view tests/test-notify.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

  $ cat > $TESTTMP/filter.py <<EOF
  > from __future__ import absolute_import, print_function
  > import re
  > import sys
  > print(re.sub("\n[ \t]", " ", sys.stdin.read()), end="")
  > EOF

  $ cat <<EOF >> $HGRCPATH
  > [extensions]
  > notify=
  > 
  > [hooks]
  > incoming.notify = python:hgext.notify.hook
  > 
  > [notify]
  > sources = pull
  > diffstat = False
  > 
  > [usersubs]
  > foo@bar = *
  > 
  > [reposubs]
  > * = baz
  > EOF
  $ hg help notify
  notify extension - hooks for sending email push notifications
  
  This extension implements hooks to send email notifications when changesets
  are sent from or received by the local repository.
  
  First, enable the extension as explained in 'hg help extensions', and register
  the hook you want to run. "incoming" and "changegroup" hooks are run when
  changesets are received, while "outgoing" hooks are for changesets sent to
  another repository:
  
    [hooks]
    # one email for each incoming changeset
    incoming.notify = python:hgext.notify.hook
    # one email for all incoming changesets
    changegroup.notify = python:hgext.notify.hook
  
    # one email for all outgoing changesets
    outgoing.notify = python:hgext.notify.hook
  
  This registers the hooks. To enable notification, subscribers must be assigned
  to repositories. The "[usersubs]" section maps multiple repositories to a
  given recipient. The "[reposubs]" section maps multiple recipients to a single
  repository:
  
    [usersubs]
    # key is subscriber email, value is a comma-separated list of repo patterns
    user@host = pattern
  
    [reposubs]
    # key is repo pattern, value is a comma-separated list of subscriber emails
    pattern = user@host
  
  A "pattern" is a "glob" matching the absolute path to a repository, optionally
  combined with a revset expression. A revset expression, if present, is
  separated from the glob by a hash. Example:
  
    [reposubs]
    */widgets#branch(release) = [e-mail]
  
  This sends to "[e-mail]" whenever a changeset on the "release"
  branch triggers a notification in any repository ending in "widgets".
  
  In order to place them under direct user management, "[usersubs]" and
  "[reposubs]" sections may be placed in a separate "hgrc" file and incorporated
  by reference:
  
    [notify]
    config = /path/to/subscriptionsfile
  
  Notifications will not be sent until the "notify.test" value is set to
  "False"; see below.
  
  Notifications content can be tweaked with the following configuration entries:
  
  notify.test
    If "True", print messages to stdout instead of sending them. Default: True.
  
  notify.sources
    Space-separated list of change sources. Notifications are activated only
    when a changeset's source is in this list. Sources may be:
  
    "serve"       changesets received via http or ssh
    "pull"        changesets received via "hg pull"
    "unbundle"    changesets received via "hg unbundle"
    "push"        changesets sent or received via "hg push"
    "bundle"      changesets sent via "hg unbundle"
  
    Default: serve.
  
  notify.strip
    Number of leading slashes to strip from url paths. By default, notifications
    reference repositories with their absolute path. "notify.strip" lets you
    turn them into relative paths. For example, "notify.strip=3" will change
    "/long/path/repository" into "repository". Default: 0.
  
  notify.domain
    Default email domain for sender or recipients with no explicit domain.
  
  notify.style
    Style file to use when formatting emails.
  
  notify.template
    Template to use when formatting emails.
  
  notify.incoming
    Template to use when run as an incoming hook, overriding "notify.template".
  
  notify.outgoing
    Template to use when run as an outgoing hook, overriding "notify.template".
  
  notify.changegroup
    Template to use when running as a changegroup hook, overriding
    "notify.template".
  
  notify.maxdiff
    Maximum number of diff lines to include in notification email. Set to 0 to
    disable the diff, or -1 to include all of it. Default: 300.
  
  notify.maxdiffstat
    Maximum number of diffstat lines to include in notification email. Set to -1
    to include all of it. Default: -1.
  
  notify.maxsubject
    Maximum number of characters in email's subject line. Default: 67.
  
  notify.diffstat
    Set to True to include a diffstat before diff content. Default: True.
  
  notify.showfunc
    If set, override "diff.showfunc" for the diff content. Default: None.
  
  notify.merge
    If True, send notifications for merge changesets. Default: True.
  
  notify.mbox
    If set, append mails to this mbox file instead of sending. Default: None.
  
  notify.fromauthor
    If set, use the committer of the first changeset in a changegroup for the
    "From" field of the notification mail. If not set, take the user from the
    pushing repo.  Default: False.
  
