com.ericsson.otp.erlang

Class OtpErlangRef

java.lang.Object

com.ericsson.otp.erlang.OtpErlangObject

com.ericsson.otp.erlang.OtpErlangRef

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable

public class OtpErlangRef
extends OtpErlangObject

Provides a Java representation of Erlang refs. There are two styles of Erlang refs, old style (one id value) and new style (array of id values). This class manages both types.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class com.ericsson.otp.erlang.OtpErlangObject

OtpErlangObject.Hash

Field Summary

Fields inherited from class com.ericsson.otp.erlang.OtpErlangObject

hashCodeValue

Constructor Summary

Constructors

Constructor and Description
OtpErlangRef(int tag, java.lang.String node, int[] ids, int creation) Create a new(er) style Erlang ref from its components.
OtpErlangRef(OtpInputStream buf) Create an Erlang ref from a stream containing a ref encoded in Erlang external format.
OtpErlangRef(OtpLocalNode self) Deprecated. use OtpLocalNode:createRef() instead
OtpErlangRef(java.lang.String node, int[] ids, int creation) Create a new style Erlang ref from its components.
OtpErlangRef(java.lang.String node, int id, int creation) Create an old style Erlang ref from its components.

Method Summary

Modifier and Type	Method and Description
java.lang.Object	clone()
int	creation() Get the creation number from the ref.
protected int	doHashCode() Compute the hashCode value for a given ref.
void	encode(OtpOutputStream buf) Convert this ref to the equivalent Erlang external representation.
boolean	equals(java.lang.Object o) Determine if two refs are equal.
int	id() Get the id number from the ref.
int[]	ids() Get the array of id numbers from the ref.
boolean	isNewRef() Determine whether this is a new style ref.
java.lang.String	node() Get the node name from the ref.
protected int	tag()
java.lang.String	toString() Get the string representation of the ref.

Methods inherited from class com.ericsson.otp.erlang.OtpErlangObject

bind, decode, hashCode, match

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

OtpErlangRef

@Deprecated
public OtpErlangRef(OtpLocalNode self)

Deprecated. use OtpLocalNode:createRef() instead

Create a unique Erlang ref belonging to the local node.

Parameters:

self - the local node.

OtpErlangRef

public OtpErlangRef(OtpInputStream buf)
             throws OtpErlangDecodeException

Create an Erlang ref from a stream containing a ref encoded in Erlang external format.

Parameters:

buf - the stream containing the encoded ref.

Throws:

OtpErlangDecodeException - if the buffer does not contain a valid external representation of an Erlang ref.

OtpErlangRef

public OtpErlangRef(java.lang.String node,
                    int id,
                    int creation)

Create an old style Erlang ref from its components.

Parameters:

node - the nodename.

id - an arbitrary number. Only the low order 18 bits will be used.

creation - another arbitrary number.

OtpErlangRef

public OtpErlangRef(java.lang.String node,
                    int[] ids,
                    int creation)

Create a new style Erlang ref from its components.

Parameters:

node - the nodename.

ids - an array of arbitrary numbers. Only the low order 18 bits of the first number will be used. If the array contains only one number, an old style ref will be written instead. At most three numbers will be read from the array.

creation - another arbitrary number. Only the low order 2 bits will be used.

OtpErlangRef

public OtpErlangRef(int tag,
                    java.lang.String node,
                    int[] ids,
                    int creation)

Create a new(er) style Erlang ref from its components.

Parameters:

tag - the external format to be compliant with. OtpExternal.newRefTag where only a subset of the bits are used (see other constructor) OtpExternal.newerRefTag where all bits of ids and creation are used. newerPortTag can only be decoded by OTP-19 and newer.

node - the nodename.

ids - an array of arbitrary numbers. At most three numbers will be read from the array.

creation - another arbitrary number.

Method Detail

tag

protected int tag()

id

public int id()

Get the id number from the ref. Old style refs have only one id number. If this is a new style ref, the first id number is returned.

Returns:

the id number from the ref.

ids

public int[] ids()

Get the array of id numbers from the ref. If this is an old style ref, the array is of length 1. If this is a new style ref, the array has length 3.

Returns:

the array of id numbers from the ref.

isNewRef

public boolean isNewRef()

Determine whether this is a new style ref.

Returns:

true if this ref is a new style ref, false otherwise.

creation

public int creation()

Get the creation number from the ref.

Returns:

the creation number from the ref.

node

public java.lang.String node()

Get the node name from the ref.

Returns:

the node name from the ref.

toString

public java.lang.String toString()

Get the string representation of the ref. Erlang refs are printed as #Ref<node.id>

Specified by:

toString in class OtpErlangObject

Returns:

the string representation of the ref.

encode

public void encode(OtpOutputStream buf)

Convert this ref to the equivalent Erlang external representation.

Specified by:

encode in class OtpErlangObject

Parameters:

buf - an output stream to which the encoded ref should be written.

equals

public boolean equals(java.lang.Object o)

Determine if two refs are equal. Refs are equal if their components are equal. New refs and old refs are considered equal if the node, creation and first id numnber are equal.

Specified by:

equals in class OtpErlangObject

Parameters:

o - the other ref to compare to.

Returns:

true if the refs are equal, false otherwise.

doHashCode

protected int doHashCode()

Compute the hashCode value for a given ref. This function is compatible with equal.

Overrides:

doHashCode in class OtpErlangObject

Returns:

the hashCode of the node.

clone

public java.lang.Object clone()

Overrides:

clone in class OtpErlangObject