view tests/test-censor.t @ 44950:f9734b2d59cc

py3: make stdout line-buffered if connected to a TTY

Status messages that are to be shown on the terminal should be written to the
file descriptor before anything further is done, to keep the user updated.

One common way to achieve this is to make stdout line-buffered if it is
connected to a TTY. This is done on Python 2 (except on Windows, where libc,
which the CPython 2 streams depend on, does not properly support this).

Python 3 rolls it own I/O streams. On Python 3, buffered binary streams can't be
set line-buffered. The previous code (added in 227ba1afcb65) incorrectly
assumed that on Python 3, pycompat.stdout (sys.stdout.buffer) is already
line-buffered. However the interpreter initializes it with a block-buffered
stream or an unbuffered stream (when the -u option or the PYTHONUNBUFFERED
environment variable is set), never with a line-buffered stream.

One example where the current behavior is unacceptable is when running
`hg pull https://www.mercurial-scm.org/repo/hg` on Python 3, where the line
"pulling from https://www.mercurial-scm.org/repo/hg" does not appear on the
terminal before the hg process blocks while waiting for the server.

Various approaches to fix this problem are possible, including:

1. Weaken the contract of procutil.stdout to not give any guarantees about
   buffering behavior. In this case, users of procutil.stdout need to be
   changed to do enough flushes. In particular,
  1. either ui must insert enough flushes for ui.write() and friends, or
  2. ui.write() and friends get split into flushing and fully buffered
     methods, or
  3. users of ui.write() and friends must flush explicitly.
2. Make stdout unbuffered.
3. Make stdout line-buffered. Since Python 3 does not natively support that for
   binary streams, we must implement it ourselves.

(2.) is problematic because using unbuffered I/O changes the performance
characteristics significantly compared to line-buffered (which is used on
Python 2) and this would be a regression.

(1.2.) and (1.3) are a substantial amount of work. It’s unclear whether the
added complexity would be justified, given that raw performance doesn’t matter
that much when writing to a terminal much faster than the user could read it.

(1.1.) pushes complexity into the ui class instead of separating the concern of
how stdout is buffered. Other users of procutil.stdout would still need to take
care of the flushes.

This patch implements (3.). The general performance considerations are very
similar to (1.1.). The extra method invocation and method forwarding add a
little more overhead if the class is used. In exchange, it doesn’t add overhead
if not used.


For the benchmarks, I compared the previous implementation (incorrect on Python
3), (1.1.), (3.) and (2.). The command was chosen so that the streams were
configured as if they were writing to a TTY, but actually write to a pager,
which is also the default:
HGRCPATH=/dev/null python3 ./hg --cwd ~/vcs/mozilla-central --time --pager yes --config pager.pager='cat > /dev/null' status --all

previous:
time: real 7.880 secs (user 7.290+0.050 sys 0.580+0.170)
time: real 7.830 secs (user 7.220+0.070 sys 0.590+0.140)
time: real 7.800 secs (user 7.210+0.050 sys 0.570+0.170)

(1.1.) using Yuya Nishihara’s patch:
time: real 9.860 secs (user 8.670+0.350 sys 1.160+0.830)
time: real 9.540 secs (user 8.430+0.370 sys 1.100+0.770)
time: real 9.830 secs (user 8.630+0.370 sys 1.180+0.840)

(3.) using this patch:
time: real 9.580 secs (user 8.480+0.350 sys 1.090+0.770)
time: real 9.670 secs (user 8.480+0.330 sys 1.170+0.860)
time: real 9.640 secs (user 8.500+0.350 sys 1.130+0.810)

(2.) using a previous patch by me:
time: real 10.480 secs (user 8.850+0.720 sys 1.590+1.500)
time: real 10.490 secs (user 8.750+0.750 sys 1.710+1.470)
time: real 10.240 secs (user 8.600+0.700 sys 1.590+1.510)


As expected, there’s no difference on Python 2, as exactly the same code paths
are used:

previous:
time: real 6.950 secs (user 5.870+0.330 sys 1.070+0.770)
time: real 7.040 secs (user 6.040+0.360 sys 0.980+0.750)
time: real 7.070 secs (user 5.950+0.360 sys 1.100+0.760)

this patch:
time: real 7.010 secs (user 5.900+0.390 sys 1.070+0.730)
time: real 7.000 secs (user 5.850+0.350 sys 1.120+0.760)
time: real 7.000 secs (user 5.790+0.380 sys 1.170+0.710)

#require no-reposimplestore

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > censor=
  > EOF
  $ cp $HGRCPATH $HGRCPATH.orig

