/**
* Opens a new transaction against all registered backend system wrapped in one {@link
* BackendTransaction}.
*
* @return
* @throws StorageException
*/
public BackendTransaction beginTransaction(TransactionConfiguration configuration)
throws StorageException {
StoreTxConfig txConfig = new StoreTxConfig(configuration.getMetricsPrefix());
if (configuration.hasTimestamp()) txConfig.setTimestamp(configuration.getTimestamp());
StoreTransaction tx = storeManager.beginTransaction(txConfig);
if (bufferSize > 1) {
Preconditions.checkArgument(storeManager.getFeatures().supportsBatchMutation());
tx =
new BufferTransaction(
tx, storeManager, bufferSize, writeAttempts, persistAttemptWaittime);
}
if (!storeFeatures.supportsLocking()) {
if (storeFeatures.supportsTransactions()) {
// No transaction wrapping needed
} else if (storeFeatures.supportsConsistentKeyOperations()) {
txConfig =
new StoreTxConfig(ConsistencyLevel.KEY_CONSISTENT, configuration.getMetricsPrefix());
if (configuration.hasTimestamp()) txConfig.setTimestamp(configuration.getTimestamp());
tx =
new ExpectedValueCheckingTransaction(
tx, storeManager.beginTransaction(txConfig), readAttempts);
}
}
// Index transactions
Map<String, IndexTransaction> indexTx = new HashMap<String, IndexTransaction>(indexes.size());
for (Map.Entry<String, IndexProvider> entry : indexes.entrySet()) {
indexTx.put(entry.getKey(), new IndexTransaction(entry.getValue()));
}
return new BackendTransaction(
tx,
storeManager.getFeatures(),
edgeStore,
vertexIndexStore,
edgeIndexStore,
readAttempts,
persistAttemptWaittime,
indexTx);
}
public StoreTransaction startTx() throws StorageException {
return manager.beginTransaction(new StoreTxConfig());
}