  If set, the following entries will also be used to customize the
  notifications:
  
  email.from
    Email "From" address to use if none can be found in the generated email
    content.
  
  web.baseurl
    Root repository URL to combine with repository paths when making references.
    See also "notify.strip".
  
  no commands defined
  $ hg init a
  $ echo a > a/a
  $ echo b > a/b

commit

  $ hg --cwd a commit -Ama -d '0 0'
  adding a
  adding b

clone

  $ hg --traceback clone a b
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo a >> a/a
  $ echo b >> a/b

commit

  $ hg --traceback --cwd a commit -Amb -d '1 0'

on Mac OS X 10.5 the tmp path is very long so would get stripped in the subject line

  $ cat <<EOF >> $HGRCPATH
  > [notify]
  > maxsubject = 200
  > EOF

the python call below wraps continuation lines, which appear on Mac OS X 10.5 because
of the very long subject line
pull (minimal config)

  $ hg --traceback --cwd b pull ../a | "$PYTHON" $TESTTMP/filter.py
  pulling from ../a
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 2 changes to 2 files
  new changesets 00a13f371396
  MIME-Version: 1.0
  Content-Type: text/plain; charset="us-ascii"
  Content-Transfer-Encoding: 7bit
  Date: * (glob)
  Subject: changeset in $TESTTMP/b: b
  From: test
  X-Hg-Notification: changeset 00a13f371396
  Message-Id: <*> (glob)
  To: baz, foo@bar
  
  changeset 00a13f371396 in $TESTTMP/b
  details: $TESTTMP/b?cmd=changeset;node=00a13f371396
  description: b
  
  diffs (12 lines):
  
  diff -r 0cd96de13884 -r 00a13f371396 a
  --- a/a	Thu Jan 01 00:00:00 1970 +0000
  +++ b/a	Thu Jan 01 00:00:01 1970 +0000
  @@ -1,1 +1,2 @@ a
  +a
  diff -r 0cd96de13884 -r 00a13f371396 b
  --- a/b	Thu Jan 01 00:00:00 1970 +0000
  +++ b/b	Thu Jan 01 00:00:01 1970 +0000
  @@ -1,1 +1,2 @@ b
  +b
  (run 'hg update' to get a working copy)

  $ cat <<EOF >> $HGRCPATH
  > [notify]
  > config = `pwd`/.notify.conf
  > domain = test.com
  > strip = 42
  > template = Subject: {desc|firstline|strip}\nFrom: {author}\nX-Test: foo\n\nchangeset {node|short} in {webroot}\ndescription:\n\t{desc|tabindent|strip}
  > 
  > [web]
  > baseurl = http://test/
  > EOF

fail for config file is missing

  $ hg --cwd b rollback
  repository tip rolled back to revision 0 (undo pull)
  $ hg --cwd b pull ../a 2>&1 | grep 'error.*\.notify\.conf' > /dev/null && echo pull failed
  pull failed
  $ touch ".notify.conf"

pull

  $ hg --cwd b rollback
  repository tip rolled back to revision 0 (undo pull)
  $ hg --traceback --cwd b pull ../a  | "$PYTHON" $TESTTMP/filter.py
  pulling from ../a
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 2 changes to 2 files
  new changesets 00a13f371396
  MIME-Version: 1.0
  Content-Type: text/plain; charset="us-ascii"
  Content-Transfer-Encoding: 7bit
  X-Test: foo
  Date: * (glob)
  Subject: b
  From: [e-mail]
  X-Hg-Notification: changeset 00a13f371396
  Message-Id: <*> (glob)
  To: [e-mail], foo@bar
  
