src/com/android/providers/contacts/AbstractContactsProvider.java - platform/packages/providers/ContactsProvider - Git at Google

 /*
  * Copyright (C) 2011 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.android.providers.contacts;

 import android.content.ContentProvider;
 import android.content.ContentProviderOperation;
 import android.content.ContentProviderResult;
 import android.content.ContentValues;
 import android.content.Context;
 import android.content.OperationApplicationException;
 import android.database.sqlite.SQLiteOpenHelper;
 import android.database.sqlite.SQLiteTransactionListener;
 import android.net.Uri;
 import android.util.Log;

 import java.util.ArrayList;

 /**
  * A common base class for the contacts and profile providers.  This handles much of the same
  * logic that SQLiteContentProvider does (i.e. starting transactions on the appropriate database),
  * but exposes awareness of batch operations to the subclass so that cross-database operations
  * can be supported.
  */
 public abstract class AbstractContactsProvider extends ContentProvider
         implements SQLiteTransactionListener {

     public static final String TAG = "ContactsProvider";

     public static final boolean VERBOSE_LOGGING = Log.isLoggable(TAG, Log.VERBOSE);

     /** Set true to enable detailed transaction logging. */
     public static final boolean ENABLE_TRANSACTION_LOG = false; // Don't submit with true.

     /**
      * Duration in ms to sleep after successfully yielding the lock during a batch operation.
      */
     protected static final int SLEEP_AFTER_YIELD_DELAY = 4000;

     /**
      * Maximum number of operations allowed in a batch between yield points.
      */
     private static final int MAX_OPERATIONS_PER_YIELD_POINT = 500;

     /**
      * Number of inserts performed in bulk to allow before yielding the transaction.
      */
     private static final int BULK_INSERTS_PER_YIELD_POINT = 50;

     /**
      * The contacts transaction that is active in this thread.
      */
     private ThreadLocal<ContactsTransaction> mTransactionHolder;

     /**
      * The DB helper to use for this content provider.
      */
     private SQLiteOpenHelper mDbHelper;

     /**
      * The database helper to serialize all transactions on.  If non-null, any new transaction
      * created by this provider will automatically retrieve a writable database from this helper
      * and initiate a transaction on that database.  This should be used to ensure that operations
      * across multiple databases are all blocked on a single DB lock (to prevent deadlock cases).
      *
      * Hint: It's always {@link ContactsDatabaseHelper}.
      *
      * TODO Change the structure to make it obvious that it's actually always set, and is the
      * {@link ContactsDatabaseHelper}.
      */
     private SQLiteOpenHelper mSerializeOnDbHelper;

     /**
      * The tag corresponding to the database used for serializing transactions.
      *
      * Hint: It's always the contacts db helper tag.
      *
      * See also the TODO on {@link #mSerializeOnDbHelper}.
      */
     private String mSerializeDbTag;

     /**
      * The transaction listener used with {@link #mSerializeOnDbHelper}.
      *
      * Hint: It's always {@link ContactsProvider2}.
      *
      * See also the TODO on {@link #mSerializeOnDbHelper}.
      */
     private SQLiteTransactionListener mSerializedDbTransactionListener;

     @Override
     public boolean onCreate() {
         Context context = getContext();
         mDbHelper = getDatabaseHelper(context);
         mTransactionHolder = getTransactionHolder();
         return true;
     }

     public SQLiteOpenHelper getDatabaseHelper() {
         return mDbHelper;
     }

     /**
      * Specifies a database helper (and corresponding tag) to serialize all transactions on.
      *
      * See also the TODO on {@link #mSerializeOnDbHelper}.
      */
     public void setDbHelperToSerializeOn(SQLiteOpenHelper serializeOnDbHelper, String tag,
             SQLiteTransactionListener listener) {
         mSerializeOnDbHelper = serializeOnDbHelper;
         mSerializeDbTag = tag;
         mSerializedDbTransactionListener = listener;
     }

     public ContactsTransaction getCurrentTransaction() {
         return mTransactionHolder.get();
     }

