mercurial/fileset.py

rebase: allow collapsing branches in place (issue3111)

We allow rebase plus collapse, but not collapse only? I imagine people would
rebase first then collapse once they are sure the rebase is correct and it is
the right time to finish it.

I was reluctant to submit this patch for reasons detailed below, but it
improves rebase --collapse usefulness so much it is worth the ugliness.

The fix is ugly because we should be fixing the collapse code path rather than
the merge. Collapsing by merging changesets repeatedly is inefficient compared
to what commit --amend does: commitctx(), update, strip. The problem with the
latter is, to generate the synthetic changeset, copy records are gathered with
copies.pathcopies(). copies.pathcopies() is still implemented with merging in
mind and discards information like file replaced by the copy of another,
criss-cross copies and so forth. I believe this information should not be lost,
even if we decide not to interpret it fully later, at merge time.

The second issue with improving rebase --collapse is the option should not be
there to begin with. Rebasing and collapsing are orthogonal and a dedicated
command would probably enable a better, simpler ui. We should avoid advertizing
rebase --collapse, but with this fix it becomes the best shipped solution to
collapse changesets.

And for the record, available techniques are:
- revert + commit + strip: lose copies
- mq/qfold: repeated patching() (mostly correct, fragile)
- rebase: repeated merges (mostly correct, fragile)
- collapse: revert + tag rewriting wizardry, lose copies
- histedit: repeated patching() (mostly correct, fragile)
- amend: copies.pathcopies() + commitctx() + update + strip

# fileset.py - file set queries for mercurial
#
# Copyright 2010 Matt Mackall <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

import parser, error, util, merge, re
from i18n import _

elements = {
    "(": (20, ("group", 1, ")"), ("func", 1, ")")),
    "-": (5, ("negate", 19), ("minus", 5)),
    "not": (10, ("not", 10)),
    "!": (10, ("not", 10)),
    "and": (5, None, ("and", 5)),
    "&": (5, None, ("and", 5)),
    "or": (4, None, ("or", 4)),
    "|": (4, None, ("or", 4)),
    "+": (4, None, ("or", 4)),
    ",": (2, None, ("list", 2)),
    ")": (0, None, None),
    "symbol": (0, ("symbol",), None),
    "string": (0, ("string",), None),
    "end": (0, None, None),
}

keywords = set(['and', 'or', 'not'])

globchars = ".*{}[]?/\\"

def tokenize(program):
    pos, l = 0, len(program)
    while pos < l:
        c = program[pos]
        if c.isspace(): # skip inter-token whitespace
            pass
        elif c in "(),-|&+!": # handle simple operators
            yield (c, None, pos)
        elif (c in '"\'' or c == 'r' and
              program[pos:pos + 2] in ("r'", 'r"')): # handle quoted strings
            if c == 'r':
                pos += 1
                c = program[pos]
                decode = lambda x: x
            else:
                decode = lambda x: x.decode('string-escape')
            pos += 1
            s = pos
            while pos < l: # find closing quote
                d = program[pos]
                if d == '\\': # skip over escaped characters
                    pos += 2
                    continue
                if d == c:
                    yield ('string', decode(program[s:pos]), s)
                    break
                pos += 1
            else:
                raise error.ParseError(_("unterminated string"), s)
        elif c.isalnum() or c in globchars or ord(c) > 127:
            # gather up a symbol/keyword
            s = pos
            pos += 1
            while pos < l: # find end of symbol
                d = program[pos]
                if not (d.isalnum() or d in globchars or ord(d) > 127):
                    break
                pos += 1
            sym = program[s:pos]
            if sym in keywords: # operator keywords
                yield (sym, None, s)
            else:
                yield ('symbol', sym, s)
            pos -= 1
        else:
            raise error.ParseError(_("syntax error"), pos)
        pos += 1
    yield ('end', None, pos)

