     53         Iterator<Long> keys = mDownloadsQueue.keySet().iterator();
     54         ArrayList<Long> ids = new ArrayList<Long>();
     55         while (mDownloadsInProgress.size() < mMaxConcurrentDownloadsAllowed && keys.hasNext()) {
     56             Long id = keys.next();
     57             DownloadInfo info = mDownloadsQueue.get(id);
     58             info.startDownloadThread();
     59             ids.add(id);
     60             mDownloadsInProgress.put(id, mDownloadsQueue.get(id));
     61             if (Constants.LOGV) {
     62                 Log.i(TAG, "started download for : " + id);
     63             }
     64         }
     65         for (Long id : ids) {
     66             mDownloadsQueue.remove(id);
     67         }
     68     }
     69 
     70     synchronized boolean hasDownloadInQueue(long id) {
     71         return mDownloadsQueue.containsKey(id) || mDownloadsInProgress.containsKey(id);
     72     }
     73 
     74     synchronized void dequeueDownload(long mId) {
     75         mDownloadsInProgress.remove(mId);
     76         startDownloadThread();
     77         if (mDownloadsInProgress.size() == 0 && mDownloadsQueue.size() == 0) {
     78             notifyAll();
     79         }
     80     }
     81 
     82     // right now this is only used by tests. but there is no reason why it can't be used
     83     // by any module using DownloadManager (TODO add API to DownloadManager.java)
     84     public synchronized void WaitUntilDownloadsTerminate() throws InterruptedException {
     85         if (mDownloadsInProgress.size() == 0 && mDownloadsQueue.size() == 0) {
     86             if (Constants.LOGVV) {
     87                 Log.i(TAG, "nothing to wait on");
     88             }
     89             return;
     90         }
     91         if (Constants.LOGVV) {
     92             for (DownloadInfo info : mDownloadsInProgress.values()) {
     93                 Log.i(TAG, "** progress: " + info.mId + ", " + info.mUri);
     94             }
     95             for (DownloadInfo info : mDownloadsQueue.values()) {
     96                 Log.i(TAG, "** in Q: " + info.mId + ", " + info.mUri);
     97             }
     98         }
     99         if (Constants.LOGVV) {
    100             Log.i(TAG, "waiting for 5 sec");
    101         }
    102         // wait upto 5 sec
    103         wait(5 * 1000);
    104     }
    105 }
    106