contrib/convert-repo

run-tests.py: make tests use same python interpreter as test harness.
this is wanted because some tests run python interpreter directly.

must use same python interpreter in tests as in main harness or problems
will happen because of e.g. different python abi if run-tests.py run
with python 2.5 but system python is 2.4.

fix is to see if system python is used and is named python.  if no,
put symlink called python at front of shell search path.

#!/usr/bin/env python
#
# This is a generalized framework for converting between SCM
# repository formats.
#
# In its current form, it's hardcoded to convert incrementally between
# git and Mercurial.
#
# To use, you must first import the first git version into Mercurial,
# and establish a mapping between the git commit hash and the hash in
# Mercurial for that version. This mapping is kept in a simple text
# file with lines like so:
#
# <git hash> <mercurial hash>
#
# To convert the rest of the repo, run:
#
# convert-repo <git-dir> <hg-dir> <mapfile>
#
# This updates the mapfile on each commit copied, so it can be
# interrupted and can be run repeatedly to copy new commits.

import sys, os, zlib, sha, time
from mercurial import hg, ui, util

class convert_git:
    def __init__(self, path):
        self.path = path

    def getheads(self):
        return [file(self.path + "/HEAD").read()[:-1]]

    def catfile(self, rev, type):
        if rev == "0" * 40: raise IOError()
        fh = os.popen("GIT_DIR=%s git-cat-file %s %s 2>/dev/null" % (self.path, type, rev))
        return fh.read()

    def getfile(self, name, rev):
        return self.catfile(rev, "blob")

    def getchanges(self, version):
        fh = os.popen("GIT_DIR=%s git-diff-tree --root -m -r %s" % (self.path, version))
        changes = []
        for l in fh:
            if "\t" not in l: continue
            m, f = l[:-1].split("\t")
            m = m.split()
            h = m[3]
            p = (m[1] == "100755")
            changes.append((f, h, p))
        return changes

    def getcommit(self, version):
        c = self.catfile(version, "commit") # read the commit hash
        end = c.find("\n\n")
        message = c[end+2:]
        l = c[:end].splitlines()
        manifest = l[0].split()[1]
        parents = []
        for e in l[1:]:
            n,v = e.split(" ", 1)
            if n == "author":
                p = v.split()
                tm, tz = p[-2:]
                author = " ".join(p[:-2])
                if author[0] == "<": author = author[1:-1]
            if n == "committer":
                p = v.split()
                tm, tz = p[-2:]
                committer = " ".join(p[:-2])
                if committer[0] == "<": committer = committer[1:-1]
                message += "\ncommitter: %s\n" % v
            if n == "parent": parents.append(v)

        tzs, tzh, tzm = tz[-5:-4] + "1", tz[-4:-2], tz[-2:]
        tz = -int(tzs) * (int(tzh) * 3600 + int(tzm))
        date = tm + " " + str(tz)
        return (parents, author, date, message)

    def gettags(self):
        tags = {}
        for f in os.listdir(self.path + "/refs/tags"):
            try:
                h = file(self.path + "/refs/tags/" + f).read().strip()
                c = self.catfile(h, "tag") # read the commit hash
                h = c.splitlines()[0].split()[1]
                tags[f] = h
            except:
                pass
        return tags

class convert_mercurial:
    def __init__(self, path):
        self.path = path
        u = ui.ui()
        self.repo = hg.repository(u, path)

    def getheads(self):
        h = self.repo.changelog.heads()
        return [ hg.hex(x) for x in h ]

    def putfile(self, f, e, data):
        self.repo.wfile(f, "w").write(data)
        if self.repo.dirstate.state(f) == '?':
            self.repo.dirstate.update([f], "a")

        util.set_exec(self.repo.wjoin(f), e)

    def delfile(self, f):
        try:
            os.unlink(self.repo.wjoin(f))
            #self.repo.remove([f])
        except:
            pass

    def putcommit(self, files, parents, author, dest, text):
        seen = {}
        pl = []
        for p in parents:
            if p not in seen:
                pl.append(p)
                seen[p] = 1
        parents = pl

        if len(parents) < 2: parents.append("0" * 40)
        if len(parents) < 2: parents.append("0" * 40)
        p2 = parents.pop(0)

