org.apache.sysds.runtime.controlprogram.caching

## Class CacheableData<T extends CacheBlock>

- java.lang.Object
- - org.apache.sysds.runtime.instructions.cp.Data
  - - org.apache.sysds.runtime.controlprogram.caching.CacheableData<T>

- All Implemented Interfaces:
    Serializable
  Direct Known Subclasses:
    FrameObject, MatrixObject, TensorObject

      public abstract class CacheableData<T extends CacheBlock>
      extends Data

  Each object of this class is a cache envelope for some large piece of data called "cache block". For example, the body of a matrix can be the cache block. The term cache block refers strictly to the cacheable portion of the data object, often excluding metadata and auxiliary parameters, as defined in the subclasses. Under the protection of the envelope, the data blob may be evicted to the file system; then the subclass must set its reference to `null` to allow Java garbage collection. If other parts of the system continue keep references to the cache block, its eviction will not release any memory.
  See Also:
    Serialized Form

- - ### Nested Class Summary

    Nested Classes
    Modifier and Type | Class and Description
    --- | ---
    `static class` | `CacheableData.CacheStatus` Defines all possible cache status types for a data blob.

  - ### Field Summary

    Fields
    Modifier and Type | Field and Description
    --- | ---
    `static String` | `cacheEvictionLocalFilePath`
    `static String` | `cacheEvictionLocalFilePrefix`
    `static boolean` | `CACHING_ASYNC_FILECLEANUP`
    `static boolean` | `CACHING_BUFFER_PAGECACHE`
    `static LazyWriteBuffer.RPolicy` | `CACHING_BUFFER_POLICY`
    `static double` | `CACHING_BUFFER_SIZE`
    `static String` | `CACHING_COUNTER_GROUP_NAME`
    `static String` | `CACHING_EVICTION_FILEEXTENSION`
    `static long` | `CACHING_THRESHOLD`
    `static boolean` | `CACHING_WRITE_CACHE_ON_READ`

  - ### Method Summary

    All Methods Static Methods Instance Methods Abstract Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `T` | `acquireModify(T newData)` Acquires the exclusive "write" lock for a thread that wants to throw away the old cache block data and link up with new cache block data.
    `T` | `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.
    `T` | `acquireReadAndRelease()`
    `static void` | `addBroadcastSize(long size)`
    `static void` | `cleanupCacheDir()`
    `static void` | `cleanupCacheDir(boolean withDir)` Deletes the DML-script-specific caching working dir.
    `void` | `clearData()`
    `void` | `clearData(long tid)` Sets the cache block reference to `null`, abandons the old block.
    `static void` | `disableCaching()`
    `static void` | `enableCaching()`
    `void` | `enableCleanup(boolean flag)` Enables or disables the cleanup of the associated data object on clearData().
    `void` | `exportData()`
    `void` | `exportData(int replication)` Writes, or flushes, the cache block data to HDFS.
    `void` | `exportData(String fName, String outputFormat)`
    `void` | `exportData(String fName, String outputFormat, FileFormatProperties formatProperties)`
    `void` | `exportData(String fName, String outputFormat, int replication, FileFormatProperties formatProperties)`
    `void` | `exportData(String fName, String outputFormat, int replication, FileFormatProperties formatProperties, String opcode)` Synchronized because there might be parallel threads (parfor local) that access the same object (in case it was created before the loop).
    `void` | `freeEvictedBlob()` Low-level cache I/O method that deletes the file containing the evicted data blob, without reading it.
    `BroadcastObject<T>` | `getBroadcastHandle()`
    `static long` | `getBroadcastSize()`
    `DataCharacteristics` | `getDataCharacteristics()`
    `long` | `getDataSize()`
    `String` | `getDebugName()`
    `FederationMap` | `getFedMapping()` Gets the mapping of indices ranges to federated objects.
    `FileFormatProperties` | `getFileFormatProperties()`
    `String` | `getFileName()`
    `GPUObject` | `getGPUObject(GPUContext gCtx)`
    `MetaData` | `getMetaData()`
    `long` | `getNumColumns()`
    `long` | `getNumRows()`
    `RDDObject` | `getRDDHandle()`
    `CacheableData.CacheStatus` | `getStatus()`
    `long` | `getUniqueID()`
    `static void` | `initCaching()` Inits caching with the default uuid of DMLScript
    `static void` | `initCaching(String uuid)` Creates the DML-script-specific caching working dir.
    `boolean` | `isCached(boolean inclCachedNoWrite)`
    `static boolean` | `isCachingActive()`
    `boolean` | `isCleanupEnabled()` Indicates if cleanup of the associated data object is enabled on clearData().
    `boolean` | `isDirty()` `true` if the in-memory or evicted matrix may be different from the matrix located at `_hdfsFileName`; `false` if the two matrices are supposed to be the same.
    `boolean` | `isFederated()` Check if object is federated.
    `boolean` | `isFederated(FederationMap.FType type)`
    `boolean` | `isHDFSFileExists()`
    `boolean` | `moveData(String fName, String outputFormat)`
    `abstract void` | `refreshMetaData()`
    `void` | `release()` Releases the shared ("read-only") or exclusive ("write") lock.
    `void` | `removeMetaData()`
    `void` | `setBroadcastHandle(BroadcastObject bc)`
    `void` | `setDirty(boolean flag)`
    `void` | `setEmptyStatus()`
    `void` | `setFedMapping(FederationMap fedMapping)` Sets the mapping of indices ranges to federated objects.
    `void` | `setFileFormatProperties(FileFormatProperties props)`
    `void` | `setFileName(String file)`
    `void` | `setGPUObject(GPUContext gCtx, GPUObject gObj)`
    `void` | `setHDFSFileExists(boolean flag)`
    `void` | `setMetaData(MetaData md)`
    `void` | `setRDDHandle(RDDObject rdd)`
    `String` | `toString()`

