nodemap: introduce append-only incremental update of the persistent data
Rewriting the full nodemap for each transaction has a cost we would like to
avoid. We introduce a new way to write persistent nodemap data by adding new
information at the end for file. Any new and updated block as added at the end
of the file. The last block is the new root node.
With this method, some of the block already on disk get "dereferenced" and
become dead data. In later changesets, We'll start tracking the amount of dead
data to eventually re-generate a full nodemap.
Differential Revision: https://phab.mercurial-scm.org/D7886
Test alignment of multibyte characters
$ HGENCODING=utf-8
$ export HGENCODING
$ hg init t
$ cd t
$ "$PYTHON" << EOF
> from mercurial import pycompat
> # (byte, width) = (6, 4)
> s = b"\xe7\x9f\xad\xe5\x90\x8d"
> # (byte, width) = (7, 7): odd width is good for alignment test
> m = b"MIDDLE_"
> # (byte, width) = (18, 12)
> l = b"\xe9\x95\xb7\xe3\x81\x84\xe9\x95\xb7\xe3\x81\x84\xe5\x90\x8d\xe5\x89\x8d"
> f = open('s', 'wb'); f.write(s); f.close()
> f = open('m', 'wb'); f.write(m); f.close()
> f = open('l', 'wb'); f.write(l); f.close()
> # instant extension to show list of options
> f = open('showoptlist.py', 'wb'); f.write(b"""# encoding: utf-8
> from mercurial import registrar
> cmdtable = {}
> command = registrar.command(cmdtable)
>
> @command(b'showoptlist',
> [(b's', b'opt1', b'', b'short width' + (b' ' +%(s)s) * 8, %(s)s),
> (b'm', b'opt2', b'', b'middle width' + (b' ' + %(m)s) * 8, %(m)s),
> (b'l', b'opt3', b'', b'long width' + (b' ' + %(l)s) * 8, %(l)s)],
> b'')
> def showoptlist(ui, repo, *pats, **opts):
> '''dummy command to show option descriptions'''
> return 0
> """ % {b's': pycompat.byterepr(s),
> b'm': pycompat.byterepr(m),
> b'l': pycompat.byterepr(l),
> })
> f.close()
> EOF
$ S=`cat s`
$ M=`cat m`
$ L=`cat l`
alignment of option descriptions in help
$ cat <<EOF > .hg/hgrc
> [extensions]
> ja_ext = `pwd`/showoptlist.py
> EOF
check alignment of option descriptions in help
$ hg help showoptlist
hg showoptlist
dummy command to show option descriptions
options:
-s --opt1 \xe7\x9f\xad\xe5\x90\x8d short width \xe7\x9f\xad\xe5\x90\x8d \xe7\x9f\xad\xe5\x90\x8d \xe7\x9f\xad\xe5\x90\x8d \xe7\x9f\xad\xe5\x90\x8d \xe7\x9f\xad\xe5\x90\x8d \xe7\x9f\xad\xe5\x90\x8d \xe7\x9f\xad\xe5\x90\x8d \xe7\x9f\xad\xe5\x90\x8d (esc)
-m --opt2 MIDDLE_ middle width MIDDLE_ MIDDLE_ MIDDLE_ MIDDLE_ MIDDLE_
MIDDLE_ MIDDLE_ MIDDLE_
-l --opt3 \xe9\x95\xb7\xe3\x81\x84\xe9\x95\xb7\xe3\x81\x84\xe5\x90\x8d\xe5\x89\x8d long width \xe9\x95\xb7\xe3\x81\x84\xe9\x95\xb7\xe3\x81\x84\xe5\x90\x8d\xe5\x89\x8d \xe9\x95\xb7\xe3\x81\x84\xe9\x95\xb7\xe3\x81\x84\xe5\x90\x8d\xe5\x89\x8d \xe9\x95\xb7\xe3\x81\x84\xe9\x95\xb7\xe3\x81\x84\xe5\x90\x8d\xe5\x89\x8d (esc)
