view tests/test-convert-cvs.t @ 40326:fed697fa1734

sqlitestore: file storage backend using SQLite

This commit provides an extension which uses SQLite to store file
data (as opposed to revlogs).

As the inline documentation describes, there are still several
aspects to the extension that are incomplete. But it's a start.
The extension does support basic clone, checkout, and commit
workflows, which makes it suitable for simple use cases.

One notable missing feature is support for "bundlerepos." This is
probably responsible for the most test failures when the extension
is activated as part of the test suite.

All revision data is stored in SQLite. Data is stored as zstd
compressed chunks (default if zstd is available), zlib compressed
chunks (default if zstd is not available), or raw chunks (if
configured or if a compressed delta is not smaller than the raw
delta). This makes things very similar to revlogs.

Unlike revlogs, the extension doesn't yet enforce a limit on delta
chain length. This is an obvious limitation and should be addressed.
This is somewhat mitigated by the use of zstd, which is much faster
than zlib to decompress.

There is a dedicated table for storing deltas. Deltas are stored
by the SHA-1 hash of their uncompressed content. The "fileindex" table
has columns that reference the delta for each revision and the base
delta that delta should be applied against. A recursive SQL query
is used to resolve the delta chain along with the delta data.

By storing deltas by hash, we are able to de-duplicate delta storage!
With revlogs, the same deltas in different revlogs would result in
duplicate storage of that delta. In this scheme, inserting the
duplicate delta is a no-op and delta chains simply reference the
existing delta.

When initially implementing this extension, I did not have
content-indexed deltas and deltas could be duplicated across files
(just like revlogs). When I implemented content-indexed deltas, the
size of the SQLite database for a full clone of mozilla-unified
dropped:

before: 2,554,261,504 bytes
after:  2,488,754,176 bytes

Surprisingly, this is still larger than the bytes size of revlog
files:

revlog files: 2,104,861,230 bytes
du -b:        2,254,381,614

I would have expected storage to be smaller since we're not limiting
delta chain length and since we're using zstd instead of zlib. I
suspect the SQLite indexes and per-column overhead account for the
bulk of the differences. (Keep in mind that revlog uses a 64-byte
packed struct for revision index data and deltas are stored without
padding. Aside from the 12 unused bytes in the 32 byte node field,
revlogs are pretty efficient.) Another source of overhead is file
name storage. With revlogs, file names are stored in the filesystem.
But with SQLite, we need to store file names in the database. This is
roughly equivalent to the size of the fncache file, which for the
mozilla-unified repository is ~34MB.

Since the SQLite database isn't append-only and since delta chains
can reference any delta, this opens some interesting possibilities.
For example, we could store deltas in reverse, such that fulltexts
are stored for newer revisions and deltas are applied to reconstruct
older revisions. This is likely a more optimal storage strategy for
version control, as new data tends to be more frequently accessed
than old data. We would obviously need wire protocol support for
transferring revision data from newest to oldest. And we would
probably need some kind of mechanism for "re-encoding" stores. But
it should be doable.

This extension is very much experimental quality. There are a handful
of features that don't work. It probably isn't suitable for day-to-day
use. But it could be used in limited cases (e.g. read-only checkouts
like in CI). And it is also a good proving ground for alternate
storage backends. As we continue to define interfaces for all things
storage, it will be useful to have a viable alternate storage backend
to see how things shake out in practice.

test-storage.py passes on Python 2 and introduces no new test failures on
Python 3. Having the storage-level unit tests has proved to be insanely
useful when developing this extension. Those tests caught numerous bugs
during development and I'm convinced this style of testing is the way
forward for ensuring alternate storage backends work as intended. Of
course, test coverage isn't close to what it needs to be. But it is
a start. And what coverage we have gives me confidence that basic store
functionality is implemented properly.

