Package com.ultikits.ultitools.manager

Class DataSourceTransactionManager

java.lang.Object

com.ultikits.ultitools.manager.DataSourceTransactionManager

All Implemented Interfaces:

JdbcTransactionManager, TransactionManager

@Internal
public class DataSourceTransactionManager
extends Object
implements JdbcTransactionManager

DataSource-based implementation of TransactionManager, and its JDBC-specific sub-interface JdbcTransactionManager.

Uses ThreadLocal to associate transactions with threads, ensuring thread safety. Each thread can have at most one active transaction at a time.

Since:

6.2.0

Author:

wisdomme

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
(package private) static class	DataSourceTransactionManager.TransactionContext	Internal class to hold transaction state.

Field Summary

Fields

Modifier and Type	Field	Description
private final ThreadLocal<DataSourceTransactionManager.TransactionContext>	contextHolder	ThreadLocal holding the current transaction context for each thread.
private final DataSource	dataSource
private static final Logger	LOGGER
private final ThreadLocal<Deque<DataSourceTransactionManager.TransactionContext>>	suspendedStack	ThreadLocal holding the stack of contexts suspend() has detached and not yet resume(Object)d, most-recently-suspended on top (D-09).

Constructor Summary

Constructors

Constructor	Description
DataSourceTransactionManager(DataSource dataSource)	Creates a new DataSourceTransactionManager.

Method Summary

Modifier and Type	Method	Description
void	begin()	Begins a new transaction.
private void	cleanup(DataSourceTransactionManager.TransactionContext ctx)	Cleans up the transaction context.
void	commit()	Commits the current transaction.
Connection	getConnection()	Gets the current connection, creating a new one if necessary.
(package private) DataSourceTransactionManager.TransactionContext	getCurrentContext()	Gets the current transaction context (for testing).
Long	getTimeoutDeadlineNanos()	Returns the System.nanoTime() value at which the active transaction's timeout budget expires, or null when no timeout is configured for the active transaction -- no active transaction at all, or @Transactional(timeout=0) (the default).
int	getTransactionDepth()	Gets the current transaction depth (for nested transactions).
boolean	hasActiveTransaction()	Checks if there is an active transaction on the current thread.
void	resume(Object suspended)	Restores a transaction previously detached by TransactionManager.suspend().
void	rollback()	Rolls back the current transaction.
void	setIsolationLevel(int level)	Sets the isolation level for the current transaction.
void	setReadOnly(boolean readOnly)	Sets read-only mode for the current transaction.
void	setTimeout(int seconds)	Sets the timeout for the current transaction.
Object	suspend()	Suspends the current transaction, if any, detaching it from this thread so an independent transaction can begin in its place.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

LOGGER

private static final Logger LOGGER

dataSource

private final DataSource dataSource

contextHolder

private final ThreadLocal<DataSourceTransactionManager.TransactionContext> contextHolder

ThreadLocal holding the current transaction context for each thread.

Instance-scoped on purpose (FOUND-04) - one DataSourceTransactionManager per plugin container, built once in PluginManager.wireAop. A static field here would let two plugin containers' transactions cross: manager A's rollback() would be able to reach a DataSourceTransactionManager.TransactionContext manager B set up for a completely different DataSource, on the same thread. Still a ThreadLocal - the fix is "no longer static", not "no longer ThreadLocal".

suspendedStack

private final ThreadLocal<Deque<DataSourceTransactionManager.TransactionContext>> suspendedStack

ThreadLocal holding the stack of contexts suspend() has detached and not yet resume(Object)d, most-recently-suspended on top (D-09).

Deliberately a sibling of contextHolder rather than folding the active context into the same structure: getTransactionDepth(), hasActiveTransaction(), commit() and rollback() all read the single active context and stay completely unchanged by this field's existence. Only suspend()/ resume(Object) ever touch it. Never left holding an empty Deque - the last pop calls ThreadLocal.remove() so a Bukkit worker thread returned to the pool does not carry a stale frame (T-02-DOS-5).

Constructor Details

DataSourceTransactionManager

public DataSourceTransactionManager(DataSource dataSource)

Creates a new DataSourceTransactionManager.

Parameters:

dataSource - the data source to use for connections

Method Details

getConnection

public Connection getConnection()

Description copied from interface: JdbcTransactionManager

Gets the current connection, creating a new one if necessary.

If a transaction is active, returns the connection associated with it. Otherwise, returns a new connection from the data source.

Specified by:

getConnection in interface JdbcTransactionManager

Specified by:

getConnection in interface TransactionManager

Returns:

the current connection

begin

public void begin()

Description copied from interface: TransactionManager

Begins a new transaction.

Creates a new connection, disables auto-commit, and associates it with the current thread.

Specified by:

begin in interface TransactionManager

commit

public void commit()

Description copied from interface: TransactionManager

Commits the current transaction.

Commits all changes made during the transaction and releases the connection.

Specified by:

commit in interface TransactionManager

rollback

public void rollback()

Description copied from interface: TransactionManager

Rolls back the current transaction.

Discards all changes made during the transaction and releases the connection.

Specified by:

rollback in interface TransactionManager

hasActiveTransaction

public boolean hasActiveTransaction()

Description copied from interface: TransactionManager

Checks if there is an active transaction on the current thread.

Specified by:

hasActiveTransaction in interface TransactionManager

Returns:

true if a transaction is active

setIsolationLevel

public void setIsolationLevel(int level)

Description copied from interface: JdbcTransactionManager

Sets the isolation level for the current transaction.

Must be called after begin() and before any statements are executed.

