Aurimas Liutikas | 88c7ff1 | 2023-08-10 12:42:26 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2009 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.common.content; |
| 18 | |
| 19 | import android.content.ContentProvider; |
| 20 | import android.content.ContentProviderOperation; |
| 21 | import android.content.ContentProviderResult; |
| 22 | import android.content.ContentValues; |
| 23 | import android.content.Context; |
| 24 | import android.content.OperationApplicationException; |
| 25 | import android.database.sqlite.SQLiteDatabase; |
| 26 | import android.database.sqlite.SQLiteOpenHelper; |
| 27 | import android.database.sqlite.SQLiteTransactionListener; |
| 28 | import android.net.Uri; |
| 29 | |
| 30 | import java.util.ArrayList; |
| 31 | |
| 32 | /** |
| 33 | * General purpose {@link ContentProvider} base class that uses SQLiteDatabase for storage. |
| 34 | */ |
| 35 | public abstract class SQLiteContentProvider extends ContentProvider |
| 36 | implements SQLiteTransactionListener { |
| 37 | |
| 38 | private static final String TAG = "SQLiteContentProvider"; |
| 39 | |
| 40 | private SQLiteOpenHelper mOpenHelper; |
| 41 | private volatile boolean mNotifyChange; |
| 42 | protected SQLiteDatabase mDb; |
| 43 | |
| 44 | private final ThreadLocal<Boolean> mApplyingBatch = new ThreadLocal<Boolean>(); |
| 45 | private static final int SLEEP_AFTER_YIELD_DELAY = 4000; |
| 46 | |
| 47 | /** |
| 48 | * Maximum number of operations allowed in a batch between yield points. |
| 49 | */ |
| 50 | private static final int MAX_OPERATIONS_PER_YIELD_POINT = 500; |
| 51 | |
| 52 | /** |
| 53 | * @return Number of operations that can be applied at once without a yield point. |
| 54 | */ |
| 55 | public int getMaxOperationsPerYield() { |
| 56 | return MAX_OPERATIONS_PER_YIELD_POINT; |
| 57 | } |
| 58 | |
| 59 | @Override |
| 60 | public boolean onCreate() { |
| 61 | Context context = getContext(); |
| 62 | mOpenHelper = getDatabaseHelper(context); |
| 63 | return true; |
| 64 | } |
| 65 | |
| 66 | protected abstract SQLiteOpenHelper getDatabaseHelper(Context context); |
| 67 | |
| 68 | /** |
| 69 | * The equivalent of the {@link #insert} method, but invoked within a transaction. |
| 70 | */ |
| 71 | protected abstract Uri insertInTransaction(Uri uri, ContentValues values); |
| 72 | |
| 73 | /** |
| 74 | * The equivalent of the {@link #update} method, but invoked within a transaction. |
| 75 | */ |
| 76 | protected abstract int updateInTransaction(Uri uri, ContentValues values, String selection, |
| 77 | String[] selectionArgs); |
| 78 | |
| 79 | /** |
| 80 | * The equivalent of the {@link #delete} method, but invoked within a transaction. |
| 81 | */ |
| 82 | protected abstract int deleteInTransaction(Uri uri, String selection, String[] selectionArgs); |
| 83 | |
| 84 | protected abstract void notifyChange(); |
| 85 | |
| 86 | public SQLiteOpenHelper getDatabaseHelper() { |
| 87 | return mOpenHelper; |
| 88 | } |
| 89 | |
| 90 | private boolean applyingBatch() { |
| 91 | return mApplyingBatch.get() != null && mApplyingBatch.get(); |
| 92 | } |
| 93 | |
| 94 | @Override |
| 95 | public Uri insert(Uri uri, ContentValues values) { |
| 96 | Uri result = null; |
| 97 | boolean applyingBatch = applyingBatch(); |
| 98 | if (!applyingBatch) { |
| 99 | mDb = mOpenHelper.getWritableDatabase(); |
| 100 | mDb.beginTransactionWithListener(this); |
| 101 | try { |
| 102 | result = insertInTransaction(uri, values); |
| 103 | if (result != null) { |
| 104 | mNotifyChange = true; |
| 105 | } |
| 106 | mDb.setTransactionSuccessful(); |
| 107 | } finally { |
| 108 | mDb.endTransaction(); |
| 109 | } |
| 110 | |
| 111 | onEndTransaction(); |
| 112 | } else { |
| 113 | result = insertInTransaction(uri, values); |
| 114 | if (result != null) { |
| 115 | mNotifyChange = true; |
| 116 | } |
| 117 | } |
| 118 | return result; |
| 119 | } |
| 120 | |
| 121 | @Override |
| 122 | public int bulkInsert(Uri uri, ContentValues[] values) { |
| 123 | int numValues = values.length; |
| 124 | mDb = mOpenHelper.getWritableDatabase(); |
| 125 | mDb.beginTransactionWithListener(this); |
| 126 | try { |
| 127 | for (int i = 0; i < numValues; i++) { |
| 128 | Uri result = insertInTransaction(uri, values[i]); |
| 129 | if (result != null) { |
| 130 | mNotifyChange = true; |
| 131 | } |
