annotate tests/test-censor.t @ 26457:7e81305092a0

demandimport: replace more references to _demandmod instances

_demandmod instances may be referenced by multiple importing modules.
Before this patch, the _demandmod instance only maintained a reference
to its first consumer when using the "from X import Y" syntax. This is
because we only created a single _demandmod instance (attached to the
parent X module). If multiple modules A and B performed
"from X import Y", we'd produce a single _demandmod instance
"demandmod" with the following references:

  X.Y = <demandmod>
  A.Y = <demandmod>
  B.Y = <demandmod>

The locals from the first consumer (A) would be stored in <demandmod1>.
When <demandmod1> was loaded, we'd look at the locals for the first
consumer and replace the symbol, if necessary. This resulted in state:

  X.Y = <module>
  A.Y = <module>
  B.Y = <demandmod>

B's reference to Y wasn't updated and was still using the proxy object
because we just didn't record that B had a reference to <demandmod> that
needed updating!

With this patch, we add support for tracking which modules in addition
to the initial importer have a reference to the _demandmod instance and
we replace those references at module load time.

In the case of posix.py, this fixes an issue where the "encoding" module
was being proxied, resulting in hundreds of thousands of
__getattribute__ lookups on the _demandmod instance during dirstate
operations on mozilla-central, speeding up execution by many
milliseconds. There are likely several other operation that benefit from
this change as well.

The new mechanism isn't perfect: references in locals (not globals) may
likely linger. So, if there is an import inside a function and a symbol
from that module is used in a hot loop, we could have unwanted overhead
from proxying through _demandmod. Non-global imports are discouraged
anyway. So hopefully this isn't a big deal in practice. We could
potentially deploy a code checker that bans use of attribute lookups of
function-level-imported modules inside loops.

This deficiency in theory could be avoided by storing the set of globals
and locals dicts to update in the _demandmod instance. However, I tried
this and it didn't work. One reason is that some globals are _demandmod
instances. We could work around this, but it's a bit more work. There
also might be other module import foo at play. The solution as
implemented is better than what we had and IMO is good enough for the
time being.

It's worth noting that this sub-optimal behavior was made worse by the
introduction of absolute_import and its recommended "from . import X"
syntax for importing modules from the "mercurial" package. If we ever
wrote performance tests, measuring the amount of module imports and
__getattribute__ proxy calls through _demandmod instances would be
something I'd have it check.

  $ 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
  2 files, 5 changesets, 7 total revisions
  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
  2 files, 5 changesets, 7 total revisions

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
  2 files, 12 changesets, 13 total revisions

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
  2 files, 1 changesets, 2 total revisions
  $ hg pull -r $H1 -r $H2
  pulling from $TESTTMP/r (glob)
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 11 changesets with 11 changes to 2 files (+1 heads)
  (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
  2 files, 12 changesets, 13 total revisions

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 (glob)
  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)
  (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
  2 files, 14 changesets, 15 total revisions

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)
  (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)
  (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
  2 files, 14 changesets, 15 total revisions
  $ 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
  (run 'hg update' to get a working copy)
  $ hg cat -r 0 target