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view mercurial/dagparser.py @ 42743:8c9a6adec67a
rust-discovery: using the children cache in add_missing
The DAG range computation often needs to get back to very old
revisions, and turns out to be disproportionately long, given
that the end goal is to remove the descendents of the given
missing revisons from the undecided set.
The fast iteration capabilities available in the Rust case make
it possible to avoid the DAG range entirely, at the cost of
precomputing the children cache, and to simply iterate on
children of the given missing revisions.
This is a case where staying on the same side of the interface
between the two languages has clear benefits.
On discoveries with initial undecided sets
small enough to bypass sampling entirely, the total cost of
computing the children cache and the subsequent iteration
becomes better than the Python + C counterpart, which relies on
reachableroots2.
For example, on a repo with more than one million revisions with
an initial undecided set of 11 elements, we get these figures:
Rust version with simple iteration
addcommons: 57.287us
first undecided computation: 184.278334ms
first children cache computation: 131.056us
addmissings iteration: 42.766us
first addinfo total: 185.24 ms
Python + C version
first addcommons: 0.29 ms
addcommons 0.21 ms
first undecided computation 191.35 ms
addmissings 45.75 ms
first addinfo total: 237.77 ms
On discoveries with large undecided sets, the initial price paid
makes the first addinfo slower than the Python + C version,
but that's more than compensated by the gain in sampling and
subsequent iterations.
Here's an extreme example with an undecided set of a million revisions:
Rust version:
first undecided computation: 293.842629ms
first children cache computation: 407.911297ms
addmissings iteration: 34.312869ms
first addinfo total: 776.02 ms
taking initial sample
query 2: sampling time: 1318.38 ms
query 2; still undecided: 1005013, sample size is: 200
addmissings: 143.062us
Python + C version:
first undecided computation 298.13 ms
addmissings 80.13 ms
first addinfo total: 399.62 ms
taking initial sample
query 2: sampling time: 3957.23 ms
query 2; still undecided: 1005013, sample size is: 200
addmissings 52.88 ms
Differential Revision: https://phab.mercurial-scm.org/D6428
author | Georges Racinet <georges.racinet@octobus.net> |
---|---|
date | Tue, 16 Apr 2019 01:16:39 +0200 |
parents | e7aa113b14f7 |
children | 2372284d9457 |
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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, pycompat, ) from .utils import ( stringutil, ) 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(b""" ... ... +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(b"")) [] A simple linear run: >>> list(parsedag(b"+3")) [('n', (0, [-1])), ('n', (1, [0])), ('n', (2, [1]))] Some non-standard ways to define such runs: >>> list(parsedag(b"+1+2")) [('n', (0, [-1])), ('n', (1, [0])), ('n', (2, [1]))] >>> list(parsedag(b"+1*1*")) [('n', (0, [-1])), ('n', (1, [0])), ('n', (2, [1]))] >>> list(parsedag(b"*")) [('n', (0, [-1]))] >>> list(parsedag(b"...")) [('n', (0, [-1])), ('n', (1, [0])), ('n', (2, [1]))] A fork and a join, using numeric back references: >>> list(parsedag(b"+2*2*/2")) [('n', (0, [-1])), ('n', (1, [0])), ('n', (2, [0])), ('n', (3, [2, 1]))] >>> list(parsedag(b"+2<2+1/2")) [('n', (0, [-1])), ('n', (1, [0])), ('n', (2, [0])), ('n', (3, [2, 1]))] Placing a label: >>> list(parsedag(b"+1 :mylabel +1")) [('n', (0, [-1])), ('l', (0, 'mylabel')), ('n', (1, [0]))] An empty label (silly, really): >>> list(parsedag(b"+1:+1")) [('n', (0, [-1])), ('l', (0, '')), ('n', (1, [0]))] Fork and join, but with labels instead of numeric back references: >>> list(parsedag(b"+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(b"+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(b"+1 $ +1")) [('n', (0, [-1])), ('n', (1, [-1]))] Annotations, which are meant to introduce sticky state for subsequent nodes: >>> list(parsedag(b"+1 @ann +1")) [('n', (0, [-1])), ('a', 'ann'), ('n', (1, [0]))] >>> list(parsedag(b'+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(b"+1 !cmd +1")) [('n', (0, [-1])), ('c', 'cmd'), ('n', (1, [0]))] >>> list(parsedag(b'+1 !"my command" +1')) [('n', (0, [-1])), ('c', 'my command'), ('n', (1, [0]))] >>> list(parsedag(b'+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(b'+1 # comment\\n+1')) [('n', (0, [-1])), ('n', (1, [0]))] Error: >>> try: list(parsedag(b'+1 bad')) ... except Exception as e: print(pycompat.sysstr(bytes(e))) invalid character in dag description: bad... ''' if not desc: return wordchars = pycompat.bytestr(string.ascii_letters + string.digits) labels = {} p1 = -1 r = 0 def resolve(ref): if not ref: return p1 elif ref[0] in pycompat.bytestr(string.digits): return r - int(ref) else: return labels[ref] chiter = pycompat.iterbytestr(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 pycompat.bytestr(string.whitespace): c = nextch() if c == '.': yield 'n', (r, [p1]) p1 = r r += 1 c = nextch() elif c == '+': c, digs = nextrun(nextch(), pycompat.bytestr(string.digits)) n = int(digs) for i in pycompat.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 '+%d' % 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 '+%d' % 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('%d' % (r - p)) yield '*' + '/'.join(prefs) else: if run: yield '+%d' % 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', '%s')") % (stringutil.escapestr(kind), stringutil.escapestr(data))) if run: yield '+%d' % 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([(b'n', (0, [-1])), (b'n', (1, [0]))]) '+2' Two roots: >>> dagtext([(b'n', (0, [-1])), (b'n', (1, [-1]))]) '+1 $ +1' Fork and join: >>> dagtext([(b'n', (0, [-1])), (b'n', (1, [0])), (b'n', (2, [0])), ... (b'n', (3, [2, 1]))]) '+2 *2 */2' Fork and join with labels: >>> dagtext([(b'n', (0, [-1])), (b'l', (0, b'f')), (b'n', (1, [0])), ... (b'l', (1, b'p2')), (b'n', (2, [0])), (b'n', (3, [2, 1]))]) '+1 :f +1 :p2 *f */p2' Annotations: >>> dagtext([(b'n', (0, [-1])), (b'a', b'ann'), (b'n', (1, [0]))]) '+1 @ann +1' >>> dagtext([(b'n', (0, [-1])), ... (b'a', b'my annotation'), ... (b'n', (1, [0]))]) '+1 @"my annotation" +1' Commands: >>> dagtext([(b'n', (0, [-1])), (b'c', b'cmd'), (b'n', (1, [0]))]) '+1 !cmd +1' >>> dagtext([(b'n', (0, [-1])), ... (b'c', b'my command'), ... (b'n', (1, [0]))]) '+1 !"my command" +1' >>> dagtext([(b'n', (0, [-1])), ... (b'C', b'my command line'), ... (b'n', (1, [0]))]) '+1 !!my command line\\n+1' Comments: >>> dagtext([(b'n', (0, [-1])), (b'#', b' comment'), (b'n', (1, [0]))]) '+1 # comment\\n+1' >>> dagtext([]) '' Combining parsedag and dagtext: >>> dagtext(parsedag(b'+1 :f +1 :p2 *f */p2')) '+1 :f +1 :p2 *f */p2' ''' return "\n".join(dagtextlines(dag, addspaces, wraplabels, wrapannotations, wrapcommands, wrapnonlinear, usedots, maxlinewidth))