contrib/all-revsets.txt

revset: improves time complexity of 'roots(xxx)'

The canonical way of doing 'roots(X)' is 'X - children(X)'. This is what the
implementation used to be. However, computing children is expensive because it
is unbounded. Any changesets in the repository may be a children of '0' so you
have to look at all changesets in the repository to compute children(0).
Moreover the current revsets implementation for children is not lazy, leading to
bad performance when fetching the first result.


There is a more restricted algorithm to compute roots:

    roots(X) = [r for r in X if not parents(r) & X]

This achieve the same result while only looking for parent/children relation in
the X set itself, making the algorithm 'O(len(X))' membership operation.
Another advantages is that it turns the check into a simple filter, preserving
all laziness property of the underlying revsets.

The speed is very significant and some laziness is restored.

-) revset without 'roots(...)' to compare to base line
0) before this change
1) after this change

revset #0: roots((tip~100::) - (tip~100::tip))
   plain         min           last
-) 0.001082      0.000993      0.000790
0) 0.001366      0.001385      0.001339
1) 0.001257  92% 0.001028  74% 0.000821  61%

revset #1: roots((0::) - (0::tip))
   plain         min           last
-) 0.134551      0.144682      0.068453
0) 0.161822      0.171786      0.157683
1) 0.137583  85% 0.146204  85% 0.070012  44%

revset #2: roots(tip~100:)
   plain         min           first         last
-) 0.000219      0.000225      0.000231      0.000229
0) 0.000513      0.000529      0.000507      0.000539
1) 0.000463  90% 0.000269  50% 0.000267  52% 0.000463  85%

revset #3: roots(:42)
   plain         min           first         last
-) 0.000119      0.000146      0.000146      0.000146
0) 0.000231      0.000254      0.000253      0.000260
1) 0.000216  93% 0.000186  73% 0.000184  72% 0.000244  93%

revset #4: roots(not public())
   plain         min           first
-) 0.000478      0.000502      0.000504
0) 0.000611      0.000639      0.000634
1) 0.000604      0.000560  87% 0.000558

revset #5: roots((0:tip)::)
   plain         min           max           first         last
-) 0.057795      0.004905      0.058260      0.004908      0.038812
0) 0.132845      0.118931      0.130306      0.114280      0.127742
1) 0.111659  84% 0.005023   4% 0.111658  85% 0.005022   4% 0.092490  72%

revset #6: roots(0::tip)
   plain         min           max           first         last
-) 0.032971      0.033947      0.033460      0.032350      0.033125
0) 0.083671      0.081953      0.084074      0.080364      0.086069
1) 0.074720  89% 0.035547  43% 0.077025  91% 0.033729  41% 0.083197

revset #7: 42:68 and roots(42:tip)
   plain         min           max           first         last
-) 0.006827      0.000251      0.006830      0.000254      0.006771
0) 0.000337      0.000353      0.000366      0.000350      0.000366
1) 0.000318  94% 0.000297  84% 0.000353      0.000293  83% 0.000351

revset #8: roots(0:tip)
   plain         min           max           first         last
-) 0.002119      0.000145      0.000147      0.000147      0.000147
0) 0.047441      0.040660      0.045662      0.040284      0.043435
1) 0.038057  80% 0.000187   0% 0.034919  76% 0.000186   0% 0.035097  80%

revset #0: roots(:42 + tip~42:)
   plain         min           max           first         last          sort
-) 0.000321      0.000317      0.000319      0.000308      0.000369      0.000343
0) 0.000772      0.000751      0.000811      0.000750      0.000802      0.000783
1) 0.000632  81% 0.000369  49% 0.000617  76% 0.000358  47% 0.000601  74% 0.000642  81%

# All revsets ever used with revsetbenchmarks.py script
#
# The goal of this file is to gather all revsets ever used for benchmarking
# revset's performance. It should be used to gather revsets that test a
# specific usecase or a specific implementation of revset predicates.
# If you are working on the smartset implementation itself, check
# 'base-revsets.txt'.
#
# Please update this file with any revsets you use for benchmarking a change so
# that future contributors can easily find and retest it when doing further
# modification. Feel free to highlight interresting variants if needed.


## Revset from this section are all extracted from changelog when this file was
# created. Feel free to dig and improve documentation.

# Used in revision da05fe01170b
(20000::) - (20000)
# Used in revision 95af98616aa7
parents(20000)
# Used in revision 186fd06283b4
(_intlist('20000\x0020001')) and merge()
# Used in revision 911f5a6579d1
p1(20000)
p2(10000)
# Used in revision b6dc3b79bb25
0::
# Used in revision faf4f63533ff
bookmark()
# Used in revision 22ba2c0825da
tip~25
# Used in revision 0cf46b8298fe
bisect(range)
# Used in revision 5b65429721d5
divergent()
# Used in revision 6261b9c549a2
file(COPYING)
# Used in revision 44f471102f3a
follow(COPYING)
# Used in revision 8040a44aab1c
origin(tip)
# Used in revision bbf4f3dfd700
rev(25)
# Used in revision a428db9ab61d
p1()
# Used in revision c1546d7400ef
min(0::)
# Used in revision 546fa6576815
author(lmoscovicz) or author(mpm)
author(mpm) or author(lmoscovicz)
# Used in revision 9bfe68357c01
public() and id("d82e2223f132")
# Used in revision ba89f7b542c9
rev(25)
# Used in revision eb763217152a
rev(210000)
# Used in revision 69524a05a7fa
10:100
parents(10):parents(100)
# Used in revision 6f1b8b3f12fd
100~5
parents(100)~5
(100~5)~5
# Used in revision 7a42e5d4c418
children(tip~100)
# Used in revision 7e8737e6ab08
100^1
parents(100)^1
(100^1)^1
# Used in revision 30e0dcd7c5ff
matching(100)
matching(parents(100))
# Used in revision aafeaba22826
0|1|2|3|4|5|6|7|8|9
# Used in revision 33c7a94d4dd0
tip:0
# Used in revision 7d369fae098e
(0:100000)
# Used in revision b333ca94403d
0 + 1 + 2 + ... + 200
0 + 1 + 2 + ... + 1000
sort(0 + 1 + 2 + ... + 200)
sort(0 + 1 + 2 + ... + 1000)
# Used in revision 7fbef7932af9
first(0 + 1 + 2 + ... + 1000)
# Used in revision ceaf04bb14ff
0:1000
# Used in revision 262e6ad93885
not public()
(tip~1000::) - public()
not public() and branch("default")
# Used in revision 15412bba5a68
0::tip

## all the revsets from this section have been taken from the former central file
# for revset's benchmarking, they are undocumented for this reason.
all()
draft()
::tip
draft() and ::tip
::tip and draft()
author(lmoscovicz)
author(mpm)
::p1(p1(tip))::
public()
:10000 and public()
:10000 and draft()
(not public() - obsolete())

# The one below is used by rebase
(children(ancestor(tip~5, tip)) and ::(tip~5))::

# those two `roots(...)` inputs are close to what phase movement use.
roots((tip~100::) - (tip~100::tip))
roots((0::) - (0::tip))

# more roots testing
roots(tip~100:)
roots(:42)
roots(not public())
roots((0:tip)::)
roots(0::tip)
42:68 and roots(42:tip)
# Used in revision f140d6207cca
roots(0:tip)
# test disjoint set with multiple roots
roots((:42) + (tip~42:))

# Testing the behavior of "head()" in various situations
head()
head() - public()
draft() and head()
head() and author("mpm")

# testing the mutable phases set
draft()
secret()