     @Override
     public Uri insert(Uri uri, ContentValues values) {
         ContactsTransaction transaction = startTransaction(false);
         try {
             Uri result = insertInTransaction(uri, values);
             if (result != null) {
                 transaction.markDirty();
             }
             transaction.markSuccessful(false);
             return result;
         } finally {
             endTransaction(false);
         }
     }

     @Override
     public int delete(Uri uri, String selection, String[] selectionArgs) {
         ContactsTransaction transaction = startTransaction(false);
         try {
             int deleted = deleteInTransaction(uri, selection, selectionArgs);
             if (deleted > 0) {
                 transaction.markDirty();
             }
             transaction.markSuccessful(false);
             return deleted;
         } finally {
             endTransaction(false);
         }
     }

     @Override
     public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
         ContactsTransaction transaction = startTransaction(false);
         try {
             int updated = updateInTransaction(uri, values, selection, selectionArgs);
             if (updated > 0) {
                 transaction.markDirty();
             }
             transaction.markSuccessful(false);
             return updated;
         } finally {
             endTransaction(false);
         }
     }

     @Override
     public int bulkInsert(Uri uri, ContentValues[] values) {
         ContactsTransaction transaction = startTransaction(true);
         int numValues = values.length;
         int opCount = 0;
         try {
             for (int i = 0; i < numValues; i++) {
                 insert(uri, values[i]);
                 if (++opCount >= BULK_INSERTS_PER_YIELD_POINT) {
                     opCount = 0;
                     try {
                         yield(transaction);
                     } catch (RuntimeException re) {
                         transaction.markYieldFailed();
                         throw re;
                     }
                 }
             }
             transaction.markSuccessful(true);
         } finally {
             endTransaction(true);
         }
         return numValues;
     }

     @Override
     public ContentProviderResult[] applyBatch(ArrayList<ContentProviderOperation> operations)
             throws OperationApplicationException {
         if (VERBOSE_LOGGING) {
             Log.v(TAG, "applyBatch: " + operations.size() + " ops");
         }
         int ypCount = 0;
         int opCount = 0;
         ContactsTransaction transaction = startTransaction(true);
         try {
             final int numOperations = operations.size();
             final ContentProviderResult[] results = new ContentProviderResult[numOperations];
             for (int i = 0; i < numOperations; i++) {
                 if (++opCount >= MAX_OPERATIONS_PER_YIELD_POINT) {
                     throw new OperationApplicationException(
                             "Too many content provider operations between yield points. "
                                     + "The maximum number of operations per yield point is "
                                     + MAX_OPERATIONS_PER_YIELD_POINT, ypCount);
                 }
                 final ContentProviderOperation operation = operations.get(i);
                 if (i > 0 && operation.isYieldAllowed()) {
                     if (VERBOSE_LOGGING) {
                         Log.v(TAG, "applyBatch: " + opCount + " ops finished; about to yield...");
                     }
                     opCount = 0;
                     try {
                         if (yield(transaction)) {
                             ypCount++;
                         }
                     } catch (RuntimeException re) {
                         transaction.markYieldFailed();
                         throw re;
                     }
                 }

                 results[i] = operation.apply(this, results, i);
             }
             transaction.markSuccessful(true);
             return results;
         } finally {
             endTransaction(true);
         }
     }

     /**
      * If we are not yet already in a transaction, this starts one (on the DB to serialize on, if
      * present) and sets the thread-local transaction variable for tracking.  If we are already in
      * a transaction, this returns that transaction, and the batch parameter is ignored.
      * @param callerIsBatch Whether the caller is operating in batch mode.
      */
     private ContactsTransaction startTransaction(boolean callerIsBatch) {
         if (ENABLE_TRANSACTION_LOG) {
             Log.i(TAG, "startTransaction " + getClass().getSimpleName() +
                     "  callerIsBatch=" + callerIsBatch, new RuntimeException("startTransaction"));
         }
         ContactsTransaction transaction = mTransactionHolder.get();
         if (transaction == null) {
             transaction = new ContactsTransaction(callerIsBatch);
             if (mSerializeOnDbHelper != null) {
                 transaction.startTransactionForDb(mSerializeOnDbHelper.getWritableDatabase(),
                         mSerializeDbTag, mSerializedDbTransactionListener);
             }
             mTransactionHolder.set(transaction);
         }
         return transaction;
     }