Create repo with unimpeachable content

  $ hg init r
  $ cd r
  $ echo 'Initially untainted file' > target
  $ echo 'Normal file here' > bystander
  $ hg add target bystander
  $ hg ci -m init

Clone repo so we can test pull later

  $ cd ..
  $ hg clone r rpull
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd r

Introduce content which will ultimately require censorship. Name the first
censored node C1, second C2, and so on

  $ echo 'Tainted file' > target
  $ echo 'Passwords: hunter2' >> target
  $ hg ci -m taint target
  $ C1=`hg id --debug -i`

  $ echo 'hunter3' >> target
  $ echo 'Normal file v2' > bystander
  $ hg ci -m moretaint target bystander
  $ C2=`hg id --debug -i`

Add a new sanitized versions to correct our mistake. Name the first head H1,
the second head H2, and so on

  $ echo 'Tainted file is now sanitized' > target
  $ hg ci -m sanitized target
  $ H1=`hg id --debug -i`

  $ hg update -r $C2
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo 'Tainted file now super sanitized' > target
  $ hg ci -m 'super sanitized' target
  created new head
  $ H2=`hg id --debug -i`

Verify target contents before censorship at each revision

  $ hg cat -r $H1 target
  Tainted file is now sanitized
  $ hg cat -r $H2 target
  Tainted file now super sanitized
  $ hg cat -r $C2 target
  Tainted file
  Passwords: hunter2
  hunter3
  $ hg cat -r $C1 target
  Tainted file
  Passwords: hunter2
  $ hg cat -r 0 target
  Initially untainted file

Try to censor revision with too large of a tombstone message

  $ hg censor -r $C1 -t 'blah blah blah blah blah blah blah blah bla' target
  abort: censor tombstone must be no longer than censored data
  [255]

Censor revision with 2 offenses

(this also tests file pattern matching: path relative to cwd case)

  $ mkdir -p foo/bar/baz
  $ hg --cwd foo/bar/baz censor -r $C2 -t "remove password" ../../../target
  $ hg cat -r $H1 target
  Tainted file is now sanitized
  $ hg cat -r $H2 target
  Tainted file now super sanitized
  $ hg cat -r $C2 target
  abort: censored node: 1e0247a9a4b7
  (set censor.policy to ignore errors)
  [255]
  $ hg cat -r $C1 target
  Tainted file
  Passwords: hunter2
  $ hg cat -r 0 target
  Initially untainted file

Censor revision with 1 offense

(this also tests file pattern matching: with 'path:' scheme)

  $ hg --cwd foo/bar/baz censor -r $C1 path:target
  $ hg cat -r $H1 target
  Tainted file is now sanitized
  $ hg cat -r $H2 target
  Tainted file now super sanitized
  $ hg cat -r $C2 target
  abort: censored node: 1e0247a9a4b7
  (set censor.policy to ignore errors)
  [255]
  $ hg cat -r $C1 target
  abort: censored node: 613bc869fceb
  (set censor.policy to ignore errors)
  [255]
  $ hg cat -r 0 target
  Initially untainted file

Can only checkout target at uncensored revisions, -X is workaround for --all

  $ hg revert -r $C2 target
  abort: censored node: 1e0247a9a4b7
  (set censor.policy to ignore errors)
  [255]
  $ hg revert -r $C1 target
  abort: censored node: 613bc869fceb
  (set censor.policy to ignore errors)
  [255]
  $ hg revert -r $C1 --all
  reverting bystander
  reverting target
  abort: censored node: 613bc869fceb
  (set censor.policy to ignore errors)
  [255]
  $ hg revert -r $C1 --all -X target
  $ cat target
  Tainted file now super sanitized
  $ hg revert -r 0 --all
  reverting target
  $ cat target
  Initially untainted file
  $ hg revert -r $H2 --all
  reverting bystander
  reverting target
  $ cat target
  Tainted file now super sanitized

Uncensored file can be viewed at any revision

  $ hg cat -r $H1 bystander
  Normal file v2
  $ hg cat -r $C2 bystander
  Normal file v2
  $ hg cat -r $C1 bystander
  Normal file here
  $ hg cat -r 0 bystander
  Normal file here

Can update to children of censored revision

  $ hg update -r $H1
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cat target
  Tainted file is now sanitized
  $ hg update -r $H2
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cat target
  Tainted file now super sanitized

Set censor policy to abort in trusted $HGRC so hg verify fails

  $ cp $HGRCPATH.orig $HGRCPATH
  $ cat >> $HGRCPATH <<EOF
  > [censor]
  > policy = abort
  > EOF

