mercurial/graphmod.py

posixfile: remove posixfile_nt and fix import bug in windows.py

The posixfile_nt class has been superseded by posixfile in osutils.c,
which works on Windows NT and above. All other systems get the regular
python file class which is assigned to posixfile in posix.py (for POSIX)
and in the pure python version of osutils.py (for Win 9x or Windows NT
in pure mode).

# Revision graph generator for Mercurial
#
# Copyright 2008 Dirkjan Ochtman <[e-mail]>
# Copyright 2007 Joel Rosdahl <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2, incorporated herein by reference.

from node import nullrev

def graph(repo, start_rev, stop_rev):
    """incremental revision grapher

    This generator function walks through the revision history from
    revision start_rev to revision stop_rev (which must be less than
    or equal to start_rev) and for each revision emits tuples with the
    following elements:

      - Current node
      - Column and color for the current node
      - Edges; a list of (col, next_col, color) indicating the edges between
        the current node and its parents.
      - First line of the changeset description
      - The changeset author
      - The changeset date/time
    """

    if start_rev == nullrev and not stop_rev:
        return

    assert start_rev >= stop_rev
    assert stop_rev >= 0
    curr_rev = start_rev
    revs = []
    cl = repo.changelog
    colors = {}
    new_color = 1

    while curr_rev >= stop_rev:
        # Compute revs and next_revs
        if curr_rev not in revs:
            revs.append(curr_rev) # new head
            colors[curr_rev] = new_color
            new_color += 1

        idx = revs.index(curr_rev)
        color = colors.pop(curr_rev)
        next = revs[:]

        # Add parents to next_revs
        parents = [x for x in cl.parentrevs(curr_rev) if x != nullrev]
        addparents = [p for p in parents if p not in next]
        next[idx:idx + 1] = addparents

        # Set colors for the parents
        for i, p in enumerate(addparents):
            if not i:
                colors[p] = color
            else:
                colors[p] = new_color
                new_color += 1

        # Add edges to the graph
        edges = []
        for col, r in enumerate(revs):
            if r in next:
                edges.append((col, next.index(r), colors[r]))
            elif r == curr_rev:
                for p in parents:
                    edges.append((col, next.index(p), colors[p]))

        # Yield and move on
        yield (repo[curr_rev], (idx, color), edges)
        revs = next
        curr_rev -= 1