org.jgroups.util

Class Digest

java.lang.Object

org.jgroups.util.Digest

All Implemented Interfaces:

java.lang.Iterable<Digest.Entry>, Streamable

Direct Known Subclasses:

MutableDigest

public class Digest
extends java.lang.Object
implements Streamable, java.lang.Iterable<Digest.Entry>

A message digest containing - for each member - the highest seqno delivered (hd) and the highest seqno received (hr). The seqnos are stored according to the order of the members in the associated membership, ie. seqnos[0] is the hd for member members[0], seqnos[1] is the hr for the same member, seqnos[2] is the hd for members[1] and so on.

Field 'members' may refer to the View.members, e.g. in a JoinRsp where we ship a view and a digest referring to the view's membership. This is done to conserve memory.

This class is immutable except for 2 cases:

• The contents are read when unmarshalling (readFrom())
• The membership is set with members(). This must only be done directly after unmarshalling

Author:

Bela Ban

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Digest.Entry Keeps track of one members plus its highest delivered and received seqnos
protected class	Digest.MyIterator

Field Summary

Fields

Modifier and Type	Field and Description
protected Address[]	members
protected long[]	seqnos

Constructor Summary

Constructors

Constructor and Description
Digest() Used for serialization
Digest(Address[] members) Only used internally, don't use !
Digest(Address[] members, long[] seqnos)
Digest(Address sender, long highest_delivered, long highest_received)
Digest(Digest digest) Only used for testing
Digest(java.util.Map<Address,long[]> map) Creates a new digest from an existing map by copying the keys and values from map

Method Summary

Modifier and Type	Method and Description
int	capacity()
protected void	checkPostcondition()
boolean	contains(Address mbr)
boolean	containsAll(Address... members)
Digest	copy()
protected void	createArrays(java.util.Map<Address,long[]> map)
boolean	equals(java.lang.Object obj) 2 digests are equal if their memberships match and all highest-delivered and highest-received seqnos match
protected int	find(Address mbr)
long[]	get(Address member) Returns the highest delivered and received seqnos associated with a member.
Address[]	getMembersRaw() Don't use, this method is reserved for Bela ! :-)
java.util.Iterator<Digest.Entry>	iterator()
void	readFrom(java.io.DataInput in) Read the state of the current object (including superclasses) from instream Note that the input stream must not be closed
void	readFrom(java.io.DataInput in, boolean read_addrs)
long	serializedSize(boolean with_members)
java.lang.String	toString()
java.lang.String	toString(Address[] order, boolean print_highest_received)
java.lang.String	toString(Digest order)
void	writeTo(java.io.DataOutput out) Write the entire state of the current object (including superclasses) to outstream.
void	writeTo(java.io.DataOutput out, boolean write_addrs)

Methods inherited from class java.lang.Object

clone, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Field Detail

members

protected Address[] members

seqnos

protected long[] seqnos

Constructor Detail

Digest

public Digest()

Used for serialization

Digest

public Digest(Address[] members,
              long[] seqnos)

Digest

public Digest(Address[] members)

Only used internally, don't use !

Digest

public Digest(Digest digest)

Only used for testing

Digest

public Digest(java.util.Map<Address,long[]> map)

Creates a new digest from an existing map by copying the keys and values from map

Digest

public Digest(Address sender,
              long highest_delivered,
              long highest_received)

Method Detail

getMembersRaw

public Address[] getMembersRaw()

Don't use, this method is reserved for Bela ! :-)

capacity

public int capacity()

contains

public boolean contains(Address mbr)

containsAll

public boolean containsAll(Address... members)

equals

public boolean equals(java.lang.Object obj)

2 digests are equal if their memberships match and all highest-delivered and highest-received seqnos match

Overrides:

equals in class java.lang.Object

get

public long[] get(Address member)

Returns the highest delivered and received seqnos associated with a member.

Parameters:

member -

Returns:

An array of 2 elements: highest_delivered and highest_received seqnos

iterator

public java.util.Iterator<Digest.Entry> iterator()

Specified by:

iterator in interface java.lang.Iterable<Digest.Entry>

copy

public Digest copy()

writeTo

public void writeTo(java.io.DataOutput out)
             throws java.lang.Exception

Description copied from interface: Streamable

Write the entire state of the current object (including superclasses) to outstream. Note that the output stream must not be closed

Specified by:

writeTo in interface Streamable

Throws:

java.lang.Exception

writeTo

public void writeTo(java.io.DataOutput out,
                    boolean write_addrs)
             throws java.lang.Exception

Throws:

java.lang.Exception

readFrom

public void readFrom(java.io.DataInput in)
              throws java.lang.Exception

Description copied from interface: Streamable

Read the state of the current object (including superclasses) from instream Note that the input stream must not be closed

Specified by:

readFrom in interface Streamable

Throws:

java.lang.Exception

readFrom

public void readFrom(java.io.DataInput in,
                     boolean read_addrs)
              throws java.lang.Exception

Throws:

java.lang.Exception

serializedSize

public long serializedSize(boolean with_members)

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

toString

public java.lang.String toString(Digest order)

toString

public java.lang.String toString(Address[] order,
                                 boolean print_highest_received)

find

protected int find(Address mbr)

createArrays

protected void createArrays(java.util.Map<Address,long[]> map)

checkPostcondition

protected void checkPostcondition()