Differential Revision: https://phab.mercurial-scm.org/D4928

#require cvs

  $ cvscall()
  > {
  >     cvs -f "$@"
  > }
  $ hgcat()
  > {
  >     hg --cwd src-hg cat -r tip "$1"
  > }
  $ echo "[extensions]" >> $HGRCPATH
  $ echo "convert = " >> $HGRCPATH
  $ cat > cvshooks.py <<EOF
  > def cvslog(ui,repo,hooktype,log):
  >     ui.write(b'%s hook: %d entries\n' % (hooktype,len(log)))
  > 
  > def cvschangesets(ui,repo,hooktype,changesets):
  >     ui.write(b'%s hook: %d changesets\n' % (hooktype,len(changesets)))
  > EOF
  $ hookpath=`pwd`
  $ cat <<EOF >> $HGRCPATH
  > [hooks]
  > cvslog = python:$hookpath/cvshooks.py:cvslog
  > cvschangesets = python:$hookpath/cvshooks.py:cvschangesets
  > EOF

create cvs repository

  $ mkdir cvsrepo
  $ cd cvsrepo
  $ CVSROOT=`pwd`
  $ export CVSROOT
  $ CVS_OPTIONS=-f
  $ export CVS_OPTIONS
  $ cd ..
  $ rmdir cvsrepo
  $ cvscall -q -d "$CVSROOT" init

create source directory

  $ mkdir src-temp
  $ cd src-temp
  $ echo a > a
  $ mkdir b
  $ cd b
  $ echo c > c
  $ cd ..

import source directory

  $ cvscall -q import -m import src INITIAL start
  N src/a
  N src/b/c
  
  No conflicts created by this import
  
  $ cd ..

checkout source directory

  $ cvscall -q checkout src
  U src/a
  U src/b/c

commit a new revision changing b/c

  $ cd src
  $ sleep 1
  $ echo c >> b/c
  $ cvscall -q commit -mci0 . | grep '<--'
  $TESTTMP/cvsrepo/src/b/c,v  <--  *c (glob)
  $ cd ..

convert fresh repo and also check localtimezone option

NOTE: This doesn't check all time zones -- it merely determines that
the configuration option is taking effect.

An arbitrary (U.S.) time zone is used here.  TZ=US/Hawaii is selected
since it does not use DST (unlike other U.S. time zones) and is always
a fixed difference from UTC.

This choice is limited to work on Linux environments. At least on
FreeBSD 11 this timezone is not known. A better choice is
TZ=Pacific/Johnston. On Linux "US/Hawaii" is just a symlink to this
name and also it is known on FreeBSD and on Solaris.

  $ TZ=Pacific/Johnston hg convert --config convert.localtimezone=True src src-hg
  initializing destination src-hg repository
  connecting to $TESTTMP/cvsrepo
  scanning source...
  collecting CVS rlog
  5 log entries
  cvslog hook: 5 entries
  creating changesets
  3 changeset entries
  cvschangesets hook: 3 changesets
  sorting...
  converting...
  2 Initial revision
  1 ci0
  0 import
  updating tags
  $ hgcat a
  a
  $ hgcat b/c
  c
  c

convert fresh repo with --filemap

  $ echo include b/c > filemap
  $ hg convert --filemap filemap src src-filemap
  initializing destination src-filemap repository
  connecting to $TESTTMP/cvsrepo
  scanning source...
  collecting CVS rlog
  5 log entries
  cvslog hook: 5 entries
  creating changesets
  3 changeset entries
  cvschangesets hook: 3 changesets
  sorting...
  converting...
  2 Initial revision
  1 ci0
  0 import
  filtering out empty revision
  repository tip rolled back to revision 1 (undo convert)
  updating tags
  $ hgcat b/c
  c
  c
  $ hg -R src-filemap log --template '{rev} {desc} files: {files}\n'
  2 update tags files: .hgtags
  1 ci0 files: b/c
  0 Initial revision files: b/c

convert full repository (issue1649)

  $ cvscall -q -d "$CVSROOT" checkout -d srcfull "." | grep -v CVSROOT
  U srcfull/src/a
  U srcfull/src/b/c
  $ ls srcfull
  CVS
  CVSROOT
  src
  $ hg convert srcfull srcfull-hg \
  >     | grep -v 'log entries' | grep -v 'hook:' \
  >     | grep -v '^[0-3] .*' # filter instable changeset order
  initializing destination srcfull-hg repository
  connecting to $TESTTMP/cvsrepo
  scanning source...
  collecting CVS rlog
  creating changesets
  4 changeset entries
  sorting...
  converting...
  updating tags
  $ hg cat -r tip --cwd srcfull-hg src/a
  a
  $ hg cat -r tip --cwd srcfull-hg src/b/c
  c
  c

commit new file revisions

  $ cd src
  $ echo a >> a
  $ echo c >> b/c
  $ cvscall -q commit -mci1 . | grep '<--'
  $TESTTMP/cvsrepo/src/a,v  <--  a
  $TESTTMP/cvsrepo/src/b/c,v  <--  *c (glob)
  $ cd ..

