Package org.nustaq.offheap

Class FSTBinaryOffheapMap

java.lang.Object
org.nustaq.offheap.FSTBinaryOffheapMap
Direct Known Subclasses:
FSTCodedOffheapMap
public class FSTBinaryOffheapMap extends Object
Baseclass of offheap maps. FST OffHeap Maps enable to store key/value pairs in offheap memory. Additionally it provides and iterator interface for all values. In order to also iterate keys, add each key to its value object, as this OffHeap map does not support iteration of keys out of the box. See subclasses for directly applicable classes (E.g. FSTStringOffheapMap) The base is a generic bytesource to bytesource map. Note that key should be as short as possible (4-20 bytes) and should have their most modified digit at the last character of their value. e.g. [0,0,0,0,123,44] where '44' changes with each new key. Else on-heap memory consumption will grow. Performance of lookup degrades with growing key size. In case entries are updated frequently with values of different size, avoid fragementation by adding extra space to each entry. Override getEntryLengthForContentLength for this.

  • Field Details

  • Constructor Details

    • FSTBinaryOffheapMap

      public FSTBinaryOffheapMap(String mappedFile, int keyLen, long sizeMemBytes, int numberOfElems) throws Exception
      Throws:
      Exception

    • FSTBinaryOffheapMap

      public FSTBinaryOffheapMap(int keyLen, long sizeMemBytes, int numberOfElems)

  • Method Details

    • getCustomFileHeader

      public Bytez getCustomFileHeader()

    • initFromFile

      protected void initFromFile(String file, int keyLen, long sizeMemBytes, int numberOfElems) throws Exception
      Throws:
      Exception

    • init

      protected void init(int keyLen, long sizeMemBytes, int numberOfElems)

    • finalize

      protected void finalize() throws Throwable
      Overrides:
      finalize in class Object
      Throws:
      Throwable

    • free

      public void free()

    • putBinary

      public void putBinary(ByteSource key, ByteSource value)

    • removeEntry

      protected void removeEntry(long offset)

    • addToFreeList

      protected void addToFreeList(long offset)

    • setEntry

      protected void setEntry(long off, int entryLen, ByteSource value)

    • addEntry

      protected long addEntry(ByteSource key, ByteSource value)

    • resizeStore

      public void resizeStore(long required, long maxgrowbytes)
      PRIVILEGED method. You gotta know what your doing here .. currently a very expensive operation .. frees everything, resize file and remap. Remapping involves rebuild of index.
      Parameters:
      required -

    • getBinary

      public BytezByteSource getBinary(ByteSource key)
      get an entry. the returned ByteSource must be processed immediately as it will be reused internally on next get Warning: Concurrent Modification (e.g. add remove elements during iteration) is NOT SUPPORTED and NOT CHECKED. Collect keys to change inside iteration and perform changes after iteration is finished.
      Parameters:
      key -
      Returns:

    • removeBinary

      public void removeBinary(ByteSource key)
      remove the key from the binary map
      Parameters:
      key -

    • decElems

      protected void decElems()

    • incElems

      protected void incElems()

    • getEntryLengthForContentLength

      protected int getEntryLengthForContentLength(long lengthOfEntry)
      called upon add, allows to reserve extra space for later growth per entry
      Parameters:
      lengthOfEntry -
      Returns:

    • writeEntryHeader

      protected void writeEntryHeader(long offset, int entryLen, int contentLen, boolean removed)

    • getHeaderLen

      protected int getHeaderLen()

    • getLenFromHeader

      protected int getLenFromHeader(long off)

    • getContentLenFromHeader

      protected int getContentLenFromHeader(long off)

    • binaryValues

      public Iterator<ByteSource> binaryValues()

    • printBinaryKey

      public String printBinaryKey(ByteSource key)

    • binaryKeys

      public FSTBinaryOffheapMap.KeyValIter binaryKeys()

    • getFreeMem

      public long getFreeMem()

    • getUsedMem

      public long getUsedMem()

    • getCapacityMB

      public int getCapacityMB()

    • getSize

      public int getSize()

    • dumpIndexStats

      public void dumpIndexStats()

    • getFileName

      public String getFileName()

    • main

      public static void main(String[] args) throws Exception
      Throws:
      Exception