filectx.parents: enforce changeid of parent to be in own changectx ancestors
Because of the way filenodes are computed, you can have multiple changesets
"introducing" the same file revision. For example, in the changeset graph
below, changeset 2 and 3 both change a file -to- and -from- the same content.
o 3: content = new
|
| o 2: content = new
|/
o 1: content = old
In such cases, the file revision is create once, when 2 is added, and just reused
for 3. So the file change in '3' (from "old" to "new)" has no linkrev pointing
to it). We'll call this situation "linkrev-shadowing". As the linkrev is used for
optimization purposes when walking a file history, the linkrev-shadowing
results in an unexpected jump to another branch during such a walk.. This leads to
multiple bugs with log, annotate and rename detection.
One element to fix such bugs is to ensure that walking the file history sticks on
the same topology as the changeset's history. For this purpose, we extend the
logic in 'basefilectx.parents' so that it always defines the proper changeset
to associate the parent file revision with. This "proper" changeset has to be an
ancestor of the changeset associated with the child file revision.
This logic is performed in the '_adjustlinkrev' function. This function is
given the starting changeset and all the information regarding the parent file
revision. If the linkrev for the file revision is an ancestor of the starting
changeset, the linkrev is valid and will be used. If it is not, we detected a
topological jump caused by linkrev shadowing, we are going to walk the
ancestors of the starting changeset until we find one setting the file to the
revision we are trying to create.
The performance impact appears acceptable:
- We are walking the changelog once for each filelog traversal (as there should
be no overlap between searches),
- changelog traversal itself is fairly cheap, compared to what is likely going
to be perform on the result on the filelog traversal,
- We only touch the manifest for ancestors touching the file, And such
changesets are likely to be the one introducing the file. (except in
pathological cases involving merge),
- We use manifest diff instead of full manifest unpacking to check manifest
content, so it does not involve applying multiple diffs in most case.
- linkrev shadowing is not the common case.
Tests for fixed issues in log, annotate and rename detection have been
added.
But this changeset does not solve all problems. It fixes -ancestry-
computation, but if the linkrev-shadowed changesets is the starting one, we'll
still get things wrong. We'll have to fix the bootstrapping of such operations
in a later changeset. Also, the usage of `hg log FILE` without --follow still
has issues with linkrev pointing to hidden changesets, because it relies on the
`filelog` revset which implement its own traversal logic that is still to be
fixed.
Thanks goes to:
- Matt Mackall: for nudging me in the right direction
- Julien Cristau and Rémi Cardona: for keep telling me linkrev bug were an
evolution show stopper for 3 years.
- Durham Goode: for finding a new linkrev issue every few weeks
- Mads Kiilerich: for that last rename bug who raise this topic over my
anoyance limit.
Function to test discovery between two repos in both directions, using both the local shortcut
(which is currently not activated by default) and the full remotable protocol:
$ testdesc() { # revs_a, revs_b, dagdesc
> if [ -d foo ]; then rm -rf foo; fi
> hg init foo
> cd foo
> hg debugbuilddag "$3"
> hg clone . a $1 --quiet
> hg clone . b $2 --quiet
> echo
> echo "% -- a -> b tree"
> hg -R a debugdiscovery b --verbose --old
> echo
> echo "% -- a -> b set"
> hg -R a debugdiscovery b --verbose --debug
> echo
> echo "% -- b -> a tree"
> hg -R b debugdiscovery a --verbose --old
> echo
> echo "% -- b -> a set"
> hg -R b debugdiscovery a --verbose --debug
> cd ..