Repo fails verification due to censorship

  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
   target@1: censored file data
   target@2: censored file data
  checked 5 changesets with 7 changes to 2 files
  2 integrity errors encountered!
  (first damaged changeset appears to be 1)
  [1]

Cannot update to revision with censored data

  $ hg update -r $C2
  abort: censored node: 1e0247a9a4b7
  (set censor.policy to ignore errors)
  [255]
  $ hg update -r $C1
  abort: censored node: 613bc869fceb
  (set censor.policy to ignore errors)
  [255]
  $ hg update -r 0
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg update -r $H2
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved

Set censor policy to ignore in trusted $HGRC so hg verify passes

  $ cp $HGRCPATH.orig $HGRCPATH
  $ cat >> $HGRCPATH <<EOF
  > [censor]
  > policy = ignore
  > EOF

Repo passes verification with warnings with explicit config

  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 5 changesets with 7 changes to 2 files

May update to revision with censored data with explicit config

  $ hg update -r $C2
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cat target
  $ hg update -r $C1
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cat target
  $ hg update -r 0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cat target
  Initially untainted file
  $ hg update -r $H2
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cat target
  Tainted file now super sanitized

Can merge in revision with censored data. Test requires one branch of history
with the file censored, but we can't censor at a head, so advance H1.

  $ hg update -r $H1
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ C3=$H1
  $ echo 'advanced head H1' > target
  $ hg ci -m 'advance head H1' target
  $ H1=`hg id --debug -i`
  $ hg censor -r $C3 target
  $ hg update -r $H2
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg merge -r $C3
  merging target
  0 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

Revisions present in repository heads may not be censored

  $ hg update -C -r $H2
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg censor -r $H2 target
  abort: cannot censor file in heads (78a8fc215e79)
  (clean/delete and commit first)
  [255]
  $ echo 'twiddling thumbs' > bystander
  $ hg ci -m 'bystander commit'
  $ H2=`hg id --debug -i`
  $ hg censor -r "$H2^" target
  abort: cannot censor file in heads (efbe78065929)
  (clean/delete and commit first)
  [255]

Cannot censor working directory

  $ echo 'seriously no passwords' > target
  $ hg ci -m 'extend second head arbitrarily' target
  $ H2=`hg id --debug -i`
  $ hg update -r "$H2^"
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg censor -r . target
  abort: cannot censor working directory
  (clean/delete/update first)
  [255]
  $ hg update -r $H2
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

Can re-add file after being deleted + censored

  $ C4=$H2
  $ hg rm target
  $ hg ci -m 'delete target so it may be censored'
  $ H2=`hg id --debug -i`
  $ hg censor -r $C4 target
  $ hg cat -r $C4 target
  $ hg cat -r "$H2^^" target
  Tainted file now super sanitized
  $ echo 'fresh start' > target
  $ hg add target
  $ hg ci -m reincarnated target
  $ H2=`hg id --debug -i`
  $ hg cat -r $H2 target
  fresh start
  $ hg cat -r "$H2^" target
  target: no such file in rev 452ec1762369
  [1]
  $ hg cat -r $C4 target
  $ hg cat -r "$H2^^^" target
  Tainted file now super sanitized

Can censor after revlog has expanded to no longer permit inline storage

  $ for x in `"$PYTHON" $TESTDIR/seq.py 0 50000`
  > do
  >   echo "Password: hunter$x" >> target
  > done
  $ hg ci -m 'add 100k passwords'
  $ H2=`hg id --debug -i`
  $ C5=$H2
  $ hg revert -r "$H2^" target
  $ hg ci -m 'cleaned 100k passwords'
  $ H2=`hg id --debug -i`
  $ hg censor -r $C5 target
  $ hg cat -r $C5 target
  $ hg cat -r $H2 target
  fresh start

Repo with censored nodes can be cloned and cloned nodes are censored

  $ cd ..
  $ hg clone r rclone
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd rclone
  $ hg cat -r $H1 target
  advanced head H1
  $ hg cat -r $H2~5 target
  Tainted file now super sanitized
  $ hg cat -r $C2 target
  $ hg cat -r $C1 target
  $ hg cat -r 0 target
  Initially untainted file
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 12 changesets with 13 changes to 2 files