     /**
      * Ends the current transaction and clears out the member variable.  This does not set the
      * transaction as being successful.
      * @param callerIsBatch Whether the caller is operating in batch mode.
      */
     private void endTransaction(boolean callerIsBatch) {
         if (ENABLE_TRANSACTION_LOG) {
             Log.i(TAG, "endTransaction " + getClass().getSimpleName() +
                     "  callerIsBatch=" + callerIsBatch, new RuntimeException("endTransaction"));
         }
         ContactsTransaction transaction = mTransactionHolder.get();
         if (transaction != null && (!transaction.isBatch() || callerIsBatch)) {
             boolean notify = false;
             try {
                 if (transaction.isDirty()) {
                     notify = true;
                 }
                 transaction.finish(callerIsBatch);
                 if (notify) {
                     notifyChange();
                 }
             } finally {
                 // No matter what, make sure we clear out the thread-local transaction reference.
                 mTransactionHolder.set(null);
             }
         }
     }

     /**
      * Gets the database helper for this contacts provider.  This is called once, during onCreate().
      */
     protected abstract SQLiteOpenHelper getDatabaseHelper(Context context);

     /**
      * Gets the thread-local transaction holder to use for keeping track of the transaction.  This
      * is called once, in onCreate().  If multiple classes are inheriting from this class that need
      * to be kept in sync on the same transaction, they must all return the same thread-local.
      */
     protected abstract ThreadLocal<ContactsTransaction> getTransactionHolder();

     protected abstract Uri insertInTransaction(Uri uri, ContentValues values);

     protected abstract int deleteInTransaction(Uri uri, String selection, String[] selectionArgs);

     protected abstract int updateInTransaction(Uri uri, ContentValues values, String selection,
             String[] selectionArgs);

     protected abstract boolean yield(ContactsTransaction transaction);

     protected abstract void notifyChange();
 }
	/*
	* Copyright (C) 2011 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.android.providers.contacts;

	import android.content.ContentProvider;
	import android.content.ContentProviderOperation;
	import android.content.ContentProviderResult;
	import android.content.ContentValues;
	import android.content.Context;
	import android.content.OperationApplicationException;
	import android.database.sqlite.SQLiteOpenHelper;
	import android.database.sqlite.SQLiteTransactionListener;
	import android.net.Uri;
	import android.util.Log;

	import java.util.ArrayList;

	/**
	* A common base class for the contacts and profile providers. This handles much of the same
	* logic that SQLiteContentProvider does (i.e. starting transactions on the appropriate database),
	* but exposes awareness of batch operations to the subclass so that cross-database operations
	* can be supported.
	*/
	public abstract class AbstractContactsProvider extends ContentProvider
	implements SQLiteTransactionListener {

	public static final String TAG = "ContactsProvider";

	public static final boolean VERBOSE_LOGGING = Log.isLoggable(TAG, Log.VERBOSE);

	/** Set true to enable detailed transaction logging. */
	public static final boolean ENABLE_TRANSACTION_LOG = false; // Don't submit with true.

	/**
	* Duration in ms to sleep after successfully yielding the lock during a batch operation.
	*/
	protected static final int SLEEP_AFTER_YIELD_DELAY = 4000;

	/**
	* Maximum number of operations allowed in a batch between yield points.
	*/
	private static final int MAX_OPERATIONS_PER_YIELD_POINT = 500;

	/**
	* Number of inserts performed in bulk to allow before yielding the transaction.
	*/
	private static final int BULK_INSERTS_PER_YIELD_POINT = 50;

	/**
	* The contacts transaction that is active in this thread.
	*/
	private ThreadLocal<ContactsTransaction> mTransactionHolder;

	/**
	* The DB helper to use for this content provider.
	*/
	private SQLiteOpenHelper mDbHelper;

