| Disable Functions: Path : /usr/lib64/python2.7/site-packages/mercurial/ |
| Current File : //usr/lib64/python2.7/site-packages/mercurial/pvec.pyc |
�
Hq�Qc @ s d Z d d l Z d d l Z d d l m Z d Z e d Z d Z e d Z e e Z e d Z
e
d d Z d � Z d
� Z
d � Z d � Z d
� Z g e d � D] Z e e � ^ q� Z d � Z d � Z d � Z d � Z d e f d � � YZ d S( s3
A "pvec" is a changeset property based on the theory of vector clocks
that can be compared to discover relatedness without consulting a
graph. This can be useful for tasks like determining how a
disconnected patch relates to a repository.
Currently a pvec consist of 448 bits, of which 24 are 'depth' and the
remainder are a bit vector. It is represented as a 70-character base85
string.
Construction:
- a root changeset has a depth of 0 and a bit vector based on its hash
- a normal commit has a changeset where depth is increased by one and
one bit vector bit is flipped based on its hash
- a merge changeset pvec is constructed by copying changes from one pvec into
the other to balance its depth
Properties:
- for linear changes, difference in depth is always <= hamming distance
- otherwise, changes are probably divergent
- when hamming distance is < 200, we can reliably detect when pvecs are near
Issues:
- hamming distance ceases to work over distances of ~ 200
- detecting divergence is less accurate when the common ancestor is very close
to either revision or total distance is high
- this could probably be improved by modeling the relation between
delta and hdist
Uses:
- a patch pvec can be used to locate the nearest available common ancestor for
resolving conflicts
- ordering of patches can be established without a DAG
- two head pvecs can be compared to determine whether push/pull/merge is needed
and approximately how many changesets are involved
- can be used to find a heuristic divergence measure between changesets on
different branches
i����N( t nullrevi� i i i i c C s/ d } x" | D] } | d t | � } q
W| S( s convert a bytestring to a longi i ( t ord( t bst vt b( ( s4 /usr/lib64/python2.7/site-packages/mercurial/pvec.pyt _bin> s
c C s? d } x2 t | � D]$ } t | d @� | } | d L} q W| S( Nt i� i ( t xranget chr( R t lR t p( ( s4 /usr/lib64/python2.7/site-packages/mercurial/pvec.pyt _strE s
c C s t | t � t | t � f S( s depth and bitvec( R t _depthbytes( R ( ( s4 /usr/lib64/python2.7/site-packages/mercurial/pvec.pyt _splitL s c C s t | t � t | t � S( N( R R t _vecbytes( t deptht bitvec( ( s4 /usr/lib64/python2.7/site-packages/mercurial/pvec.pyt _joinP s c C s8 d } x+ | r3 | d @r& | d 7} n | d L} q W| S( Ni i ( ( t xt c( ( s4 /usr/lib64/python2.7/site-packages/mercurial/pvec.pyt _hweightS s
i c C s= | | A} d } x& | r8 | t | d @7} | d L} q W| S( s+ find the hamming distance between two longsi i� i ( t _htab( t aR t dR ( ( s4 /usr/lib64/python2.7/site-packages/mercurial/pvec.pyt _hamming\ s
c C s� | \ } } | \ } } | | k rE | | | | f \ } } } } n t | | � } | | } | } | | A}
d } | | k r� | | d d } n d } | | }
|
r� xG | r� |
| @r� | | N} | d 8} n | d K} q� Wn t | | � } |
| f S( Ni i ( R t _flipbit( R t yR t d1t v1t d2t v2t hdistt ddistR t mt it changesR ( ( s4 /usr/lib64/python2.7/site-packages/mercurial/pvec.pyt _mergevece s* !
c C s t | � d @t } | d | >AS( NI���� i ( t hasht _vecbits( R t nodet bit( ( s4 /usr/lib64/python2.7/site-packages/mercurial/pvec.pyR � s c C sR | j } t j | d � s' i | _ n | j } | j � | k r)| j } x� t | j � d � D]� } | | k rb | j | � } | j | � \ } } | t k r� d t
| d t � f | | <q"| t k r| | \ } } | d t | | � f | | <q"t
| | | | | � | | <qb qb Wn t | | j � � }
t t j |
� � S( s3 construct a pvec for ctx while filling in the cachet
_pveccachei i i ( t _repot utilt safehasattrR) t revt changelogR R' t
parentrevsR R R R R$ R t pvect base85t b85encode( t ctxt rt pvct clt nR' t p1t p2R R R ( ( s4 /usr/lib64/python2.7/site-packages/mercurial/pvec.pyt ctxpvec� s$ ! (R0 c B sY e Z d � Z d � Z d � Z d � Z d � Z d � Z d � Z d � Z d � Z
RS( c C sO t | t � r< | | _ t t j | � � \ | _ | _ n t | � | _ d S( N( t
isinstancet strt _bsR
R1 t b85decodet _deptht _vecR: ( t selft hashorctx( ( s4 /usr/lib64/python2.7/site-packages/mercurial/pvec.pyt __init__� s $c C s | j S( N( R= ( RA ( ( s4 /usr/lib64/python2.7/site-packages/mercurial/pvec.pyt __str__� s c C s" | j | j k o! | j | j k S( N( R@ R? ( RA R ( ( s4 /usr/lib64/python2.7/site-packages/mercurial/pvec.pyt __eq__� s c C sC | j | j } | d k r t St | j | j � | k r? t St S( Ni ( R? t FalseR R@ t True( RA R t delta( ( s4 /usr/lib64/python2.7/site-packages/mercurial/pvec.pyt __lt__� s c C s
| | k S( N( ( RA R ( ( s4 /usr/lib64/python2.7/site-packages/mercurial/pvec.pyt __gt__� s c C s9 t | j | j � } t | j | j � | k r5 t St S( N( t absR? R R@ RF RG ( RA R RH ( ( s4 /usr/lib64/python2.7/site-packages/mercurial/pvec.pyt __or__� s c C s' | | Br t d � � n | j | j S( Ns concurrent pvecs( t
ValueErrorR? ( RA R ( ( s4 /usr/lib64/python2.7/site-packages/mercurial/pvec.pyt __sub__� s
c C s8 t | j | j � } t | j | j � } t | | � S( N( RK R? R R@ t max( RA R R t h( ( s4 /usr/lib64/python2.7/site-packages/mercurial/pvec.pyt distance� s c C sE t | j | j � } | t k s= t | j | j � t k rA t Sd S( N( RK R R? t _radiusR R@ RF ( RA R t dist( ( s4 /usr/lib64/python2.7/site-packages/mercurial/pvec.pyt near� s '( t __name__t
__module__RC RD RE RI RJ RL RN RQ RT ( ( ( s4 /usr/lib64/python2.7/site-packages/mercurial/pvec.pyR0 � s ( t __doc__R1 R+ R' R t _sizet _bytest
_depthbitsR R R& RR R R R
R R R R R R R$ R R: t objectR0 ( ( ( s4 /usr/lib64/python2.7/site-packages/mercurial/pvec.pyt <module>1 s(
% %