Repo cloned before tainted content introduced can pull censored nodes

  $ cd ../rpull
  $ hg cat -r tip target
  Initially untainted file
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 1 changesets with 2 changes to 2 files
  $ hg pull -r $H1 -r $H2
  pulling from $TESTTMP/r
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 11 changesets with 11 changes to 2 files (+1 heads)
  new changesets 186fb27560c3:683e4645fded
  (run 'hg heads' to see heads, 'hg merge' to merge)
  $ hg update 4
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cat target
  Tainted file now super sanitized
  $ hg cat -r $H1 target
  advanced head H1
  $ hg cat -r $H2~5 target
  Tainted file now super sanitized
  $ hg cat -r $C2 target
  $ hg cat -r $C1 target
  $ hg cat -r 0 target
  Initially untainted file
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 12 changesets with 13 changes to 2 files

Censored nodes can be pushed if they censor previously unexchanged nodes

  $ echo 'Passwords: hunter2hunter2' > target
  $ hg ci -m 're-add password from clone' target
  created new head
  $ H3=`hg id --debug -i`
  $ REV=$H3
  $ echo 'Re-sanitized; nothing to see here' > target
  $ hg ci -m 're-sanitized' target
  $ H2=`hg id --debug -i`
  $ CLEANREV=$H2
  $ hg cat -r $REV target
  Passwords: hunter2hunter2
  $ hg censor -r $REV target
  $ hg cat -r $REV target
  $ hg cat -r $CLEANREV target
  Re-sanitized; nothing to see here
  $ hg push -f -r $H2
  pushing to $TESTTMP/r
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 1 files (+1 heads)

  $ cd ../r
  $ hg cat -r $REV target
  $ hg cat -r $CLEANREV target
  Re-sanitized; nothing to see here
  $ hg update $CLEANREV
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cat target
  Re-sanitized; nothing to see here

Censored nodes can be bundled up and unbundled in another repo

  $ hg bundle --base 0 ../pwbundle
  13 changesets found
  $ cd ../rclone
  $ hg unbundle ../pwbundle
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 2 files (+1 heads)
  new changesets 075be80ac777:dcbaf17bf3a1 (2 drafts)
  (run 'hg heads .' to see heads, 'hg merge' to merge)
  $ hg cat -r $REV target
  $ hg cat -r $CLEANREV target
  Re-sanitized; nothing to see here
  $ hg update $CLEANREV
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cat target
  Re-sanitized; nothing to see here
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 14 changesets with 15 changes to 2 files

Grepping only warns, doesn't error out

  $ cd ../rpull
  $ hg grep 'Normal file'
  bystander:Normal file v2
  $ hg grep nothing
  target:Re-sanitized; nothing to see here
  $ hg grep --diff 'Normal file'
  cannot search in censored file: target:7
  cannot search in censored file: target:10
  cannot search in censored file: target:12
  bystander:6:-:Normal file v2
  cannot search in censored file: target:1
  cannot search in censored file: target:2
  cannot search in censored file: target:3
  bystander:2:-:Normal file here
  bystander:2:+:Normal file v2
  bystander:0:+:Normal file here
  $ hg grep --diff nothing
  cannot search in censored file: target:7
  cannot search in censored file: target:10
  cannot search in censored file: target:12
  target:13:+:Re-sanitized; nothing to see here
  cannot search in censored file: target:1
  cannot search in censored file: target:2
  cannot search in censored file: target:3

Censored nodes can be imported on top of censored nodes, consecutively

  $ hg init ../rimport
  $ hg bundle --base 1 ../rimport/splitbundle
  12 changesets found
  $ cd ../rimport
  $ hg pull -r $H1 -r $H2 ../r
  pulling from ../r
  adding changesets
  adding manifests
  adding file changes
  added 8 changesets with 10 changes to 2 files (+1 heads)
  new changesets e97f55b2665a:dcbaf17bf3a1
  (run 'hg heads' to see heads, 'hg merge' to merge)
  $ hg unbundle splitbundle
  adding changesets
  adding manifests
  adding file changes
  added 6 changesets with 5 changes to 2 files (+1 heads)
  new changesets efbe78065929:683e4645fded (6 drafts)
  (run 'hg heads .' to see heads, 'hg merge' to merge)
  $ hg update $H2
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cat target
  Re-sanitized; nothing to see here
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 14 changesets with 15 changes to 2 files
  $ cd ../r

Can import bundle where first revision of a file is censored

  $ hg init ../rinit
  $ hg censor -r 0 target
  $ hg bundle -r 0 --base null ../rinit/initbundle
  1 changesets found
  $ cd ../rinit
  $ hg unbundle initbundle
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 2 changes to 2 files
  new changesets e97f55b2665a (1 drafts)
  (run 'hg update' to get a working copy)
  $ hg cat -r 0 target