parse = parser.parser(tokenize, elements).parse

def getstring(x, err):
    if x and (x[0] == 'string' or x[0] == 'symbol'):
        return x[1]
    raise error.ParseError(err)

def getset(mctx, x):
    if not x:
        raise error.ParseError(_("missing argument"))
    return methods[x[0]](mctx, *x[1:])

def stringset(mctx, x):
    m = mctx.matcher([x])
    return [f for f in mctx.subset if m(f)]

def andset(mctx, x, y):
    return getset(mctx.narrow(getset(mctx, x)), y)

def orset(mctx, x, y):
    # needs optimizing
    xl = getset(mctx, x)
    yl = getset(mctx, y)
    return xl + [f for f in yl if f not in xl]

def notset(mctx, x):
    s = set(getset(mctx, x))
    return [r for r in mctx.subset if r not in s]

def listset(mctx, a, b):
    raise error.ParseError(_("can't use a list in this context"))

def modified(mctx, x):
    """``modified()``
    File that is modified according to status.
    """
    # i18n: "modified" is a keyword
    getargs(x, 0, 0, _("modified takes no arguments"))
    s = mctx.status()[0]
    return [f for f in mctx.subset if f in s]

def added(mctx, x):
    """``added()``
    File that is added according to status.
    """
    # i18n: "added" is a keyword
    getargs(x, 0, 0, _("added takes no arguments"))
    s = mctx.status()[1]
    return [f for f in mctx.subset if f in s]

def removed(mctx, x):
    """``removed()``
    File that is removed according to status.
    """
    # i18n: "removed" is a keyword
    getargs(x, 0, 0, _("removed takes no arguments"))
    s = mctx.status()[2]
    return [f for f in mctx.subset if f in s]

def deleted(mctx, x):
    """``deleted()``
    File that is deleted according to status.
    """
    # i18n: "deleted" is a keyword
    getargs(x, 0, 0, _("deleted takes no arguments"))
    s = mctx.status()[3]
    return [f for f in mctx.subset if f in s]

def unknown(mctx, x):
    """``unknown()``
    File that is unknown according to status. These files will only be
    considered if this predicate is used.
    """
    # i18n: "unknown" is a keyword
    getargs(x, 0, 0, _("unknown takes no arguments"))
    s = mctx.status()[4]
    return [f for f in mctx.subset if f in s]

def ignored(mctx, x):
    """``ignored()``
    File that is ignored according to status. These files will only be
    considered if this predicate is used.
    """
    # i18n: "ignored" is a keyword
    getargs(x, 0, 0, _("ignored takes no arguments"))
    s = mctx.status()[5]
    return [f for f in mctx.subset if f in s]

def clean(mctx, x):
    """``clean()``
    File that is clean according to status.
    """
    # i18n: "clean" is a keyword
    getargs(x, 0, 0, _("clean takes no arguments"))
    s = mctx.status()[6]
    return [f for f in mctx.subset if f in s]

def func(mctx, a, b):
    if a[0] == 'symbol' and a[1] in symbols:
        return symbols[a[1]](mctx, b)
    raise error.ParseError(_("not a function: %s") % a[1])

def getlist(x):
    if not x:
        return []
    if x[0] == 'list':
        return getlist(x[1]) + [x[2]]
    return [x]

def getargs(x, min, max, err):
    l = getlist(x)
    if len(l) < min or len(l) > max:
        raise error.ParseError(err)
    return l

def binary(mctx, x):
    """``binary()``
    File that appears to be binary (contains NUL bytes).
    """
    # i18n: "binary" is a keyword
    getargs(x, 0, 0, _("binary takes no arguments"))
    return [f for f in mctx.existing() if util.binary(mctx.ctx[f].data())]

def exec_(mctx, x):
    """``exec()``
    File that is marked as executable.
    """
    # i18n: "exec" is a keyword
    getargs(x, 0, 0, _("exec takes no arguments"))
    return [f for f in mctx.existing() if mctx.ctx.flags(f) == 'x']