  changeset 00a13f371396 in b
  description: b
  diffs (12 lines):
  
  diff -r 0cd96de13884 -r 00a13f371396 a
  --- a/a	Thu Jan 01 00:00:00 1970 +0000
  +++ b/a	Thu Jan 01 00:00:01 1970 +0000
  @@ -1,1 +1,2 @@ a
  +a
  diff -r 0cd96de13884 -r 00a13f371396 b
  --- a/b	Thu Jan 01 00:00:00 1970 +0000
  +++ b/b	Thu Jan 01 00:00:01 1970 +0000
  @@ -1,1 +1,2 @@ b
  +b
  (run 'hg update' to get a working copy)

  $ cat << EOF >> $HGRCPATH
  > [hooks]
  > incoming.notify = python:hgext.notify.hook
  > 
  > [notify]
  > sources = pull
  > diffstat = True
  > EOF

pull

  $ hg --cwd b rollback
  repository tip rolled back to revision 0 (undo pull)
  $ hg --traceback --config notify.maxdiffstat=1 --cwd b pull ../a | "$PYTHON" $TESTTMP/filter.py
  pulling from ../a
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 2 changes to 2 files
  new changesets 00a13f371396
  MIME-Version: 1.0
  Content-Type: text/plain; charset="us-ascii"
  Content-Transfer-Encoding: 7bit
  X-Test: foo
  Date: * (glob)
  Subject: b
  From: [e-mail]
  X-Hg-Notification: changeset 00a13f371396
  Message-Id: <*> (glob)
  To: [e-mail], foo@bar
  
  changeset 00a13f371396 in b
  description: b
  diffstat (truncated from 2 to 1 lines):
   a |  1 + 2 files changed, 2 insertions(+), 0 deletions(-)
  
  diffs (12 lines):
  
  diff -r 0cd96de13884 -r 00a13f371396 a
  --- a/a	Thu Jan 01 00:00:00 1970 +0000
  +++ b/a	Thu Jan 01 00:00:01 1970 +0000
  @@ -1,1 +1,2 @@ a
  +a
  diff -r 0cd96de13884 -r 00a13f371396 b
  --- a/b	Thu Jan 01 00:00:00 1970 +0000
  +++ b/b	Thu Jan 01 00:00:01 1970 +0000
  @@ -1,1 +1,2 @@ b
  +b
  (run 'hg update' to get a working copy)

test merge

  $ cd a
  $ hg up -C 0
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo a >> a
  $ hg ci -Am adda2 -d '2 0'
  created new head
  $ hg merge
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg ci -m merge -d '3 0'
  $ cd ..
  $ hg --traceback --cwd b pull ../a | "$PYTHON" $TESTTMP/filter.py
  pulling from ../a
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 0 changes to 0 files
  new changesets 3332653e1f3c:fccf66cd0c35
  MIME-Version: 1.0
  Content-Type: text/plain; charset="us-ascii"
  Content-Transfer-Encoding: 7bit
  X-Test: foo
  Date: * (glob)
  Subject: adda2
  From: [e-mail]
  X-Hg-Notification: changeset 3332653e1f3c
  Message-Id: <*> (glob)
  To: [e-mail], foo@bar
  
  changeset 3332653e1f3c in b
  description: adda2
  diffstat:
   a |  1 + 1 files changed, 1 insertions(+), 0 deletions(-)
  
  diffs (6 lines):
  
  diff -r 0cd96de13884 -r 3332653e1f3c a
  --- a/a	Thu Jan 01 00:00:00 1970 +0000
  +++ b/a	Thu Jan 01 00:00:02 1970 +0000
  @@ -1,1 +1,2 @@ a
  +a
  MIME-Version: 1.0
  Content-Type: text/plain; charset="us-ascii"
  Content-Transfer-Encoding: 7bit
  X-Test: foo
  Date: * (glob)
  Subject: merge
  From: [e-mail]
  X-Hg-Notification: changeset fccf66cd0c35
  Message-Id: <*> (glob)
  To: [e-mail], foo@bar
  