Specified by:

setIsolationLevel in interface JdbcTransactionManager

Specified by:

setIsolationLevel in interface TransactionManager

Parameters:

level - the JDBC isolation level constant

setReadOnly

public void setReadOnly(boolean readOnly)

Description copied from interface: JdbcTransactionManager

Sets read-only mode for the current transaction.

Specified by:

setReadOnly in interface JdbcTransactionManager

Specified by:

setReadOnly in interface TransactionManager

Parameters:

readOnly - true for read-only mode

setTimeout

public void setTimeout(int seconds)

Sets the timeout for the current transaction.

Note: Not all databases/drivers support transaction timeout.

D-10: records a deadline on the active DataSourceTransactionManager.TransactionContext rather than a wall-clock bound on the transaction as a whole -- getTimeoutDeadlineNanos() exposes it so each statement issued afterward can be given the time remaining, not a fresh full allowance. seconds <= 0 is inert (no deadline recorded), matching @Transactional(timeout=0)'s default -- TransactionInterceptor itself never calls this method for a non-positive value in the first place, so this is a second, defensive guard for any other caller. Called with no active transaction, this logs a warning and records nothing, the same shape commit()/rollback() already use for that case.

Specified by:

setTimeout in interface TransactionManager

Parameters:

seconds - the timeout in seconds

getTimeoutDeadlineNanos

public Long getTimeoutDeadlineNanos()

Returns the System.nanoTime() value at which the active transaction's timeout budget expires, or null when no timeout is configured for the active transaction -- no active transaction at all, or @Transactional(timeout=0) (the default).

D-10: consulted per statement (by TimeoutAwareQueryRunner and the two direct PreparedStatement call sites AbstractRelationalDataOperator.insertAll/ updateAll build themselves) to compute the time remaining in the budget, not a value captured once -- the caller re-reads this on every statement.

The default implementation always returns null, meaning "never enforced" -- the same posture a backend whose setTimeout(int) refuses any positive value outright (rather than ever recording a deadline) naturally has, since it never has anything to report here either. A backend that wants per-statement enforcement overrides this together with TransactionManager.setTimeout(int) -- overriding only one half of the pair leaves the other silently inert, the same caution TransactionManager.suspend()'s javadoc gives for its pair.

Reads DataSourceTransactionManager.TransactionContext.timeoutDeadlineNanos off the active context -- null when no transaction is active, or when setTimeout(int) was never called (or called only with a non-positive value) for it. suspend()/resume(Object) detach and restore the whole DataSourceTransactionManager.TransactionContext object, so a suspended-then-resumed transaction's deadline travels with it automatically -- no separate handling needed here.

Specified by:

getTimeoutDeadlineNanos in interface TransactionManager

Returns:

the deadline, as a System.nanoTime() value, or null if none is active

getTransactionDepth

public int getTransactionDepth()

Description copied from interface: TransactionManager

Gets the current transaction depth (for nested transactions).

Specified by:

getTransactionDepth in interface TransactionManager

Returns:

the transaction depth (0 if no transaction)

suspend

public Object suspend()

Suspends the current transaction, if any, detaching it from this thread so an independent transaction can begin in its place. Backs Propagation.REQUIRES_NEW and Propagation.NOT_SUPPORTED (D-09).

Deliberately typed to return an opaque Object rather than a backend-specific context type: a JDBC-backed manager suspends a Connection-holding context, a JSON snapshot manager (02-05) suspends a set of operator snapshots (D-03) - neither shape belongs on this base interface. Pass whatever this returns to TransactionManager.resume(Object) to restore it; the caller must not otherwise inspect or reuse the returned value.

The default implementation does not support suspension: it always returns null, meaning nothing was suspended. A backend that maintains thread-bound transaction state (JDBC, JSON) must override this together with TransactionManager.resume(Object) - overriding only one of the pair breaks the contract silently.

Detaches the current DataSourceTransactionManager.TransactionContext (connection included) from this thread and pushes it onto suspendedStack, leaving hasActiveTransaction() false. A begin() that runs while the original stays suspended opens a fully independent transaction, on its own connection - the suspended one is never touched until resume(Object) restores it.

Specified by:

suspend in interface TransactionManager

Returns:

an opaque handle to resume later, or null if no transaction was active

resume

public void resume(Object suspended)

Restores a transaction previously detached by TransactionManager.suspend().

null is a no-op - it means TransactionManager.suspend() found nothing active in the first place, so there is nothing to restore. Passing a handle this TransactionManager did not itself produce is a programming error.

The default implementation is a no-op, pairing with TransactionManager.suspend()'s default of always returning null.

null is a no-op - suspend() found nothing active in the first place, so there is nothing on suspendedStack for this call to pop. A non-null handle must be exactly what this manager's own suspend() most recently returned; restoring it sets it back as the active context (same DataSourceTransactionManager.TransactionContext instance, same Connection, same depth) and pops it off suspendedStack, removing the ThreadLocal entirely once the stack is empty rather than leaving a dangling empty Deque behind.

Specified by:

resume in interface TransactionManager

Parameters:

suspended - the handle returned by a prior TransactionManager.suspend() call, or null

Throws:

IllegalArgumentException - if suspended is non-null but was not produced by this manager's own suspend()

cleanup

private void cleanup(DataSourceTransactionManager.TransactionContext ctx)

Cleans up the transaction context.

getCurrentContext

DataSourceTransactionManager.TransactionContext getCurrentContext()

Gets the current transaction context (for testing).

Instance method, not static, per the same FOUND-04 fix as contextHolder itself: two DataSourceTransactionManager instances now have independent state.