Mercurial > hg
view mercurial/dagparser.py @ 29375:fcaf20175b1b
demandimport: delay loading for "from a import b" with absolute_import
Before this patch, "from a import b" doesn't delay loading module "b",
if absolute_import is enabled, even though "from . import b" does.
For example:
- it is assumed that extension X has "from P import M" for module M
under package P with absolute_import feature
- if importing module M is already delayed before loading extension
X, loading module M in extension X is delayed until actually
referring
util, cmdutil, scmutil or so of Mercurial itself should be
imported by "from . import M" style before loading extension X
- otherwise, module M is loaded immediately at loading extension X,
even if extension X itself isn't used at that "hg" command invocation
Some minor modules (e.g. filemerge or so) of Mercurial itself
aren't imported by "from . import M" style before loading
extension X. And of course, external libraries aren't, too.
This might cause startup performance problem of hg command, because
many bundled extensions already enable absolute_import feature.
To delay loading module for "from a import b" with absolute_import
feature, this patch does below in "from a (or .a) import b" with
absolute_import case:
1. import root module of "name" by system built-in __import__
(referred as _origimport)
2. recurse down the module chain for hierarchical "name"
This logic can be shared with non absolute_import
case. Therefore, this patch also centralizes it into chainmodules().
3. and fall through to process elements in "fromlist" for the leaf
module of "name"
Processing elements in "fromlist" is executed in the code path
after "if _pypy: .... else: ..." clause. Therefore, this patch
replaces "if _pypy:" with "elif _pypy:" to share it.
At 4f1144c3c72b introducing original "work around" for "from a import
b" case, elements in "fromlist" were imported with "level=level". But
"level" might be grater than 1 (e.g. level=2 in "from .. import b"
case) at demandimport() invocation, and importing direct sub-module in
"fromlist" with level grater than 1 causes unexpected result.
IMHO, this seems main reason of "errors for unknown reason" described
in 4f1144c3c72b, and we don't have to worry about it, because this
issue was already fixed by 78d05778907b.
This is reason why this patch removes "errors for unknown reasons"
comment.
author | FUJIWARA Katsunori <foozy@lares.dti.ne.jp> |
---|---|
date | Sun, 19 Jun 2016 02:17:33 +0900 |
parents | 56b2bcea2529 |
children | c91013452b33 |
line wrap: on
line source
# 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))