Package com.tangosol.io.nio

Class BinaryMap.Block

java.lang.Object
com.tangosol.util.Base
com.tangosol.io.nio.BinaryMap.Block
Enclosing class:
BinaryMap
public class BinaryMap.Block extends Base
A Block is the unit of storage within a Buffer. There are free blocks and Entry blocks (that store key/value pairs).

  • Field Details

    • NONE

      public static final int NONE
      Initial state, also state of an allocated block that has not been linked.
      See Also:

    • FREE

      public static final int FREE
      State of a block that is available for use.
      See Also:

    • ENTRY

      public static final int ENTRY
      State of a block that holds an Entry object's data.
      See Also:

    • OFFSET_HASH

      public static final int OFFSET_HASH
      Offset of the key's hash within an Entry block.
      See Also:

    • OFFSET_KEY

      public static final int OFFSET_KEY
      Offset of the key data within an Entry block.
      See Also:

    • OFFSET_VALUE

      public static final int OFFSET_VALUE
      Offset (not counting key length) of the value data within an Entry block.
      See Also:

    • MIN_SPLIT

      public static final int MIN_SPLIT
      Minimum size of a block to split off a free block.
      See Also:

    • MIN_FREE

      public static final int MIN_FREE
      Minimum size of a free block.
      See Also:

    • MIN_ENTRY

      public static final int MIN_ENTRY
      Minimum size of an Entry block.
      See Also:

  • Constructor Details

    • Block

      public Block()
      Construct a Block.

  • Method Details

    • init

      public void init(int of)
      Configure the Block object to point to a specific offset within the Buffer.
      Parameters:
      of - the offset of the Block within the Buffer

    • use

      protected void use()
      Increment the use count for this block.

    • finishUse

      protected boolean finishUse()
      Decrement the use count for this block and check if it is now zero.

    • reset

      public void reset()
      Reset the Block object so that it doesn't point into the Buffer. Block objects can be re-used to reduce allocations by calling the close() method.

    • flush

      public void flush()
      Close the Block object by resetting its contents and recycling the object.

    • close

      public void close()
      Close the Block object, flushing any pending changes, resetting its contents and recycling the object.

    • discard

      public void discard()
      Recycle the Block object, discarding any changes, resetting its contents and recycling the object.

    • clear

      public void clear()
      Zero the block.

    • clearValue

      public void clearValue()
      Zero the value portion of the block.

    • getType

      public int getType()
      Determine the current Block type.
      Returns:
      one of {NONE, FREE, ENTRY}

    • setType

      public void setType(int nType)
      Set the Block type.
      Parameters:
      nType - the new Block type

    • isFree

      public boolean isFree()
      Determine if the Block is marked as free.
      Returns:
      true if and only if the type is FREE

    • isEntry

      public boolean isEntry()
      Determine if the Block is marked as an Entry.
      Returns:
      true if and only if the type is ENTRY

    • getOffset

      public int getOffset()
      Determine the offset of this Block in the Buffer.
      Returns:
      the offset of this Block in the Buffer, or NIL if this Block has not been initialized

    • setOffset

      public void setOffset(int ofBlock)
      Specify the offset of this Block in the Buffer.
      Parameters:
      ofBlock - the offset of this Block

    • getLength

      public int getLength()
      Determine the length of the block.
      Returns:
      the length, in bytes, of this block

    • length

      public int length()
      Determine the length of the block.
      Returns:
      the length, in bytes, of this block

    • getSizeCode

      public int getSizeCode()
      Determine the "free block size code" for a block of this size.
      Returns:
      the size code for this block

    • getNextBlockOffset

      public int getNextBlockOffset()
      Determine the offset of the next Block in the Buffer.
      Returns:
      the offset of the next Block in the Buffer, or NIL if this Block is the last in the Buffer

    • setNextBlockOffset

      public void setNextBlockOffset(int ofBlock)
      Specify the offset of the next Block in the Buffer.
      Parameters:
      ofBlock - the offset of the next contiguous Block