def symlink(mctx, x):
    """``symlink()``
    File that is marked as a symlink.
    """
    # i18n: "symlink" is a keyword
    getargs(x, 0, 0, _("symlink takes no arguments"))
    return [f for f in mctx.existing() if mctx.ctx.flags(f) == 'l']

def resolved(mctx, x):
    """``resolved()``
    File that is marked resolved according to the resolve state.
    """
    # i18n: "resolved" is a keyword
    getargs(x, 0, 0, _("resolved takes no arguments"))
    if mctx.ctx.rev() is not None:
        return []
    ms = merge.mergestate(mctx.ctx._repo)
    return [f for f in mctx.subset if f in ms and ms[f] == 'r']

def unresolved(mctx, x):
    """``unresolved()``
    File that is marked unresolved according to the resolve state.
    """
    # i18n: "unresolved" is a keyword
    getargs(x, 0, 0, _("unresolved takes no arguments"))
    if mctx.ctx.rev() is not None:
        return []
    ms = merge.mergestate(mctx.ctx._repo)
    return [f for f in mctx.subset if f in ms and ms[f] == 'u']

def hgignore(mctx, x):
    """``hgignore()``
    File that matches the active .hgignore pattern.
    """
    getargs(x, 0, 0, _("hgignore takes no arguments"))
    ignore = mctx.ctx._repo.dirstate._ignore
    return [f for f in mctx.subset if ignore(f)]

def grep(mctx, x):
    """``grep(regex)``
    File contains the given regular expression.
    """
    pat = getstring(x, _("grep requires a pattern"))
    r = re.compile(pat)
    return [f for f in mctx.existing() if r.search(mctx.ctx[f].data())]

_units = dict(k=2**10, K=2**10, kB=2**10, KB=2**10,
              M=2**20, MB=2**20, G=2**30, GB=2**30)

def _sizetoint(s):
    try:
        s = s.strip()
        for k, v in _units.items():
            if s.endswith(k):
                return int(float(s[:-len(k)]) * v)
        return int(s)
    except ValueError:
        raise error.ParseError(_("couldn't parse size: %s") % s)

def _sizetomax(s):
    try:
        s = s.strip()
        for k, v in _units.items():
            if s.endswith(k):
                # max(4k) = 5k - 1, max(4.5k) = 4.6k - 1
                n = s[:-len(k)]
                inc = 1.0
                if "." in n:
                    inc /= 10 ** len(n.split(".")[1])
                return int((float(n) + inc) * v) - 1
        # no extension, this is a precise value
        return int(s)
    except ValueError:
        raise error.ParseError(_("couldn't parse size: %s") % s)

def size(mctx, x):
    """``size(expression)``
    File size matches the given expression. Examples:

    - 1k (files from 1024 to 2047 bytes)
    - < 20k (files less than 20480 bytes)
    - >= .5MB (files at least 524288 bytes)
    - 4k - 1MB (files from 4096 bytes to 1048576 bytes)
    """

    # i18n: "size" is a keyword
    expr = getstring(x, _("size requires an expression")).strip()
    if '-' in expr: # do we have a range?
        a, b = expr.split('-', 1)
        a = _sizetoint(a)
        b = _sizetoint(b)
        m = lambda x: x >= a and x <= b
    elif expr.startswith("<="):
        a = _sizetoint(expr[2:])
        m = lambda x: x <= a
    elif expr.startswith("<"):
        a = _sizetoint(expr[1:])
        m = lambda x: x < a
    elif expr.startswith(">="):
        a = _sizetoint(expr[2:])
        m = lambda x: x >= a
    elif expr.startswith(">"):
        a = _sizetoint(expr[1:])
        m = lambda x: x > a
    elif expr[0].isdigit or expr[0] == '.':
        a = _sizetoint(expr)
        b = _sizetomax(expr)
        m = lambda x: x >= a and x <= b
    else:
        raise error.ParseError(_("couldn't parse size: %s") % expr)

    return [f for f in mctx.existing() if m(mctx.ctx[f].size())]

def encoding(mctx, x):
    """``encoding(name)``
    File can be successfully decoded with the given character
    encoding. May not be useful for encodings other than ASCII and
    UTF-8.
    """

