Overview  Package   Class  Use  Deprecated  Index
Home >> All >> org >> apache >> derby >> iapi >> store >> [ access overview ]	PREV CLASS  NEXT CLASS
SUMMARY:  JAVADOC |  SOURCE |  DOWNLOAD | NESTED | FIELD | CONSTR | METHOD	DETAIL: FIELD | CONSTR | METHOD

---

org.apache.derby.iapi.store.access
Class DiskHashtable  

java.lang.Object
  org.apache.derby.iapi.store.access.DiskHashtable

---

public class DiskHashtable

extends java.lang.Object

This class is used by BackingStoreHashtable when the BackingStoreHashtable must spill to disk. It implements the methods of a hash table: put, get, remove, elements, however it is not implemented as a hash table. In order to minimize the amount of unique code it is implemented using a Btree and a heap conglomerate. The Btree indexes the hash code of the row key. The actual key may be too long for our Btree implementation. Created: Fri Jan 28 13:58:03 2005

Version:

1.0

---

Nested Class Summary
private  class	DiskHashtable.ElementEnum

 

Field Summary
private  ConglomerateController	btreeConglomerate
private  long	btreeConglomerateId
private  org.apache.derby.iapi.types.DataValueDescriptor[]	btreeRow
private  boolean	keepStatistics
private  int[]	key_column_numbers
private  boolean	remove_duplicates
private  org.apache.derby.iapi.types.DataValueDescriptor[]	row
private  ConglomerateController	rowConglomerate
private  long	rowConglomerateId
private  org.apache.derby.iapi.types.DataValueDescriptor[]	scanKey
private  int	size
private  TransactionController	tc

 

Constructor Summary

DiskHashtable(TransactionController tc, org.apache.derby.iapi.types.DataValueDescriptor[] template, int[] key_column_numbers, boolean remove_duplicates, boolean keepAfterCommit)           Creates a new DiskHashtable instance.

 

Method Summary
void	close()
java.util.Enumeration	elements()           Return an Enumeration that can be used to scan entire table.
java.lang.Object	get(java.lang.Object key)           Get a row from the overflow structure.
private  java.lang.Object	getRemove(java.lang.Object key, boolean remove, boolean existenceOnly)
boolean	put(java.lang.Object key, java.lang.Object[] row)           Put a new row in the overflow structure.
java.lang.Object	remove(java.lang.Object key)           remove all rows with a given key from the hash table.
private  boolean	rowMatches(org.apache.derby.iapi.types.DataValueDescriptor[] row, java.lang.Object key)
int	size()

 

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

 

Field Detail

rowConglomerateId

private final long rowConglomerateId

---

rowConglomerate

private ConglomerateController rowConglomerate

---

btreeConglomerateId

private final long btreeConglomerateId

---

btreeConglomerate

private ConglomerateController btreeConglomerate

---

btreeRow

private final org.apache.derby.iapi.types.DataValueDescriptor[] btreeRow

---

key_column_numbers

private final int[] key_column_numbers

---

remove_duplicates

private final boolean remove_duplicates

---

tc

private final TransactionController tc

---

row

private final org.apache.derby.iapi.types.DataValueDescriptor[] row

---

scanKey

private final org.apache.derby.iapi.types.DataValueDescriptor[] scanKey

---

size

private int size

---

keepStatistics

private boolean keepStatistics

Constructor Detail

DiskHashtable

public DiskHashtable(TransactionController tc,
                     org.apache.derby.iapi.types.DataValueDescriptor[] template,
                     int[] key_column_numbers,
                     boolean remove_duplicates,
                     boolean keepAfterCommit)
              throws org.apache.derby.iapi.error.StandardException

Creates a new DiskHashtable instance.

Method Detail

close

public void close()
           throws org.apache.derby.iapi.error.StandardException

---

put

public boolean put(java.lang.Object key,
                   java.lang.Object[] row)
            throws org.apache.derby.iapi.error.StandardException

Put a new row in the overflow structure.

---

get

public java.lang.Object get(java.lang.Object key)
                     throws org.apache.derby.iapi.error.StandardException

Get a row from the overflow structure.

---

getRemove

private java.lang.Object getRemove(java.lang.Object key,
                                   boolean remove,
                                   boolean existenceOnly)
                            throws org.apache.derby.iapi.error.StandardException

---

rowMatches

private boolean rowMatches(org.apache.derby.iapi.types.DataValueDescriptor[] row,
                           java.lang.Object key)

---

remove

public java.lang.Object remove(java.lang.Object key)
                        throws org.apache.derby.iapi.error.StandardException

remove all rows with a given key from the hash table.

---

size

public int size()

---

elements

public java.util.Enumeration elements()
                               throws org.apache.derby.iapi.error.StandardException

Return an Enumeration that can be used to scan entire table.

RESOLVE - is it worth it to support this routine?

---

Overview  Package   Class  Use  Deprecated  Index
Home >> All >> org >> apache >> derby >> iapi >> store >> [ access overview ]	PREV CLASS  NEXT CLASS
SUMMARY:  JAVADOC |  SOURCE |  DOWNLOAD | NESTED | FIELD | CONSTR | METHOD	DETAIL: FIELD | CONSTR | METHOD

---