| 132 | boolean savedNotifyChange = mNotifyChange; |
| 133 | SQLiteDatabase savedDb = mDb; |
| 134 | mDb.yieldIfContendedSafely(); |
| 135 | mDb = savedDb; |
| 136 | mNotifyChange = savedNotifyChange; |
| 137 | } |
| 138 | mDb.setTransactionSuccessful(); |
| 139 | } finally { |
| 140 | mDb.endTransaction(); |
| 141 | } |
| 142 | |
| 143 | onEndTransaction(); |
| 144 | return numValues; |
| 145 | } |
| 146 | |
| 147 | @Override |
| 148 | public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) { |
| 149 | int count = 0; |
| 150 | boolean applyingBatch = applyingBatch(); |
| 151 | if (!applyingBatch) { |
| 152 | mDb = mOpenHelper.getWritableDatabase(); |
| 153 | mDb.beginTransactionWithListener(this); |
| 154 | try { |
| 155 | count = updateInTransaction(uri, values, selection, selectionArgs); |
| 156 | if (count > 0) { |
| 157 | mNotifyChange = true; |
| 158 | } |
| 159 | mDb.setTransactionSuccessful(); |
| 160 | } finally { |
| 161 | mDb.endTransaction(); |
| 162 | } |
| 163 | |
| 164 | onEndTransaction(); |
| 165 | } else { |
| 166 | count = updateInTransaction(uri, values, selection, selectionArgs); |
| 167 | if (count > 0) { |
| 168 | mNotifyChange = true; |
| 169 | } |
| 170 | } |
| 171 | |
| 172 | return count; |
| 173 | } |
| 174 | |
| 175 | @Override |
| 176 | public int delete(Uri uri, String selection, String[] selectionArgs) { |
| 177 | int count = 0; |
| 178 | boolean applyingBatch = applyingBatch(); |
| 179 | if (!applyingBatch) { |
| 180 | mDb = mOpenHelper.getWritableDatabase(); |
| 181 | mDb.beginTransactionWithListener(this); |
| 182 | try { |
| 183 | count = deleteInTransaction(uri, selection, selectionArgs); |
| 184 | if (count > 0) { |
| 185 | mNotifyChange = true; |
| 186 | } |
| 187 | mDb.setTransactionSuccessful(); |
| 188 | } finally { |
| 189 | mDb.endTransaction(); |
| 190 | } |
| 191 | |
| 192 | onEndTransaction(); |
| 193 | } else { |
| 194 | count = deleteInTransaction(uri, selection, selectionArgs); |
| 195 | if (count > 0) { |
| 196 | mNotifyChange = true; |
| 197 | } |
| 198 | } |
| 199 | return count; |
| 200 | } |
| 201 | |
| 202 | @Override |
| 203 | public ContentProviderResult[] applyBatch(ArrayList<ContentProviderOperation> operations) |
| 204 | throws OperationApplicationException { |
| 205 | int ypCount = 0; |
| 206 | int opCount = 0; |
| 207 | mDb = mOpenHelper.getWritableDatabase(); |
| 208 | mDb.beginTransactionWithListener(this); |
| 209 | try { |
| 210 | mApplyingBatch.set(true); |
| 211 | final int numOperations = operations.size(); |
| 212 | final ContentProviderResult[] results = new ContentProviderResult[numOperations]; |
| 213 | for (int i = 0; i < numOperations; i++) { |
| 214 | if (++opCount > getMaxOperationsPerYield()) { |
| 215 | throw new OperationApplicationException( |
| 216 | "Too many content provider operations between yield points. " |
| 217 | + "The maximum number of operations per yield point is " |
| 218 | + MAX_OPERATIONS_PER_YIELD_POINT, ypCount); |
| 219 | } |
| 220 | final ContentProviderOperation operation = operations.get(i); |
| 221 | if (i > 0 && operation.isYieldAllowed()) { |
| 222 | opCount = 0; |
| 223 | boolean savedNotifyChange = mNotifyChange; |
| 224 | if (mDb.yieldIfContendedSafely(SLEEP_AFTER_YIELD_DELAY)) { |
| 225 | mDb = mOpenHelper.getWritableDatabase(); |
| 226 | mNotifyChange = savedNotifyChange; |
| 227 | ypCount++; |
| 228 | } |
| 229 | } |
| 230 | |
| 231 | results[i] = operation.apply(this, results, i); |
| 232 | } |
| 233 | mDb.setTransactionSuccessful(); |
| 234 | return results; |
| 235 | } finally { |
| 236 | mApplyingBatch.set(false); |
| 237 | mDb.endTransaction(); |
| 238 | onEndTransaction(); |
| 239 | } |
| 240 | } |
| 241 | |
| 242 | @Override |
| 243 | public void onBegin() { |
| 244 | onBeginTransaction(); |
| 245 | } |
| 246 | |
| 247 | @Override |
| 248 | public void onCommit() { |
| 249 | beforeTransactionCommit(); |
| 250 | } |
| 251 | |
| 252 | @Override |
| 253 | public void onRollback() { |
| 254 | // not used |
| 255 | } |
| 256 | |
| 257 | protected void onBeginTransaction() { |
| 258 | } |
| 259 | |
| 260 | protected void beforeTransactionCommit() { |
| 261 | } |
| 262 | |
| 263 | protected void onEndTransaction() { |
| 264 | if (mNotifyChange) { |
| 265 | mNotifyChange = false; |
| 266 | notifyChange(); |
| 267 | } |
| 268 | } |
| 269 | } |