wireproto: implement basic frame reading and processing
We just implemented support for writing frames. Now let's implement
support for reading them.
The bulk of the new code is for a class that maintains the state of
a server. Essentially, you construct an instance, feed frames to it,
and it tells you what you should do next. The design is inspired by
the "sans I/O" movement and the reactor pattern. We don't want to
perform I/O or any major blocking event during frame ingestion because
this arbitrarily limits ways that server pieces can be implemented.
For example, it makes it much harder to swap in an alternate
implementation based on asyncio or do crazy things like have requests
dispatch to other processes.
We do still implement readframe() which does I/O. But it is decoupled
from the server reactor. And important parsing of frame headers is
a standalone function. So I/O is only needed to obtain frame data.
Because testing server-side ingest is useful and difficult on running
servers, we create a new "debugreflect" endpoint that will echo back
to the client what was received and how it was interpreted. This could
be useful for a server admin, someone implementing a client. But
immediately, it is useful for testing: we're able to demonstrate that
frames are parsed correctly and turned into requests to run commands
without having to implement command dispatch on the server!
In addition, we implement Python level unit tests for the reactor.
This is vastly more efficient than sending requests to the
"debugreflect" endpoint and vastly more powerful for advanced
testing.
Differential Revision: https://phab.mercurial-scm.org/D2852
prepare repo
$ hg init a
$ cd a
$ echo "some text" > FOO.txt
$ echo "another text" > bar.txt
$ echo "more text" > QUICK.txt
$ hg add
adding FOO.txt
adding QUICK.txt
adding bar.txt
$ hg ci -mtest1
verify
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
3 files, 1 changesets, 3 total revisions
verify with journal
$ touch .hg/store/journal
$ hg verify
abandoned transaction found - run hg recover
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
3 files, 1 changesets, 3 total revisions
$ rm .hg/store/journal
introduce some bugs in repo
$ cd .hg/store/data
$ mv _f_o_o.txt.i X_f_o_o.txt.i
$ mv bar.txt.i xbar.txt.i
$ rm _q_u_i_c_k.txt.i
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
warning: revlog 'data/FOO.txt.i' not in fncache!
0: empty or missing FOO.txt
FOO.txt@0: manifest refers to unknown revision f62022d3d590
warning: revlog 'data/QUICK.txt.i' not in fncache!
0: empty or missing QUICK.txt
QUICK.txt@0: manifest refers to unknown revision 88b857db8eba
warning: revlog 'data/bar.txt.i' not in fncache!
0: empty or missing bar.txt
bar.txt@0: manifest refers to unknown revision 256559129457
3 files, 1 changesets, 0 total revisions
3 warnings encountered!
hint: run "hg debugrebuildfncache" to recover from corrupt fncache
6 integrity errors encountered!
(first damaged changeset appears to be 0)
[1]
$ cd ../../..
$ cd ..
Set up a repo for testing missing revlog entries
$ hg init missing-entries
$ cd missing-entries
$ echo 0 > file
$ hg ci -Aqm0
$ cp -R .hg/store .hg/store-partial
$ echo 1 > file
$ hg ci -Aqm1
$ cp -R .hg/store .hg/store-full
Entire changelog missing
$ rm .hg/store/00changelog.*
$ hg verify -q
0: empty or missing changelog
manifest@0: d0b6632564d4 not in changesets
manifest@1: 941fc4534185 not in changesets
3 integrity errors encountered!
(first damaged changeset appears to be 0)
[1]
$ cp -R .hg/store-full/. .hg/store
Entire manifest log missing
$ rm .hg/store/00manifest.*
$ hg verify -q
0: empty or missing manifest
1 integrity errors encountered!
(first damaged changeset appears to be 0)
[1]
$ cp -R .hg/store-full/. .hg/store
Entire filelog missing
$ rm .hg/store/data/file.*
$ hg verify -q
warning: revlog 'data/file.i' not in fncache!
0: empty or missing file
file@0: manifest refers to unknown revision 362fef284ce2
file@1: manifest refers to unknown revision c10f2164107d
1 warnings encountered!
hint: run "hg debugrebuildfncache" to recover from corrupt fncache
3 integrity errors encountered!
(first damaged changeset appears to be 0)
[1]
$ cp -R .hg/store-full/. .hg/store
Entire changelog and manifest log missing
$ rm .hg/store/00changelog.*
$ rm .hg/store/00manifest.*
$ hg verify -q
warning: orphan revlog 'data/file.i'
1 warnings encountered!
$ cp -R .hg/store-full/. .hg/store
Entire changelog and filelog missing
$ rm .hg/store/00changelog.*
$ rm .hg/store/data/file.*
$ hg verify -q
0: empty or missing changelog
manifest@0: d0b6632564d4 not in changesets
manifest@1: 941fc4534185 not in changesets
warning: revlog 'data/file.i' not in fncache!
?: empty or missing file
file@0: manifest refers to unknown revision 362fef284ce2
file@1: manifest refers to unknown revision c10f2164107d
1 warnings encountered!
hint: run "hg debugrebuildfncache" to recover from corrupt fncache
6 integrity errors encountered!
(first damaged changeset appears to be 0)
[1]
$ cp -R .hg/store-full/. .hg/store
Entire manifest log and filelog missing
$ rm .hg/store/00manifest.*
$ rm .hg/store/data/file.*
$ hg verify -q
0: empty or missing manifest
warning: revlog 'data/file.i' not in fncache!
0: empty or missing file
1 warnings encountered!
hint: run "hg debugrebuildfncache" to recover from corrupt fncache
2 integrity errors encountered!