    - ### Methods inherited from class org.apache.sysds.runtime.instructions.cp.Data

      `getDataType, getPrivacyConstraint, getValueType, setPrivacyConstraints, updateDataCharacteristics`

    - ### Methods inherited from class java.lang.Object

      `equals, getClass, hashCode, notify, notifyAll, wait, wait, wait`

- - ### Field Detail

    - #### CACHING_THRESHOLD

          public static final long CACHING_THRESHOLD

    - #### CACHING_BUFFER_SIZE

          public static final double CACHING_BUFFER_SIZE

      See Also:
        Constant Field Values

    - #### CACHING_BUFFER_POLICY

          public static final LazyWriteBuffer.RPolicy CACHING_BUFFER_POLICY

    - #### CACHING_BUFFER_PAGECACHE

          public static final boolean CACHING_BUFFER_PAGECACHE

      See Also:
        Constant Field Values

    - #### CACHING_WRITE_CACHE_ON_READ

          public static final boolean CACHING_WRITE_CACHE_ON_READ

      See Also:
        Constant Field Values

    - #### CACHING_COUNTER_GROUP_NAME

          public static final String CACHING_COUNTER_GROUP_NAME

      See Also:
        Constant Field Values

    - #### CACHING_EVICTION_FILEEXTENSION

          public static final String CACHING_EVICTION_FILEEXTENSION

      See Also:
        Constant Field Values

    - #### CACHING_ASYNC_FILECLEANUP

          public static final boolean CACHING_ASYNC_FILECLEANUP

      See Also:
        Constant Field Values

    - #### cacheEvictionLocalFilePath

          public static String cacheEvictionLocalFilePath

    - #### cacheEvictionLocalFilePrefix

          public static String cacheEvictionLocalFilePrefix

  - ### Method Detail

    - #### enableCleanup

          public void enableCleanup(boolean flag)

      Enables or disables the cleanup of the associated data object on clearData().
      Parameters:
        `flag` - true if cleanup

    - #### isCleanupEnabled

          public boolean isCleanupEnabled()

      Indicates if cleanup of the associated data object is enabled on clearData().
      Returns:
        true if cleanup enabled

    - #### getStatus

          public CacheableData.CacheStatus getStatus()

    - #### isHDFSFileExists

          public boolean isHDFSFileExists()

    - #### setHDFSFileExists

          public void setHDFSFileExists(boolean flag)

    - #### getFileName

          public String getFileName()

    - #### getUniqueID

          public long getUniqueID()

    - #### setFileName

          public void setFileName(String file)

    - #### isDirty

          public boolean isDirty()

      `true` if the in-memory or evicted matrix may be different from the matrix located at `_hdfsFileName`; `false` if the two matrices are supposed to be the same.
      Returns:
        true if dirty

    - #### setDirty

          public void setDirty(boolean flag)

    - #### getFileFormatProperties

          public FileFormatProperties getFileFormatProperties()

    - #### setFileFormatProperties

          public void setFileFormatProperties(FileFormatProperties props)

    - #### setMetaData

          public void setMetaData(MetaData md)

      Overrides:
        `setMetaData` in class `Data`

    - #### getMetaData

          public MetaData getMetaData()

      Overrides:
        `getMetaData` in class `Data`

    - #### removeMetaData

          public void removeMetaData()

      Overrides:
        `removeMetaData` in class `Data`

    - #### getDataCharacteristics

          public DataCharacteristics getDataCharacteristics()

    - #### getNumRows

          public long getNumRows()

    - #### getNumColumns

          public long getNumColumns()

    - #### refreshMetaData

          public abstract void refreshMetaData()

    - #### isFederated

          public boolean isFederated()

      Check if object is federated.
      Returns:
        true if federated else false

    - #### isFederated

          public boolean isFederated(FederationMap.FType type)

    - #### getFedMapping

          public FederationMap getFedMapping()

      Gets the mapping of indices ranges to federated objects.
      Returns:
        fedMapping mapping

