streamclone: define first iteration of version 2 of stream format
(This patch is based on a first draft from Gregory Szorc, with deeper rework)
Version 1 of the stream clone format was invented many years ago and suffers
from a few deficiencies:
1) Filenames are stored in store-encoded (on filesystem) form rather than in
their internal form. This makes future compatibility with new store
filename encodings more difficult.
2) File entry "headers" consist of a newline of the file name followed by the
string file size. Converting strings to integers is avoidable overhead. We
can't store filenames with newlines (manifests have this limitation as
well, so it isn't a major concern). But the big concern here is the
necessity for readline(). Scanning for newlines means reading ahead and
that means extra buffer allocations and slicing (in Python) and this makes
performance suffer.
3) Filenames aren't compressed optimally. Filenames should be compressed well
since there is a lot of repeated data. However, since they are scattered
all over the stream (with revlog data in between), they typically fall
outside the window size of the compressor and don't compress.
4) It can only exchange stored based content, being able to exchange caches
too would be nice.
5) It is limited to a stream-based protocol and isn't suitable for an on-disk
format for general repository reading because the offset of individual file
entries requires scanning the entire file to find file records.
As part of enabling streaming clones to work in bundle2, #2 proved to have a
significant negative impact on performance. Since bundle2 provides the
opportunity to start fresh, Gregory Szorc figured he would take the
opportunity to invent a new streaming clone data format.
The new format devised in this series addresses #1, #2, and #4. It punts on #3
because it was complex without yielding a significant gain and on #5 because
devising a new store format that "packs" multiple revlogs into a single
"packed revlog" is massive scope bloat. However, this v2 format might be
suitable for streaming into a "packed revlog" with minimal processing. If it
works, great. If not, we can always invent stream format when it is needed.
This patch only introduces the bases of the format. We'll get it usable through
bundle2 first, then we'll extend the format in future patches to bring it to its
full potential (especially #4).
#require icasefs
$ hg debugfs | grep 'case-sensitive:'
case-sensitive: no
test file addition with bad case
$ hg init repo1
$ cd repo1
$ echo a > a
$ hg add A
$ hg st
A a
$ hg ci -m adda
$ hg manifest
a
$ cd ..
test case collision on rename (issue750)
$ hg init repo2
$ cd repo2
$ echo a > a
$ hg --debug ci -Am adda
adding a
committing files:
a
committing manifest
committing changelog
updating the branch cache
committed changeset 0:07f4944404050f47db2e5c5071e0e84e7a27bba9
Case-changing renames should work:
$ hg mv a A
$ hg mv A a
$ hg st
addremove after case-changing rename has no effect (issue4590)
$ hg mv a A
$ hg addremove
recording removal of a as rename to A (100% similar)
$ hg revert --all
forgetting A
undeleting a
test changing case of path components
$ mkdir D
$ echo b > D/b
$ hg ci -Am addb D/b
$ hg mv D/b d/b
D/b: not overwriting - file already committed
(hg rename --force to replace the file by recording a rename)
$ hg mv D/b d/c
$ hg st
A D/c
R D/b
$ mv D temp
$ mv temp d
$ hg st
A D/c
R D/b
$ hg revert -aq
$ rm d/c
$ echo c > D/c
$ hg add D/c
$ hg st
A D/c
$ hg ci -m addc D/c
$ hg mv d/b d/e
$ hg st
A D/e
R D/b
$ hg revert -aq
$ rm d/e
$ hg mv d/b D/B
$ hg st
A D/B
R D/b
$ cd ..
test case collision between revisions (issue912)
$ hg init repo3
$ cd repo3
$ echo a > a
$ hg ci -Am adda
adding a
$ hg rm a
$ hg ci -Am removea
$ echo A > A
on linux hfs keeps the old case stored, force it
$ mv a aa
$ mv aa A
$ hg ci -Am addA
adding A
used to fail under case insensitive fs
$ hg up -C 0
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ hg up -C
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
no clobbering of untracked files with wrong casing
$ hg up -r null
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ echo gold > a
$ hg up
A: untracked file differs
abort: untracked files in working directory differ from files in requested revision
[255]
$ cat a
gold
$ rm a
test that normal file in different case on target context is not
unlinked by largefiles extension.
$ cat >> .hg/hgrc <<EOF
> [extensions]
> largefiles=
> EOF
$ hg update -q -C 1
$ hg status -A
$ echo 'A as largefiles' > A
$ hg add --large A
$ hg commit -m '#3'
created new head
$ hg manifest -r 3
.hglf/A
$ hg manifest -r 0
a
$ hg update -q -C 0
$ hg status -A
C a
$ hg update -q -C 3
$ hg update -q 0
$ hg up -C -r 2
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg mv A a
$ hg diff -g > rename.diff
$ hg ci -m 'A -> a'
$ hg up -q '.^'
$ hg import rename.diff -m "import rename A -> a"
applying rename.diff
$ hg st
? rename.diff
$ hg files
a
$ find * | sort
a
rename.diff
$ rm rename.diff
$ cd ..
issue 3342: file in nested directory causes unexpected abort
$ hg init issue3342
$ cd issue3342
$ mkdir -p a/B/c/D
$ echo e > a/B/c/D/e
$ hg add a/B/c/D/e
$ hg ci -m 'add e'
issue 4481: revert across case only renames
$ hg mv a/B/c/D/e a/B/c/d/E
$ hg ci -m "uppercase E"
$ echo 'foo' > a/B/c/D/E
$ hg ci -m 'e content change'
$ hg revert --all -r 0
removing a/B/c/D/E
adding a/B/c/D/e
$ find * | sort
a
a/B
a/B/c
a/B/c/D
a/B/c/D/e
a/B/c/D/e.orig
$ cd ..
issue 3340: mq does not handle case changes correctly
in addition to reported case, 'hg qrefresh' is also tested against
case changes.
$ echo "[extensions]" >> $HGRCPATH
$ echo "mq=" >> $HGRCPATH
$ hg init issue3340
$ cd issue3340
$ echo a > mIxEdCaSe
$ hg add mIxEdCaSe
$ hg commit -m '#0'
$ hg rename mIxEdCaSe tmp
$ hg rename tmp MiXeDcAsE
$ hg status -A
A MiXeDcAsE
mIxEdCaSe
R mIxEdCaSe
$ hg qnew changecase
$ hg status -A
C MiXeDcAsE
$ hg qpop -a
popping changecase
patch queue now empty
$ hg qnew refresh-casechange
$ hg status -A
C mIxEdCaSe
$ hg rename mIxEdCaSe tmp
$ hg rename tmp MiXeDcAsE
$ hg status -A
A MiXeDcAsE
mIxEdCaSe
R mIxEdCaSe
$ hg qrefresh
$ hg status -A
C MiXeDcAsE
$ hg qpop -a
popping refresh-casechange
patch queue now empty
$ hg qnew refresh-pattern
$ hg status
$ echo A > A
$ hg add
adding A
$ hg qrefresh a # issue 3271, qrefresh with file handled case wrong
$ hg status # empty status means the qrefresh worked
#if osx
We assume anyone running the tests on a case-insensitive volume on OS
X will be using HFS+. If that's not true, this test will fail.
$ rm A
>>> open(u'a\u200c'.encode('utf-8'), 'w').write('unicode is fun')
$ hg status
M A
#endif
$ cd ..