Mercurial > hg
view mercurial/dagparser.py @ 29304:5e32852fa4bd
revset: make filteredset.__nonzero__ respect the order of the filteredset
This fix allows __nonzero__ to respect the direction of iteration of the
whole filteredset. Here's the case when it matters. Imagine that we have a
very large repository and we want to execute a command like:
$ hg log --rev '(tip:0) and user(ikostia)' --limit 1
(we want to get the latest commit by me).
Mercurial will evaluate a filteredset lazy data structure, an
instance of the filteredset class, which will know that it has to iterate
in a descending order (isdescending() will return True if called). This
means that when some code iterates over the instance of this filteredset,
the 'and user(ikostia)' condition will be first checked on the latest
revision, then on the second latest and so on, allowing Mercurial to
print matches as it founds them. However, cmdutil.getgraphlogrevs
contains the following code:
revs = _logrevs(repo, opts)
if not revs:
return revset.baseset(), None, None
The "not revs" expression is evaluated by calling filteredset.__nonzero__,
which in its current implementation will try to iterate the filteredset
in ascending order until it finds a revision that matches the 'and user(..'
condition. If the condition is only true on late revisions, a lot of
useless iterations will be done. These iterations could be avoided if
__nonzero__ followed the order of the filteredset, which in my opinion
is a sensible thing to do here.
The problem gets even worse when instead of 'user(ikostia)' some more
expensive check is performed, like grepping the commit diff.
I tested this fix on a very large repo where tip is my commit and my very
first commit comes fairly late in the revision history. Results of timing
of the above command on that very large repo.
-with my fix:
real 0m1.795s
user 0m1.657s
sys 0m0.135s
-without my fix:
real 1m29.245s
user 1m28.223s
sys 0m0.929s
I understand that this is a very specific kind of problem that presents
itself very rarely, only on very big repositories and with expensive
checks and so on. But I don't see any disadvantages to this kind of fix
either.
author | Kostia Balytskyi <ikostia@fb.com> |
---|---|
date | Thu, 02 Jun 2016 22:39:01 +0100 |
parents | 56b2bcea2529 |
children | c91013452b33 |
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# dagparser.py - parser and generator for concise description of DAGs # # Copyright 2010 Peter Arrenbrecht <peter@arrenbrecht.ch> # # 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 import re import string from .i18n import _ from . import error def parsedag(desc): '''parses a DAG from a concise textual description; generates events "+n" is a linear run of n nodes based on the current default parent "." is a single node based on the current default parent "$" resets the default parent to -1 (implied at the start); otherwise the default parent is always the last node created "<p" sets the default parent to the backref p "*p" is a fork at parent p, where p is a backref "*p1/p2/.../pn" is a merge of parents p1..pn, where the pi are backrefs "/p2/.../pn" is a merge of the preceding node and p2..pn ":name" defines a label for the preceding node; labels can be redefined "@text" emits an annotation event for text "!command" emits an action event for the current node "!!my command\n" is like "!", but to the end of the line "#...\n" is a comment up to the end of the line Whitespace between the above elements is ignored. A backref is either * a number n, which references the node curr-n, where curr is the current node, or * the name of a label you placed earlier using ":name", or * empty to denote the default parent. All string valued-elements are either strictly alphanumeric, or must be enclosed in double quotes ("..."), with "\" as escape character. Generates sequence of ('n', (id, [parentids])) for node creation ('l', (id, labelname)) for labels on nodes ('a', text) for annotations ('c', command) for actions (!) ('C', command) for line actions (!!) Examples -------- Example of a complex graph (output not shown for brevity): >>> len(list(parsedag(""" ... ... +3 # 3 nodes in linear run ... :forkhere # a label for the last of the 3 nodes from above ... +5 # 5 more nodes on one branch ... :mergethis # label again ... <forkhere # set default parent to labeled fork node ... +10 # 10 more nodes on a parallel branch ... @stable # following nodes will be annotated as "stable" ... +5 # 5 nodes in stable ... !addfile # custom command; could trigger new file in next node ... +2 # two more nodes ... /mergethis # merge last node with labeled node ... +4 # 4 more nodes descending from merge node ... ... """))) 34 Empty list: >>> list(parsedag("")) [] A simple linear run: >>> list(parsedag("+3")) [('n', (0, [-1])), ('n', (1, [0])), ('n', (2, [1]))] Some non-standard ways to define such runs: >>> list(parsedag("+1+2")) [('n', (0, [-1])), ('n', (1, [0])), ('n', (2, [1]))] >>> list(parsedag("+1*1*")) [('n', (0, [-1])), ('n', (1, [0])), ('n', (2, [1]))] >>> list(parsedag("*")) [('n', (0, [-1]))] >>> list(parsedag("...")) [('n', (0, [-1])), ('n', (1, [0])), ('n', (2, [1]))] A fork and a join, using numeric back references: >>> list(parsedag("+2*2*/2")) [('n', (0, [-1])), ('n', (1, [0])), ('n', (2, [0])), ('n', (3, [2, 1]))] >>> list(parsedag("+2<2+1/2")) [('n', (0, [-1])), ('n', (1, [0])), ('n', (2, [0])), ('n', (3, [2, 1]))] Placing a label: >>> list(parsedag("+1 :mylabel +1")) [('n', (0, [-1])), ('l', (0, 'mylabel')), ('n', (1, [0]))] An empty label (silly, really): >>> list(parsedag("+1:+1")) [('n', (0, [-1])), ('l', (0, '')), ('n', (1, [0]))] Fork and join, but with labels instead of numeric back references: >>> list(parsedag("+1:f +1:p2 *f */p2")) [('n', (0, [-1])), ('l', (0, 'f')), ('n', (1, [0])), ('l', (1, 'p2')), ('n', (2, [0])), ('n', (3, [2, 1]))] >>> list(parsedag("+1:f +1:p2 <f +1 /p2")) [('n', (0, [-1])), ('l', (0, 'f')), ('n', (1, [0])), ('l', (1, 'p2')), ('n', (2, [0])), ('n', (3, [2, 1]))] Restarting from the root: >>> list(parsedag("+1 $ +1")) [('n', (0, [-1])), ('n', (1, [-1]))] Annotations, which are meant to introduce sticky state for subsequent nodes: >>> list(parsedag("+1 @ann +1")) [('n', (0, [-1])), ('a', 'ann'), ('n', (1, [0]))] >>> list(parsedag('+1 @"my annotation" +1')) [('n', (0, [-1])), ('a', 'my annotation'), ('n', (1, [0]))] Commands, which are meant to operate on the most recently created node: >>> list(parsedag("+1 !cmd +1")) [('n', (0, [-1])), ('c', 'cmd'), ('n', (1, [0]))] >>> list(parsedag('+1 !"my command" +1')) [('n', (0, [-1])), ('c', 'my command'), ('n', (1, [0]))] >>> list(parsedag('+1 !!my command line\\n +1')) [('n', (0, [-1])), ('C', 'my command line'), ('n', (1, [0]))] Comments, which extend to the end of the line: >>> list(parsedag('+1 # comment\\n+1')) [('n', (0, [-1])), ('n', (1, [0]))] Error: >>> try: list(parsedag('+1 bad')) ... except Exception, e: print e invalid character in dag description: bad... ''' if not desc: return wordchars = string.ascii_letters + string.digits labels = {} p1 = -1 r = 0 def resolve(ref): if not ref: return p1 elif ref[0] in string.digits: return r - int(ref) else: return labels[ref] chiter = (c for c in desc) def nextch(): return next(chiter, '\0') def nextrun(c, allow): s = '' while c in allow: s += c c = nextch() return c, s def nextdelimited(c, limit, escape): s = '' while c != limit: if c == escape: c = nextch() s += c c = nextch() return nextch(), s def nextstring(c): if c == '"': return nextdelimited(nextch(), '"', '\\') else: return nextrun(c, wordchars) c = nextch() while c != '\0': while c in string.whitespace: c = nextch() if c == '.': yield 'n', (r, [p1]) p1 = r r += 1 c = nextch() elif c == '+': c, digs = nextrun(nextch(), string.digits) n = int(digs) for i in xrange(0, n): yield 'n', (r, [p1]) p1 = r r += 1 elif c in '*/': if c == '*': c = nextch() c, pref = nextstring(c) prefs = [pref] while c == '/': c, pref = nextstring(nextch()) prefs.append(pref) ps = [resolve(ref) for ref in prefs] yield 'n', (r, ps) p1 = r r += 1 elif c == '<': c, ref = nextstring(nextch()) p1 = resolve(ref) elif c == ':': c, name = nextstring(nextch()) labels[name] = p1 yield 'l', (p1, name) elif c == '@': c, text = nextstring(nextch()) yield 'a', text