        while parents:
            p1 = p2
            p2 = parents.pop(0)
            self.repo.rawcommit(files, text, author, dest,
                                hg.bin(p1), hg.bin(p2))
            text = "(octopus merge fixup)\n"
            p2 = hg.hex(self.repo.changelog.tip())

        return p2

    def puttags(self, tags):
        try:
            old = self.repo.wfile(".hgtags").read()
            oldlines = old.splitlines(1)
            oldlines.sort()
        except:
            oldlines = []

        k = tags.keys()
        k.sort()
        newlines = []
        for tag in k:
            newlines.append("%s %s\n" % (tags[tag], tag))

        newlines.sort()

        if newlines != oldlines:
            #print "updating tags"
            f = self.repo.wfile(".hgtags", "w")
            f.write("".join(newlines))
            f.close()
            if not oldlines: self.repo.add([".hgtags"])
            date = "%s 0" % int(time.mktime(time.gmtime()))
            self.repo.rawcommit([".hgtags"], "update tags", "convert-repo",
                                date, self.repo.changelog.tip(), hg.nullid)
            return hg.hex(self.repo.changelog.tip())

class convert:
    def __init__(self, source, dest, mapfile):
        self.source = source
        self.dest = dest
        self.mapfile = mapfile
        self.commitcache = {}

        self.map = {}
        try:
            for l in file(self.mapfile):
                sv, dv = l[:-1].split()
                self.map[sv] = dv
        except IOError:
            pass

    def walktree(self, heads):
        visit = heads
        known = {}
        parents = {}
        while visit:
            n = visit.pop(0)
            if n in known or n in self.map: continue
            known[n] = 1
            self.commitcache[n] = self.source.getcommit(n)
            cp = self.commitcache[n][0]
            for p in cp:
                parents.setdefault(n, []).append(p)
                visit.append(p)

        return parents

    def toposort(self, parents):
        visit = parents.keys()
        seen = {}
        children = {}

        while visit:
            n = visit.pop(0)
            if n in seen: continue
            seen[n] = 1
            pc = 0
            if n in parents:
                for p in parents[n]:
                    if p not in self.map: pc += 1
                    visit.append(p)
                    children.setdefault(p, []).append(n)
            if not pc: root = n

        s = []
        removed = {}
        visit = children.keys()
        while visit:
            n = visit.pop(0)
            if n in removed: continue
            dep = 0
            if n in parents:
                for p in parents[n]:
                    if p in self.map: continue
                    if p not in removed:
                        # we're still dependent
                        visit.append(n)
                        dep = 1
                        break

            if not dep:
                # all n's parents are in the list
                removed[n] = 1
                s.append(n)
                if n in children:
                    for c in children[n]:
                        visit.insert(0, c)

        return s

    def copy(self, rev):
        p, a, d, t = self.commitcache[rev]
        files = self.source.getchanges(rev)

        for f,v,e in files:
            try:
                data = self.source.getfile(f, v)
            except IOError, inst:
                self.dest.delfile(f)
            else:
                self.dest.putfile(f, e, data)

        r = [self.map[v] for v in p]
        f = [f for f,v,e in files]
        self.map[rev] = self.dest.putcommit(f, r, a, d, t)
        file(self.mapfile, "a").write("%s %s\n" % (rev, self.map[rev]))

    def convert(self):
        heads = self.source.getheads()
        parents = self.walktree(heads)
        t = self.toposort(parents)
        t = [n for n in t if n not in self.map]
        num = len(t)
        c = None

        for c in t:
            num -= 1
            desc = self.commitcache[c][3].splitlines()[0]
            #print num, desc
            self.copy(c)

        tags = self.source.gettags()
        ctags = {}
        for k in tags:
            v = tags[k]
            if v in self.map:
                ctags[k] = self.map[v]

        if c and ctags:
            nrev = self.dest.puttags(ctags)
            # write another hash correspondence to override the previous
            # one so we don't end up with extra tag heads
            file(self.mapfile, "a").write("%s %s\n" % (c, nrev))

gitpath, hgpath, mapfile = sys.argv[1:]
if os.path.isdir(gitpath + "/.git"):
    gitpath += "/.git"

c = convert(convert_git(gitpath), convert_mercurial(hgpath), mapfile)
c.convert()