    - #### setFedMapping

          public void setFedMapping(FederationMap fedMapping)

      Sets the mapping of indices ranges to federated objects.
      Parameters:
        `fedMapping` - mapping

    - #### getRDDHandle

          public RDDObject getRDDHandle()

    - #### setRDDHandle

          public void setRDDHandle(RDDObject rdd)

    - #### getBroadcastHandle

          public BroadcastObject<T> getBroadcastHandle()

    - #### setBroadcastHandle

          public void setBroadcastHandle(BroadcastObject bc)

    - #### getGPUObject

          public GPUObject getGPUObject(GPUContext gCtx)

    - #### setGPUObject

          public void setGPUObject(GPUContext gCtx,
                                   GPUObject gObj)

    - #### acquireReadAndRelease

          public T acquireReadAndRelease()

    - #### acquireRead

          public T 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. 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).
      Returns:
        cacheable data

    - #### acquireModify

          public T acquireModify(T newData)

      Acquires the exclusive "write" lock for a thread that wants to throw away the old cache block data and link up with new cache block data. Abandons the old data without reading it and sets the new data reference. In-Status: EMPTY, EVICTABLE, EVICTED; Out-Status: MODIFY.
      Parameters:
        `newData` - new data
      Returns:
        cacheable data

    - #### release

          public void release()

      Releases the shared ("read-only") or exclusive ("write") lock. Updates size information, last-access time, metadata, etc. Synchronized because there might be parallel threads (parfor local) that access the same object (in case it was created before the loop). In-Status: READ, MODIFY; Out-Status: READ(-1), EVICTABLE, EMPTY.

    - #### clearData

          public void clearData()

    - #### clearData

          public void clearData(long tid)

      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.
      Parameters:
        `tid` - thread ID

    - #### exportData

          public void exportData()

    - #### exportData

          public void exportData(int replication)

      Writes, or flushes, the cache block data to HDFS. In-Status: EMPTY, EVICTABLE, EVICTED, READ; Out-Status: EMPTY, EVICTABLE, EVICTED, READ.
      Parameters:
        `replication` - ?

    - #### exportData

          public void exportData(String fName,
                                 String outputFormat)

    - #### exportData

          public void exportData(String fName,
                                 String outputFormat,
                                 FileFormatProperties formatProperties)

    - #### exportData

          public void exportData(String fName,
                                 String outputFormat,
                                 int replication,
                                 FileFormatProperties formatProperties)

    - #### exportData

          public void exportData(String fName,
                                 String outputFormat,
                                 int replication,
                                 FileFormatProperties formatProperties,
                                 String opcode)

      Synchronized because there might be parallel threads (parfor local) that access the same object (in case it was created before the loop). If all threads export the same data object concurrently it results in errors because they all write to the same file. Efficiency for loops and parallel threads is achieved by checking if the in-memory block is dirty. NOTE: MB: we do not use dfs copy from local (evicted) to HDFS because this would ignore the output format and most importantly would bypass reblocking during write (which effects the potential degree of parallelism). However, we copy files on HDFS if certain criteria are given.
      Parameters:
        `fName` - file name
        `outputFormat` - format
        `replication` - ?
        `formatProperties` - file format properties
        `opcode` - instruction opcode if available

    - #### freeEvictedBlob

          public final void freeEvictedBlob()

      Low-level cache I/O method that deletes the file containing the evicted data blob, without reading it. Must be defined by a subclass, never called by users.

    - #### getDataSize

          public long getDataSize()

    - #### getDebugName

          public String getDebugName()

      Specified by:
        `getDebugName` in class `Data`

    - #### isCached

          public boolean isCached(boolean inclCachedNoWrite)

    - #### setEmptyStatus

          public void setEmptyStatus()

    - #### addBroadcastSize

          public static void addBroadcastSize(long size)

    - #### getBroadcastSize

          public static long getBroadcastSize()

    - #### cleanupCacheDir

          public static void cleanupCacheDir()

    - #### cleanupCacheDir

          public static void cleanupCacheDir(boolean withDir)

      Deletes the DML-script-specific caching working dir.
      Parameters:
        `withDir` - if true, delete directory

    - #### initCaching

          public static void initCaching()
                                  throws IOException

      Inits caching with the default uuid of DMLScript
      Throws:
        `IOException` - if IOException occurs

    - #### initCaching

          public static void initCaching(String uuid)
                                  throws IOException

      Creates the DML-script-specific caching working dir. Takes the UUID in order to allow for custom uuid, e.g., for remote parfor caching
      Parameters:
        `uuid` - ID
      Throws:
        `IOException` - if IOException occurs

    - #### isCachingActive

          public static boolean isCachingActive()

    - #### disableCaching

          public static void disableCaching()

    - #### enableCaching

          public static void enableCaching()

    - #### moveData

          public boolean moveData(String fName,
                                  String outputFormat)

    - #### toString

          public String toString()

      Overrides:
        `toString` in class `Object`

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