comparison mercurial/context.py @ 30718:ce662ee40d2d

context: add a `blockancestors(fctx, fromline, toline)` function

This yields ancestors of `fctx` by only keeping changesets touching the file
within specified linerange = (fromline, toline).

Matching revisions are found by inspecting the result of `mdiff.allblocks()`,
filtered by `mdiff.blocksinrange()`, to find out if there are blocks of type
"!" within specified line range.

If, at some iteration, an ancestor with an empty line range is encountered,
the algorithm stops as it means that the considered block of lines actually
has been introduced in the revision of this iteration. Otherwise, we finally
yield the initial revision of the file as the block originates from it.

When a merge changeset is encountered during ancestors lookup, we consider
there's a diff in the current line range as long as there is a diff between
the merge changeset and at least one of its parents (in the current line
range).

30717:3eeb8e138e5c

        # hard for renames
        c = self._filelog.children(self._filenode)
        return [filectx(self._repo, self._path, fileid=x,
                        filelog=self._filelog) for x in c]

class committablectx(basectx):
    """A committablectx object provides common functionality for a context that
    wants the ability to commit, e.g. workingctx or memctx."""
    def __init__(self, repo, text="", user=None, date=None, extra=None,
                 changes=None):

30718:ce662ee40d2d

        # hard for renames
        c = self._filelog.children(self._filenode)
        return [filectx(self._repo, self._path, fileid=x,
                        filelog=self._filelog) for x in c]

def blockancestors(fctx, fromline, toline):
    """Yield ancestors of `fctx` with respect to the block of lines within
    `fromline`-`toline` range.
    """
    def changesrange(fctx1, fctx2, linerange2):
        """Return `(diffinrange, linerange1)` where `diffinrange` is True
        if diff from fctx2 to fctx1 has changes in linerange2 and
        `linerange1` is the new line range for fctx1.
        """
        diffopts = patch.diffopts(fctx._repo.ui)
        blocks = mdiff.allblocks(fctx1.data(), fctx2.data(), diffopts)
        filteredblocks, linerange1 = mdiff.blocksinrange(blocks, linerange2)
        diffinrange = any(stype == '!' for _, stype in filteredblocks)
        return diffinrange, linerange1

    visit = {(fctx.linkrev(), fctx.filenode()): (fctx, (fromline, toline))}
    while visit:
        c, linerange2 = visit.pop(max(visit))
        pl = c.parents()
        if not pl:
            # The block originates from the initial revision.
            yield c
            continue
        inrange = False
        for p in pl:
            inrangep, linerange1 = changesrange(p, c, linerange2)
            inrange = inrange or inrangep
            if linerange1[0] == linerange1[1]:
                # Parent's linerange is empty, meaning that the block got
                # introduced in this revision; no need to go futher in this
                # branch.
                continue
            visit[p.linkrev(), p.filenode()] = p, linerange1
        if inrange:
            yield c

class committablectx(basectx):
    """A committablectx object provides common functionality for a context that
    wants the ability to commit, e.g. workingctx or memctx."""
    def __init__(self, repo, text="", user=None, date=None, extra=None,
                 changes=None):