  changeset fccf66cd0c35 in b
  description: merge
  diffstat:
   b |  1 + 1 files changed, 1 insertions(+), 0 deletions(-)
  
  diffs (6 lines):
  
  diff -r 3332653e1f3c -r fccf66cd0c35 b
  --- a/b	Thu Jan 01 00:00:02 1970 +0000
  +++ b/b	Thu Jan 01 00:00:03 1970 +0000
  @@ -1,1 +1,2 @@ b
  +b
  (run 'hg update' to get a working copy)

non-ascii content and truncation of multi-byte subject

  $ cat <<EOF >> $HGRCPATH
  > [notify]
  > maxsubject = 4
  > EOF
  $ echo a >> a/a
  $ hg --cwd a --encoding utf-8 commit -A -d '0 0' \
  >   -m `"$PYTHON" -c 'print("\xc3\xa0\xc3\xa1\xc3\xa2\xc3\xa3\xc3\xa4")'`
  $ hg --traceback --cwd b --encoding utf-8 pull ../a | \
  >   "$PYTHON" $TESTTMP/filter.py
  pulling from ../a
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  new changesets 0f25f9c22b4c
  MIME-Version: 1.0
  Content-Type: text/plain; charset="us-ascii"
  Content-Transfer-Encoding: 8bit
  X-Test: foo
  Date: * (glob)
  Subject: \xc3\xa0... (esc)
  From: [e-mail]
  X-Hg-Notification: changeset 0f25f9c22b4c
  Message-Id: <*> (glob)
  To: [e-mail], foo@bar
  
  changeset 0f25f9c22b4c in b
  description: \xc3\xa0\xc3\xa1\xc3\xa2\xc3\xa3\xc3\xa4 (esc)
  diffstat:
   a |  1 + 1 files changed, 1 insertions(+), 0 deletions(-)
  
  diffs (7 lines):
  
  diff -r fccf66cd0c35 -r 0f25f9c22b4c a
  --- a/a	Thu Jan 01 00:00:03 1970 +0000
  +++ b/a	Thu Jan 01 00:00:00 1970 +0000
  @@ -1,2 +1,3 @@ a a
  +a
  (run 'hg update' to get a working copy)

long lines

  $ cat <<EOF >> $HGRCPATH
  > [notify]
  > maxsubject = 67
  > test = False
  > mbox = mbox
  > EOF
  $ "$PYTHON" -c 'open("a/a", "ab").write("no" * 500 + "\xd1\x84" + "\n")'
  $ hg --cwd a commit -A -m "long line"
  $ hg --traceback --cwd b pull ../a
  pulling from ../a
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  new changesets a846b5f6ebb7
  notify: sending 2 subscribers 1 changes
  (run 'hg update' to get a working copy)
  $ "$PYTHON" $TESTTMP/filter.py < b/mbox
  From [e-mail] ... ... .. ..:..:.. .... (re)
  MIME-Version: 1.0
  Content-Type: text/plain; charset="*" (glob)
  Content-Transfer-Encoding: quoted-printable
  X-Test: foo
  Date: * (glob)
  Subject: long line
  From: [e-mail]
  X-Hg-Notification: changeset a846b5f6ebb7
  Message-Id: <hg.a846b5f6ebb7.*.*@*> (glob)
  To: [e-mail], foo@bar
  
  changeset a846b5f6ebb7 in b
  description: long line
  diffstat:
   a |  1 + 1 files changed, 1 insertions(+), 0 deletions(-)
  
  diffs (8 lines):
  
