Mercurial > hg
view tests/test-diff-unified.t @ 32697:19b9fc40cc51
revlog: skeleton support for version 2 revlogs
There are a number of improvements we want to make to revlogs
that will require a new version - version 2. It is unclear what the
full set of improvements will be or when we'll be done with them.
What I do know is that the process will likely take longer than a
single release, will require input from various stakeholders to
evaluate changes, and will have many contentious debates and
bikeshedding.
It is unrealistic to develop revlog version 2 up front: there
are just too many uncertainties that we won't know until things
are implemented and experiments are run. Some changes will also
be invasive and prone to bit rot, so sitting on dozens of patches
is not practical.
This commit introduces skeleton support for version 2 revlogs in
a way that is flexible and not bound by backwards compatibility
concerns.
An experimental repo requirement for denoting revlog v2 has been
added. The requirement string has a sub-version component to it.
This will allow us to declare multiple requirements in the course
of developing revlog v2. Whenever we change the in-development
revlog v2 format, we can tweak the string, creating a new
requirement and locking out old clients. This will allow us to
make as many backwards incompatible changes and experiments to
revlog v2 as we want. In other words, we can land code and make
meaningful progress towards revlog v2 while still maintaining
extreme format flexibility up until the point we freeze the
format and remove the experimental labels.
To enable the new repo requirement, you must supply an experimental
and undocumented config option. But not just any boolean flag
will do: you need to explicitly use a value that no sane person
should ever type. This is an additional guard against enabling
revlog v2 on an installation it shouldn't be enabled on. The
specific scenario I'm trying to prevent is say a user with a
4.4 client with a frozen format enabling the option but then
downgrading to 4.3 and accidentally creating repos with an
outdated and unsupported repo format. Requiring a "challenge"
string should prevent this.
Because the format is not yet finalized and I don't want to take
any chances, revlog v2's version is currently 0xDEAD. I figure
squatting on a value we're likely never to use as an actual revlog
version to mean "internal testing only" is acceptable. And
"dead" is easily recognized as something meaningful.
There is a bunch of cleanup that is needed before work on revlog
v2 begins in earnest. I plan on doing that work once this patch
is accepted and we're comfortable with the idea of starting down
this path.
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Fri, 19 May 2017 20:29:11 -0700 |
parents | 897726622877 |
children | 44c4a38bf563 |
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$ hg init repo $ cd repo $ cat > a <<EOF > c > c > a > a > b > a > a > c > c > EOF $ hg ci -Am adda adding a $ cat > a <<EOF > c > c > a > a > dd > a > a > c > c > EOF default context $ hg diff --nodates diff -r cf9f4ba66af2 a --- a/a +++ b/a @@ -2,7 +2,7 @@ c a a -b +dd a a c invalid --unified $ hg diff --nodates -U foo abort: diff context lines count must be an integer, not 'foo' [255] $ hg diff --nodates -U 2 diff -r cf9f4ba66af2 a --- a/a +++ b/a @@ -3,5 +3,5 @@ a a -b +dd a a $ hg --config diff.unified=2 diff --nodates diff -r cf9f4ba66af2 a --- a/a +++ b/a @@ -3,5 +3,5 @@ a a -b +dd a a $ hg diff --nodates -U 1 diff -r cf9f4ba66af2 a --- a/a +++ b/a @@ -4,3 +4,3 @@ a -b +dd a invalid diff.unified $ hg --config diff.unified=foo diff --nodates abort: diff context lines count must be an integer, not 'foo' [255] noprefix config and option $ hg --config diff.noprefix=True diff --nodates diff -r cf9f4ba66af2 a --- a +++ a @@ -2,7 +2,7 @@ c a a -b +dd a a c $ hg diff --noprefix --nodates diff -r cf9f4ba66af2 a --- a +++ a @@ -2,7 +2,7 @@ c a a -b +dd a a c noprefix config disabled in plain mode, but option still enabled $ HGPLAIN=1 hg --config diff.noprefix=True diff --nodates diff -r cf9f4ba66af2 a --- a/a +++ b/a @@ -2,7 +2,7 @@ c a a -b +dd a a c $ HGPLAIN=1 hg diff --noprefix --nodates diff -r cf9f4ba66af2 a --- a +++ a @@ -2,7 +2,7 @@ c a a -b +dd a a c $ cd .. 