> }
Small superset:
$ testdesc '-ra1 -ra2' '-rb1 -rb2 -rb3' '
> +2:f +1:a1:b1
> <f +4 :a2
> +5 :b2
> <f +3 :b3'
% -- a -> b tree
comparing with b
searching for changes
unpruned common: 01241442b3c2 66f7d451a68b b5714e113bc0
common heads: 01241442b3c2 b5714e113bc0
local is subset
% -- a -> b set
comparing with b
query 1; heads
searching for changes
all local heads known remotely
common heads: 01241442b3c2 b5714e113bc0
local is subset
% -- b -> a tree
comparing with a
searching for changes
unpruned common: 01241442b3c2 b5714e113bc0
common heads: 01241442b3c2 b5714e113bc0
remote is subset
% -- b -> a set
comparing with a
query 1; heads
searching for changes
all remote heads known locally
common heads: 01241442b3c2 b5714e113bc0
remote is subset
Many new:
$ testdesc '-ra1 -ra2' '-rb' '
> +2:f +3:a1 +3:b
> <f +30 :a2'
% -- a -> b tree
comparing with b
searching for changes
unpruned common: bebd167eb94d
common heads: bebd167eb94d
% -- a -> b set
comparing with b
query 1; heads
searching for changes
taking initial sample
searching: 2 queries
query 2; still undecided: 29, sample size is: 29
2 total queries
common heads: bebd167eb94d
% -- b -> a tree
comparing with a
searching for changes
unpruned common: 66f7d451a68b bebd167eb94d
common heads: bebd167eb94d
% -- b -> a set
comparing with a
query 1; heads
searching for changes
taking initial sample
searching: 2 queries
query 2; still undecided: 2, sample size is: 2
2 total queries
common heads: bebd167eb94d
Both sides many new with stub:
$ testdesc '-ra1 -ra2' '-rb' '
> +2:f +2:a1 +30 :b
> <f +30 :a2'
% -- a -> b tree
comparing with b
searching for changes
unpruned common: 2dc09a01254d
common heads: 2dc09a01254d
% -- a -> b set
comparing with b
query 1; heads
searching for changes
taking initial sample
searching: 2 queries
query 2; still undecided: 29, sample size is: 29
2 total queries
common heads: 2dc09a01254d
% -- b -> a tree
comparing with a
searching for changes
unpruned common: 2dc09a01254d 66f7d451a68b
common heads: 2dc09a01254d
% -- b -> a set
comparing with a
query 1; heads
searching for changes
taking initial sample
searching: 2 queries
query 2; still undecided: 29, sample size is: 29
2 total queries
common heads: 2dc09a01254d
Both many new:
$ testdesc '-ra' '-rb' '
> +2:f +30 :b
> <f +30 :a'
% -- a -> b tree
comparing with b
searching for changes
unpruned common: 66f7d451a68b
common heads: 66f7d451a68b
% -- a -> b set
comparing with b
query 1; heads
searching for changes
taking quick initial sample
searching: 2 queries
query 2; still undecided: 31, sample size is: 31
2 total queries
common heads: 66f7d451a68b
% -- b -> a tree
comparing with a
searching for changes
unpruned common: 66f7d451a68b
common heads: 66f7d451a68b
% -- b -> a set
comparing with a
query 1; heads
searching for changes
taking quick initial sample
searching: 2 queries
query 2; still undecided: 31, sample size is: 31
2 total queries
common heads: 66f7d451a68b
Both many new skewed:
$ testdesc '-ra' '-rb' '
> +2:f +30 :b
> <f +50 :a'
% -- a -> b tree
comparing with b
searching for changes
unpruned common: 66f7d451a68b
common heads: 66f7d451a68b
% -- a -> b set
comparing with b
query 1; heads
searching for changes
taking quick initial sample
searching: 2 queries
query 2; still undecided: 51, sample size is: 51
2 total queries
common heads: 66f7d451a68b
% -- b -> a tree
comparing with a
searching for changes
unpruned common: 66f7d451a68b
common heads: 66f7d451a68b
% -- b -> a set
comparing with a
query 1; heads
searching for changes
taking quick initial sample
searching: 2 queries
query 2; still undecided: 31, sample size is: 31
2 total queries
common heads: 66f7d451a68b
Both many new on top of long history:
$ testdesc '-ra' '-rb' '
> +1000:f +30 :b
> <f +50 :a'
% -- a -> b tree
comparing with b
searching for changes
unpruned common: 7ead0cba2838
common heads: 7ead0cba2838
% -- a -> b set
comparing with b
query 1; heads
searching for changes
taking quick initial sample
searching: 2 queries
query 2; still undecided: 1049, sample size is: 11
sampling from both directions
searching: 3 queries
query 3; still undecided: 31, sample size is: 31
3 total queries
common heads: 7ead0cba2838
% -- b -> a tree
comparing with a
searching for changes
unpruned common: 7ead0cba2838
common heads: 7ead0cba2838
% -- b -> a set
comparing with a
query 1; heads
searching for changes
taking quick initial sample
searching: 2 queries
query 2; still undecided: 1029, sample size is: 11
sampling from both directions
searching: 3 queries
query 3; still undecided: 15, sample size is: 15
3 total queries
common heads: 7ead0cba2838
One with >200 heads, which used to use up all of the sample:
$ hg init manyheads
$ cd manyheads
$ echo "+300:r @a" >dagdesc
$ echo "*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3 *r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3" >>dagdesc # 20 heads
$ echo "*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3 *r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3" >>dagdesc # 20 heads
$ echo "*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3 *r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3" >>dagdesc # 20 heads