  diff -r 0f25f9c22b4c -r a846b5f6ebb7 a
  --- a/a	Thu Jan 01 00:00:00 1970 +0000
  +++ b/a	Thu Jan 01 00:00:00 1970 +0000
  @@ -1,3 +1,4 @@ a a a
  +nonononononononononononononononononononononononononononononononononononono=
  nononononononononononononononononononononononononononononononononononononon=
  ononononononononononononononononononononononononononononononononononononono=
  nononononononononononononononononononononononononononononononononononononon=
  ononononononononononononononononononononononononononononononononononononono=
  nononononononononononononononononononononononononononononononononononononon=
  ononononononononononononononononononononononononononononononononononononono=
  nononononononononononononononononononononononononononononononononononononon=
  ononononononononononononononononononononononononononononononononononononono=
  nononononononononononononononononononononononononononononononononononononon=
  ononononononononononononononononononononononononononononononononononononono=
  nononononononononononononononononononononononononononononononononononononon=
  ononononononononononononononononononononononononononononononononononononono=
  nonononononononononononono=D1=84
  
 revset selection: send to address that matches branch and repo

  $ cat << EOF >> $HGRCPATH
  > [hooks]
  > incoming.notify = python:hgext.notify.hook
  > 
  > [notify]
  > sources = pull
  > test = True
  > diffstat = False
  > maxdiff = 0
  > 
  > [reposubs]
  > */a#branch(test) = [e-mail]
  > */b#branch(test) = [e-mail]
  > EOF
  $ hg --cwd a branch test
  marked working directory as branch test
  (branches are permanent and global, did you want a bookmark?)
  $ echo a >> a/a
  $ hg --cwd a ci -m test -d '1 0'
  $ hg --traceback --cwd b pull ../a | "$PYTHON" $TESTTMP/filter.py
  pulling from ../a
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  new changesets f7e5aaed4080
  MIME-Version: 1.0
  Content-Type: text/plain; charset="us-ascii"
  Content-Transfer-Encoding: 7bit
  X-Test: foo
  Date: * (glob)
  Subject: test
  From: [e-mail]
  X-Hg-Notification: changeset f7e5aaed4080
  Message-Id: <hg.f7e5aaed4080.*.*@*> (glob)
  To: [e-mail], foo@bar, [e-mail]
  
  changeset f7e5aaed4080 in b
  description: test
  (run 'hg update' to get a working copy)

revset selection: don't send to address that waits for mails
from different branch

  $ hg --cwd a update default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo a >> a/a
  $ hg --cwd a ci -m test -d '1 0'
  $ hg --traceback --cwd b pull ../a | "$PYTHON" $TESTTMP/filter.py
  pulling from ../a
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 0 changes to 0 files (+1 heads)
  new changesets 645eb6690ecf
  MIME-Version: 1.0
  Content-Type: text/plain; charset="us-ascii"
  Content-Transfer-Encoding: 7bit
  X-Test: foo
  Date: * (glob)
  Subject: test
  From: [e-mail]
  X-Hg-Notification: changeset 645eb6690ecf
  Message-Id: <hg.645eb6690ecf.*.*@*> (glob)
  To: [e-mail], foo@bar
  
  changeset 645eb6690ecf in b
  description: test
  (run 'hg heads' to see heads)

default template:

  $ grep -v '^template =' $HGRCPATH > "$HGRCPATH.new"
  $ mv "$HGRCPATH.new" $HGRCPATH
  $ echo a >> a/a
  $ hg --cwd a commit -m 'default template'
  $ hg --cwd b pull ../a -q | "$PYTHON" $TESTTMP/filter.py
  MIME-Version: 1.0
  Content-Type: text/plain; charset="us-ascii"
  Content-Transfer-Encoding: 7bit
  Date: * (glob)
  Subject: changeset in b: default template
  From: [e-mail]
  X-Hg-Notification: changeset 5cd4346eed47
  Message-Id: <hg.5cd4346eed47.*.*@*> (glob)
  To: [e-mail], foo@bar
  
  changeset 5cd4346eed47 in $TESTTMP/b
  details: http://test/b?cmd=changeset;node=5cd4346eed47
  description: default template

with style:

