Class COM.odi.util.OSTreeMapByteArray

java.lang.Object
   |
   +----COM.odi.util.OSTreeMap
           |
           +----COM.odi.util.OSTreeMapByteArray

public class OSTreeMapByteArray

extends OSTreeMap

This class is included in PSE Pro, but not in PSE.

Additional information about OSTreeMapByteArray is in the user guide.

Here are exceptions that might be thrown by many of the methods in this class:

DatabaseNotOpenException If the database containing the object is not open.

NoTransactionInProgressException If there is no transaction in progress.

ObjectNotFoundException If the object was not found, either because the object itself, its segment, or its database was destroyed.

ObjectException Ifthe object was local and was fetched in a previous transaction.

ObjectStoreException If the session implied by an argument to the call or the object the method is called on is not the same as the session associated with the current thread.

UpdateReadOnlyException If there is a readonly transaction in progress or if the database is open for readonly.

OSTreeMapByteArray(Placement)

Creates an OSTreeMapByteArray with variable length keys.

OSTreeMapByteArray(Placement, int, boolean, boolean)

Creates an OSTreeMapByteArray.

byteArrayToKey(byte[])

Decodes a byte array encoding of a key, and returns the corresponding key.

containsKey(byte[])

Returns true if this Map contains a mapping for the specified key.

get(byte[])

Returns the value to which this Map maps the specified key.

keyToByteArray(Object, byte[])

Encodes a key into a byte array.

put(byte[], Object)

Associates the specified value with the specified key in this Map (optional operation).

remove(byte[])

Removes the mapping for this key from this Map if present (optional operation).

  public OSTreeMapByteArray(Placement placement)

Creates an OSTreeMapByteArray with variable length keys. Note that the database containing the placement needs to be open for update and an update transaction needs to be in progress.

Parameters:

placement - The database or segment in which to create the OSTreeMap.

Returns:

The new OSTreeMap.

Throws: NoTransactionInProgressException

If no transaction is in progress.

Throws: ObjectStoreException

If the current thread is not associated with a session and there is no global session.

Throws: UpdateReadOnlyException

If there is a read-only transaction in progress or if the database is open read-only.

  public OSTreeMapByteArray(Placement placement,
                            int keySize,
                            boolean fixedSizeKeys,
                            boolean export)

Creates an OSTreeMapByteArray. Note that the database containing the placement needs to be open for update and an update transaction needs to be in progress.

Parameters:

placement - The database or segment in which to create the OSTreeMap.

keySize - The size of the key -- must be a number greater than 0. If variable size keys are permitted, this is the size key which can be stored without using overflow storage. Note that three combinations of key size and key variability are handled specially to provide better efficiency: 4 and 8 byte fixed sized keys, and 28 byte variable sized keys.

fixedSizeKeys - True specifies that keys will not be longer than the specified key size, and that overflow storage is therefore unnecessary. False indicates that keys may be larger than the specified key size, in which case the remainder of the key is stored in overflow storage.

export - If true, create an exported object.

Returns:

The new OSTreeMap.

Throws: NoTransactionInProgressException

If no transaction is in progress.

Throws: ObjectStoreException

If the current thread is not associated with a session and there is no global session.

Throws: UpdateReadOnlyException

If there is a read-only transaction in progress or if the database is open read-only.

  public boolean containsKey(byte key[])

Returns true if this Map contains a mapping for the specified key.

Parameters:

key - key whose presence in this Map is to be tested.

  public Object get(byte key[])

Returns the value to which this Map maps the specified key. Returns null if the Map contains no mapping for this key. A return value of null does not necessarily indicate that the Map contains no mapping for the key; it's also possible that the Map explicitly maps the key to null. The containsKey operation may be used to distinguish these two cases.

Parameters:

key - key whose associated value is to be returned.

  public Object put(byte key[],
                    Object value)

Associates the specified value with the specified key in this Map (optional operation). If the Map previously contained a mapping for this key, the old value is replaced.

Parameters:

key - key with which the specified value is to be associated.

value - value to be associated with the specified key.

Returns:

previous value associated with specified key, or null if there was no mapping for key. (A null return can also indicate that the Map previously associated null with the specified key, if the implementation supports null values.)

  public Object remove(byte key[])

Removes the mapping for this key from this Map if present (optional operation).

Parameters:

key - key whose mapping is to be removed from the Map.

Returns:

previous value associated with specified key, or null if there was no mapping for key. (A null return can also indicate that the Map previously associated null with the specified key, if the implementation supports null values.)

  public byte[] keyToByteArray(Object key,
                               byte buffer[])

Encodes a key into a byte array.

Parameters:

key - key to be encoded.

ignored - a byte[] to use as a buffer for the returned encoding -- this is ignored, because the input key is itself a byte[], which is returned directly.

Overrides:

keyToByteArray in class OSTreeMap

  public Object byteArrayToKey(byte key[])

Decodes a byte array encoding of a key, and returns the corresponding key. Since OSTreeMapByteArray keys are already byte arrays, this method simply returns its argument (other subtypes of OSTreeMap must perform a more substantive decoding).

Overrides:

byteArrayToKey in class OSTreeMap