view mercurial/templater.py @ 11060:e6df01776e08

findrenames: Optimise "addremove -s100" by matching files by their SHA1 hashes.

We speed up 'findrenames' for the usecase when a user specifies they
want a similarity of 100% by matching files by their exact SHA1 hash
value. This reduces the number of comparisons required to find exact
matches from O(n^2) to O(n).

While it would be nice if we could just use mercurial's pre-calculated
SHA1 hash for existing files, this hash includes the file's ancestor
information making it unsuitable for our purposes. Instead, we calculate
the hash of old content from scratch.

The following benchmarks were taken on the current head of crew:

addremove 100% similarity:
  rm -rf *; hg up -C; mv tests tests.new
  hg --time addremove -s100 --dry-run

  before:  real 176.350 secs (user 128.890+0.000 sys 47.430+0.000)
  after:   real   2.130 secs (user   1.890+0.000 sys  0.240+0.000)

addremove 75% similarity:
  rm -rf *; hg up -C; mv tests tests.new; \
      for i in tests.new/*; do echo x >> $i; done
  hg --time addremove -s75  --dry-run

  before: real 264.560 secs (user 215.130+0.000 sys 49.410+0.000)
  after:  real 218.710 secs (user 172.790+0.000 sys 45.870+0.000)

# templater.py - template expansion for output
#
# Copyright 2005, 2006 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 i18n import _
import sys, os
import util, config, templatefilters

path = ['templates', '../templates']
stringify = templatefilters.stringify

def _flatten(thing):
    '''yield a single stream from a possibly nested set of iterators'''
    if isinstance(thing, str):
        yield thing
    elif not hasattr(thing, '__iter__'):
        if i is not None:
            yield str(thing)
    else:
        for i in thing:
            if isinstance(i, str):
                yield i
            elif not hasattr(i, '__iter__'):
                if i is not None:
                    yield str(i)
            elif i is not None:
                for j in _flatten(i):
                    yield j

def parsestring(s, quoted=True):
    '''parse a string using simple c-like syntax.
    string must be in quotes if quoted is True.'''
    if quoted:
        if len(s) < 2 or s[0] != s[-1]:
            raise SyntaxError(_('unmatched quotes'))
        return s[1:-1].decode('string_escape')

    return s.decode('string_escape')

class engine(object):
    '''template expansion engine.

    template expansion works like this. a map file contains key=value
    pairs. if value is quoted, it is treated as string. otherwise, it
    is treated as name of template file.

    templater is asked to expand a key in map. it looks up key, and
    looks for strings like this: {foo}. it expands {foo} by looking up
    foo in map, and substituting it. expansion is recursive: it stops
    when there is no more {foo} to replace.

    expansion also allows formatting and filtering.

    format uses key to expand each item in list. syntax is
    {key%format}.

    filter uses function to transform value. syntax is
    {key|filter1|filter2|...}.'''

    def __init__(self, loader, filters={}, defaults={}):
        self._loader = loader
        self._filters = filters
        self._defaults = defaults
        self._cache = {}

    def process(self, t, mapping):
        '''Perform expansion. t is name of map element to expand.
        mapping contains added elements for use during expansion. Is a
        generator.'''
        return _flatten(self._process(self._load(t), mapping))

    def _load(self, t):
        '''load, parse, and cache a template'''
        if t not in self._cache:
            self._cache[t] = self._parse(self._loader(t))
        return self._cache[t]

    def _get(self, mapping, key):
        v = mapping.get(key)
        if v is None:
            v = self._defaults.get(key, '')
        if hasattr(v, '__call__'):
            v = v(**mapping)
        return v

    def _filter(self, mapping, parts):
        filters, val = parts
        x = self._get(mapping, val)
        for f in filters:
            x = f(x)
        return x

    def _format(self, mapping, args):
        key, parsed = args
        v = self._get(mapping, key)
        if not hasattr(v, '__iter__'):
            raise SyntaxError(_("error expanding '%s%%%s'")
                              % (key, format))
        lm = mapping.copy()
        for i in v:
            if isinstance(i, dict):
                lm.update(i)
                yield self._process(parsed, lm)
            else:
                # v is not an iterable of dicts, this happen when 'key'
                # has been fully expanded already and format is useless.
                # If so, return the expanded value.
                yield i

    def _parse(self, tmpl):
        '''preparse a template'''
        parsed = []
        pos, stop = 0, len(tmpl)
        while pos < stop:
            n = tmpl.find('{', pos)
            if n < 0:
                parsed.append((None, tmpl[pos:stop]))
                break
            if n > 0 and tmpl[n - 1] == '\\':
                # escaped
                parsed.append((None, tmpl[pos:n - 1] + "{"))
                pos = n + 1
                continue
            if n > pos:
                parsed.append((None, tmpl[pos:n]))

