"{ Package: 'stx:libscm/mercurial' }"

ByteArray variableByteSubclass:#HGChangesetId

	instanceVariableNames:'revno'

	classVariableNames:'NullId'

	poolDictionaries:''

	category:'SCM-Mercurial-Core'

!

!HGChangesetId class methodsFor:'documentation'!

documentation

"

    Represent a changeset id in Mercurial repository.

    !!!!!! WARNING !!!!!!

    Due to a stupid design here, DO NOT USE put it into hashed collections!!

    I have to change it later...

    [author:]

        Jan Vrany <jan.vrany@fit.cvut.cz>

    [instance variables:]

    [class variables:]

    [see also:]

"

! !

!HGChangesetId class methodsFor:'instance creation'!

fromBytes: aByteArrayOrString

    | sz |

    sz := aByteArrayOrString size.

    (sz ~~ 20 and:[sz ~~ 6]) ifTrue:[

        self error:'Node ID has either 20 or 6 bytes (short form)'.

        ^nil.

    ].

    ^(self new: sz) replaceBytesFrom: 1 to: sz with: aByteArrayOrString startingAt: 1

    "Created: / 25-09-2012 / 21:00:06 / Jan Vrany <jan.vrany@fit.cvut.cz>"

    "Modified: / 13-11-2012 / 16:47:40 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

fromString: aString

    ^self readFrom: aString readStream

    "Created: / 10-09-2012 / 10:49:43 / Jan Vrany <jan.vrany@fit.cvut.cz>"

    "Modified: / 13-11-2012 / 16:49:39 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

new

    ^self new: 20

    "Created: / 10-09-2012 / 10:42:39 / Jan Vrany <jan.vrany@fit.cvut.cz>"

    "Modified: / 19-10-2012 / 15:51:45 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

new: size

    (size ~~ 0 and:[size ~~ 20 and:[size ~~ 6]]) ifTrue:[

        self error: 'Size of HGNodeId must be either 20 bytes or 6 bytes (short form) or 0 (revno only)'.

        ^nil.

    ].

    ^super new: size

    "Created: / 10-09-2012 / 10:44:00 / Jan Vrany <jan.vrany@fit.cvut.cz>"

    "Modified: / 16-11-2012 / 21:24:52 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

readFrom: aStringOrStream 

    ^self readFrom: aStringOrStream onError:[:msg|self error:msg].

    "Created: / 13-11-2012 / 16:56:58 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

readFrom: aStringOrStream onError: aBlock

    "Parses node id from stream and returns it. Support both,

     short and full node ids"

    | stream c c2 sign revno hash short |

    stream := aStringOrStream readStream.

    stream peek == $- ifTrue:[        

        stream next.

        sign := -1.

    ] ifFalse:[

        sign := 1.

    ].

    "/ Read revno...

    revno := 0.

    [ (c := stream peek) == $: ] whileFalse:[

        c isDigit ifFalse:[

            self error:'Digit ([0-9]) expected but ', c , 'found'.

        ].

        revno := (revno * 10) + c digitValue.

        stream next.

    ].

    stream next. "/eat :

    revno := revno * sign.

    "/ Read hash

    hash := ByteArray new: 20.

    short := true.

    1 to: 6 do:[:i|

        stream atEnd ifTrue:[

            aBlock valueWithOptionalArgument:'Unexpected end of stream, hex digit expected'.

        ].

        c := stream peek.

        c isHexDigit ifFalse:[

            aBlock valueWithOptionalArgument:'Hex digit ([0-9a-z]) expected but ', c , ' found'.

        ].

        stream next.

        stream atEnd ifTrue:[

            aBlock valueWithOptionalArgument:'Unexpected end of stream, hex digit expected'.

        ].

        c2 := stream peek.

        c2 isHexDigit ifFalse:[

            aBlock valueWithOptionalArgument:'Hex digit ([0-9a-z]) expected but ', c , ' found'.

        ].

        hash at:i put: (c digitValue << 4) | c2 digitValue.

        stream next.

    ].

    (stream atEnd not and:[stream peek isHexDigit]) ifTrue:[

        "/OK, full 40-char node id

        short := false.

        7 to: 20 do:[:i|

            stream atEnd ifTrue:[

                aBlock valueWithOptionalArgument:'Unexpected end of stream, hex digit expected'.

            ].

                        c := stream peek.

            c isHexDigit ifFalse:[

                aBlock valueWithOptionalArgument:'Hex digit ([0-9a-z]) expected but ', c , ' found'.

            ].

            stream next.

            stream atEnd ifTrue:[

                aBlock valueWithOptionalArgument:'Unexpected end of stream, hex digit expected'.

