MatrixObjectFuture (Apache SystemDS 3.3.0-SNAPSHOT API)

java.lang.Object
- org.apache.sysds.runtime.instructions.cp.Data
- - org.apache.sysds.runtime.controlprogram.caching.CacheableData<MatrixBlock>
  - - org.apache.sysds.runtime.controlprogram.caching.MatrixObject
    - - org.apache.sysds.runtime.controlprogram.context.MatrixObjectFuture

All Implemented Interfaces:

Serializable
```
public class MatrixObjectFuture
extends MatrixObject
```
See Also:

Serialized Form

Nested Class Summary
- Nested classes/interfaces inherited from class org.apache.sysds.runtime.controlprogram.caching.MatrixObject
  MatrixObject.UpdateType
- Nested classes/interfaces inherited from class org.apache.sysds.runtime.controlprogram.caching.CacheableData
  CacheableData.CacheStatus

Field Summary
- Fields inherited from class org.apache.sysds.runtime.controlprogram.caching.CacheableData
  cacheEvictionLocalFilePath, cacheEvictionLocalFilePrefix, CACHING_ASYNC_FILECLEANUP, CACHING_ASYNC_SERIALIZE, CACHING_BUFFER_POLICY, CACHING_COUNTER_GROUP_NAME, CACHING_EVICTION_FILEEXTENSION, CACHING_THRESHOLD

Constructor Summary

Constructors
Constructor	Description
`MatrixObjectFuture(Types.ValueType vt, String file, Future<MatrixBlock> fmb)`
`MatrixObjectFuture(MatrixObject mo, Future<MatrixBlock> fmb)`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`MatrixBlock`	`acquireRead()`	Acquires a shared "read-only" lock, produces the reference to the cache block, restores the cache block to main memory, reads from HDFS if needed.
`void`	`clearData(long tid)`	Sets the cache block reference to `null`, abandons the old block.

Methods inherited from class org.apache.sysds.runtime.controlprogram.caching.MatrixObject
getBlocksize, getNnz, getPartitionFileName, getPartitionFormat, getPartitionSize, getSparsity, getUpdateType, isCompressed, isDiag, isMarked, isPartitioned, readMatrixPartition, refreshMetaData, setDiag, setInMemoryPartition, setMarkForLinCache, setPartitioned, setUpdateType, toString, unsetPartitioned, updateDataCharacteristics

Methods inherited from class org.apache.sysds.runtime.controlprogram.caching.CacheableData
acquireModify, acquireReadAndRelease, addBroadcastSize, cleanupCacheDir, cleanupCacheDir, clearData, disableCaching, enableCaching, enableCleanup, exportData, exportData, exportData, exportData, exportData, freeEvictedBlob, getBroadcastHandle, getBroadcastSize, getCacheLineage, getCompressedSize, getDataCharacteristics, getDataSize, getDebugName, getDim, getFedMapping, getFileFormatProperties, getFileName, getGPUObject, getMetaData, getNumColumns, getNumRows, getRDDHandle, getStatus, getUniqueID, hasBroadcastHandle, hasRDDHandle, hasValidLineage, initCaching, initCaching, isBelowCachingThreshold, isCached, isCachingActive, isCleanupEnabled, isDeviceToHostCopy, isDirty, isFederated, isFederated, isFederatedExcept, isHDFSFileExists, isPendingRDDOps, moveData, release, removeGPUObject, removeMetaData, setBroadcastHandle, setCacheLineage, setCompressedSize, setDirty, setEmptyStatus, setFedMapping, setFileFormatProperties, setFileName, setGPUObject, setHDFSFileExists, setMetaData, setRDDHandle

Methods inherited from class org.apache.sysds.runtime.instructions.cp.Data
getDataType, getValueType

Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - MatrixObjectFuture
```
public MatrixObjectFuture(Types.ValueType vt,
                          String file,
                          Future<MatrixBlock> fmb)
```
  - MatrixObjectFuture
```
public MatrixObjectFuture(MatrixObject mo,
                          Future<MatrixBlock> fmb)
```
- Method Detail
  - acquireRead
```
public MatrixBlock acquireRead()
```
    Description copied from class: CacheableData
    
    Acquires a shared "read-only" lock, produces the reference to the cache block, restores the cache block to main memory, reads from HDFS if needed. Synchronized because there might be parallel threads (parfor local) that access the same object (in case it was created before the loop). In-Status: EMPTY, EVICTABLE, EVICTED, READ; Out-Status: READ(+1).
    
    Overrides:
    
    acquireRead in class CacheableData<MatrixBlock>
    
    Returns:
    
    cacheable data
  - clearData
```
public void clearData(long tid)
```
    Description copied from class: CacheableData
    
    Sets the cache block reference to null, abandons the old block. Makes the "envelope" empty. Run it to finalize the object (otherwise the evicted cache block file may remain undeleted). In-Status: EMPTY, EVICTABLE, EVICTED; Out-Status: EMPTY.
    
    Overrides:
    
    clearData in class CacheableData<MatrixBlock>
    
    Parameters:
    
    tid - thread ID