/*
Copyright © 2013-2014, Silent Circle, LLC.
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
* Any redistribution, use, or modification is done solely for personal
benefit and not for any commercial purpose or for monetary gain
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
* Neither the name Silent Circle nor the names of its contributors may
be used to endorse or promote products derived from this software
without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL SILENT CIRCLE, LLC BE LIABLE FOR ANY
DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* This implementation is edited version of original Android sources.
*/
/*
* 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.silentcircle.contacts.providers;
import android.util.Log;
import net.sqlcipher.database.SQLiteDatabase;
import net.sqlcipher.database.SQLiteTransactionListener;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
* A transaction for interacting with a Contacts provider. This is used to pass state around
* throughout the operations comprising the transaction, including which databases the overall
* transaction is involved in, and whether the operation being performed is a batch operation.
*/
public class ContactsTransaction {
/**
* Whether this transaction is encompassing a batch of operations. If we're in batch mode,
* transactional operations from non-batch callers are ignored.
*/
private final boolean mBatch;
/**
* The list of databases that have been enlisted in this transaction.
*
* Note we insert elements to the head of the list, so that we endTransaction() in the reverse
* order.
*/
private final List<SQLiteDatabase> mDatabasesForTransaction;
/**
* The mapping of tags to databases involved in this transaction.
*/
private final Map<String, SQLiteDatabase> mDatabaseTagMap;
/**
* Whether any actual changes have been made successfully in this transaction.
*/
private boolean mIsDirty;
/**
* Whether a yield operation failed with an exception. If this occurred, we may not have a
* lock on one of the databases that we started the transaction with (the yield code cleans
* that up itself), so we should do an extra check before ending transactions.
*/
private boolean mYieldFailed;
/**
* Creates a new transaction object, optionally marked as a batch transaction.
* @param batch Whether the transaction is in batch mode.
*/
public ContactsTransaction(boolean batch) {
mBatch = batch;
mDatabasesForTransaction = new ArrayList<SQLiteDatabase>();
mDatabaseTagMap = new HashMap<String, SQLiteDatabase>();
mIsDirty = false;
}
public boolean isBatch() {
return mBatch;
}
public boolean isDirty() {
return mIsDirty;
}
public void markDirty() {
mIsDirty = true;
}
public void markYieldFailed() {
mYieldFailed = true;
}
/**
* If the given database has not already been enlisted in this transaction, adds it to our
* list of affected databases and starts a transaction on it. If we already have the given
* database in this transaction, this is a no-op.
* @param db The database to start a transaction on, if necessary.
* @param tag A constant that can be used to retrieve the DB instance in this transaction.
* @param listener A transaction listener to attach to this transaction. May be null.
*/
public void startTransactionForDb(SQLiteDatabase db, String tag,
SQLiteTransactionListener listener) {
if (AbstractContactsProvider.ENABLE_TRANSACTION_LOG) {
Log.i(AbstractContactsProvider.TAG, "startTransactionForDb: db=" + db.getPath() +
" tag=" + tag + " listener=" + listener +
" startTransaction=" + !hasDbInTransaction(tag),
new RuntimeException("startTransactionForDb"));
}
if (!hasDbInTransaction(tag)) {
// Insert a new db into the head of the list, so that we'll endTransaction() in
// the reverse order.
mDatabasesForTransaction.add(0, db);
mDatabaseTagMap.put(tag, db);
if (listener != null) {
db.beginTransactionWithListener(listener);
} else {
db.beginTransaction();
}
}
}
/**
* Returns whether DB corresponding to the given tag is currently enlisted in this transaction.
*/
public boolean hasDbInTransaction(String tag) {
return mDatabaseTagMap.containsKey(tag);
}
/**
* Retrieves the database enlisted in the transaction corresponding to the given tag.
* @param tag The tag of the database to look up.
* @return The database corresponding to the tag, or null if no database with that tag has been
* enlisted in this transaction.
*/
public SQLiteDatabase getDbForTag(String tag) {
return mDatabaseTagMap.get(tag);
}
/**
* Removes the database corresponding to the given tag from this transaction. It is now the
* caller's responsibility to do whatever needs to happen with this database - it is no longer
* a part of this transaction.
* @param tag The tag of the database to remove.
* @return The database corresponding to the tag, or null if no database with that tag has been
* enlisted in this transaction.
*/
public SQLiteDatabase removeDbForTag(String tag) {
SQLiteDatabase db = mDatabaseTagMap.get(tag);
mDatabaseTagMap.remove(tag);
mDatabasesForTransaction.remove(db);
return db;
}
/**
* Marks all active DB transactions as successful.
* @param callerIsBatch Whether this is being performed in the context of a batch operation.
* If it is not, and the transaction is marked as batch, this call is a no-op.
*/
public void markSuccessful(boolean callerIsBatch) {
if (!mBatch || callerIsBatch) {
for (SQLiteDatabase db : mDatabasesForTransaction) {
db.setTransactionSuccessful();
}
}
}
/**
* @return the tag for a database. Only intended to be used for logging.
*/
private String getTagForDb(SQLiteDatabase db) {
for (String tag : mDatabaseTagMap.keySet()) {
if (db == mDatabaseTagMap.get(tag)) {
return tag;
}
}
return null;
}
/**
* Completes the transaction, ending the DB transactions for all associated databases.
* @param callerIsBatch Whether this is being performed in the context of a batch operation.
* If it is not, and the transaction is marked as batch, this call is a no-op.
*/
public void finish(boolean callerIsBatch) {
if (AbstractContactsProvider.ENABLE_TRANSACTION_LOG) {
Log.i(AbstractContactsProvider.TAG, "ContactsTransaction.finish callerIsBatch=" +
callerIsBatch, new RuntimeException("ContactsTransaction.finish"));
}
if (!mBatch || callerIsBatch) {
for (SQLiteDatabase db : mDatabasesForTransaction) {
if (AbstractContactsProvider.ENABLE_TRANSACTION_LOG) {
Log.i(AbstractContactsProvider.TAG, "ContactsTransaction.finish: " +
"endTransaction for " + getTagForDb(db));
}
// If an exception was thrown while yielding, it's possible that we no longer have
// a lock on this database, so we need to check before attempting to end its
// transaction. Otherwise, we should always expect to be in a transaction (and will
// throw an exception if this is not the case).
if (mYieldFailed && !db.isDbLockedByCurrentThread()) {
// We no longer hold the lock, so don't do anything with this database.
continue;
}
db.endTransaction();
}
mDatabasesForTransaction.clear();
mDatabaseTagMap.clear();
mIsDirty = false;
}
}
}