// Copyright (c) 2003-2014, Jodd Team (jodd.org). All Rights Reserved.
package jodd.jtx;
import jodd.log.Logger;
import jodd.log.LoggerFactory;
import static jodd.jtx.JtxIsolationLevel.*;
import static jodd.jtx.JtxStatus.STATUS_ACTIVE;
import java.util.ArrayList;
import java.util.Map;
import java.util.HashMap;
/**
* {@link JtxTransaction} manager is responsible for handling transaction
* propagation and resource managers. Holds various JTX configuration data.
* <p>
* Note that transactions are hold inside a thread-local transaction stack.
* Therefore, if one transaction is created after the other during the
* same thread, the second transaction will be aware that it is 'after'
* the first one.
*/
public class JtxTransactionManager {
private static final Logger log = LoggerFactory.getLogger(JtxTransactionManager.class);
protected int maxResourcesPerTransaction;
protected boolean oneResourceManager;
protected boolean validateExistingTransaction;
protected boolean ignoreScope;
protected Map<Class, JtxResourceManager> resourceManagers;
protected final ThreadLocal<ArrayList<JtxTransaction>> txStack = new ThreadLocal<ArrayList<JtxTransaction>>();
/**
* Creates new transaction manager.
*/
public JtxTransactionManager() {
this.maxResourcesPerTransaction = -1;
this.resourceManagers = new HashMap<Class, JtxResourceManager>();
}
// ---------------------------------------------------------------- config
/**
* Returns max number of resources per transaction.
*/
public int getMaxResourcesPerTransaction() {
return maxResourcesPerTransaction;
}
/**
* Sets max number of resources per transaction.
*/
public void setMaxResourcesPerTransaction(int maxResourcesPerTransaction) {
this.maxResourcesPerTransaction = maxResourcesPerTransaction;
}
/**
* Returns whether existing transactions should be validated before participating in them.
*/
public boolean isValidateExistingTransaction() {
return validateExistingTransaction;
}
/**
* Sets whether existing transactions should be validated before participating
* in them.
* <p>When participating in an existing transaction (e.g. with
* PROPAGATION_REQUIRES or PROPAGATION_SUPPORTS encountering an existing
* transaction), this outer transaction's characteristics will apply even
* to the inner transaction scope. Validation will detect incompatible
* isolation level and read-only settings on the inner transaction definition
* and reject participation accordingly through throwing a corresponding exception.
*/
public void setValidateExistingTransaction(boolean validateExistingTransaction) {
this.validateExistingTransaction = validateExistingTransaction;
}
/**
* Returns <code>true</code> if this transaction manager works with just one resource.
*/
public boolean isSingleResourceManager() {
return oneResourceManager;
}
/**
* Specifies if transaction manager works with just one resource.
*/
public void setSingleResourceManager(boolean oneResourceManager) {
this.oneResourceManager = oneResourceManager;
}
/**
* Returns if transaction scope should be ignored.
*/
public boolean isIgnoreScope() {
return ignoreScope;
}
/**
* Sets if transaction scope should be ignored. If ignored,
* there may be more then one transaction in one scope.
* Scopes may be ignored if set to <code>null</code>
*/
public void setIgnoreScope(boolean ignoreScope) {
this.ignoreScope = ignoreScope;
}
// ---------------------------------------------------------------- count
/**
* Returns total number of transactions associated with current thread.
*/
public int totalThreadTransactions() {
ArrayList<JtxTransaction> txList = txStack.get();
if (txList == null) {
return 0;
}
return txList.size();
}
/**
* Returns total number of transactions of the specified status associated with current thread.
*/
public int totalThreadTransactionsWithStatus(JtxStatus status) {
ArrayList<JtxTransaction> txlist = txStack.get();
if (txlist == null) {
return 0;
}
int count = 0;
for (JtxTransaction tx : txlist) {
if (tx.getStatus() == status) {
count++;
}
}
return count;
}
/**
* Returns total number of active transactions associated with current thread.
*/
public int totalActiveThreadTransactions() {
return totalThreadTransactionsWithStatus(STATUS_ACTIVE);
}
/**
* Returns <code>true</code> if provided transaction
* is associated with current thread.
*/
public boolean isAssociatedWithThread(JtxTransaction tx) {
ArrayList<JtxTransaction> txList = txStack.get();
if (txList == null) {
return false;
}
return txList.contains(tx);
}
// ---------------------------------------------------------------- thread work
/**
* Removes transaction association with current thread.
