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* Licensed under the Apache License, Version 2.0 (the "License");
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* database integrations.
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package org.jooq.impl;
import static org.jooq.impl.Tools.DataKey.DATA_DEFAULT_TRANSACTION_PROVIDER_AUTOCOMMIT;
import static org.jooq.impl.Tools.DataKey.DATA_DEFAULT_TRANSACTION_PROVIDER_CONNECTION;
import static org.jooq.impl.Tools.DataKey.DATA_DEFAULT_TRANSACTION_PROVIDER_SAVEPOINTS;
import java.sql.Connection;
import java.sql.SQLException;
import java.sql.Savepoint;
import java.util.ArrayDeque;
import java.util.Deque;
import org.jooq.Configuration;
import org.jooq.ConnectionProvider;
import org.jooq.TransactionContext;
import org.jooq.TransactionProvider;
import org.jooq.exception.DataAccessException;
/**
* A default implementation for the {@link TransactionProvider} SPI.
* <p>
* This implementation is entirely based on JDBC transactions and is intended to
* work with {@link DefaultConnectionProvider} (which is implicitly created when
* using {@link DSL#using(Connection)}).
* <p>
* <h3>Nesting of transactions</h3> By default, nested transactions are
* supported by modeling them implicitly with JDBC {@link Savepoint}s, if
* supported by the underlying JDBC driver, and if {@link #nested()} is
* <code>true</code>. To deactivate nested transactions, use
* {@link #DefaultTransactionProvider(ConnectionProvider, boolean)}.
*
* @author Lukas Eder
*/
public class DefaultTransactionProvider implements TransactionProvider {
/**
* This {@link Savepoint} serves as a marker for top level
* transactions in dialects that do not support Savepoints.
*/
private static final Savepoint UNSUPPORTED_SAVEPOINT = new DefaultSavepoint();
/**
* This {@link Savepoint} serves as a marker for top level
* transactions if {@link #nested()} transactions are deactivated.
*/
private static final Savepoint IGNORED_SAVEPOINT = new DefaultSavepoint();
private final ConnectionProvider connectionProvider;
private final boolean nested;
public DefaultTransactionProvider(ConnectionProvider connectionProvider) {
this(connectionProvider, true);
}
/**
* @param nested Whether nested transactions via {@link Savepoint}s are
* supported.
*/
public DefaultTransactionProvider(ConnectionProvider connectionProvider, boolean nested) {
this.connectionProvider = connectionProvider;
this.nested = nested;
}
public final boolean nested() {
return nested;
}
final int nestingLevel(Configuration configuration) {
return savepoints(configuration).size();
}
@SuppressWarnings("unchecked")
private final Deque<Savepoint> savepoints(Configuration configuration) {
Deque<Savepoint> savepoints = (Deque<Savepoint>) configuration.data(DATA_DEFAULT_TRANSACTION_PROVIDER_SAVEPOINTS);
if (savepoints == null) {
savepoints = new ArrayDeque<Savepoint>();
configuration.data(DATA_DEFAULT_TRANSACTION_PROVIDER_SAVEPOINTS, savepoints);
}
return savepoints;
}
private final boolean autoCommit(Configuration configuration) {
Boolean autoCommit = (Boolean) configuration.data(DATA_DEFAULT_TRANSACTION_PROVIDER_AUTOCOMMIT);
if (autoCommit == null) {
autoCommit = connection(configuration).getAutoCommit();
configuration.data(DATA_DEFAULT_TRANSACTION_PROVIDER_AUTOCOMMIT, autoCommit);
}
return autoCommit;
}
private final DefaultConnectionProvider connection(Configuration configuration) {
DefaultConnectionProvider connectionWrapper = (DefaultConnectionProvider) configuration.data(DATA_DEFAULT_TRANSACTION_PROVIDER_CONNECTION);
if (connectionWrapper == null) {
connectionWrapper = new DefaultConnectionProvider(connectionProvider.acquire());
configuration.data(DATA_DEFAULT_TRANSACTION_PROVIDER_CONNECTION, connectionWrapper);
}
return connectionWrapper;
}
@Override
public final void begin(TransactionContext ctx) {
Deque<Savepoint> savepoints = savepoints(ctx.configuration());
// This is the top-level transaction
boolean topLevel = savepoints.isEmpty();
if (topLevel)
brace(ctx.configuration(), true);
Savepoint savepoint = setSavepoint(ctx.configuration(), topLevel);
if (savepoint == UNSUPPORTED_SAVEPOINT && !topLevel)
throw new DataAccessException("Cannot nest transactions because Savepoints are not supported");
savepoints.push(savepoint);
}
private final Savepoint setSavepoint(Configuration configuration, boolean topLevel) {
if (topLevel || !nested())
return IGNORED_SAVEPOINT;
switch (configuration.family()) {
case CUBRID:
return UNSUPPORTED_SAVEPOINT;
default:
return connection(configuration).setSavepoint();
}
}
@Override
public final void commit(TransactionContext ctx) {
Deque<Savepoint> savepoints = savepoints(ctx.configuration());
Savepoint savepoint = savepoints.pop();
// [#3489] Explicitly release savepoints prior to commit
if (savepoint != null && savepoint != UNSUPPORTED_SAVEPOINT && savepoint != IGNORED_SAVEPOINT)
try {
connection(ctx.configuration()).releaseSavepoint(savepoint);
}
// [#3537] Ignore those cases where the JDBC driver incompletely implements the API
// See also http://stackoverflow.com/q/10667292/521799
catch (DataAccessException ignore) {}
// This is the top-level transaction
if (savepoints.isEmpty()) {
connection(ctx.configuration()).commit();
brace(ctx.configuration(), false);
}
// Nested commits have no effect
else {
}
}
@Override
public final void rollback(TransactionContext ctx) {
Deque<Savepoint> savepoints = savepoints(ctx.configuration());
Savepoint savepoint = null;
// [#3537] If something went wrong with the savepoints per se
if (!savepoints.isEmpty())
savepoint = savepoints.pop();
try {
if (savepoint == null || savepoint == UNSUPPORTED_SAVEPOINT) {
connection(ctx.configuration()).rollback();
}
// [#3955] ROLLBACK is only effective if an exception reaches the
// top-level transaction.
else if (savepoint == IGNORED_SAVEPOINT) {
if (savepoints.isEmpty())
connection(ctx.configuration()).rollback();
}
else {
connection(ctx.configuration()).rollback(savepoint);
}
}
finally {
if (savepoints.isEmpty())
brace(ctx.configuration(), false);
}
}
/**
* Ensure an <code>autoCommit</code> value on the connection, if it was set
* to <code>true</code>, originally.
*/
private final void brace(Configuration configuration, boolean start) {
DefaultConnectionProvider connection = connection(configuration);
try {
boolean autoCommit = autoCommit(configuration);
// Transactions cannot run with autoCommit = true. Change the value for
// the duration of a transaction
if (autoCommit == true)
connection.setAutoCommit(!start);
}
// [#3718] Chances are that the above JDBC interactions throw additional exceptions
// try-finally will ensure that the ConnectionProvider.release() call is made
finally {
if (!start) {
connectionProvider.release(connection.connection);
configuration.data().remove(DATA_DEFAULT_TRANSACTION_PROVIDER_CONNECTION);
}
}
}
private static class DefaultSavepoint implements Savepoint {
@Override
public int getSavepointId() throws SQLException {
return 0;
}
@Override
public String getSavepointName() throws SQLException {
return null;
}
}
}