##// END OF EJS Templates
rebase: do not invent successor to skipped changeset...
rebase: do not invent successor to skipped changeset When rebase results in an empty a changeset it is "skipped" and no related changeset is created at all. When we added obsolescence support to rebase (in fc2a6114f0a0) it seemed a good idea to use its parent successor as the successors for such dropped changesets. (see old version of the altered test). This option was chosen because it seems a good way to hint about were the dropped changeset "intended" to be. Such hint would have been used by automatic evolution mechanism to rebase potential unstable children. However, field testing of this version are not conclusive. It very often leads to the creation of (totally unfounded) evolution divergence. This changeset changes this behavior and mark skipped changesets as pruned (obsolete without successors). This prevents the issue and seems semantically better probably a win for obsolescence reading tool. See example bellow for details: User Babar has five changesets of interest: - O, its current base of development. - U, the new upstream - A and C, some development changesets - B another development changeset independent from A O - A - B - C \ U Babar decides that B is more critical than the A and C and rebase it first $ hg rebase --rev B --dest U B is now obsolete (in lower case bellow). Rebase result, B', is its successors.(note, C is unstable) O - A - b - C \ U - B' Babar is now done with B', and want to rebase the rest of its history: $ hg rebase --source A --dest B' hg rebase process A, B and C. B is skipped as all its changes are already contained in B'. O - U - B' - A' - C' Babar have the expected result graph wise, obsolescence marker are as follow: B -> B' (from first rebase) A -> A' (from second rebase) C -> C' (from second rebase) B -> ?? (from second rebase) Before this changeset, the last marker is `B -> A'`. This cause two issues: - This is semantically wrong. B have nothing to do with A' - B has now two successors sets: (B',) and (A',). We detect a divergent rewriting. The B' and A' are reported as "divergent" to Babar, confusion ensues. In addition such divergent situation (divergent changeset are children to each other) is tricky to solve. With this changeset the last marker is `B -> ΓΈ`: - This is semantically better. - B has a single successors set (B',) This scenario is added to the tests suite.

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dagparser.py
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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.
import re, string
import util
from i18n import _
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():
try:
return chiter.next()
except StopIteration:
return '\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 == '$':
p1 = -1
c = nextch()
elif c == '\0':
return # in case it was preceded by whitespace
else:
s = ''
i = 0
while c != '\0' and i < 10:
s += c
i += 1
c = nextch()
raise util.Abort(_('invalid character in dag description: '
'%s...') % s)
def dagtextlines(events,
addspaces=True,
wraplabels=False,
wrapannotations=False,
wrapcommands=False,
wrapnonlinear=False,
usedots=False,
maxlinewidth=70):
'''generates single lines for dagtext()'''
def wrapstring(text):
if re.match("^[0-9a-z]*$", 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 util.Abort(_("expected id %i, got %i") % (wantr, r))
if not ps:
ps = [-1]
else:
for p in ps:
if p >= r:
raise util.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 util.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))