convert again

  $ TZ=Pacific/Johnston hg convert --config convert.localtimezone=True src src-hg
  connecting to $TESTTMP/cvsrepo
  scanning source...
  collecting CVS rlog
  7 log entries
  cvslog hook: 7 entries
  creating changesets
  4 changeset entries
  cvschangesets hook: 4 changesets
  sorting...
  converting...
  0 ci1
  $ hgcat a
  a
  a
  $ hgcat b/c
  c
  c
  c

convert again with --filemap

  $ hg convert --filemap filemap src src-filemap
  connecting to $TESTTMP/cvsrepo
  scanning source...
  collecting CVS rlog
  7 log entries
  cvslog hook: 7 entries
  creating changesets
  4 changeset entries
  cvschangesets hook: 4 changesets
  sorting...
  converting...
  0 ci1
  $ hgcat b/c
  c
  c
  c
  $ hg -R src-filemap log --template '{rev} {desc} files: {files}\n'
  3 ci1 files: b/c
  2 update tags files: .hgtags
  1 ci0 files: b/c
  0 Initial revision files: b/c

commit branch

  $ cd src
  $ cvs -q update -r1.1 b/c
  U b/c
  $ cvs -q tag -b branch
  T a
  T b/c
  $ cvs -q update -r branch > /dev/null
  $ sleep 1
  $ echo d >> b/c
  $ cvs -q commit -mci2 . | grep '<--'
  $TESTTMP/cvsrepo/src/b/c,v  <--  *c (glob)
  $ cd ..

convert again

  $ TZ=Pacific/Johnston hg convert --config convert.localtimezone=True src src-hg
  connecting to $TESTTMP/cvsrepo
  scanning source...
  collecting CVS rlog
  8 log entries
  cvslog hook: 8 entries
  creating changesets
  5 changeset entries
  cvschangesets hook: 5 changesets
  sorting...
  converting...
  0 ci2
  $ hgcat b/c
  c
  d

convert again with --filemap

  $ TZ=Pacific/Johnston hg convert --config convert.localtimezone=True --filemap filemap src src-filemap
  connecting to $TESTTMP/cvsrepo
  scanning source...
  collecting CVS rlog
  8 log entries
  cvslog hook: 8 entries
  creating changesets
  5 changeset entries
  cvschangesets hook: 5 changesets
  sorting...
  converting...
  0 ci2
  $ hgcat b/c
  c
  d
  $ hg -R src-filemap log --template '{rev} {desc} files: {files}\n'
  4 ci2 files: b/c
  3 ci1 files: b/c
  2 update tags files: .hgtags
  1 ci0 files: b/c
  0 Initial revision files: b/c

commit a new revision with funny log message

  $ cd src
  $ sleep 1
  $ echo e >> a
  $ cvscall -q commit -m'funny
  > ----------------------------
  > log message' . | grep '<--' |\
  >  sed -e 's:.*src/\(.*\),v.*:checking in src/\1,v:g'
  checking in src/a,v

commit new file revisions with some fuzz

  $ sleep 1
  $ echo f >> a
  $ cvscall -q commit -mfuzzy . | grep '<--'
  $TESTTMP/cvsrepo/src/a,v  <--  a
  $ sleep 4 # the two changes will be split if fuzz < 4
  $ echo g >> b/c
  $ cvscall -q commit -mfuzzy . | grep '<--'
  $TESTTMP/cvsrepo/src/b/c,v  <--  *c (glob)
  $ cd ..

convert again

  $ TZ=Pacific/Johnston hg convert --config convert.cvsps.fuzz=2 --config convert.localtimezone=True src src-hg
  connecting to $TESTTMP/cvsrepo
  scanning source...
  collecting CVS rlog
  11 log entries
  cvslog hook: 11 entries
  creating changesets
  8 changeset entries
  cvschangesets hook: 8 changesets
  sorting...
  converting...
  2 funny
  1 fuzzy
  0 fuzzy
  $ hg -R src-hg log -G --template '{rev} ({branches}) {desc} date: {date|date} files: {files}\n'
  o  8 (branch) fuzzy date: * -1000 files: b/c (glob)
  |
  o  7 (branch) fuzzy date: * -1000 files: a (glob)
  |
  o  6 (branch) funny
  |  ----------------------------
  |  log message date: * -1000 files: a (glob)
  o  5 (branch) ci2 date: * -1000 files: b/c (glob)
  
