This is naive implementation using two-pass scanning. Tracking descendants
isn't an easy problem if both start and stop depths are specified. It's
impractical to remember all possible depths of each node while scanning from
roots to descendants because the number of depths explodes. Instead, we could
cache (min, max) depths as a good approximation and track ancestors back when
needed, but that's likely to have off-by-one bug.
Since this implementation appears not significantly slower, and is quite
straightforward, I think it's good enough for practical use cases. The time
and space complexity is O(n) ish.
revisions:
0) 1-pass scanning with (min, max)-depth cache (worst-case quadratic)
1) 2-pass scanning (this version)
repository:
mozilla-central
# descendants(0) (for reference)
*) 0.430353
# descendants(0, depth=1000)
0) 0.264889
1) 0.398289
# descendants(limit(tip:0, 1, offset=10000), depth=1000)
0) 0.025478
1) 0.029099
# descendants(0, depth=2000, startdepth=1000)
0) painfully slow (due to quadratic backtracking of ancestors)
1) 1.531138
Prepares for adding depth support. I want to process depth=0 in
revdescendants() to make things simpler.
only() also calls dagop.revdescendants(), but it filters out root revisions
explicitly. So this should cause no problem.
# descendants(0) using hg repo
0) 0.052380
1) 0.051226
# only(tip) using hg repo
0) 0.001433
1) 0.001425
This is necessary to implement the set{gen} (set subscript) operator. For
example, set{-n} will be translated to ancestors(set, depth=n, startdepth=n).
https://www.mercurial-scm.org/wiki/RevsetOperatorPlan#ideas_from_mpm
The UI is undecided and I doubt if the startdepth option would be actually
useful, so the option is hidden for now. 'depth' could be extended to take
min:max range, in which case, integer depth should select a single generation.
ancestors(set, depth=:y) # scan up to y-th generation
ancestors(set, depth=x:) # skip until (x-1)-th generation
ancestors(set, depth=x) # select only x-th generation
Any ideas are welcomed.
# reverse(ancestors(tip)) using hg repo
3) 0.075951
4) 0.076175
This replaces 'if y in subset' with '& subset'. first(null) and last(wdir())
are fixed thanks to fullreposet.__and__.
This also revealed that first() and last() don't follow the order of the
input set. 'ls & subset' is valid only if the ordering requirement is 'define'
or 'any'.
No performance regression observed:
revset #0: limit(0:9999, 100, 9000)
0) 0.001164
1) 0.001135
revset #2: 9000 & limit(0:9999, 100, 9000)
0) 0.001224
1) 0.001181
revset #3: last(0:9999, 100)
0) 0.000237
1) 0.000199
last() is implemented using a reversed iterator, so the result should be
reversed again.
I've marked this as BC since it's quite old bug seen in 3.0. The first bad
revision is 1ef0875a62f8 "revset: changed last implementation to use lazy
classes."
Negative offsets to the `~` operator now search for descendents. The search is
aborted when a node has more than one child as we do not have a definition for
'nth child'. Optionally we can introduce such a notion and take the nth child
ordered by rev number.
The current revset language does provides a short operator for ancestor lookup
but not for descendents. This gives user a simple revset to move to the previous
changeset, e.g. `hg up '.~1'` but not to the 'next' changeset. With this change
userse can now use `.~-1` as a shortcut to move to the next changeset.
This fits better into allowing users to specify revisions via revsets and
avoiding the need for special `hg next` and `hg prev` operations.
The alternative to negative offsets is adding a new operator. We do not have
many operators in ascii left that do not require bash escaping (',', '_', and
'/' come to mind). If we decide that we should add a more convenient short
operator such as ('/', e.g. './1') we can later add it and allow ascendents
lookup via negative numbers.
The idea is simple. If the given node id prefix is 'ff...f', add +1 to the
number of matches (e.g. ambiguous if partial + maybewdir > 1).