            pos = n
            n = tmpl.find('}', pos)
            if n < 0:
                # no closing
                parsed.append((None, tmpl[pos:stop]))
                break

            expr = tmpl[pos + 1:n]
            pos = n + 1

            if '%' in expr:
                key, t = expr.split('%')
                parsed.append((self._format, (key.strip(),
                                              self._load(t.strip()))))
            elif '|' in expr:
                parts = expr.split('|')
                val = parts[0].strip()
                try:
                    filters = [self._filters[f.strip()] for f in parts[1:]]
                except KeyError, i:
                    raise SyntaxError(_("unknown filter '%s'") % i[0])
                parsed.append((self._filter, (filters, val)))
            else:
                parsed.append((self._get, expr.strip()))

        return parsed

    def _process(self, parsed, mapping):
        '''Render a template. Returns a generator.'''
        for f, e in parsed:
            if f:
                yield f(mapping, e)
            else:
                yield e

engines = {'default': engine}

class templater(object):

    def __init__(self, mapfile, filters={}, defaults={}, cache={},
                 minchunk=1024, maxchunk=65536):
        '''set up template engine.
        mapfile is name of file to read map definitions from.
        filters is dict of functions. each transforms a value into another.
        defaults is dict of default map definitions.'''
        self.mapfile = mapfile or 'template'
        self.cache = cache.copy()
        self.map = {}
        self.base = (mapfile and os.path.dirname(mapfile)) or ''
        self.filters = templatefilters.filters.copy()
        self.filters.update(filters)
        self.defaults = defaults
        self.minchunk, self.maxchunk = minchunk, maxchunk
        self.engines = {}

        if not mapfile:
            return
        if not os.path.exists(mapfile):
            raise util.Abort(_('style not found: %s') % mapfile)

        conf = config.config()
        conf.read(mapfile)

        for key, val in conf[''].items():
            if val[0] in "'\"":
                try:
                    self.cache[key] = parsestring(val)
                except SyntaxError, inst:
                    raise SyntaxError('%s: %s' %
                                      (conf.source('', key), inst.args[0]))
            else:
                val = 'default', val
                if ':' in val[1]:
                    val = val[1].split(':', 1)
                self.map[key] = val[0], os.path.join(self.base, val[1])

    def __contains__(self, key):
        return key in self.cache or key in self.map

    def load(self, t):
        '''Get the template for the given template name. Use a local cache.'''
        if not t in self.cache:
            try:
                self.cache[t] = open(self.map[t][1]).read()
            except IOError, inst:
                raise IOError(inst.args[0], _('template file %s: %s') %
                              (self.map[t][1], inst.args[1]))
        return self.cache[t]

    def __call__(self, t, **mapping):
        ttype = t in self.map and self.map[t][0] or 'default'
        proc = self.engines.get(ttype)
        if proc is None:
            proc = engines[ttype](self.load, self.filters, self.defaults)
            self.engines[ttype] = proc

        stream = proc.process(t, mapping)
        if self.minchunk:
            stream = util.increasingchunks(stream, min=self.minchunk,
                                           max=self.maxchunk)
        return stream

def templatepath(name=None):
    '''return location of template file or directory (if no name).
    returns None if not found.'''
    normpaths = []

    # executable version (py2exe) doesn't support __file__
    if hasattr(sys, 'frozen'):
        module = sys.executable
    else:
        module = __file__
    for f in path:
        if f.startswith('/'):
            p = f
        else:
            fl = f.split('/')
            p = os.path.join(os.path.dirname(module), *fl)
        if name:
            p = os.path.join(p, name)
        if name and os.path.exists(p):
            return os.path.normpath(p)
        elif os.path.isdir(p):
            normpaths.append(os.path.normpath(p))

    return normpaths

def stylemap(styles, paths=None):
    """Return path to mapfile for a given style.

    Searches mapfile in the following locations:
    1. templatepath/style/map
    2. templatepath/map-style
    3. templatepath/map
    """

    if paths is None:
        paths = templatepath()
    elif isinstance(paths, str):
        paths = [paths]

    if isinstance(styles, str):
        styles = [styles]

    for style in styles:
        if not style:
            continue
        locations = [os.path.join(style, 'map'), 'map-' + style]
        locations.append('map')

        for path in paths:
            for location in locations:
                mapfile = os.path.join(path, location)
                if os.path.isfile(mapfile):
                    return style, mapfile

    raise RuntimeError("No hgweb templates found in %r" % paths)