elif c == '!': c = nextch() if c == '!': cmd = '' c = nextch() while c not in '\n\r\0': cmd += c c = nextch() yield 'C', cmd else: c, cmd = nextstring(c) yield 'c', cmd elif c == '#': while c not in '\n\r\0': c = nextch() elif c == '$': p1 = -1 c = nextch() elif c == '\0': return # in case it was preceded by whitespace else: s = '' i = 0 while c != '\0' and i < 10: s += c i += 1 c = nextch() raise error.Abort(_('invalid character in dag description: ' '%s...') % s) def dagtextlines(events, addspaces=True, wraplabels=False, wrapannotations=False, wrapcommands=False, wrapnonlinear=False, usedots=False, maxlinewidth=70): '''generates single lines for dagtext()''' def wrapstring(text): if re.match("^[0-9a-z]*$", text): return text return '"' + text.replace('\\', '\\\\').replace('"', '\"') + '"' def gen(): labels = {} run = 0 wantr = 0 needroot = False for kind, data in events: if kind == 'n': r, ps = data # sanity check if r != wantr: raise error.Abort(_("expected id %i, got %i") % (wantr, r)) if not ps: ps = [-1] else: for p in ps: if p >= r: raise error.Abort(_("parent id %i is larger than " "current id %i") % (p, r)) wantr += 1 # new root? p1 = r - 1 if len(ps) == 1 and ps[0] == -1: if needroot: if run: yield '+' + str(run) run = 0 if wrapnonlinear: yield '\n' yield '$' p1 = -1 else: needroot = True if len(ps) == 1 and ps[0] == p1: if usedots: yield "." else: run += 1 else: if run: yield '+' + str(run) run = 0 if wrapnonlinear: yield '\n' prefs = [] for p in ps: if p == p1: prefs.append('') elif p in labels: prefs.append(labels[p]) else: prefs.append(str(r - p)) yield '*' + '/'.join(prefs) else: if run: yield '+' + str(run) run = 0 if kind == 'l': rid, name = data labels[rid] = name yield ':' + name if wraplabels: yield '\n' elif kind == 'c': yield '!' + wrapstring(data) if wrapcommands: yield '\n' elif kind == 'C': yield '!!' + data yield '\n' elif kind == 'a': if wrapannotations: yield '\n' yield '@' + wrapstring(data) elif kind == '#': yield '#' + data yield '\n' else: raise error.Abort(_("invalid event type in dag: %s") % str((type, data))) if run: yield '+' + str(run) line = '' for part in gen(): if part == '\n': if line: yield line line = '' else: if len(line) + len(part) >= maxlinewidth: yield line line = '' elif addspaces and line and part != '.': line += ' ' line += part if line: yield line def dagtext(dag, addspaces=True, wraplabels=False, wrapannotations=False, wrapcommands=False, wrapnonlinear=False, usedots=False, maxlinewidth=70): '''generates lines of a textual representation for a dag event stream events should generate what parsedag() does, so: ('n', (id, [parentids])) for node creation ('l', (id, labelname)) for labels on nodes ('a', text) for annotations ('c', text) for commands ('C', text) for line commands ('!!') ('#', text) for comment lines Parent nodes must come before child nodes. Examples -------- Linear run: >>> dagtext([('n', (0, [-1])), ('n', (1, [0]))]) '+2' Two roots: >>> dagtext([('n', (0, [-1])), ('n', (1, [-1]))]) '+1 $ +1' Fork and join: >>> dagtext([('n', (0, [-1])), ('n', (1, [0])), ('n', (2, [0])), ... ('n', (3, [2, 1]))]) '+2 *2 */2' Fork and join with labels: >>> dagtext([('n', (0, [-1])), ('l', (0, 'f')), ('n', (1, [0])), ... ('l', (1, 'p2')), ('n', (2, [0])), ('n', (3, [2, 1]))]) '+1 :f +1 :p2 *f */p2' Annotations: >>> dagtext([('n', (0, [-1])), ('a', 'ann'), ('n', (1, [0]))]) '+1 @ann +1' >>> dagtext([('n', (0, [-1])), ... ('a', 'my annotation'), ... ('n', (1, [0]))]) '+1 @"my annotation" +1' Commands: >>> dagtext([('n', (0, [-1])), ('c', 'cmd'), ('n', (1, [0]))]) '+1 !cmd +1' >>> dagtext([('n', (0, [-1])), ('c', 'my command'), ('n', (1, [0]))]) '+1 !"my command" +1' >>> dagtext([('n', (0, [-1])), ... ('C', 'my command line'), ... ('n', (1, [0]))]) '+1 !!my command line\\n+1' Comments: >>> dagtext([('n', (0, [-1])), ('#', ' comment'), ('n', (1, [0]))]) '+1 # comment\\n+1' >>> dagtext([]) '' Combining parsedag and dagtext: >>> dagtext(parsedag('+1 :f +1 :p2 *f */p2')) '+1 :f +1 :p2 *f */p2' ''' return "\n".join(dagtextlines(dag, addspaces, wraplabels, wrapannotations, wrapcommands, wrapnonlinear, usedots, maxlinewidth))