$ echo "*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3 *r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3" >>dagdesc # 20 heads
$ echo "*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3 *r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3" >>dagdesc # 20 heads
$ echo "*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3 *r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3" >>dagdesc # 20 heads
$ echo "*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3 *r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3" >>dagdesc # 20 heads
$ echo "*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3 *r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3" >>dagdesc # 20 heads
$ echo "*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3 *r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3" >>dagdesc # 20 heads
$ echo "*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3 *r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3" >>dagdesc # 20 heads
$ echo "*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3 *r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3" >>dagdesc # 20 heads
$ echo "*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3 *r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3" >>dagdesc # 20 heads
$ echo "*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3 *r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3" >>dagdesc # 20 heads
$ echo "@b *r+3" >>dagdesc # one more head
$ hg debugbuilddag <dagdesc
reading DAG from stdin
$ hg heads -t --template . | wc -c
\s*261 (re)
$ hg clone -b a . a
adding changesets
adding manifests
adding file changes
added 1340 changesets with 0 changes to 0 files (+259 heads)
updating to branch a
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg clone -b b . b
adding changesets
adding manifests
adding file changes
added 304 changesets with 0 changes to 0 files
updating to branch b
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg -R a debugdiscovery b --debug --verbose
comparing with b
query 1; heads
searching for changes
taking quick initial sample
searching: 2 queries
query 2; still undecided: 1240, sample size is: 100
sampling from both directions
searching: 3 queries
query 3; still undecided: 1140, sample size is: 200
sampling from both directions
searching: 4 queries
query 4; still undecided: 940, sample size is: 200
sampling from both directions
searching: 5 queries
query 5; still undecided: 740, sample size is: 200
sampling from both directions
searching: 6 queries
query 6; still undecided: 540, sample size is: 200
sampling from both directions
searching: 7 queries
query 7; still undecided: 44, sample size is: 44
7 total queries
common heads: 3ee37d65064a
Test actual protocol when pulling one new head in addition to common heads
$ hg clone -U b c
$ hg -R c id -ir tip
513314ca8b3a
$ hg -R c up -qr default
$ touch c/f
$ hg -R c ci -Aqm "extra head"
$ hg -R c id -i
e64a39e7da8b
$ hg serve -R c -p $HGPORT -d --pid-file=hg.pid -A access.log -E errors.log
$ cat hg.pid >> $DAEMON_PIDS
$ hg -R b incoming http://localhost:$HGPORT/ -T '{node|short}\n'
comparing with http://localhost:$HGPORT/
searching for changes
e64a39e7da8b
$ "$TESTDIR/killdaemons.py" $DAEMON_PIDS
$ cut -d' ' -f6- access.log | grep -v cmd=known # cmd=known uses random sampling
"GET /?cmd=capabilities HTTP/1.1" 200 -
"GET /?cmd=batch HTTP/1.1" 200 - x-hgarg-1:cmds=heads+%3Bknown+nodes%3D513314ca8b3ae4dac8eec56966265b00fcf866db
"GET /?cmd=getbundle HTTP/1.1" 200 - x-hgarg-1:common=513314ca8b3ae4dac8eec56966265b00fcf866db&heads=e64a39e7da8b0d54bc63e81169aff001c13b3477
"GET /?cmd=listkeys HTTP/1.1" 200 - x-hgarg-1:namespace=phases
$ cat errors.log
$ cd ..
Issue 4438 - test coverage for 3ef893520a85 issues.
$ mkdir issue4438
$ cd issue4438
#if false
generate new bundles:
$ hg init r1
$ for i in `seq 101`; do hg -R r1 up -qr null && hg -R r1 branch -q b$i && hg -R r1 ci -qmb$i; done
$ hg clone -q r1 r2
$ for i in `seq 10`; do hg -R r1 up -qr null && hg -R r1 branch -q c$i && hg -R r1 ci -qmc$i; done
$ hg -R r2 branch -q r2change && hg -R r2 ci -qmr2change
$ hg -R r1 bundle -qa $TESTDIR/bundles/issue4438-r1.hg
$ hg -R r2 bundle -qa $TESTDIR/bundles/issue4438-r2.hg
#else
use existing bundles:
$ hg clone -q $TESTDIR/bundles/issue4438-r1.hg r1
$ hg clone -q $TESTDIR/bundles/issue4438-r2.hg r2
#endif
Set iteration order could cause wrong and unstable results - fixed in 73cfaa348650:
$ hg -R r1 outgoing r2 -T'{rev} '
comparing with r2
searching for changes
101 102 103 104 105 106 107 108 109 110 (no-eol)
The case where all the 'initialsamplesize' samples already were common would
give 'all remote heads known locally' without checking the remaining heads -
fixed in 86c35b7ae300:
$ cat >> $TESTTMP/unrandomsample.py << EOF
> import random
> def sample(population, k):
> return sorted(population)[:k]
> random.sample = sample
> EOF
$ cat >> r1/.hg/hgrc << EOF
> [extensions]
> unrandomsample = $TESTTMP/unrandomsample.py
> EOF
$ hg -R r1 outgoing r2 -T'{rev} '
comparing with r2
searching for changes
101 102 103 104 105 106 107 108 109 110 (no-eol)
$ cd ..