* Transaction should be properly handled (committed or rolledback)
* before removing from current thread.
* Also removes thread list from this thread.
*/
protected boolean removeTransaction(JtxTransaction tx) {
ArrayList<JtxTransaction> txList = txStack.get();
if (txList == null) {
return false;
}
boolean removed = txList.remove(tx);
if (removed) {
totalTransactions--;
}
if (txList.isEmpty()) {
txStack.remove();
}
return removed;
}
/**
* Returns last transaction associated with current thread or
* <code>null</code> when thread has no associated transactions created
* by this transaction manager.
*/
public JtxTransaction getTransaction() {
ArrayList<JtxTransaction> txlist = txStack.get();
if (txlist == null) {
return null;
}
if (txlist.isEmpty() == true) {
return null;
}
return txlist.get(txlist.size() - 1); // get last
}
/**
* Associate transaction to current thread.
*/
protected void associateTransaction(JtxTransaction tx) {
totalTransactions++;
ArrayList<JtxTransaction> txList = txStack.get();
if (txList == null) {
txList = new ArrayList<JtxTransaction>();
txStack.set(txList);
}
txList.add(tx); // add last
}
protected int totalTransactions;
/**
* Returns total number of transactions issued by this transaction manager.
*/
public int totalTransactions() {
return totalTransactions;
}
// ---------------------------------------------------------------- create
/**
* Creates new {@link jodd.jtx.JtxTransaction} instance.
* Custom implementations of manager may override this method for
* creating custom transaction instances.
*/
protected JtxTransaction createNewTransaction(JtxTransactionMode tm, Object scope, boolean active) {
return new JtxTransaction(this, tm, scope, active);
}
// ---------------------------------------------------------------- propagation
public JtxTransaction requestTransaction(JtxTransactionMode mode) {
return requestTransaction(mode, null);
}
/**
* Requests transaction with specified {@link JtxTransactionMode mode}.
* Depending on propagation behavior, it will return either <b>existing</b> or <b>new</b> transaction.
* Only one transaction can be opened over one scope.
* The exception may be thrown indicating propagation mismatch.
*/
public JtxTransaction requestTransaction(JtxTransactionMode mode, Object scope) {
if (log.isDebugEnabled()) {
log.debug("Requesting TX " + mode.toString());
}
JtxTransaction currentTx = getTransaction();
if (isNewTxScope(currentTx, scope) == false) {
return currentTx;
}
switch (mode.getPropagationBehavior()) {
case PROPAGATION_REQUIRED: return propRequired(currentTx, mode, scope);
case PROPAGATION_SUPPORTS: return propSupports(currentTx, mode, scope);
case PROPAGATION_MANDATORY: return propMandatory(currentTx, mode, scope);
case PROPAGATION_REQUIRES_NEW: return propRequiresNew(currentTx, mode, scope);
case PROPAGATION_NOT_SUPPORTED: return propNotSupported(currentTx, mode, scope);
case PROPAGATION_NEVER: return propNever(currentTx, mode, scope);
}
throw new JtxException("Invalid TX propagation value: " + mode.getPropagationBehavior().value());
}
/**
* Returns <code>true</code> if scope is specified and it is different then of existing transaction.
*/
protected boolean isNewTxScope(JtxTransaction currentTx, Object destScope) {
if (ignoreScope == true) {
return true;
}
if (currentTx == null) {
return true;
}
if (destScope == null) {
return true;
}
if (currentTx.getScope() == null) {
return true;
}
return !destScope.equals(currentTx.getScope());
}
/**
* Check if propagation of a transaction is possible, due to source and destination transaction modes.
* @see #setValidateExistingTransaction(boolean)
*/
protected void continueTx(JtxTransaction sourceTx, JtxTransactionMode destMode) {
if (validateExistingTransaction == false) {
return;
}
JtxTransactionMode sourceMode = sourceTx.getTransactionMode();
JtxIsolationLevel destIsolationLevel = destMode.getIsolationLevel();
if (destIsolationLevel != ISOLATION_DEFAULT) {
JtxIsolationLevel currentIsolationLevel = sourceMode.getIsolationLevel();
if (currentIsolationLevel != destIsolationLevel) {
throw new JtxException("Participating TX specifies isolation level: " + destIsolationLevel +
" which is incompatible with existing TX: " + currentIsolationLevel);
}
}
if ((destMode.isReadOnly() == false) && (sourceMode.isReadOnly())) {
throw new JtxException("Participating TX is not marked as read-only, but existing TX is");
}
}
/**
* Propagation: REQUIRED
* <pre>{@code
* None -> T2
* T1 -> T1 (cont.)