    • getPrevBlockOffset

      public int getPrevBlockOffset()
      Determine the offset of the previous Block in the Buffer.
      Returns:
      the offset of the previous Block in the Buffer, or NIL if this Block is the first in the Buffer

    • setPrevBlockOffset

      public void setPrevBlockOffset(int ofBlock)
      Specify the offset of the previous Block in the Buffer.
      Parameters:
      ofBlock - the offset of the previous contiguous Block

    • getNextNodeOffset

      public int getNextNodeOffset()
      Determine the offset of the next Block in the linked list.
      Returns:
      the offset of the next Block in the linked list, or NIL if this Block is the last in the linked list

    • setNextNodeOffset

      public void setNextNodeOffset(int ofBlock)
      Specify the offset of the next Block in the linked list.
      Parameters:
      ofBlock - the offset of the next Block in the linked list of Blocks

    • getPrevNodeOffset

      public int getPrevNodeOffset()
      Determine the offset of the previous Block in the linked list.
      Returns:
      the offset of the previous Block in the linked list, or NIL if this Block is the first in the linked list of Blocks

    • setPrevNodeOffset

      public void setPrevNodeOffset(int ofBlock)
      Specify the offset of the previous Block in the linked list.
      Parameters:
      ofBlock - the offset of the previous Block in the linked list of blocks

    • getKeyHash

      public int getKeyHash()
      Get the hash code for the Entry block.
      Returns:
      the hash code for the Entry block

    • getKeyLength

      public int getKeyLength()
      Get the length of the Entry key in the block.
      Returns:
      the length, in bytes, of the key

    • getKey

      public Binary getKey()
      Get the Entry key in the block, lazy loading it if necessary.
      Returns:
      the Entry key

    • setKey

      public void setKey(Binary bin)
      Update the Entry key in the block. The write is deferred.
      Parameters:
      bin - the Entry key

    • getValueLength

      public int getValueLength()
      Get the length of the Entry value in the block.
      Returns:
      the length, in bytes, of the value

    • getValue

      public Binary getValue()
      Get the Entry value in the block, lazy loading it if necessary.
      Returns:
      the Entry value

    • setValue

      public void setValue(Binary bin)
      Update the Entry value in the block. The write is deferred.
      Parameters:
      bin - the Entry value

    • getFillLength

      public int getFillLength()
      Get the size of the fill in the block.
      Returns:
      the length, in bytes, of the fill

    • readHeader

      public void readHeader()
      Read a block's header data from the Buffer. Also reads key hash, key length and value length.

    • writeHeader

      public void writeHeader()
      Write the block's data to the Buffer.

    • readKey

      public void readKey()
      Read the "key" portion of an Entry block.

    • writeKey

      public void writeKey()
      Write the "key" portion of an Entry block, including the key hash.

    • readValue

      public void readValue()
      Read the "value" portion of an Entry block. Note that if the length of the key is modified, the value must be read first or it will be unreadable.

    • writeValue

      public void writeValue()
      Write the "value" portion of an Entry block.

    • link

      public void link()
      Link this block (either an Entry or free block) into the appropriate data structures (either the hash bucket or the free list.)

    • unlink

      public void unlink()
      Unlink this block (either an Entry or free block) from the appropriate data structures (either the hash bucket or the free list.)

    • split

      public void split(int cbRetain)
      If possible, chop a free block into two free blocks, or chop the end of an Entry block to make a free block.
      Parameters:
      cbRetain - the number of bytes to allocate to the first of the two free blocks

    • merge

      public void merge()
      Merge a free block with any free blocks that it borders.

    • allocate

      public void allocate(int cb)
      Allocate this free block (or at least a specified number of bytes of this block) as an Entry block. Note that the block is an Entry in an unlinked state at the termination of this method.
      Parameters:
      cb - the minimum number of bytes required for the Entry block

    • free

      public void free()
      Free this Entry block. Note that this has the effect of closing the block.