com.sleepycat.bind.tuple

## Class TupleBase<E>

- java.lang.Object
- - com.sleepycat.bind.tuple.TupleBase<E>

Direct Known Subclasses:
  TupleBinding, TupleSerialBinding, TupleSerialKeyCreator, TupleTupleBinding, TupleTupleKeyCreator

    public class TupleBase<E>
    extends java.lang.Object

A base class for tuple bindings and tuple key creators that provides control over the allocation of the output buffer.

Tuple bindings and key creators append data to a `TupleOutput` instance, which is also a `FastOutputStream` instance. This object has a byte array buffer that is resized when it is full. The reallocation of this buffer can be a performance factor for some applications using large objects. To manage this issue, the `setTupleBufferSize(int)` method may be used to control the initial size of the buffer, and the `getTupleOutput(E)` method may be overridden by subclasses to take over creation of the TupleOutput object.

### Constructor Summary

Constructors
Constructor and Description
`TupleBase()` Initializes the initial output buffer size to zero.

### Method Summary

All Methods Static Methods Instance Methods Concrete Methods Deprecated Methods
`static TupleInput` `entryToInput(DatabaseEntry entry)` Utility method to create a new tuple input object for reading the data from a given buffer.
`int` `getTupleBufferSize()` Returns the initial byte size of the output buffer.
`protected TupleOutput` `getTupleOutput(E object)` Returns an empty TupleOutput instance that will be used by the tuple binding or key creator.
`static void` `inputToEntry(TupleInput input, DatabaseEntry entry)` Utility method to set the data in a entry buffer to the data in a tuple input object.
`static TupleOutput` `newOutput()` Deprecated. replaced by `getTupleOutput(E)`
`static TupleOutput` `newOutput(byte[] buffer)` Deprecated. replaced by `getTupleOutput(E)`
`static void` `outputToEntry(TupleOutput output, DatabaseEntry entry)` Utility method to set the data in a entry buffer to the data in a tuple output object.
`void` `setTupleBufferSize(int byteSize)` Sets the initial byte size of the output buffer that is allocated by the default implementation of `getTupleOutput(E)`.

### Methods inherited from class java.lang.Object

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

### Constructor Detail

#### TupleBase

    public TupleBase()

Initializes the initial output buffer size to zero.

Unless `setTupleBufferSize(int)` is called, the default `FastOutputStream.DEFAULT_INIT_SIZE` size will be used.

### Method Detail

#### setTupleBufferSize

    public void setTupleBufferSize(int byteSize)

Sets the initial byte size of the output buffer that is allocated by the default implementation of `getTupleOutput(E)`.

If this property is zero (the default), the default `FastOutputStream.DEFAULT_INIT_SIZE` size is used.

Parameters:
  `byteSize` - the initial byte size of the output buffer, or zero to use the default size.

#### getTupleBufferSize

    public int getTupleBufferSize()

Returns the initial byte size of the output buffer.

Returns:
  the initial byte size of the output buffer.
See Also:
  `setTupleBufferSize(int)`

#### getTupleOutput

    protected TupleOutput getTupleOutput(E object)

Returns an empty TupleOutput instance that will be used by the tuple binding or key creator.

The default implementation of this method creates a new TupleOutput with an initial buffer size that can be changed using the `setTupleBufferSize(int)` method.

This method may be overridden to return a TupleOutput instance. For example, an instance per thread could be created and returned by this method. If a TupleOutput instance is reused, be sure to call its `FastOutputStream.reset()` method before each use.

Parameters:
  `object` - is the object to be written to the tuple output, and may be used by subclasses to determine the size of the output buffer.
Returns:
  an empty TupleOutput instance.
See Also:
  `setTupleBufferSize(int)`

#### outputToEntry

    public static void outputToEntry(TupleOutput output,
                                     DatabaseEntry entry)

Utility method to set the data in a entry buffer to the data in a tuple output object.

Parameters:
  `output` - is the source tuple output object.
  `entry` - is the destination entry buffer.

#### inputToEntry

    public static void inputToEntry(TupleInput input,
                                    DatabaseEntry entry)

Utility method to set the data in a entry buffer to the data in a tuple input object.

Parameters:
  `input` - is the source tuple input object.
  `entry` - is the destination entry buffer.

#### entryToInput

    public static TupleInput entryToInput(DatabaseEntry entry)

Utility method to create a new tuple input object for reading the data from a given buffer. If an existing input is reused, it is reset before returning it.

Parameters:
  `entry` - is the source entry buffer.
Returns:
  the new tuple input object.

#### newOutput

    public static TupleOutput newOutput()

Deprecated. replaced by `getTupleOutput(E)`
Utility method for use by bindings to create a tuple output object.

Returns:
  a new tuple output object.

#### newOutput

    public static TupleOutput newOutput(byte[] buffer)

Deprecated. replaced by `getTupleOutput(E)`
Utility method for use by bindings to create a tuple output object with a specific starting size.

Parameters:
  `buffer` - is the byte array to use as the buffer.
Returns:
  a new tuple output object.