  o  4 () ci1 date: * -1000 files: a b/c (glob)
  |
  o  3 () update tags date: * +0000 files: .hgtags (glob)
  |
  | o  2 (INITIAL) import date: * -1000 files: (glob)
  | |
  o |  1 () ci0 date: * -1000 files: b/c (glob)
  |/
  o  0 () Initial revision date: * -1000 files: a b/c (glob)
  

testing debugcvsps

  $ cd src
  $ hg debugcvsps --fuzz=2 -x >/dev/null

commit a new revision changing a and removing b/c

  $ cvscall -q update -A
  U a
  U b/c
  $ sleep 1
  $ echo h >> a
  $ cvscall -Q remove -f b/c
  $ cvscall -q commit -mci | grep '<--'
  $TESTTMP/cvsrepo/src/a,v  <--  a
  $TESTTMP/cvsrepo/src/b/c,v  <--  *c (glob)

update and verify the cvsps cache

  $ hg debugcvsps --fuzz=2 -u
  collecting CVS rlog
  13 log entries
  cvslog hook: 13 entries
  creating changesets
  11 changeset entries
  cvschangesets hook: 11 changesets
  ---------------------
  PatchSet 1 
  Date: * (glob)
  Author: * (glob)
  Branch: HEAD
  Tag: (none) 
  Branchpoints: INITIAL 
  Log:
  Initial revision
  
  Members: 
  	a:INITIAL->1.1 
  
  ---------------------
  PatchSet 2 
  Date: * (glob)
  Author: * (glob)
  Branch: HEAD
  Tag: (none) 
  Branchpoints: INITIAL, branch 
  Log:
  Initial revision
  
  Members: 
  	b/c:INITIAL->1.1 
  
  ---------------------
  PatchSet 3 
  Date: * (glob)
  Author: * (glob)
  Branch: INITIAL
  Tag: start 
  Log:
  import
  
  Members: 
  	a:1.1->1.1.1.1 
  	b/c:1.1->1.1.1.1 
  
  ---------------------
  PatchSet 4 
  Date: * (glob)
  Author: * (glob)
  Branch: HEAD
  Tag: (none) 
  Log:
  ci0
  
  Members: 
  	b/c:1.1->1.2 
  
  ---------------------
  PatchSet 5 
  Date: * (glob)
  Author: * (glob)
  Branch: HEAD
  Tag: (none) 
  Branchpoints: branch 
  Log:
  ci1
  
  Members: 
  	a:1.1->1.2 
  
  ---------------------
  PatchSet 6 
  Date: * (glob)
  Author: * (glob)
  Branch: HEAD
  Tag: (none) 
  Log:
  ci1
  
  Members: 
  	b/c:1.2->1.3 
  
  ---------------------
  PatchSet 7 
  Date: * (glob)
  Author: * (glob)
  Branch: branch
  Tag: (none) 
  Log:
  ci2
  
  Members: 
  	b/c:1.1->1.1.2.1 
  
  ---------------------
  PatchSet 8 
  Date: * (glob)
  Author: * (glob)
  Branch: branch
  Tag: (none) 
  Log:
  funny
  ----------------------------
  log message
  
  Members: 
  	a:1.2->1.2.2.1 
  
  ---------------------
  PatchSet 9 
  Date: * (glob)
  Author: * (glob)
  Branch: branch
  Tag: (none) 
  Log:
  fuzzy
  
  Members: 
  	a:1.2.2.1->1.2.2.2 
  
  ---------------------
  PatchSet 10 
  Date: * (glob)
  Author: * (glob)
  Branch: branch
  Tag: (none) 
  Log:
  fuzzy
  
  Members: 
  	b/c:1.1.2.1->1.1.2.2 
  
  ---------------------
  PatchSet 11 
  Date: * (glob)
  Author: * (glob)
  Branch: HEAD
  Tag: (none) 
  Log:
  ci
  
  Members: 
  	a:1.2->1.3 
  	b/c:1.3->1.4(DEAD) 
  

  $ cd ..

Test transcoding CVS log messages (issue5597)
=============================================

To emulate commit messages in (non-ascii) multiple encodings portably,
this test scenario writes CVS history file (*,v file) directly via
python code.

