votorola.a.diff

Class DiffKey

java.lang.Object

DiffKey

@ThreadSafe
public final class DiffKey
extends Object

The identifier of a difference between two draft revisions (a and b). A difference key is unique within the context of a single vote-server. It is expressed as a string in the following form:

     a0 [. a1 [. a2]] - b0 [. b1 [. b2]] [! series]
    |----------------| |----------------|
     revision path (a)  revision path (b)

For example:

     9712-8303.441

     9059.9863.524-9360.9851.486!1

Each of the two draft revisions (left and right) is identified by a sequence of one to 3 page revisions that is known as a draft revision path. A series identifier is appended if the pollwiki revision series is non-zero.

Normal order between draft revisions (R/C/U)

Which of the two draft revisions is expressed as 'a' and which as 'b' is determined by the first applicable rule from the rule lists below. The following rule list applies only if both revisions have the same author. In that case they are ordered numerically by revision number. Traversing the two revision paths beginning at index zero yields a sequence of numeric pairs, one of which eventually differs:

• (R1) Where the difference is that one number of the pair is smaller, that one is 'b'.
• (R2) Otherwise the difference is that one number of the pair is missing because its revision path is shorter. That one is 'b'.

The next rule list applies only if both revisions are position drafts in the same poll. In that case they are ordered by exclusive cast relation:

• (C1) Where the exclusive cast relation of the authors is base co-candidate and exactly one is the direct recipient of the other's vote (non-tight cycle), then that recipient's revision is 'b'.
• (C2) Where the exclusive cast relation of one author for the other is voter, that author's revision is 'a'.
• (C3) Where the exclusive cast relation of the authors is base co-candidate (non-cyclic or tight cyclic) or co-voter and the dart sector of one is less than the other, that author's revision is 'a'.

Otherwise the order is lexical by username:

• (U1) Where the username of one author is prior to the other in a caseless comparison, that author's revision is 'a'.
• (U2) Otherwise the username of one author must be prior to the other in a cased comparison. That author's revision is 'a'.

Method Summary

Methods

Modifier and Type	Method and Description
static boolean	isDartOrdered(CountNode aNode, String aName, CountNode bNode, String bName) Answers whether aNode is dart-wise or lexically prior to bNode for purposes of normal ordering.
static boolean	isLexicallyOrdered(String aName, String bName) Answers whether aName is lexically prior to bName for purposes of normal ordering.
static String	newReverseKey(String diffKey) Constructs the reverse of the specified diff key in which the a-draft revision path and b-draft revision path are interchanged.

Methods inherited from class java.lang.Object

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

Method Detail

isDartOrdered

public static boolean isDartOrdered(CountNode aNode,
                    String aName,
                    CountNode bNode,
                    String bName)

Answers whether aNode is dart-wise or lexically prior to bNode for purposes of normal ordering.

Throws:

IllegalArgumentException - if aName and bName are equal.

isLexicallyOrdered

public static boolean isLexicallyOrdered(String aName,
                         String bName)

Answers whether aName is lexically prior to bName for purposes of normal ordering.

Throws:

IllegalArgumentException - if aName and bName are equal.

newReverseKey

public static String newReverseKey(String diffKey)

Constructs the reverse of the specified diff key in which the a-draft revision path and b-draft revision path are interchanged.