Subspace (FoundationDB Java Client API)

java.lang.Object
- com.foundationdb.subspace.Subspace

Direct Known Subclasses:

DirectorySubspace
```
public class Subspace
extends Object
```
Subspace provide a convenient way to use Tuples to define namespaces for different categories of data. The namespace is specified by a prefix Tuple which is prepended to all Tuples packed by the Subspace. When unpacking a key with the Subspace, the prefix Tuple will be removed from the result.
For general guidance on subspace usage, see the discussion in Developer Guide.

As a best practice, API clients should use at least one subspace for application data.

Constructor Summary

Constructors
Constructor and Description
`Subspace()` Constructor for a subspace formed with an empty prefix `Tuple`.
`Subspace(byte[] rawPrefix)` Constructor for a subspace formed with the specified byte string, which will be prepended to all packed keys.
`Subspace(Tuple prefix)` Constructor for a subspace formed with the specified prefix `Tuple`.
`Subspace(Tuple prefix, byte[] rawPrefix)` Constructor for a subspace formed with both a prefix `Tuple` and a prefix byte string.

Method Summary

Methods
Modifier and Type	Method and Description
`boolean`	`contains(byte[] key)` Tests whether the specified key starts with this `Subspace`'s prefix, indicating that the `Subspace` logically contains key.
`boolean`	`equals(Object rhs)` Returns true if this `Subspace` is equal to `rhs`.
`Subspace`	`get(Object obj)` Gets a new subspace which is equivalent to this subspace with its prefix `Tuple` extended by the specified `Object`.
`Subspace`	`get(Tuple tuple)` Gets a new subspace which is equivalent to this subspace with its prefix `Tuple` extended by the specified `Tuple`.
`byte[]`	`getKey()` Gets the key encoding the prefix used for this `Subspace`.
`byte[]`	`pack()` Gets the key encoding the prefix used for this `Subspace`.
`byte[]`	`pack(Object obj)` Gets the key encoding the specified `Object` in this `Subspace`.
`byte[]`	`pack(Tuple tuple)` Gets the key encoding the specified tuple in this `Subspace`.
`Range`	`range()` Gets a `Range` respresenting all keys strictly in the `Subspace`.
`Range`	`range(Tuple tuple)` Gets a `Range` representing all keys in the `Subspace` strictly starting with the specified `Tuple`.
`Subspace`	`subspace(Tuple tuple)` Gets a new subspace which is equivalent to this subspace with its prefix `Tuple` extended by the specified `Tuple`.
`String`	`toString()`
`Tuple`	`unpack(byte[] key)` Gets the `Tuple` encoded by the given key, with this `Subspace`'s prefix `Tuple` and `raw prefix` removed.

Methods inherited from class java.lang.Object
getClass, hashCode, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - Subspace
```
public Subspace()
```
    Constructor for a subspace formed with an empty prefix Tuple.
  - Subspace
```
public Subspace(Tuple prefix)
```
    Constructor for a subspace formed with the specified prefix Tuple.
    
    Parameters:
    prefix - a Tuple used to form the subspace
  - Subspace
```
public Subspace(byte[] rawPrefix)
```
    Constructor for a subspace formed with the specified byte string, which will be prepended to all packed keys.
    
    Parameters:
    rawPrefix - a byte array used as the prefix for all packed keys
  - Subspace
```
public Subspace(Tuple prefix,
        byte[] rawPrefix)
```
    Constructor for a subspace formed with both a prefix Tuple and a prefix byte string. The prefix Tuple will be prepended to all Tuples packed by the Subspace, and the byte string prefix will be prepended to the packed result.
    
    Parameters:
    prefix - a Tuple used to form the subspace
    rawPrefix - a byte array used as the prefix for all packed keys
- Method Detail
  - equals
```
public boolean equals(Object rhs)
```
    Returns true if this Subspace is equal to rhs. Two Subspaces are equal if they have the same prefix.
    
    Overrides:
    
    equals in class Object
    
    Parameters:
    rhs - the object to check for equality
    
    Returns:
    true if this Subspace and rhs have equal prefixes
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object
    
    Returns:
    a printable representation of the subspace
  - get
```
public Subspace get(Object obj)
```
    Gets a new subspace which is equivalent to this subspace with its prefix Tuple extended by the specified Object. The object will be inserted into a Tuple and passed to get(Tuple).
    
    Parameters:
    obj - an Object compatible with Tuples
    
    Returns:
    a new subspace formed by joining this Subspace's prefix to obj
  - get
```
public Subspace get(Tuple tuple)
```
    Gets a new subspace which is equivalent to this subspace with its prefix Tuple extended by the specified Tuple.
    
    Parameters:
    tuple - the Tuple used to form the new Subspace
    
    Returns:
    a new subspace formed by joining this Subspace's prefix to tuple
  - getKey
```
public byte[] getKey()
```
    Gets the key encoding the prefix used for this Subspace. This is equivalent to pack()ing the empty Tuple.
    
    Returns:
    the key encoding the prefix used for this Subspace
  - pack
```
public byte[] pack()
```
    Gets the key encoding the prefix used for this Subspace.
    
    Returns:
    the key encoding the prefix used for this Subspace
  - pack
```
public byte[] pack(Object obj)
```
    Gets the key encoding the specified Object in this Subspace. obj is inserted into a Tuple and packed with pack(Tuple).
    
    Parameters:
    obj - an Object to be packed that is compatible with Tuples
    
    Returns:
    the key encoding the tuple derived from obj
  - pack
```
public byte[] pack(Tuple tuple)
```
    Gets the key encoding the specified tuple in this Subspace. For example, if you have a Subspace with prefix Tuple ("users") and you use it to pack the Tuple ("Smith"), the result is the same as if you packed the Tuple ("users", "Smith").
    
    Parameters:
    tuple - the Tuple to be packed
    
    Returns:
    the key encoding the specified tuple in this Subspace
  - unpack
```
public Tuple unpack(byte[] key)
```
    Gets the Tuple encoded by the given key, with this Subspace's prefix Tuple and raw prefix removed.
    
    Parameters:
    key - The key being decoded
    
    Returns:
    the Tuple encoded by key with the prefix removed
  - range
```
public Range range()
```
    Gets a Range respresenting all keys strictly in the Subspace.
    
    Returns:
    the Range of keyspace corresponding to this Subspace
  - range
```
public Range range(Tuple tuple)
```
    Gets a Range representing all keys in the Subspace strictly starting with the specified Tuple.
    
    Parameters:
    tuple - the Tuple whose sub-keys we are searching for
    
    Returns:
    the Range of keyspace corresponding to tuple
  - contains
```
public boolean contains(byte[] key)
```
    Tests whether the specified key starts with this Subspace's prefix, indicating that the Subspace logically contains key.
    
    Parameters:
    key - the key to be tested
    
    Returns:
    true if key starts with Subspace.key()
  - subspace
```
public Subspace subspace(Tuple tuple)
```
    Gets a new subspace which is equivalent to this subspace with its prefix Tuple extended by the specified Tuple.
    
    Parameters:
    tuple - the Tuple used to form the new Subspace
    
    Returns:
    a new subspace formed by joining this Subspace's prefix to tuple

Class Subspace

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

Subspace

Subspace

Subspace

Subspace

Method Detail

equals

toString

get

get

getKey

pack

pack

pack

unpack

range

range

contains

subspace