Commit messages of version 1.2 - 1.4 use u3042 in 3 encodings below.

|encoding  |byte sequence | decodable as:      |
|          |              | utf-8 euc-jp cp932 |
+----------+--------------+--------------------+
|utf-8     |\xe3\x81\x82  |  o      x     x    |
|euc-jp    |\xa4\xa2      |  x      o     o    |
|cp932     |\x82\xa0      |  x      x     o    |

  $ mkdir -p cvsrepo/transcoding
  $ python <<EOF
  > fp = open('cvsrepo/transcoding/file,v', 'wb')
  > fp.write((b'''
  > head	1.4;
  > access;
  > symbols
  > 	start:1.1.1.1 INITIAL:1.1.1;
  > locks; strict;
  > comment	@# @;
  > 
  > 
  > 1.4
  > date	2017.07.10.00.00.04;	author nobody;	state Exp;
  > branches;
  > next	1.3;
  > commitid	10059635D016A510FFA;
  > 
  > 1.3
  > date	2017.07.10.00.00.03;	author nobody;	state Exp;
  > branches;
  > next	1.2;
  > commitid	10059635CFF6A4FF34E;
  > 
  > 1.2
  > date	2017.07.10.00.00.02;	author nobody;	state Exp;
  > branches;
  > next	1.1;
  > commitid	10059635CFD6A4D5095;
  > 
  > 1.1
  > date	2017.07.10.00.00.01;	author nobody;	state Exp;
  > branches
  > 	1.1.1.1;
  > next	;
  > commitid	10059635CFB6A4A3C33;
  > 
  > 1.1.1.1
  > date	2017.07.10.00.00.01;	author nobody;	state Exp;
  > branches;
  > next	;
  > commitid	10059635CFB6A4A3C33;
  > 
  > 
  > desc
  > @@
  > 
  > 
  > 1.4
  > log
  > @''' + u'\u3042'.encode('cp932') + b''' (cp932)
  > @
  > text
  > @1
  > 2
  > 3
  > 4
  > @
  > 
  > 
  > 1.3
  > log
  > @''' + u'\u3042'.encode('euc-jp') + b''' (euc-jp)
  > @
  > text
  > @d4 1
  > @
  > 
  > 
  > 1.2
  > log
  > @''' + u'\u3042'.encode('utf-8') +  b''' (utf-8)
  > @
  > text
  > @d3 1
  > @
  > 
  > 
  > 1.1
  > log
  > @Initial revision
  > @
  > text
  > @d2 1
  > @
  > 
  > 
  > 1.1.1.1
  > log
  > @import
  > @
  > text
  > @@
  > ''').lstrip())
  > EOF

  $ cvscall -q checkout transcoding
  U transcoding/file

Test converting in normal case
------------------------------

(filtering by grep in order to check only form of debug messages)

  $ hg convert --config convert.cvsps.logencoding=utf-8,euc-jp,cp932 -q --debug transcoding transcoding-hg | grep 'transcoding by'
  transcoding by utf-8: 1.1 of file
  transcoding by utf-8: 1.1.1.1 of file
  transcoding by utf-8: 1.2 of file
  transcoding by euc-jp: 1.3 of file
  transcoding by cp932: 1.4 of file
  $ hg -R transcoding-hg --encoding utf-8 log -T "{rev}: {desc}\n"
  5: update tags
  4: import
  3: \xe3\x81\x82 (cp932) (esc)
  2: \xe3\x81\x82 (euc-jp) (esc)
  1: \xe3\x81\x82 (utf-8) (esc)
  0: Initial revision
  $ rm -rf transcoding-hg

Test converting in error cases
------------------------------

unknown encoding in convert.cvsps.logencoding

  $ hg convert --config convert.cvsps.logencoding=foobar -q transcoding transcoding-hg
  abort: unknown encoding: foobar
  (check convert.cvsps.logencoding configuration)
  [255]
  $ rm -rf transcoding-hg

no acceptable encoding in convert.cvsps.logencoding

  $ hg convert --config convert.cvsps.logencoding=utf-8,euc-jp -q transcoding transcoding-hg
  abort: no encoding can transcode CVS log message for 1.4 of file
  (check convert.cvsps.logencoding configuration)
  [255]
  $ rm -rf transcoding-hg