	/**
	* The database helper to serialize all transactions on. If non-null, any new transaction
	* created by this provider will automatically retrieve a writable database from this helper
	* and initiate a transaction on that database. This should be used to ensure that operations
	* across multiple databases are all blocked on a single DB lock (to prevent deadlock cases).
	*
	* Hint: It's always {@link ContactsDatabaseHelper}.
	*
	* TODO Change the structure to make it obvious that it's actually always set, and is the
	* {@link ContactsDatabaseHelper}.
	*/
	private SQLiteOpenHelper mSerializeOnDbHelper;

	/**
	* The tag corresponding to the database used for serializing transactions.
	*
	* Hint: It's always the contacts db helper tag.
	*
	* See also the TODO on {@link #mSerializeOnDbHelper}.
	*/
	private String mSerializeDbTag;

	/**
	* The transaction listener used with {@link #mSerializeOnDbHelper}.
	*
	* Hint: It's always {@link ContactsProvider2}.
	*
	* See also the TODO on {@link #mSerializeOnDbHelper}.
	*/
	private SQLiteTransactionListener mSerializedDbTransactionListener;

	@Override
	public boolean onCreate() {
	Context context = getContext();
	mDbHelper = getDatabaseHelper(context);
	mTransactionHolder = getTransactionHolder();
	return true;
	}

	public SQLiteOpenHelper getDatabaseHelper() {
	return mDbHelper;
	}

	/**
	* Specifies a database helper (and corresponding tag) to serialize all transactions on.
	*
	* See also the TODO on {@link #mSerializeOnDbHelper}.
	*/
	public void setDbHelperToSerializeOn(SQLiteOpenHelper serializeOnDbHelper, String tag,
	SQLiteTransactionListener listener) {
	mSerializeOnDbHelper = serializeOnDbHelper;
	mSerializeDbTag = tag;
	mSerializedDbTransactionListener = listener;
	}

	public ContactsTransaction getCurrentTransaction() {
	return mTransactionHolder.get();
	}

	@Override
	public Uri insert(Uri uri, ContentValues values) {
	ContactsTransaction transaction = startTransaction(false);
	try {
	Uri result = insertInTransaction(uri, values);
	if (result != null) {
	transaction.markDirty();
	}
	transaction.markSuccessful(false);
	return result;
	} finally {
	endTransaction(false);
	}
	}

	@Override
	public int delete(Uri uri, String selection, String[] selectionArgs) {
	ContactsTransaction transaction = startTransaction(false);
	try {
	int deleted = deleteInTransaction(uri, selection, selectionArgs);
	if (deleted > 0) {
	transaction.markDirty();
	}
	transaction.markSuccessful(false);
	return deleted;
	} finally {
	endTransaction(false);
	}
	}

	@Override
	public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
	ContactsTransaction transaction = startTransaction(false);
	try {
	int updated = updateInTransaction(uri, values, selection, selectionArgs);
	if (updated > 0) {
	transaction.markDirty();
	}
	transaction.markSuccessful(false);
	return updated;
	} finally {
	endTransaction(false);
	}
	}

	@Override
	public int bulkInsert(Uri uri, ContentValues[] values) {
	ContactsTransaction transaction = startTransaction(true);
	int numValues = values.length;
	int opCount = 0;
	try {
	for (int i = 0; i < numValues; i++) {
	insert(uri, values[i]);
	if (++opCount >= BULK_INSERTS_PER_YIELD_POINT) {
	opCount = 0;
	try {
	yield(transaction);
	} catch (RuntimeException re) {
	transaction.markYieldFailed();
	throw re;
	}
	}
	}
	transaction.markSuccessful(true);
	} finally {
	endTransaction(true);
	}
	return numValues;
	}

