net.openhft.chronicle.map

Interface PrepareValueBytes<K,V>

Type Parameters:

K - the key type of ChronicleMap, on which acquireUsing() is queried

V - the value type of ChronicleMap, on which acquireUsing() is queried

All Superinterfaces:

Serializable

public interface PrepareValueBytes<K,V>
extends Serializable

Strategy of preparing bytes of off-heap memory before assigning them into Byteable value during chronicleMap.acquireUsing() call, when the given key is absent in the map. Example: if you want 1L to be the off-heap updatable ChronicleMap's default value, the most simple way to achieve this is to configure custom PrepareValueBytes strategy in OffHeapUpdatableChronicleMapBuilder:

OffHeapUpdatableChronicleMapBuilder.of(Key.class, LongValue.class)
     .prepareValueBytesOnAcquire((bytes, k) -> bytes.writeLong(1L))
     ...
     .create();

Although the value type is not used in the API, PrepareValueBytes is not intended to be generic by value type, because strategy should know the value layout and how much bytes does it take in memory.

See Also:

OffHeapUpdatableChronicleMapBuilder.prepareValueBytesOnAcquire(PrepareValueBytes)

Method Summary

Methods

Modifier and Type	Method and Description
void	prepare(Bytes bytes, K key) Prepares bytes before assigning them into Byteable.

Method Detail

prepare

void prepare(Bytes bytes,
           K key)

Prepares bytes before assigning them into Byteable. The given bytes' position corresponds to the start of value bytes to be assigned into. This method should increment the given bytes' position by the value size. Bytes' contents outside of this range shouldn't be altered.

Parameters:

bytes - the bytes, positioned at the first value byte. Bytes' limit and BytesCommon.remaining() are not specified, but it is guaranteed that the latter is not less than the value size.

key - the key which is absent in the ChronicleMap during acquireUsing() call and value bytes are prepared for