GcHelper (Hazelcast Enterprise Hot Restart 3.12.12 API)

java.lang.Object
- com.hazelcast.spi.hotrestart.impl.gc.GcHelper

All Implemented Interfaces:

com.hazelcast.nio.Disposable

Direct Known Subclasses:

GcHelper.OffHeap, GcHelper.OnHeap
```
public abstract class GcHelper
extends Object
implements com.hazelcast.nio.Disposable
```
Contains common constants, global counters, static utility methods, and system resource-oriented methods used throughout the Hot Restart module.

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`static class`	`GcHelper.OffHeap` The GC helper specialization for off-heap Hot Restart store
`static class`	`GcHelper.OnHeap` The GC helper specialization for on-heap Hot Restart store

Field Summary

Fields
Modifier and Type	Field and Description
`static int`	`BITS_PER_HEX_DIGIT` A hex digit represents this many bits.
`static int`	`BUCKET_DIR_MASK` Bitmask used for the operation "modulo MAX_BUCKET_DIRS"
`static int`	`BUCKET_DIRNAME_DIGITS` The number of hex digits in the name of a bucket dir
`static int`	`CHUNK_FNAME_LENGTH` Chunk filename is a zero-padded long in hex notation.
`static int`	`MAX_BUCKET_DIRS` To optimize file access times, chunk files are distributed across bucket directories.
`static String`	`PREFIX_TOMBSTONES_FILENAME` Name of the file that contains prefix tombstones

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`changeSuffix(String base, long seq, String suffixNow, String suffixToBe)` Changes the filename suffix of a chunk file.
`File`	`chunkFile(String base, long seq, String suffix, boolean mkdirs)` Returns a `File` instance representing the chunk file described by the parameters.
`long`	`chunkSeq()`
`void`	`deleteChunkFile(long seq, boolean isValChunk)` Deletes chunk file with the given `seq`.
`void`	`deleteChunkFile(StableChunk chunk)` Deletes the stable chunk file associated with the given instance of `StableChunk`.
`void`	`deleteChunkFiles(long[] chunkSeqs, boolean areValChunks)` Deletes chunk files with the given `chunkSeqs`.
`void`	`initChunkSeq(long seq)` Initializes the chunk sequence counter to the given value.
`WriteThroughTombChunk`	`newActiveTombChunk()` Creates a new active tombstone chunk file and returns an instance of `WriteThroughTombChunk` that wraps it.
`ActiveValChunk`	`newActiveValChunk()` Creates a new active value chunk file and returns an instance of `ActiveValChunk` that wraps it.
`abstract SetOfKeyHandle`	`newSetOfKeyHandle()` Creates and returns an instance of `SetOfKeyHandle`.
`SurvivorValChunk`	`newSurvivorValChunk(MutatorCatchup mc)` Creates a new survivor value chunk file and returns an instance of `SurvivorValChunk` that wraps it.
`abstract TrackerMap`	`newTrackerMap()` Creates and returns an instance of `TrackerMap`.
`long`	`nextRecordSeq()` Increments the record sequence counter and returns the new value.
`long`	`recordSeq()`
`File`	`stableChunkFile(StableChunk chunk, boolean mkdirs)` Returns a `File` instance representing the file associated with the given stable chunk.

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

Methods inherited from interface com.hazelcast.nio.Disposable
dispose

- Field Detail
  - PREFIX_TOMBSTONES_FILENAME
```
public static final String PREFIX_TOMBSTONES_FILENAME
```
    Name of the file that contains prefix tombstones
    
    See Also:
    
    Constant Field Values
  - BITS_PER_HEX_DIGIT
```
public static final int BITS_PER_HEX_DIGIT
```
    A hex digit represents this many bits.
    
    See Also:
    
    Constant Field Values
  - CHUNK_FNAME_LENGTH
```
public static final int CHUNK_FNAME_LENGTH
```
    Chunk filename is a zero-padded long in hex notation. This constant equals the max number of hex digits in a long.
    
    See Also:
    
    Constant Field Values
  - BUCKET_DIRNAME_DIGITS
```
public static final int BUCKET_DIRNAME_DIGITS
```
    The number of hex digits in the name of a bucket dir
    
    See Also:
    
    Constant Field Values
  - MAX_BUCKET_DIRS
```
public static final int MAX_BUCKET_DIRS
```
    To optimize file access times, chunk files are distributed across bucket directories. This is the maximum number of such directories. INVARIANT: this number is a power of two.
    