* }</pre>
*/
protected JtxTransaction propRequired(JtxTransaction currentTx, JtxTransactionMode mode, Object scope) {
if ((currentTx == null) || (currentTx.isNoTransaction() == true)) {
currentTx = createNewTransaction(mode, scope, true);
} else {
continueTx(currentTx, mode);
}
return currentTx;
}
/**
* Propagation: REQUIRES_NEW
* <pre>{@code
* None -> T2
* T1 -> T2
* }</pre>
*/
@SuppressWarnings({"UnusedDeclaration"})
protected JtxTransaction propRequiresNew(JtxTransaction currentTx, JtxTransactionMode mode, Object scope) {
return createNewTransaction(mode, scope, true);
}
/**
* Propagation: SUPPORTS
* <pre>{@code
* None -> None
* T1 -> T1 (cont.)
* }</pre>
*/
protected JtxTransaction propSupports(JtxTransaction currentTx, JtxTransactionMode mode, Object scope) {
if ((currentTx != null) && (currentTx.isNoTransaction() != true)) {
continueTx(currentTx, mode);
}
if (currentTx == null) {
currentTx = createNewTransaction(mode, scope, false);
}
return currentTx;
}
/**
* Propagation: MANDATORY
* <pre>{@code
* None -> Error
* T1 -> T1 (cont.)
* }</pre>
*/
@SuppressWarnings({"UnusedDeclaration"})
protected JtxTransaction propMandatory(JtxTransaction currentTx, JtxTransactionMode mode, Object scope) {
if ((currentTx == null) || (currentTx.isNoTransaction() == true)) {
throw new JtxException("No existing TX found for TX marked with propagation 'mandatory'");
}
continueTx(currentTx, mode);
return currentTx;
}
/**
* Propagation: NOT_SUPPORTED
* <pre>{@code
* None -> None
* T1 -> None
* }</pre>
*/
protected JtxTransaction propNotSupported(JtxTransaction currentTx, JtxTransactionMode mode, Object scope) {
if (currentTx == null) {
return createNewTransaction(mode, scope, false);
}
if (currentTx.isNoTransaction() == true) {
return currentTx;
}
return createNewTransaction(mode, scope, false);
}
/**
* Propagation: NEVER
* <pre>{@code
* None -> None
* T1 -> Error
* }</pre>
*/
protected JtxTransaction propNever(JtxTransaction currentTx, JtxTransactionMode mode, Object scope) {
if ((currentTx != null) && (currentTx.isNoTransaction() == false)) {
throw new JtxException("Existing TX found for TX marked with propagation 'never'");
}
if (currentTx == null) {
currentTx = createNewTransaction(mode, scope, false);
}
return currentTx;
}
// ---------------------------------------------------------------- resources
/**
* Registers new {@link JtxResourceManager resource manager}.
*/
public void registerResourceManager(JtxResourceManager resourceManager) {
if ((oneResourceManager == true) && (resourceManagers.isEmpty() == false)) {
throw new JtxException("TX manager allows only one resource manager");
}
this.resourceManagers.put(resourceManager.getResourceType(), resourceManager);
}
/**
* Lookups resource manager for provided type. Throws an exception if provider doesn't exists.
*/
protected <E> JtxResourceManager<E> lookupResourceManager(Class<E> resourceType) {
//noinspection unchecked
JtxResourceManager<E> resourceManager = this.resourceManagers.get(resourceType);
if (resourceManager == null) {
throw new JtxException("No registered resource manager for resource type: " + resourceType.getSimpleName());
}
return resourceManager;
}
// ---------------------------------------------------------------- close
/**
* Closes transaction manager. All registered {@link JtxResourceManager}
* will be closed.
*/
public void close() {
for (JtxResourceManager resourceManager : this.resourceManagers.values()) {
try {
resourceManager.close();
} catch (Exception ex) {
// ignore
}
}
resourceManagers.clear();
}
}