Package com.palantir.atlasdb.transaction.api

Class NoOpLockWatchingCache

java.lang.Object

com.palantir.atlasdb.transaction.api.NoOpLockWatchingCache

All Implemented Interfaces:

LockWatchingCache

public final class NoOpLockWatchingCache
extends Object
implements LockWatchingCache

Field Summary

Fields

Modifier and Type	Field	Description
static NoOpLockWatchingCache	INSTANCE

Method Summary

Modifier and Type	Method	Description
Map<Cell,GuardedValue>	getCached(TableReference tableRef, Set<Cell> reads)	Given a table and a set of cells, the cache returns a map containing the latest cached GuardedValues for cells present in the cache.
TransactionLockWatchingCacheView	getView(long startTimestamp, com.palantir.lock.watch.LockWatchStateUpdate lockWatchState)	Creates a view of the cache for a transaction, based on the start timestamp and the lock watch state.
void	maybeCacheCommittedWrites(TableReference tableRef, Map<Cell,byte[]> writes)	After a transaction has committed, this notifies the cache that the writes can be cached, if desired.
void	maybeCacheEntriesRead(TableReference tableRef, Map<Cell,byte[]> writes, com.palantir.lock.watch.LockWatchStateUpdate lwState)	A transaction can attempt to cache entries read during the transaction using this method.

Methods inherited from class java.lang.Object

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

Field Detail

INSTANCE

public static final NoOpLockWatchingCache INSTANCE

Method Detail

getCached

public Map<Cell,GuardedValue> getCached(TableReference tableRef,
                                              Set<Cell> reads)

Description copied from interface: LockWatchingCache

Given a table and a set of cells, the cache returns a map containing the latest cached GuardedValues for cells present in the cache.

Specified by:

getCached in interface LockWatchingCache

Parameters:

tableRef - table to read from

reads - set of cells to read

Returns:

Cached values that are guaranteed to be the latest visible entries to the transaction making the request if the GuardedValue's timestamp matches the transaction's lock watch state

maybeCacheCommittedWrites

public void maybeCacheCommittedWrites(TableReference tableRef,
                                      Map<Cell,byte[]> writes)

Description copied from interface: LockWatchingCache

After a transaction has committed, this notifies the cache that the writes can be cached, if desired.

Specified by:

maybeCacheCommittedWrites in interface LockWatchingCache

Parameters:

tableRef - the table to which the transaction wrote

writes - actual writes

maybeCacheEntriesRead

public void maybeCacheEntriesRead(TableReference tableRef,
                                  Map<Cell,byte[]> writes,
                                  com.palantir.lock.watch.LockWatchStateUpdate lwState)

Description copied from interface: LockWatchingCache

A transaction can attempt to cache entries read during the transaction using this method. The implementation of the LockWatchStateUpdate must correctly arbitrate which of the passed entries are safe to cache.

Specified by:

maybeCacheEntriesRead in interface LockWatchingCache

Parameters:

tableRef - table to cache entries for

writes - entries read by the transaction

lwState - lock watch state at the start of the transaction that read the entries

getView

public TransactionLockWatchingCacheView getView(long startTimestamp,
                                                com.palantir.lock.watch.LockWatchStateUpdate lockWatchState)

Description copied from interface: LockWatchingCache

Creates a view of the cache for a transaction, based on the start timestamp and the lock watch state.

Specified by:

getView in interface LockWatchingCache

Parameters:

startTimestamp - of the transaction

lockWatchState - returned from the StartTransactionWithWatchesResponse

Returns:

view of the cache