Package com.palantir.atlasdb.keyvalue.api.cache

Class ReadOnlyTransactionScopedCache

java.lang.Object

com.palantir.atlasdb.keyvalue.api.cache.ReadOnlyTransactionScopedCache

All Implemented Interfaces:

TransactionScopedCache

public final class ReadOnlyTransactionScopedCache
extends Object
implements TransactionScopedCache

Method Summary

Modifier and Type	Method	Description
static TransactionScopedCache	create(TransactionScopedCache delegate)
TransactionScopedCache	createReadOnlyCache(com.palantir.lock.watch.CommitUpdate commitUpdate)
void	delete(TableReference tableReference, Set<Cell> cells)
void	finalise()	This method should be called before retrieving the value or hit digest, as it guarantees that no more reads or writes will be performed on the cache.
Map<Cell,byte[]>	get(TableReference tableReference, Set<Cell> cells, java.util.function.Function<Set<Cell>,com.google.common.util.concurrent.ListenableFuture<Map<Cell,byte[]>>> valueLoader)	This should be used for performing *synchronous* gets.
com.google.common.util.concurrent.ListenableFuture<Map<Cell,byte[]>>	getAsync(TableReference tableReference, Set<Cell> cells, java.util.function.Function<Set<Cell>,com.google.common.util.concurrent.ListenableFuture<Map<Cell,byte[]>>> valueLoader)
HitDigest	getHitDigest()
NavigableMap<byte[],RowResult<byte[]>>	getRows(TableReference tableRef, Iterable<byte[]> rows, ColumnSelection columnSelection, java.util.function.Function<Set<Cell>,Map<Cell,byte[]>> cellLoader, java.util.function.Function<Iterable<byte[]>,NavigableMap<byte[],RowResult<byte[]>>> rowLoader)	The cache will try to fulfil as much of the request as possible with cached values.
ValueDigest	getValueDigest()
void	write(TableReference tableReference, Map<Cell,byte[]> values)

Methods inherited from class java.lang.Object

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

Method Detail

create

public static TransactionScopedCache create(TransactionScopedCache delegate)

write

public void write(TableReference tableReference,
                  Map<Cell,byte[]> values)

Specified by:

write in interface TransactionScopedCache

delete

public void delete(TableReference tableReference,
                   Set<Cell> cells)

Specified by:

delete in interface TransactionScopedCache

get

public Map<Cell,byte[]> get(TableReference tableReference,
                                  Set<Cell> cells,
                                  java.util.function.Function<Set<Cell>,com.google.common.util.concurrent.ListenableFuture<Map<Cell,byte[]>>> valueLoader)

Description copied from interface: TransactionScopedCache

This should be used for performing *synchronous* gets. The reason the value loader function returns a listenable future is to optimise parallel requests to the cache: only the code that directly affects the state of the cache is synchronised, while loads from the database are done outside synchronised blocks.

Specified by:

get in interface TransactionScopedCache

getAsync

public com.google.common.util.concurrent.ListenableFuture<Map<Cell,byte[]>> getAsync(TableReference tableReference,
                                                                                           Set<Cell> cells,
                                                                                           java.util.function.Function<Set<Cell>,com.google.common.util.concurrent.ListenableFuture<Map<Cell,byte[]>>> valueLoader)

Specified by:

getAsync in interface TransactionScopedCache

getRows

public NavigableMap<byte[],RowResult<byte[]>> getRows(TableReference tableRef,
                                                            Iterable<byte[]> rows,
                                                            ColumnSelection columnSelection,
                                                            java.util.function.Function<Set<Cell>,Map<Cell,byte[]>> cellLoader,
                                                            java.util.function.Function<Iterable<byte[]>,NavigableMap<byte[],RowResult<byte[]>>> rowLoader)

Description copied from interface: TransactionScopedCache

The cache will try to fulfil as much of the request as possible with cached values. In the case where some of the columns are present in the cache for a row, the cellLoader will be used to read the remaining cells remotely. For rows that have none of the columns present in the cache, the rowLoader will be used. Note that this may result in two KVS reads, but it is expected to be offset by not having to read the already cached values. The result map uses UnsignedBytes.lexicographicalComparator() on the keys, so there will be no duplicate rows, even if duplicates were specified in rows. Any row with no columns present will be absent in the result map, as long as the rowLoader behaves in the same way.

Specified by:

getRows in interface TransactionScopedCache

finalise

public void finalise()

Description copied from interface: TransactionScopedCache

This method should be called before retrieving the value or hit digest, as it guarantees that no more reads or writes will be performed on the cache. This method is idempotent, and may legitimately be called multiple times.

Specified by:

finalise in interface TransactionScopedCache

getValueDigest

public ValueDigest getValueDigest()

Specified by:

getValueDigest in interface TransactionScopedCache

getHitDigest

public HitDigest getHitDigest()

Specified by:

getHitDigest in interface TransactionScopedCache

createReadOnlyCache

public TransactionScopedCache createReadOnlyCache(com.palantir.lock.watch.CommitUpdate commitUpdate)

Specified by:

createReadOnlyCache in interface TransactionScopedCache