org.h2.mvstore.tx

Class TransactionStore

java.lang.Object

org.h2.mvstore.tx.TransactionStore

public class TransactionStore
extends java.lang.Object

A store that supports concurrent MVCC read-committed transactions.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	TransactionStore.ArrayType A data type that contains an array of objects with the specified data types.
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 and Description
static java.lang.String	UNDO_LOG_NAME_PREFIX The prefix for undo log entries.

Constructor Summary

Constructors

Constructor and Description
TransactionStore(MVStore store) Create a new transaction store.
TransactionStore(MVStore store, DataType dataType, int timeoutMillis) Create a new transaction store.

Method Summary

Methods

Modifier and Type	Method and Description
Transaction	begin() Begin a new transaction.
Transaction	begin(TransactionStore.RollbackListener listener, int timeoutMillis, int ownerId) Begin a new transaction.
void	close() Close the transaction store.
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.
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,
                int timeoutMillis)

Create a new transaction store.

Parameters:

store - the store

dataType - the 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. 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.

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.

begin

public Transaction begin()

Begin a new transaction.

Returns:

the transaction

begin

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

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

Returns:

the transaction