view mercurial/filesetlang.py @ 42121:6578654916ae

branchcache: lazily validate nodes from the branchmap

On my personal hg-repository with 365 entries in .hg/cache/branch2, following
are the numbers for perfbranchmapload.

Before this patch:

! wall 0.000866 comb 0.000000 user 0.000000 sys 0.000000 (best of 2680)
! wall 0.001525 comb 0.000000 user 0.000000 sys 0.000000 (max of 2680)
! wall 0.001107 comb 0.001097 user 0.001086 sys 0.000011 (avg of 2680)
! wall 0.001104 comb 0.000000 user 0.000000 sys 0.000000 (median of 2680)

With this patch:

! wall 0.000530 comb 0.000000 user 0.000000 sys 0.000000 (best of 4240)
! wall 0.001078 comb 0.000000 user 0.000000 sys 0.000000 (max of 4240)
! wall 0.000696 comb 0.000693 user 0.000677 sys 0.000017 (avg of 4240)
! wall 0.000690 comb 0.000000 user 0.000000 sys 0.000000 (median of 4240)

On our internal repository with ~20k entries in branchcache, I see improvement
from 0.125 sec to 0.066 sec which is 47% speed up.

The above are the numbers of perfbranchmapload which shows how much time we
saved by not validating the nodes. But we need to validate some nodes. Following
are timings of some mercurial operations which have speed up because of this
lazy validation of nodes:

No-op `hg update` on our internal repository (Avg on 4 runs):

Before: 0.540 secs
After: 0.430 secs

Setting a branch name which already exists without --force (Avg of 4 runs):

Before: 0.510 secs
After: 0.250 secs

I ran the ASV performance suite and was unable to see any improvements except
there was improvement of perfdirstatewrite() on netbeans which I think was not
related.

I looked into the commit code, the command which I am trying to speedup, it
looks like it uses revbranchcache to update the branchcache.

Differential Revision: https://phab.mercurial-scm.org/D6208

# filesetlang.py - parser, tokenizer and utility for file set language
#
# 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.

from __future__ import absolute_import

from .i18n import _
from . import (
    error,
    parser,
    pycompat,
)

# common weight constants for static optimization
# (see registrar.filesetpredicate for details)
WEIGHT_CHECK_FILENAME = 0.5
WEIGHT_READ_CONTENTS = 30
WEIGHT_STATUS = 10
WEIGHT_STATUS_THOROUGH = 50

elements = {
    # token-type: binding-strength, primary, prefix, infix, suffix
    "(": (20, None, ("group", 1, ")"), ("func", 1, ")"), None),
    ":": (15, None, None, ("kindpat", 15), None),
    "-": (5, None, ("negate", 19), ("minus", 5), None),
    "not": (10, None, ("not", 10), None, None),
    "!": (10, None, ("not", 10), None, None),
    "and": (5, None, None, ("and", 5), None),
    "&": (5, None, None, ("and", 5), None),
    "or": (4, None, None, ("or", 4), None),
    "|": (4, None, None, ("or", 4), None),
    "+": (4, None, None, ("or", 4), None),
    ",": (2, None, None, ("list", 2), None),
    ")": (0, None, None, None, None),
    "symbol": (0, "symbol", None, None, None),
    "string": (0, "string", None, None, None),
    "end": (0, None, None, None, None),
}

keywords = {'and', 'or', 'not'}

symbols = {}

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

def tokenize(program):
    pos, l = 0, len(program)
    program = pycompat.bytestr(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 = parser.unescapestr
            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)

def parse(expr):
    p = parser.parser(elements)
    tree, pos = p.parse(tokenize(expr))
    if pos != len(expr):
        raise error.ParseError(_("invalid token"), pos)
    return parser.simplifyinfixops(tree, {'list', 'or'})

def getsymbol(x):
    if x and x[0] == 'symbol':
        return x[1]
    raise error.ParseError(_('not a symbol'))

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

def getkindpat(x, y, allkinds, err):
    kind = getsymbol(x)
    pat = getstring(y, err)
    if kind not in allkinds:
        raise error.ParseError(_("invalid pattern kind: %s") % kind)
    return '%s:%s' % (kind, pat)

def getpattern(x, allkinds, err):
    if x and x[0] == 'kindpat':
        return getkindpat(x[1], x[2], allkinds, err)
    return getstring(x, err)

def getlist(x):
    if not x:
        return []
    if x[0] == 'list':
        return list(x[1:])
    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 _analyze(x):
    if x is None:
        return x

    op = x[0]
    if op in {'string', 'symbol'}:
        return x
    if op == 'kindpat':
        getsymbol(x[1])  # kind must be a symbol
        t = _analyze(x[2])
        return (op, x[1], t)
    if op == 'group':
        return _analyze(x[1])
    if op == 'negate':
        raise error.ParseError(_("can't use negate operator in this context"))
    if op == 'not':
        t = _analyze(x[1])
        return (op, t)
    if op == 'and':
        ta = _analyze(x[1])
        tb = _analyze(x[2])
        return (op, ta, tb)
    if op == 'minus':
        return _analyze(('and', x[1], ('not', x[2])))
    if op in {'list', 'or'}:
        ts = tuple(_analyze(y) for y in x[1:])
        return (op,) + ts
    if op == 'func':
        getsymbol(x[1])  # function name must be a symbol
        ta = _analyze(x[2])
        return (op, x[1], ta)
    raise error.ProgrammingError('invalid operator %r' % op)

def _insertstatushints(x):
    """Insert hint nodes where status should be calculated (first path)

    This works in bottom-up way, summing up status names and inserting hint
    nodes at 'and' and 'or' as needed. Thus redundant hint nodes may be left.

