mercurial/fileset.py

serve: use chunked encoding in hgweb responses

'hg serve' used to close connections when sending a response with unknown
length ... such as a bundle or archive.

Now chunked encoding will be used for responses with unknown length, and the
connection do thus not have to be closed to indicate the end of the response.

Chunked encoding is only used if the length is unknown, if the connection
wouldn't be closed for other reasons, AND if it is a HTTP 1.1 request.

This will not benefit other users of hgweb ... but it can serve as an example
that it can be done.

# 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 minusset(mctx, x, y):
    xl = getset(mctx, x)
    yl = set(getset(mctx, y))
    return [f for f in xl if f not in yl]

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.
    """
    try:
        # i18n: "grep" is a keyword
        r = re.compile(getstring(x, _("grep requires a pattern")))
    except re.error, e:
        raise error.ParseError(_('invalid match pattern: %s') % e)
    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,
    'minus': minusset,
    '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):
        if self._status is not None:
            removed = set(self._status[3])
            unknown = set(self._status[4] + self._status[5])
        else:
            removed = set()
            unknown = set()
        return (f for f in self.subset
                if (f in self.ctx and f not in removed) or f in unknown)
    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

# filesets using matchctx.existing()
_existingcallers = [
    'binary',
    'exec',
    'grep',
    'size',
    'symlink',
]

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) or
        # Using matchctx.existing() on a workingctx requires us to check
        # for deleted files.
        (ctx.rev() is None and _intree(_existingcallers, 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 = list(ctx.walk(ctx.match([])))

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

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