\xe9\x95\xb7\xe3\x81\x84\xe9\x95\xb7\xe3\x81\x84\xe5\x90\x8d\xe5\x89\x8d \xe9\x95\xb7\xe3\x81\x84\xe9\x95\xb7\xe3\x81\x84\xe5\x90\x8d\xe5\x89\x8d \xe9\x95\xb7\xe3\x81\x84\xe9\x95\xb7\xe3\x81\x84\xe5\x90\x8d\xe5\x89\x8d \xe9\x95\xb7\xe3\x81\x84\xe9\x95\xb7\xe3\x81\x84\xe5\x90\x8d\xe5\x89\x8d (esc)
\xe9\x95\xb7\xe3\x81\x84\xe9\x95\xb7\xe3\x81\x84\xe5\x90\x8d\xe5\x89\x8d (esc)
(some details hidden, use --verbose to show complete help)
$ rm -f s; touch s
$ rm -f m; touch m
$ rm -f l; touch l
add files
$ cp s $S
$ hg add $S
$ cp m $M
$ hg add $M
$ cp l $L
$ hg add $L
commit(1)
$ echo 'first line(1)' >> s; cp s $S
$ echo 'first line(2)' >> m; cp m $M
$ echo 'first line(3)' >> l; cp l $L
$ hg commit -m 'first commit' -u $S
commit(2)
$ echo 'second line(1)' >> s; cp s $S
$ echo 'second line(2)' >> m; cp m $M
$ echo 'second line(3)' >> l; cp l $L
$ hg commit -m 'second commit' -u $M
commit(3)
$ echo 'third line(1)' >> s; cp s $S
$ echo 'third line(2)' >> m; cp m $M
$ echo 'third line(3)' >> l; cp l $L
$ hg commit -m 'third commit' -u $L
check alignment of user names in annotate
$ hg annotate -u $M
\xe7\x9f\xad\xe5\x90\x8d: first line(2) (esc)
MIDDLE_: second line(2)
\xe9\x95\xb7\xe3\x81\x84\xe9\x95\xb7\xe3\x81\x84\xe5\x90\x8d\xe5\x89\x8d: third line(2) (esc)
check alignment of filenames in diffstat
$ hg diff -c tip --stat
MIDDLE_ | 1 +
\xe7\x9f\xad\xe5\x90\x8d | 1 + (esc)
\xe9\x95\xb7\xe3\x81\x84\xe9\x95\xb7\xe3\x81\x84\xe5\x90\x8d\xe5\x89\x8d | 1 + (esc)
3 files changed, 3 insertions(+), 0 deletions(-)
add branches/tags
$ hg branch $S
marked working directory as branch \xe7\x9f\xad\xe5\x90\x8d (esc)
(branches are permanent and global, did you want a bookmark?)
$ hg tag $S
$ hg book -f $S
$ hg branch $M
marked working directory as branch MIDDLE_
$ hg tag $M
$ hg book -f $M
$ hg branch $L
marked working directory as branch \xe9\x95\xb7\xe3\x81\x84\xe9\x95\xb7\xe3\x81\x84\xe5\x90\x8d\xe5\x89\x8d (esc)
$ hg tag $L
$ hg book -f $L
check alignment of branches
$ hg branches
\xe9\x95\xb7\xe3\x81\x84\xe9\x95\xb7\xe3\x81\x84\xe5\x90\x8d\xe5\x89\x8d 5:d745ff46155b (esc)
MIDDLE_ 4:9259be597f19 (inactive)
\xe7\x9f\xad\xe5\x90\x8d 3:b06c5b6def9e (inactive) (esc)
default 2:64a70663cee8 (inactive)
check alignment of tags
$ hg tags
tip 5:d745ff46155b
\xe9\x95\xb7\xe3\x81\x84\xe9\x95\xb7\xe3\x81\x84\xe5\x90\x8d\xe5\x89\x8d 4:9259be597f19 (esc)
MIDDLE_ 3:b06c5b6def9e
\xe7\x9f\xad\xe5\x90\x8d 2:64a70663cee8 (esc)
check alignment of bookmarks
$ hg book
MIDDLE_ 5:d745ff46155b
\xe7\x9f\xad\xe5\x90\x8d 4:9259be597f19 (esc)
* \xe9\x95\xb7\xe3\x81\x84\xe9\x95\xb7\xe3\x81\x84\xe5\x90\x8d\xe5\x89\x8d 5:d745ff46155b (esc)