    Returns (status-names, new-tree) at the given subtree, where status-names
    is a sum of status names referenced in the given subtree.
    """
    if x is None:
        return (), x

    op = x[0]
    if op in {'string', 'symbol', 'kindpat'}:
        return (), x
    if op == 'not':
        h, t = _insertstatushints(x[1])
        return h, (op, t)
    if op == 'and':
        ha, ta = _insertstatushints(x[1])
        hb, tb = _insertstatushints(x[2])
        hr = ha + hb
        if ha and hb:
            return hr, ('withstatus', (op, ta, tb), ('string', ' '.join(hr)))
        return hr, (op, ta, tb)
    if op == 'or':
        hs, ts = zip(*(_insertstatushints(y) for y in x[1:]))
        hr = sum(hs, ())
        if sum(bool(h) for h in hs) > 1:
            return hr, ('withstatus', (op,) + ts, ('string', ' '.join(hr)))
        return hr, (op,) + ts
    if op == 'list':
        hs, ts = zip(*(_insertstatushints(y) for y in x[1:]))
        return sum(hs, ()), (op,) + ts
    if op == 'func':
        f = getsymbol(x[1])
        # don't propagate 'ha' crossing a function boundary
        ha, ta = _insertstatushints(x[2])
        if getattr(symbols.get(f), '_callstatus', False):
            return (f,), ('withstatus', (op, x[1], ta), ('string', f))
        return (), (op, x[1], ta)
    raise error.ProgrammingError('invalid operator %r' % op)

def _mergestatushints(x, instatus):
    """Remove redundant status hint nodes (second path)

    This is the top-down path to eliminate inner hint nodes.
    """
    if x is None:
        return x

    op = x[0]
    if op == 'withstatus':
        if instatus:
            # drop redundant hint node
            return _mergestatushints(x[1], instatus)
        t = _mergestatushints(x[1], instatus=True)
        return (op, t, x[2])
    if op in {'string', 'symbol', 'kindpat'}:
        return x
    if op == 'not':
        t = _mergestatushints(x[1], instatus)
        return (op, t)
    if op == 'and':
        ta = _mergestatushints(x[1], instatus)
        tb = _mergestatushints(x[2], instatus)
        return (op, ta, tb)
    if op in {'list', 'or'}:
        ts = tuple(_mergestatushints(y, instatus) for y in x[1:])
        return (op,) + ts
    if op == 'func':
        # don't propagate 'instatus' crossing a function boundary
        ta = _mergestatushints(x[2], instatus=False)
        return (op, x[1], ta)
    raise error.ProgrammingError('invalid operator %r' % op)

def analyze(x):
    """Transform raw parsed tree to evaluatable tree which can be fed to
    optimize() or getmatch()

    All pseudo operations should be mapped to real operations or functions
    defined in methods or symbols table respectively.
    """
    t = _analyze(x)
    _h, t = _insertstatushints(t)
    return _mergestatushints(t, instatus=False)

def _optimizeandops(op, ta, tb):
    if tb is not None and tb[0] == 'not':
        return ('minus', ta, tb[1])
    return (op, ta, tb)

def _optimizeunion(xs):
    # collect string patterns so they can be compiled into a single regexp
    ws, ts, ss = [], [], []
    for x in xs:
        w, t = _optimize(x)
        if t is not None and t[0] in {'string', 'symbol', 'kindpat'}:
            ss.append(t)
            continue
        ws.append(w)
        ts.append(t)
    if ss:
        ws.append(WEIGHT_CHECK_FILENAME)
        ts.append(('patterns',) + tuple(ss))
    return ws, ts

def _optimize(x):
    if x is None:
        return 0, x

    op = x[0]
    if op == 'withstatus':
        w, t = _optimize(x[1])
        return w, (op, t, x[2])
    if op in {'string', 'symbol'}:
        return WEIGHT_CHECK_FILENAME, x
    if op == 'kindpat':
        w, t = _optimize(x[2])
        return w, (op, x[1], t)
    if op == 'not':
        w, t = _optimize(x[1])
        return w, (op, t)
    if op == 'and':
        wa, ta = _optimize(x[1])
        wb, tb = _optimize(x[2])
        if wa <= wb:
            return wa, _optimizeandops(op, ta, tb)
        else:
            return wb, _optimizeandops(op, tb, ta)
    if op == 'or':
        ws, ts = _optimizeunion(x[1:])
        if len(ts) == 1:
            return ws[0], ts[0] # 'or' operation is fully optimized out
        ts = tuple(it[1] for it in sorted(enumerate(ts),
                                          key=lambda it: ws[it[0]]))
        return max(ws), (op,) + ts
    if op == 'list':
        ws, ts = zip(*(_optimize(y) for y in x[1:]))
        return sum(ws), (op,) + ts
    if op == 'func':
        f = getsymbol(x[1])
        w = getattr(symbols.get(f), '_weight', 1)
        wa, ta = _optimize(x[2])
        return w + wa, (op, x[1], ta)
    raise error.ProgrammingError('invalid operator %r' % op)

def optimize(x):
    """Reorder/rewrite evaluatable tree for optimization

    All pseudo operations should be transformed beforehand.
    """
    _w, t = _optimize(x)
    return t

def prettyformat(tree):
    return parser.prettyformat(tree, ('string', 'symbol'))