Package org.h2.mvstore.tx

Class TransactionStore

java.lang.Object

org.h2.mvstore.tx.TransactionStore

All Implemented Interfaces:

java.lang.AutoCloseable

public class TransactionStore
extends java.lang.Object
implements java.lang.AutoCloseable

A store that supports concurrent MVCC read-committed transactions.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	TransactionStore.Change	A change in a map.
static interface	TransactionStore.RollbackListener	This listener can be registered with the transaction to be notified of every compensating change during transaction rollback.

Field Summary

Fields

Modifier and Type	Field	Description
static java.lang.String	UNDO_LOG_NAME_PREFIX	The prefix for undo log entries.

Constructor Summary

Constructors

Constructor	Description
TransactionStore(MVStore store)	Create a new transaction store.
TransactionStore(MVStore store, DataType<?> dataType)
TransactionStore(MVStore store, MetaType<?> metaDataType, DataType<?> dataType, int timeoutMillis)	Create a new transaction store.

Method Summary

Modifier and Type	Method	Description
Transaction	begin()	Begin a new transaction.
Transaction	begin(TransactionStore.RollbackListener listener, int timeoutMillis, int ownerId, IsolationLevel isolationLevel)	Begin a new transaction.
void	close()	Close the transaction store.
void	closeImmediately()
void	endLeftoverTransactions()	Commit all transactions that are in the committed state, and rollback all open transactions.
java.util.List<Transaction>	getOpenTransactions()	Get the list of unclosed transactions that have pending writes.
boolean	hasMap(java.lang.String name)	Check whether a given map exists.
void	init()	Initialize the store without any RollbackListener.
void	init(TransactionStore.RollbackListener listener)	Initialize the store.
boolean	isTransactionClosed(int transactionId)	Checks if transaction is completely closed - status set to CLOSED, corresponding bit in open and committing bit sets cleared, transaction slot emptied.
<K,V> MVMap<K,V>	openMap(java.lang.String name, DataType<K> keyType, DataType<V> valueType)	Open the map with the given name.
void	setMaxTransactionId(int max)	Set the maximum transaction id, after which ids are re-used.

Methods inherited from class java.lang.Object

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

Field Detail

UNDO_LOG_NAME_PREFIX

public static final java.lang.String UNDO_LOG_NAME_PREFIX

The prefix for undo log entries.

See Also:

Constant Field Values

Constructor Detail

TransactionStore

public TransactionStore(MVStore store)

Create a new transaction store.

Parameters:

store - the store

TransactionStore

public TransactionStore(MVStore store,
                        DataType<?> dataType)

TransactionStore

public TransactionStore(MVStore store,
                        MetaType<?> metaDataType,
                        DataType<?> dataType,
                        int timeoutMillis)

Create a new transaction store.

Parameters:

store - the store

metaDataType - the data type for type registry map values

dataType - default data type for map keys and values

timeoutMillis - lock acquisition timeout in milliseconds, 0 means no wait

Method Detail

init

public void init()

Initialize the store without any RollbackListener.

See Also:

init(RollbackListener)

init

public void init(TransactionStore.RollbackListener listener)

Initialize the store. This is needed before a transaction can be opened. If the transaction store is corrupt, this method can throw an exception, in which case the store can only be used for reading.

Parameters:

listener - to notify about transaction rollback

isTransactionClosed

public boolean isTransactionClosed(int transactionId)

Checks if transaction is completely closed - status set to CLOSED, corresponding bit in open and committing bit sets cleared, transaction slot emptied. That also means that all uncommitted entries from this transaction, has been re-written as committed.

Parameters:

transactionId - to check

Returns:

true if transaction is completely closed, false otherwise

endLeftoverTransactions

public void endLeftoverTransactions()

Commit all transactions that are in the committed state, and rollback all open transactions.

setMaxTransactionId

public void setMaxTransactionId(int max)

Set the maximum transaction id, after which ids are re-used. If the old transaction is still in use when re-using an old id, the new transaction fails.

Parameters:

max - the maximum id

hasMap

public boolean hasMap(java.lang.String name)

Check whether a given map exists.

Parameters:

name - the map name

Returns:

true if it exists

getOpenTransactions

public java.util.List<Transaction> getOpenTransactions()

Get the list of unclosed transactions that have pending writes.

Returns:

the list of transactions (sorted by id)

close

public void close()

Close the transaction store.

Specified by:

close in interface java.lang.AutoCloseable

closeImmediately

public void closeImmediately()

begin

public Transaction begin()

Begin a new transaction.

Returns:

the transaction

begin

public Transaction begin(TransactionStore.RollbackListener listener,
                         int timeoutMillis,
                         int ownerId,
                         IsolationLevel isolationLevel)

Begin a new transaction.

Parameters:

listener - to be notified in case of a rollback

timeoutMillis - to wait for a blocking transaction

ownerId - of the owner (Session?) to be reported by getBlockerId

isolationLevel - of new transaction

Returns:

the transaction

openMap

public <K,V> MVMap<K,V> openMap(java.lang.String name,
                                            DataType<K> keyType,
                                            DataType<V> valueType)

Open the map with the given name.

Type Parameters:

K - the key type

V - the value type

Parameters:

name - the map name

keyType - the key type

valueType - the value type

Returns:

the map