This patch also fixes id() revset and shortest() template since _partialmatch()
can raise WdirUnsupported exception.
d46a7814be5f refactored util.parsedate in order to raise ValueError instead
of Abort for using with ui.configwith. It causes several problems, putting
arbitrary bytes in ValueError can cause issues with Python 3. Moreover, we
added a function to convert ValueError exceptions back to Abort.
A better approach would be to make parsedate raises ParseError, removing
the convert function and update configwith to also catch ParseError.
The side-effect is that error message when giving an invalid date in CLI
change from:
abort: invalid date: 'foo bar'
to:
hg: parse error: invalid date: 'foo bar'
I'm not sure if it's an acceptable change, I found personally the error
message more clear but more verbose too.
cmdutil.command wasn't a member of the registrar framework only for a
historical reason. Let's make that happen. This patch keeps cmdutil.command
as an alias for extension compatibility.
This makes the next patch slightly simpler. We don't need to check the
excessive number of keyword arguments since unknown and duplicated kwargs
are rejected.
New revsetlang module hosts parser, tokenizer, and miscellaneous functions
working on parsed tree. It does not include functions for evaluation such as
getset() and match().
2288 mercurial/revset.py
684 mercurial/revsetlang.py
2972 total
get*() functions are aliased since they are common in revset.py.
These classes are pretty large and independent from revset computation.
2961 mercurial/revset.py
973 mercurial/smartset.py
3934 total
revset.prettyformatset() is renamed to smartset.prettyformat(). Smartset
classes are aliased since they are quite common in revset.py.
It was probably unintentional for regex, as the meaning of some sequences like
\S and \s is actually inverted by changing the case. For backward compatibility
however, the matching is forced to case insensitive.
Let's resurrect the docstring since our help module can detect the EXPERIMENTAL
tag and display it only if -v is specified.
This patch updates the test added by bbdfa2d5aaa2 since wdir() is now
documented.
Unlike p1 = null, p2 = null denotes the revision has only one parent, which
shouldn't be considered a child of the null revision. This was spotted while
fixing the issue4682 and rediscovered as issue5439.
Because smartset.reverse() may modify the underlying subset, it should be
called only if the set can define the ordering.
In the following example, 'a' and 'c' is the same object, so 'b.reverse()'
would reverse 'a' unexpectedly.
# '0:2 & reverse(all())'
<filteredset
<spanset- 0:2>, # a
<filteredset # b
<spanset- 0:2>, # c
<spanset+ 0:9>>>
present() is special in that it returns the argument set with no
modification, so the ordering requirement should be forwarded.
We could make present() fix the order like orset(), but that would be silly
because we know the extra filtering cost is unnecessary.
This fixes the order of 'x & (y + z)' where 'y' and 'z' are trivial, and the
other uses of _list()-family functions. The original functions are renamed to
'_ordered(|int|hex)list' to say clearly that they do not follow the subset
ordering.
This fixes the order of 'x & (y + z)' where 'y' and 'z' are not trivial.
The follow-order 'or' operation is slower than the ordered operation if
an input set is large:
#0#1#2#3
0) 0.002968 0.002980 0.002982 0.073042
1) 0.004513 0.004485 0.012029 0.075261
#0: 0:4000 & (0:1099 + 1000:2099 + 2000:3099)
#1: 4000:0 & (0:1099 + 1000:2099 + 2000:3099)
#2: 10000:0 & (0:1099 + 1000:2099 + 2000:3099)
#3: file("path:hg") & (0:1099 + 1000:2099 + 2000:3099)
I've tried another implementation, but which appeared to be slower than
this version.
ss = [getset(repo, fullreposet(repo), x) for x in xs]
return subset.filter(lambda r: any(r in s for s in ss), cache=False)
This makes the number of 'or' arguments deterministic so we can attach
additional ordering flag to all operator nodes. See the next patch.
We rewrite the tree immediately after chained 'or' operations are flattened
by simplifyinfixops(), so we don't need to care if arguments are stored in
x[1] or x[1:].