    See Also:
    
    Constant Field Values
  - BUCKET_DIR_MASK
```
public static final int BUCKET_DIR_MASK
```
    Bitmask used for the operation "modulo MAX_BUCKET_DIRS"
    
    See Also:
    
    Constant Field Values
- Method Detail
  - newActiveValChunk
```
public ActiveValChunk newActiveValChunk()
```
    Creates a new active value chunk file and returns an instance of ActiveValChunk that wraps it.
  - newSurvivorValChunk
```
public final SurvivorValChunk newSurvivorValChunk(MutatorCatchup mc)
```
    Creates a new survivor value chunk file and returns an instance of SurvivorValChunk that wraps it.
  - newActiveTombChunk
```
public WriteThroughTombChunk newActiveTombChunk()
```
    Creates a new active tombstone chunk file and returns an instance of WriteThroughTombChunk that wraps it.
  - initChunkSeq
```
public final void initChunkSeq(long seq)
```
    Initializes the chunk sequence counter to the given value.
  - chunkSeq
```
public final long chunkSeq()
```
    Returns:
    
    the current value of the chunk sequence counter
  - recordSeq
```
public final long recordSeq()
```
    Returns:
    
    the current value of the record sequence counter
  - nextRecordSeq
```
public final long nextRecordSeq()
```
    Increments the record sequence counter and returns the new value.
  - deleteChunkFile
```
public void deleteChunkFile(StableChunk chunk)
```
    Deletes the stable chunk file associated with the given instance of StableChunk.
  - deleteChunkFiles
```
public void deleteChunkFiles(long[] chunkSeqs,
                             boolean areValChunks)
```
    Deletes chunk files with the given chunkSeqs.
    
    Parameters:
    
    chunkSeqs - the sequences of the chunks to be deleted
    
    areValChunks - if the chunk sequences are for value chunks
  - deleteChunkFile
```
public void deleteChunkFile(long seq,
                            boolean isValChunk)
```
    Deletes chunk file with the given seq.
    
    Parameters:
    
    seq - the sequence of the chunk to be deleted
    
    isValChunk - if the chunk is a value chunk
  - changeSuffix
```
public void changeSuffix(String base,
                         long seq,
                         String suffixNow,
                         String suffixToBe)
```
    Changes the filename suffix of a chunk file.
    
    Parameters:
    
    base - name of the chunk's base directory (inside the overal Hot Restart home directory).
    
    seq - chunk's seq
    
    suffixNow - chunk file's current filename suffix
    
    suffixToBe - desired new filename suffix
  - stableChunkFile
```
public final File stableChunkFile(StableChunk chunk,
                                  boolean mkdirs)
```
    Returns a File instance representing the file associated with the given stable chunk.
    
    Parameters:
    
    chunk - the stable chunk
    
    mkdirs - whether to also create any missing ancestor directories of the chunk file
  - chunkFile
```
public File chunkFile(String base,
                      long seq,
                      String suffix,
                      boolean mkdirs)
```
    Returns a File instance representing the chunk file described by the parameters.
    
    Parameters:
    
    base - name of the chunk's base directory (inside the overal Hot Restart home directory).
    
    seq - seq of the chunk
    
    suffix - filename suffix
    
    mkdirs - whether to also create any missing ancestor directories of the chunk file
  - newTrackerMap
```
public abstract TrackerMap newTrackerMap()
```
    Creates and returns an instance of TrackerMap.
  - newSetOfKeyHandle
```
public abstract SetOfKeyHandle newSetOfKeyHandle()
```
    Creates and returns an instance of SetOfKeyHandle.

Class GcHelper

Nested Class Summary

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface com.hazelcast.nio.Disposable

Field Detail

PREFIX_TOMBSTONES_FILENAME

BITS_PER_HEX_DIGIT

CHUNK_FNAME_LENGTH

BUCKET_DIRNAME_DIGITS

MAX_BUCKET_DIRS

BUCKET_DIR_MASK

Method Detail

newActiveValChunk

newSurvivorValChunk

newActiveTombChunk

initChunkSeq

chunkSeq

recordSeq

nextRecordSeq

deleteChunkFile

deleteChunkFiles

deleteChunkFile

changeSuffix

stableChunkFile

chunkFile

newTrackerMap

newSetOfKeyHandle