(first damaged changeset appears to be 0)
[1]
$ cp -R .hg/store-full/. .hg/store
Changelog missing entry
$ cp -f .hg/store-partial/00changelog.* .hg/store
$ hg verify -q
manifest@?: rev 1 points to nonexistent changeset 1
manifest@?: 941fc4534185 not in changesets
file@?: rev 1 points to nonexistent changeset 1
(expected 0)
1 warnings encountered!
3 integrity errors encountered!
[1]
$ cp -R .hg/store-full/. .hg/store
Manifest log missing entry
$ cp -f .hg/store-partial/00manifest.* .hg/store
$ hg verify -q
manifest@1: changeset refers to unknown revision 941fc4534185
file@1: c10f2164107d not in manifests
2 integrity errors encountered!
(first damaged changeset appears to be 1)
[1]
$ cp -R .hg/store-full/. .hg/store
Filelog missing entry
$ cp -f .hg/store-partial/data/file.* .hg/store/data
$ hg verify -q
file@1: manifest refers to unknown revision c10f2164107d
1 integrity errors encountered!
(first damaged changeset appears to be 1)
[1]
$ cp -R .hg/store-full/. .hg/store
Changelog and manifest log missing entry
$ cp -f .hg/store-partial/00changelog.* .hg/store
$ cp -f .hg/store-partial/00manifest.* .hg/store
$ hg verify -q
file@?: rev 1 points to nonexistent changeset 1
(expected 0)
file@?: c10f2164107d not in manifests
1 warnings encountered!
2 integrity errors encountered!
[1]
$ cp -R .hg/store-full/. .hg/store
Changelog and filelog missing entry
$ cp -f .hg/store-partial/00changelog.* .hg/store
$ cp -f .hg/store-partial/data/file.* .hg/store/data
$ hg verify -q
manifest@?: rev 1 points to nonexistent changeset 1
manifest@?: 941fc4534185 not in changesets
file@?: manifest refers to unknown revision c10f2164107d
3 integrity errors encountered!
[1]
$ cp -R .hg/store-full/. .hg/store
Manifest and filelog missing entry
$ cp -f .hg/store-partial/00manifest.* .hg/store
$ cp -f .hg/store-partial/data/file.* .hg/store/data
$ hg verify -q
manifest@1: changeset refers to unknown revision 941fc4534185
1 integrity errors encountered!
(first damaged changeset appears to be 1)
[1]
$ cp -R .hg/store-full/. .hg/store
Corrupt changelog base node to cause failure to read revision
$ printf abcd | dd conv=notrunc of=.hg/store/00changelog.i bs=1 seek=16 \
> 2> /dev/null
$ hg verify -q
0: unpacking changeset 08b1860757c2: * (glob)
manifest@?: rev 0 points to unexpected changeset 0
manifest@?: d0b6632564d4 not in changesets
file@?: rev 0 points to unexpected changeset 0
(expected 1)
1 warnings encountered!
4 integrity errors encountered!
(first damaged changeset appears to be 0)
[1]
$ cp -R .hg/store-full/. .hg/store
Corrupt manifest log base node to cause failure to read revision
$ printf abcd | dd conv=notrunc of=.hg/store/00manifest.i bs=1 seek=16 \
> 2> /dev/null
$ hg verify -q
manifest@0: reading delta d0b6632564d4: * (glob)
file@0: 362fef284ce2 not in manifests
2 integrity errors encountered!
(first damaged changeset appears to be 0)
[1]
$ cp -R .hg/store-full/. .hg/store
Corrupt filelog base node to cause failure to read revision
$ printf abcd | dd conv=notrunc of=.hg/store/data/file.i bs=1 seek=16 \
> 2> /dev/null
$ hg verify -q
file@0: unpacking 362fef284ce2: * (glob)
1 integrity errors encountered!
(first damaged changeset appears to be 0)
[1]
$ cp -R .hg/store-full/. .hg/store
$ cd ..
test changelog without a manifest
$ hg init b
$ cd b
$ hg branch foo
marked working directory as branch foo
(branches are permanent and global, did you want a bookmark?)
$ hg ci -m branchfoo
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
0 files, 1 changesets, 0 total revisions
test revlog corruption
$ touch a
$ hg add a
$ hg ci -m a
$ echo 'corrupted' > b
$ dd if=.hg/store/data/a.i of=start bs=1 count=20 2>/dev/null
$ cat start b > .hg/store/data/a.i
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
a@1: broken revlog! (index data/a.i is corrupted)
warning: orphan revlog 'data/a.i'
1 files, 2 changesets, 0 total revisions
1 warnings encountered!
1 integrity errors encountered!
(first damaged changeset appears to be 1)
[1]
$ cd ..
test revlog format 0
$ revlog-formatv0.py
$ cd formatv0
$ hg verify
repository uses revlog format 0
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 1 changesets, 1 total revisions
$ cd ..
test flag processor and skipflags
$ hg init skipflags
$ cd skipflags
$ cat >> .hg/hgrc <<EOF
> [extensions]
> flagprocessor=$RUNTESTDIR/flagprocessorext.py
> EOF
$ echo '[BASE64]content' > base64
$ hg commit -Aqm 'flag processor content' base64
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 1 changesets, 1 total revisions
$ cat >> $TESTTMP/break-base64.py <<EOF
> from __future__ import absolute_import
> import base64
> base64.b64decode=lambda x: x
> EOF
$ cat >> .hg/hgrc <<EOF
> breakbase64=$TESTTMP/break-base64.py
> EOF
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
base64@0: unpacking 794cee7777cb: integrity check failed on data/base64.i:0
1 files, 1 changesets, 1 total revisions
1 integrity errors encountered!
(first damaged changeset appears to be 0)
[1]
$ hg verify --config verify.skipflags=2147483647
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 1 changesets, 1 total revisions