	@Override
	public ContentProviderResult[] applyBatch(ArrayList<ContentProviderOperation> operations)
	throws OperationApplicationException {
	if (VERBOSE_LOGGING) {
	Log.v(TAG, "applyBatch: " + operations.size() + " ops");
	}
	int ypCount = 0;
	int opCount = 0;
	ContactsTransaction transaction = startTransaction(true);
	try {
	final int numOperations = operations.size();
	final ContentProviderResult[] results = new ContentProviderResult[numOperations];
	for (int i = 0; i < numOperations; i++) {
	if (++opCount >= MAX_OPERATIONS_PER_YIELD_POINT) {
	throw new OperationApplicationException(
	"Too many content provider operations between yield points. "
	+ "The maximum number of operations per yield point is "
	+ MAX_OPERATIONS_PER_YIELD_POINT, ypCount);
	}
	final ContentProviderOperation operation = operations.get(i);
	if (i > 0 && operation.isYieldAllowed()) {
	if (VERBOSE_LOGGING) {
	Log.v(TAG, "applyBatch: " + opCount + " ops finished; about to yield...");
	}
	opCount = 0;
	try {
	if (yield(transaction)) {
	ypCount++;
	}
	} catch (RuntimeException re) {
	transaction.markYieldFailed();
	throw re;
	}
	}

	results[i] = operation.apply(this, results, i);
	}
	transaction.markSuccessful(true);
	return results;
	} finally {
	endTransaction(true);
	}
	}

	/**
	* If we are not yet already in a transaction, this starts one (on the DB to serialize on, if
	* present) and sets the thread-local transaction variable for tracking. If we are already in
	* a transaction, this returns that transaction, and the batch parameter is ignored.
	* @param callerIsBatch Whether the caller is operating in batch mode.
	*/
	private ContactsTransaction startTransaction(boolean callerIsBatch) {
	if (ENABLE_TRANSACTION_LOG) {
	Log.i(TAG, "startTransaction " + getClass().getSimpleName() +
	" callerIsBatch=" + callerIsBatch, new RuntimeException("startTransaction"));
	}
	ContactsTransaction transaction = mTransactionHolder.get();
	if (transaction == null) {
	transaction = new ContactsTransaction(callerIsBatch);
	if (mSerializeOnDbHelper != null) {
	transaction.startTransactionForDb(mSerializeOnDbHelper.getWritableDatabase(),
	mSerializeDbTag, mSerializedDbTransactionListener);
	}
	mTransactionHolder.set(transaction);
	}
	return transaction;
	}

	/**
	* Ends the current transaction and clears out the member variable. This does not set the
	* transaction as being successful.
	* @param callerIsBatch Whether the caller is operating in batch mode.
	*/
	private void endTransaction(boolean callerIsBatch) {
	if (ENABLE_TRANSACTION_LOG) {
	Log.i(TAG, "endTransaction " + getClass().getSimpleName() +
	" callerIsBatch=" + callerIsBatch, new RuntimeException("endTransaction"));
	}
	ContactsTransaction transaction = mTransactionHolder.get();
	if (transaction != null && (!transaction.isBatch() \|\| callerIsBatch)) {
	boolean notify = false;
	try {
	if (transaction.isDirty()) {
	notify = true;
	}
	transaction.finish(callerIsBatch);
	if (notify) {
	notifyChange();
	}
	} finally {
	// No matter what, make sure we clear out the thread-local transaction reference.
	mTransactionHolder.set(null);
	}
	}
	}

	/**
	* Gets the database helper for this contacts provider. This is called once, during onCreate().
	*/
	protected abstract SQLiteOpenHelper getDatabaseHelper(Context context);

	/**
	* Gets the thread-local transaction holder to use for keeping track of the transaction. This
	* is called once, in onCreate(). If multiple classes are inheriting from this class that need
	* to be kept in sync on the same transaction, they must all return the same thread-local.
	*/
	protected abstract ThreadLocal<ContactsTransaction> getTransactionHolder();

	protected abstract Uri insertInTransaction(Uri uri, ContentValues values);

	protected abstract int deleteInTransaction(Uri uri, String selection, String[] selectionArgs);

	protected abstract int updateInTransaction(Uri uri, ContentValues values, String selection,
	String[] selectionArgs);

	protected abstract boolean yield(ContactsTransaction transaction);

	protected abstract void notifyChange();
	}