            ].

            c2 := stream peek.

            c2 isHexDigit ifFalse:[

                aBlock valueWithOptionalArgument:'Hex digit ([0-9a-z]) expected but ', c , ' found'.

            ].

            hash at:i put: (c digitValue << 4) + c2 digitValue.

            stream next.

        ].

    ].

    (revno == -1) ifTrue:[

        (hash = #[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0] 

            or:[hash = #[0 0 0 0 0 0]]) ifTrue:[

            ^self null

        ].

    ].

    short ifTrue:[

        ^(HGChangesetId new: 6)

            revno: revno;

            replaceBytesFrom: 1 to: 6 with: hash startingAt: 1;

            yourself

    ] ifFalse:[

        ^(HGChangesetId fromBytes: hash) revno: revno.

    ]

    "

    HGNodeId fromString:'4:6f88e1f44d9eb86e0b56ca15e30e5d786acd83c7'

    Bad ones:

    HGNodeId fromString:'4:6f88e1f44d9eb86e0b56ca15e30e5d786acd' 

    HGNodeId fromString:'4:6f88Z1f44d9eb86e0b56ca15e30e5d786acd83c7' 

    "

    "Created: / 13-11-2012 / 16:49:19 / Jan Vrany <jan.vrany@fit.cvut.cz>"

! !

!HGChangesetId class methodsFor:'accessing'!

null

    NullId isNil ifTrue:[

        NullId := self new.

        NullId revno: -1

    ].

    ^NullId

    "

        HGChangesetId null

    "

    "Created: / 19-10-2012 / 15:51:25 / Jan Vrany <jan.vrany@fit.cvut.cz>"

    "Modified (comment): / 30-11-2012 / 22:00:52 / Jan Vrany <jan.vrany@fit.cvut.cz>"

! !

!HGChangesetId methodsFor:'accessing'!

revno

    ^ revno

    "Created: / 13-11-2012 / 09:52:02 / Jan Vrany <jan.vrany@fit.cvut.cz>"

    "Modified: / 30-11-2012 / 22:05:47 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

revno:anInteger

    revno := anInteger.

! !

!HGChangesetId methodsFor:'comparing'!

= anotherId

    self class == anotherId class ifFalse:[ ^ false].

    (self size == 0 or:[anotherId size == 0]) ifTrue:[

        ^(self revno == anotherId revno and:[ self revno ~~ -2 ])

    ].

    self size == anotherId size ifTrue:[

        ^super = anotherId

    ].

    "One of them must be short, another long"

    1 to: 6 do:[:i|

        (self at:i) ~~ (anotherId at:i) ifTrue:[ ^ false ].

    ].

    ^true

    "Created: / 13-11-2012 / 17:37:48 / Jan Vrany <jan.vrany@fit.cvut.cz>"

    "Modified: / 16-11-2012 / 21:39:17 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

hash

    ^self size > 0 

        ifTrue:[self computeXorHashFrom:1 to:6]

        ifFalse:[revno hash].

    "Created: / 16-11-2012 / 21:45:16 / Jan Vrany <jan.vrany@fit.cvut.cz>"

! !

!HGChangesetId methodsFor:'converting'!

asHGChangesetId

    ^ self

    "Created: / 16-11-2012 / 21:22:20 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

asString

    ^self printString

    "Created: / 17-11-2012 / 01:08:05 / Jan Vrany <jan.vrany@fit.cvut.cz>"

! !

!HGChangesetId methodsFor:'printing & storing'!

displayOn:aStream

    ^self printOn: aStream

    "Created: / 13-11-2012 / 09:55:00 / Jan Vrany <jan.vrany@fit.cvut.cz>"

    "Modified: / 30-11-2012 / 22:01:12 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

printOn:aStream

    "append a printed representation if the receiver to the argument, aStream"

    | rn |

    rn := self revno.

    rn notNil ifTrue:[

        rn printOn: aStream.

        self isEmpty ifTrue:[ ^ self ].

        aStream nextPut: $:.

    ].

    aStream nextPutAll: (self copyTo: 6) hexPrintString asLowercase

! !

!HGChangesetId methodsFor:'queries'!

hasHashOnly

    ^revno isNil

    "Created: / 16-11-2012 / 21:54:38 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

hasRevnoOnly

    ^self size == 0

    "Created: / 16-11-2012 / 21:54:18 / Jan Vrany <jan.vrany@fit.cvut.cz>"

! !

!HGChangesetId class methodsFor:'documentation'!

version_HG

    ^ '$Changeset: <not expanded> $'

!

version_SVN

    ^ '§Id::                                                                                                                        §'

! !