com.coyotegulch.jisp
Interface ObjectIndex

All Known Implementing Classes:
BTreeIndex, HashIndex

public interface ObjectIndex

ObjectIndex defines the concept of an index that associates key values with references to serializable objects. Concrete subclasses of ObjectIndex assume that an object's position (as given by a long value) is constant, regardless of the actual meaning of that position. In general, the position represents the * location (file pointer) of a Serializable object in an IndexedObjectDatabase. *

* Use the IndexedObjectDatabase.attachIndex method to attach an ObjectIndex * to a database. A database updates all attached indexes when it writes or removes objects * from its file.

See Also:
ObjectIndex, IndexedObjectDatabase

Method Summary
 long findKey(KeyObject key)
          Find the position of the object associated with a given key.
 void insertKey(KeyObject key, long pos)
          Insert a key into the database, associating a record position with the given key.
 void removeKey(KeyObject key)
          Removes the given key from the index.
 void replaceKey(KeyObject key, long pos)
          Replace the reference pos for the given key.
 void storeKey(KeyObject key, long pos)
          If the key already exists, replace the reference pos for the given key.
 

Method Detail

insertKey

void insertKey(KeyObject key,
               long pos)
               throws java.io.IOException,
                      java.lang.ClassNotFoundException
Insert a key into the database, associating a record position with the given key. Throws a DuplicateKey exception if the key already exists.

Parameters:
key - A key identifying the record to be read.
pos - File position of record associated with key
Throws:
java.io.IOException - when an I/O exception is thrown by an underlying java.io.* class
java.lang.ClassNotFoundException - for a casting error, usually when a persistent object or index does match the expected type
DuplicateKey - when inserting a duplicate key into an index that does not support duplicates
See Also:
DuplicateKey, KeyObject

replaceKey

void replaceKey(KeyObject key,
                long pos)
                throws java.io.IOException,
                       java.lang.ClassNotFoundException
Replace the reference pos for the given key. Throws a KeyNotFound exception if the requested key does not exist in the index.

Parameters:
key - A key identifying the record to be read.
pos - File position of record associated with key
Throws:
java.io.IOException - when an I/O exception is thrown by an underlying java.io.* class
java.lang.ClassNotFoundException - for a casting error, usually when a persistent object or index does match the expected type
KeyNotFound - when the specified key can not be found in the index
See Also:
KeyNotFound, KeyObject

storeKey

void storeKey(KeyObject key,
              long pos)
              throws java.io.IOException,
                     java.lang.ClassNotFoundException
If the key already exists, replace the reference pos for the given key. Otherwise, insert a key into the database, associating a record position with the given key.

Parameters:
key - A key identifying the record to be read.
pos - File position of record associated with key
Throws:
java.io.IOException - when an I/O exception is thrown by an underlying java.io.* class
java.lang.ClassNotFoundException - for a casting error, usually when a persistent object or index does match the expected type
See Also:
KeyObject

findKey

long findKey(KeyObject key)
             throws java.io.IOException,
                    java.lang.ClassNotFoundException
Find the position of the object associated with a given key.

Parameters:
key - A key identifying the record to be read.
Returns:
The position of the record associated with key.
Throws:
java.io.IOException - when an I/O exception is thrown by an underlying java.io.* class
java.lang.ClassNotFoundException - for a casting error, usually when a persistent object or index does match the expected type
KeyNotFound - when the specified key can not be found in the index
See Also:
KeyNotFound, KeyObject

removeKey

void removeKey(KeyObject key)
               throws java.io.IOException,
                      java.lang.ClassNotFoundException
Removes the given key from the index.

Parameters:
key - A key identifying the record to be read.
Throws:
java.io.IOException - when an I/O exception is thrown by an underlying java.io.* class
java.lang.ClassNotFoundException - for a casting error, usually when a persistent object or index does match the expected type
KeyNotFound - when the specified key can not be found in the index
See Also:
KeyNotFound, KeyObject