  $ cat <<EOF > notifystyle.map
  > changeset = "Subject: {desc|firstline|strip}
  >              From: {author}
  >              {""}
  >              changeset {node|short}"
  > EOF
  $ cat <<EOF >> $HGRCPATH
  > [notify]
  > style = $TESTTMP/notifystyle.map
  > EOF
  $ echo a >> a/a
  $ hg --cwd a commit -m 'with style'
  $ hg --cwd b pull ../a -q | "$PYTHON" $TESTTMP/filter.py
  MIME-Version: 1.0
  Content-Type: text/plain; charset="us-ascii"
  Content-Transfer-Encoding: 7bit
  Date: * (glob)
  Subject: with style
  From: [e-mail]
  X-Hg-Notification: changeset ec8d9d852f56
  Message-Id: <hg.ec8d9d852f56.*.*@*> (glob)
  To: [e-mail], foo@bar
  
  changeset ec8d9d852f56

with template (overrides style):

  $ cat <<EOF >> $HGRCPATH
  > template = Subject: {node|short}: {desc|firstline|strip}
  >            From: {author}
  >            {""}
  >            {desc}
  > EOF
  $ echo a >> a/a
  $ hg --cwd a commit -m 'with template'
  $ hg --cwd b pull ../a -q | "$PYTHON" $TESTTMP/filter.py
  MIME-Version: 1.0
  Content-Type: text/plain; charset="us-ascii"
  Content-Transfer-Encoding: 7bit
  Date: * (glob)
  Subject: 14721b538ae3: with template
  From: [e-mail]
  X-Hg-Notification: changeset 14721b538ae3
  Message-Id: <hg.14721b538ae3.*.*@*> (glob)
  To: [e-mail], foo@bar
  
  with template

showfunc diff
  $ cat <<EOF >> $HGRCPATH
  > showfunc = True
  > template =
  > maxdiff = -1
  > EOF
  $ cd a
  $ 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 -Am addfunction
  adding f1
  $ hg --cwd ../b pull ../a
  pulling from ../a
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  new changesets b86bc16ff894
  MIME-Version: 1.0
  Content-Type: text/plain; charset="us-ascii"
  Content-Transfer-Encoding: 7bit
  Date: * (glob)
  Subject: addfunction
  From: [e-mail]
  X-Hg-Notification: changeset b86bc16ff894
  Message-Id: <hg.b86bc16ff894.*.*@*> (glob)
  To: [e-mail], foo@bar
  
  changeset b86bc16ff894
  diffs (11 lines):
  
  diff -r 14721b538ae3 -r b86bc16ff894 f1
  --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
  +++ b/f1	Thu Jan 01 00:00:00 1970 +0000
  @@ -0,0 +1,7 @@
  +int main() {
  +    int a = 0;
  +    int b = 1;
  +    int c = 2;
  +    int d = 3;
  +    return a + b + c + d;
  +}
  (run 'hg update' to get a working copy)
  $ cat > f1 << EOF
  > int main() {
  >     int a = 0;
  >     int b = 1;
  >     int c = 2;
  >     int e = 3;
  >     return a + b + c + e;
  > }
  > EOF
  $ hg commit -m changefunction
  $ hg --cwd ../b --config notify.showfunc=True pull ../a
  pulling from ../a
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  new changesets e81040e9838c
  MIME-Version: 1.0
  Content-Type: text/plain; charset="us-ascii"
  Content-Transfer-Encoding: 7bit
  Date: * (glob)
  Subject: changefunction
  From: [e-mail]
  X-Hg-Notification: changeset e81040e9838c
  Message-Id: <hg.e81040e9838c.*.*@*> (glob)
  To: [e-mail], foo@bar
  
  changeset e81040e9838c
  diffs (12 lines):
  
  diff -r b86bc16ff894 -r e81040e9838c f1
  --- a/f1	Thu Jan 01 00:00:00 1970 +0000
  +++ b/f1	Thu Jan 01 00:00:00 1970 +0000
  @@ -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;
   }
  (run 'hg update' to get a working copy)