com.sleepycat.bdb.bind.tuple
Class TupleTupleKeyExtractor

java.lang.Object
  |
  +--com.sleepycat.bdb.bind.tuple.TupleTupleKeyExtractor

All Implemented Interfaces:

KeyExtractor

Direct Known Subclasses:

TupleTupleMarshalledKeyExtractor

public abstract class TupleTupleKeyExtractor

extends Object

implements KeyExtractor

An abstract key extractor that uses a tuple key and a tuple value. This class takes care of converting the key and value data to/from TupleInput and TupleOutput objects. Its two abstract methods must be implemented by a concrete subclass to extract and clear the index key using these objects.

• extractIndexKey(TupleInput,TupleInput,TupleOutput)
• clearIndexKey(TupleInput,TupleOutput)

Constructor Summary

TupleTupleKeyExtractor(TupleFormat primaryKeyFormat, TupleFormat valueFormat, TupleFormat indexKeyFormat)
Creates a tuple-tuple key extractor.

Method Summary

void	clearIndexKey(DataBuffer valueData) Clears the index key in a value buffer.
abstract void	clearIndexKey(TupleInput valueInput, TupleOutput valueOutput) Clears the index key in the tuple value data.
void	extractIndexKey(DataBuffer primaryKeyData, DataBuffer valueData, DataBuffer indexKeyData) Extracts the index key data from primary key and value buffers.
abstract void	extractIndexKey(TupleInput primaryKeyInput, TupleInput valueInput, TupleOutput indexKeyOutput) Extracts the index key data from primary key tuple and value tuple data.
DataFormat	getIndexKeyFormat() Returns the format of the index key data.
DataFormat	getPrimaryKeyFormat() Returns the format of the primary key data or null if the index key data is not derived from the primary key data.
DataFormat	getValueFormat() Returns the format of the value data or null if the index key data is not derived from the value data.

Methods inherited from class java.lang.Object

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

Constructor Detail

TupleTupleKeyExtractor

public TupleTupleKeyExtractor(TupleFormat primaryKeyFormat,
                              TupleFormat valueFormat,
                              TupleFormat indexKeyFormat)

Creates a tuple-tuple key extractor.

Parameters:

primaryKeyFormat - is the primary key format, or null if no primary key data is used to construct the index key.

valueFormat - is the value format, or null if no value data is used to construct the index key.

indexKeyFormat - is the index key format.

Method Detail

getPrimaryKeyFormat

public DataFormat getPrimaryKeyFormat()

Description copied from interface: KeyExtractor

Returns the format of the primary key data or null if the index key data is not derived from the primary key data. If this method returns null, then null will be passed for the primaryKeyData parameter of KeyExtractor.extractIndexKey(com.sleepycat.bdb.bind.DataBuffer, com.sleepycat.bdb.bind.DataBuffer, com.sleepycat.bdb.bind.DataBuffer).

Specified by:

getPrimaryKeyFormat in interface KeyExtractor

Returns:

the format of the primary key data or null.

getValueFormat

public DataFormat getValueFormat()

Description copied from interface: KeyExtractor

Returns the format of the value data or null if the index key data is not derived from the value data. If this method returns null, then null will be passed for the valueData parameter of KeyExtractor.extractIndexKey(com.sleepycat.bdb.bind.DataBuffer, com.sleepycat.bdb.bind.DataBuffer, com.sleepycat.bdb.bind.DataBuffer).

Specified by:

getValueFormat in interface KeyExtractor

Returns:

the format of the value data or null.

getIndexKeyFormat

public DataFormat getIndexKeyFormat()

Description copied from interface: KeyExtractor

Returns the format of the index key data.

Specified by:

getIndexKeyFormat in interface KeyExtractor

Returns:

the format of the index key data.

extractIndexKey

public void extractIndexKey(DataBuffer primaryKeyData,
                            DataBuffer valueData,
                            DataBuffer indexKeyData)
                     throws IOException

Description copied from interface: KeyExtractor

Extracts the index key data from primary key and value buffers. The index key is extracted when saving the data record identified by the primary key and value buffers, in order to add or remove an index entry in the database for that data record.

Specified by:

extractIndexKey in interface KeyExtractor

Parameters:

primaryKeyData - is the source primary key data, or null if no primary key data is used to construct the index key, in which case KeyExtractor.getPrimaryKeyFormat() should also return null.

valueData - is the source value data, or null if no value data is used to construct the index key, in which case KeyExtractor.getValueFormat() should also return null.

indexKeyData - is the destination index key buffer. For index keys which are optionally present, the buffer's length should be set to zero to indicate that the key is not present or null.

IOException

clearIndexKey

public void clearIndexKey(DataBuffer valueData)
                   throws IOException

Description copied from interface: KeyExtractor

Clears the index key in a value buffer. The index key is cleared when the index is for a foreign key identifying a record that has been deleted. This method is called only if the ForeignKeyIndex is configured with ForeignKeyIndex.ON_DELETE_CLEAR. It is never called for index keys that are derived from primary key data, since in this case ForeignKeyIndex.ON_DELETE_CLEAR is not allowed.

Specified by:

clearIndexKey in interface KeyExtractor

Parameters:

valueData - is the source and destination value data. On entry this contains the index key to be cleared. It should be changed by this method such that KeyExtractor.extractIndexKey(com.sleepycat.bdb.bind.DataBuffer, com.sleepycat.bdb.bind.DataBuffer, com.sleepycat.bdb.bind.DataBuffer) will extract a null key (set the buffer length to zero). Other data in the buffer should remain unchanged.

IOException

extractIndexKey

public abstract void extractIndexKey(TupleInput primaryKeyInput,
                                     TupleInput valueInput,
                                     TupleOutput indexKeyOutput)
                              throws IOException

Extracts the index key data from primary key tuple and value tuple data.

Parameters:

primaryKeyInput - is the TupleInput for the primary key data, or null if no primary key data is used to construct the index key.

valueInput - is the TupleInput for the value data, or null if no value data is used to construct the index key.

indexKeyOutput - is the destination index key tuple. For index keys which are optionally present, no tuple data should be output to indicate that the key is not present or null.

IOException

clearIndexKey

public abstract void clearIndexKey(TupleInput valueInput,
                                   TupleOutput valueOutput)
                            throws IOException

Clears the index key in the tuple value data. The valueInput should be read and then written to the valueOutput, clearing the index key in the

Parameters:

valueInput - is the TupleInput for the value data.

valueOutput - is the destination TupleOutput.

IOException