0 lines of context hunk header matches gnu diff hunk header $ hg init diffzero $ cd diffzero $ cat > f1 << EOF > c2 > c4 > c5 > EOF $ hg commit -Am0 adding f1 $ cat > f2 << EOF > c1 > c2 > c3 > c4 > EOF $ mv f2 f1 $ hg diff -U0 --nodates diff -r 55d8ff78db23 f1 --- a/f1 +++ b/f1 @@ -0,0 +1,1 @@ +c1 @@ -1,0 +3,1 @@ +c3 @@ -3,1 +4,0 @@ -c5 $ hg diff -U0 --nodates --git diff --git a/f1 b/f1 --- a/f1 +++ b/f1 @@ -0,0 +1,1 @@ +c1 @@ -1,0 +3,1 @@ +c3 @@ -3,1 +4,0 @@ -c5 $ hg diff -U0 --nodates -p diff -r 55d8ff78db23 f1 --- a/f1 +++ b/f1 @@ -0,0 +1,1 @@ +c1 @@ -1,0 +3,1 @@ c2 +c3 @@ -3,1 +4,0 @@ c4 -c5 $ echo a > f1 $ hg ci -m movef2 Test diff headers terminating with TAB when necessary (issue3357) Regular diff --nodates, file creation $ hg mv f1 'f 1' $ echo b > 'f 1' $ hg diff --nodates 'f 1' diff -r 7574207d0d15 f 1 --- /dev/null +++ b/f 1 @@ -0,0 +1,1 @@ +b Git diff, adding space $ hg diff --git diff --git a/f1 b/f 1 rename from f1 rename to f 1 --- a/f1 +++ b/f 1 @@ -1,1 +1,1 @@ -a +b Git diff, adding extended headers $ hg diff --git --config experimental.extendedheader.index=7 --config experimental.extendedheader.similarity=True diff --git a/f1 b/f 1 similarity index 0% rename from f1 rename to f 1 index 7898192..6178079 100644 --- a/f1 +++ b/f 1 @@ -1,1 +1,1 @@ -a +b $ hg diff --git --config experimental.extendedheader.index=-1 invalid length for extendedheader.index: '-1' diff --git a/f1 b/f 1 rename from f1 rename to f 1 --- a/f1 +++ b/f 1 @@ -1,1 +1,1 @@ -a +b $ hg diff --git --config experimental.extendedheader.index=whatever invalid value for extendedheader.index: 'whatever' diff --git a/f1 b/f 1 rename from f1 rename to f 1 --- a/f1 +++ b/f 1 @@ -1,1 +1,1 @@ -a +b Git diff with noprefix $ hg --config diff.noprefix=True diff --git --nodates diff --git f1 f 1 rename from f1 rename to f 1 --- f1 +++ f 1 @@ -1,1 +1,1 @@ -a +b noprefix config disabled in plain mode, but option still enabled $ HGPLAIN=1 hg --config diff.noprefix=True diff --git --nodates diff --git a/f1 b/f 1 rename from f1 rename to f 1 --- a/f1 +++ b/f 1 @@ -1,1 +1,1 @@ -a +b $ HGPLAIN=1 hg diff --git --noprefix --nodates diff --git f1 f 1 rename from f1 rename to f 1 --- f1 +++ f 1 @@ -1,1 +1,1 @@ -a +b Regular diff --nodates, file deletion $ hg ci -m addspace $ hg mv 'f 1' f1 $ echo a > f1 $ hg diff --nodates 'f 1' diff -r ca50fe67c9c7 f 1 --- a/f 1 +++ /dev/null @@ -1,1 +0,0 @@ -b Git diff, removing space $ hg diff --git diff --git a/f 1 b/f1 rename from f 1 rename to f1 --- a/f 1 +++ b/f1 @@ -1,1 +1,1 @@ -b +a showfunc diff $ cat > f1 << EOF > int main() { > int a = 0; > int b = 1; > int c = 2; > int d = 3; > return a + b + c + d; > } > EOF $ hg commit -m addfunction $ cat > f1 << EOF > int main() { > int a = 0; > int b = 1; > int c = 2; > int e = 3; > return a + b + c + e; > } > EOF $ hg diff --git diff --git a/f1 b/f1 --- a/f1 +++ b/f1 @@ -2,6 +2,6 @@ int a = 0; int b = 1; int c = 2; - int d = 3; - return a + b + c + d; + int e = 3; + return a + b + c + e; } $ hg diff --config diff.showfunc=True --git diff --git a/f1 b/f1 --- a/f1 +++ b/f1 @@ -2,6 +2,6 @@ int main() { int a = 0; int b = 1; int c = 2; - int d = 3; - return a + b + c + d; + int e = 3; + return a + b + c + e; } If [diff] git is set to true, but the user says --no-git, we should *not* get git diffs $ hg diff --nodates --config diff.git=1 --no-git diff -r f2c7c817fa55 f1 --- a/f1 +++ b/f1 @@ -2,6 +2,6 @@ int a = 0; int b = 1; int c = 2; - int d = 3; - return a + b + c + d; + int e = 3; + return a + b + c + e; } $ cd ..