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      1 /*
      2  * Copyright (C) 2015 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.tv.dvr.provider;
     18 
     19 import android.content.Context;
     20 import android.database.Cursor;
     21 import android.os.AsyncTask;
     22 import android.support.annotation.Nullable;
     23 
     24 import com.android.tv.dvr.ScheduledRecording;
     25 import com.android.tv.dvr.provider.DvrContract.Recordings;
     26 import com.android.tv.util.NamedThreadFactory;
     27 
     28 import java.util.ArrayList;
     29 import java.util.List;
     30 import java.util.concurrent.ExecutorService;
     31 import java.util.concurrent.Executors;
     32 
     33 /**
     34  * {@link AsyncTask} that defaults to executing on its own single threaded Executor Service.
     35  */
     36 public abstract class AsyncDvrDbTask<Params, Progress, Result>
     37         extends AsyncTask<Params, Progress, Result> {
     38     private static final NamedThreadFactory THREAD_FACTORY = new NamedThreadFactory(
     39             AsyncDvrDbTask.class.getSimpleName());
     40     private static final ExecutorService DB_EXECUTOR = Executors
     41             .newSingleThreadExecutor(THREAD_FACTORY);
     42 
     43     private static DvrDatabaseHelper sDbHelper;
     44 
     45     private static synchronized DvrDatabaseHelper initializeDbHelper(Context context) {
     46         if (sDbHelper == null) {
     47             sDbHelper = new DvrDatabaseHelper(context.getApplicationContext());
     48         }
     49         return sDbHelper;
     50     }
     51 
     52     final Context mContext;
     53 
     54     private AsyncDvrDbTask(Context context) {
     55         mContext = context;
     56     }
     57 
     58     /**
     59      * Execute the task on the {@link #DB_EXECUTOR} thread.
     60      */
     61     @SafeVarargs
     62     public final void executeOnDbThread(Params... params) {
     63         executeOnExecutor(DB_EXECUTOR, params);
     64     }
     65 
     66     @Override
     67     protected final Result doInBackground(Params... params) {
     68         initializeDbHelper(mContext);
     69         return doInDvrBackground(params);
     70     }
     71 
     72     /**
     73      * Executes in the background after {@link #initializeDbHelper(Context)}
     74      */
     75     @Nullable
     76     protected abstract Result doInDvrBackground(Params... params);
     77 
     78      /**
     79      * Inserts recordings returning the list of recordings with id set.
     80      * The id will be -1 if there was an error.
     81      */
     82     public abstract static class AsyncAddRecordingTask
     83             extends AsyncDvrDbTask<ScheduledRecording, Void, List<ScheduledRecording>> {
     84 
     85         public AsyncAddRecordingTask(Context context) {
     86             super(context);
     87         }
     88 
     89         @Override
     90         protected final List<ScheduledRecording> doInDvrBackground(ScheduledRecording... params) {
     91             return sDbHelper.insertRecordings(params);
     92         }
     93     }
     94 
     95     /**
     96      * Update recordings.
     97      *
     98      * @return list of row update counts.  The count will be -1 if there was an error or 0
     99      * if no match was found. The count is expected to be exactly 1 for each recording.
    100      */
    101     public abstract static class AsyncUpdateRecordingTask
    102             extends AsyncDvrDbTask<ScheduledRecording, Void, List<Integer>> {
    103         public AsyncUpdateRecordingTask(Context context) {
    104             super(context);
    105         }
    106 
    107         @Override
    108         protected final List<Integer> doInDvrBackground(ScheduledRecording... params) {
    109             return sDbHelper.updateRecordings(params);
    110         }
    111     }
    112 
    113     /**
    114      * Delete recordings.
    115      *
    116      * @return list of row delete counts.  The count will be -1 if there was an error or 0
    117      * if no match was found. The count is expected to be exactly 1 for each recording.
    118      */
    119     public abstract static class AsyncDeleteRecordingTask
    120             extends AsyncDvrDbTask<ScheduledRecording, Void, List<Integer>> {
    121         public AsyncDeleteRecordingTask(Context context) {
    122             super(context);
    123         }
    124 
    125         @Override
    126         protected final List<Integer> doInDvrBackground(ScheduledRecording... params) {
    127             return sDbHelper.deleteRecordings(params);
    128         }
    129     }
    130 
    131     public abstract static class AsyncDvrQueryTask
    132             extends AsyncDvrDbTask<Void, Void, List<ScheduledRecording>> {
    133         public AsyncDvrQueryTask(Context context) {
    134             super(context);
    135         }
    136 
    137         @Override
    138         @Nullable
    139         protected final List<ScheduledRecording> doInDvrBackground(Void... params) {
    140             if (isCancelled()) {
    141                 return null;
    142             }
    143 
    144             if (isCancelled()) {
    145                 return null;
    146             }
    147             if (isCancelled()) {
    148                 return null;
    149             }
    150             List<ScheduledRecording> scheduledRecordings = new ArrayList<>();
    151             try (Cursor c = sDbHelper.query(Recordings.TABLE_NAME, ScheduledRecording.PROJECTION)) {
    152                 while (c.moveToNext() && !isCancelled()) {
    153                     scheduledRecordings.add(ScheduledRecording.fromCursor(c));
    154                 }
    155             }
    156             return scheduledRecordings;
    157         }
    158     }
    159 }
    160