# filelog.py - file history class for mercurial

#

# Copyright 2005, 2006 Matt Mackall <mpm@selenic.com>

#

# This software may be used and distributed according to the terms

# of the GNU General Public License, incorporated herein by reference.

from revlog import *

from demandload import *

demandload(globals(), "bdiff os")

class filelog(revlog):

    def __init__(self, opener, path, defversion=REVLOG_DEFAULT_VERSION):

        revlog.__init__(self, opener,

                        os.path.join("data", self.encodedir(path + ".i")),

                        os.path.join("data", self.encodedir(path + ".d")),

                        defversion)

    # This avoids a collision between a file named foo and a dir named

    # foo.i or foo.d

    def encodedir(self, path):

        return (path

                .replace(".hg/", ".hg.hg/")

                .replace(".i/", ".i.hg/")

                .replace(".d/", ".d.hg/"))

    def decodedir(self, path):

        return (path

                .replace(".d.hg/", ".d/")

                .replace(".i.hg/", ".i/")

                .replace(".hg.hg/", ".hg/"))

    def read(self, node):

        t = self.revision(node)

        if not t.startswith('\1\n'):

            return t

        s = t.index('\1\n', 2)

        return t[s+2:]

    def readmeta(self, node):

        t = self.revision(node)

        if not t.startswith('\1\n'):

            return {}

        s = t.index('\1\n', 2)

        mt = t[2:s]

        m = {}

        for l in mt.splitlines():

            k, v = l.split(": ", 1)

            m[k] = v

        return m

    def add(self, text, meta, transaction, link, p1=None, p2=None):

        if meta or text.startswith('\1\n'):

            mt = ""

            if meta:

                mt = [ "%s: %s\n" % (k, v) for k,v in meta.items() ]

            text = "\1\n%s\1\n%s" % ("".join(mt), text)

        return self.addrevision(text, transaction, link, p1, p2)

    def renamed(self, node):

        if self.parents(node)[0] != nullid:

            return False

        m = self.readmeta(node)

        if m and m.has_key("copy"):

            return (m["copy"], bin(m["copyrev"]))

        return False

    def size(self, rev):

        """return the size of a given revision"""

        # for revisions with renames, we have to go the slow way

        node = self.node(rev)

        if self.renamed(node):

            return len(self.read(node))

        return revlog.size(self, rev)

    def cmp(self, node, text):

        """compare text with a given file revision"""

        # for renames, we have to go the slow way

        if self.renamed(node):

            t2 = self.read(node)

            return t2 != text

        return revlog.cmp(self, node, text)

    def annotate(self, node):

        def decorate(text, rev):

            return ([rev] * len(text.splitlines()), text)

        def pair(parent, child):

            for a1, a2, b1, b2 in bdiff.blocks(parent[1], child[1]):

                child[0][b1:b2] = parent[0][a1:a2]

            return child

        # find all ancestors

        needed = {(self, node):1}

        files = [self]

        visit = [(self, node)]

        while visit:

            f, n = visit.pop(0)

            rn = f.renamed(n)

            if rn:

                f, n = rn

                f = filelog(self.opener, f, self.defversion)

                files.insert(0, f)

                if (f, n) not in needed:

                    needed[(f, n)] = 1

                else:

                    needed[(f, n)] += 1

            for p in f.parents(n):

                if p == nullid:

                    continue

                if (f, p) not in needed:

                    needed[(f, p)] = 1

                    visit.append((f, p))

                else:

                    # count how many times we'll use this

                    needed[(f, p)] += 1

        # sort by revision (per file) which is a topological order

        visit = []

        for f in files:

            fn = [(f.rev(n[1]), f, n[1]) for n in needed.keys() if n[0] == f]

            fn.sort()

            visit.extend(fn)

        hist = {}

        for i in range(len(visit)):

            r, f, n = visit[i]

            curr = decorate(f.read(n), f.linkrev(n))

            if r == -1:

                continue

            parents = f.parents(n)

            # follow parents across renames

            if r < 1 and i > 0:

                j = i

                while j > 0 and visit[j][1] == f:

                    j -= 1

                parents = (visit[j][2],)

                f = visit[j][1]

            else:

                parents = f.parents(n)

            for p in parents:

                if p != nullid:

                    curr = pair(hist[p], curr)

                    # trim the history of unneeded revs

                    needed[(f, p)] -= 1

                    if not needed[(f, p)]:

                        del hist[p]

            hist[n] = curr

        return zip(hist[n][0], hist[n][1].splitlines(1))