    # i18n: "encoding" is a keyword
    enc = getstring(x, _("encoding requires an encoding name"))

    s = []
    for f in mctx.existing():
        d = mctx.ctx[f].data()
        try:
            d.decode(enc)
        except LookupError:
            raise util.Abort(_("unknown encoding '%s'") % enc)
        except UnicodeDecodeError:
            continue
        s.append(f)

    return s

def copied(mctx, x):
    """``copied()``
    File that is recorded as being copied.
    """
    # i18n: "copied" is a keyword
    getargs(x, 0, 0, _("copied takes no arguments"))
    s = []
    for f in mctx.subset:
        p = mctx.ctx[f].parents()
        if p and p[0].path() != f:
            s.append(f)
    return s

def subrepo(mctx, x):
    """``subrepo([pattern])``
    Subrepositories whose paths match the given pattern.
    """
    # i18n: "subrepo" is a keyword
    getargs(x, 0, 1, _("subrepo takes at most one argument"))
    ctx = mctx.ctx
    sstate = ctx.substate
    if x:
        pat = getstring(x, _("subrepo requires a pattern or no arguments"))

        import match as matchmod # avoid circular import issues
        fast = not matchmod.patkind(pat)
        if fast:
            def m(s):
                return (s == pat)
        else:
            m = matchmod.match(ctx._repo.root, '', [pat], ctx=ctx)
        return [sub for sub in sstate if m(sub)]
    else:
        return [sub for sub in sstate]

symbols = {
    'added': added,
    'binary': binary,
    'clean': clean,
    'copied': copied,
    'deleted': deleted,
    'encoding': encoding,
    'exec': exec_,
    'grep': grep,
    'ignored': ignored,
    'hgignore': hgignore,
    'modified': modified,
    'removed': removed,
    'resolved': resolved,
    'size': size,
    'symlink': symlink,
    'unknown': unknown,
    'unresolved': unresolved,
    'subrepo': subrepo,
}

methods = {
    'string': stringset,
    'symbol': stringset,
    'and': andset,
    'or': orset,
    'list': listset,
    'group': getset,
    'not': notset,
    'func': func,
}

class matchctx(object):
    def __init__(self, ctx, subset=None, status=None):
        self.ctx = ctx
        self.subset = subset
        self._status = status
    def status(self):
        return self._status
    def matcher(self, patterns):
        return self.ctx.match(patterns)
    def filter(self, files):
        return [f for f in files if f in self.subset]
    def existing(self):
        return (f for f in self.subset if f in self.ctx)
    def narrow(self, files):
        return matchctx(self.ctx, self.filter(files), self._status)

def _intree(funcs, tree):
    if isinstance(tree, tuple):
        if tree[0] == 'func' and tree[1][0] == 'symbol':
            if tree[1][1] in funcs:
                return True
        for s in tree[1:]:
            if _intree(funcs, s):
                return True
    return False

def getfileset(ctx, expr):
    tree, pos = parse(expr)
    if (pos != len(expr)):
        raise error.ParseError(_("invalid token"), pos)

    # do we need status info?
    if _intree(['modified', 'added', 'removed', 'deleted',
                'unknown', 'ignored', 'clean'], tree):
        unknown = _intree(['unknown'], tree)
        ignored = _intree(['ignored'], tree)

        r = ctx._repo
        status = r.status(ctx.p1(), ctx,
                          unknown=unknown, ignored=ignored, clean=True)
        subset = []
        for c in status:
            subset.extend(c)
    else:
        status = None
        subset = ctx.walk(ctx.match([]))

    return getset(matchctx(ctx, subset, status), tree)

# tell hggettext to extract docstrings from these functions:
i18nfunctions = symbols.values()