##// END OF EJS Templates
sshpeer: initial definition and implementation of new SSH protocol...
sshpeer: initial definition and implementation of new SSH protocol The existing SSH protocol has several design flaws. Future commits will elaborate on these flaws as new features are introduced to combat these flaws. For now, hopefully you can take me for my word that a ground up rewrite of the SSH protocol is needed. This commit lays the foundation for a new SSH protocol by defining a mechanism to upgrade the SSH transport channel away from the default (version 1) protocol to something modern (which we'll call "version 2" for now). This upgrade process is detailed in the internals documentation for the wire protocol. The gist of it is the client sends a request line preceding the "hello" command/line which basically says "I'm requesting an upgrade: here's what I support." If the server recognizes that line, it processes the upgrade request and the transport channel is switched to use the new version of the protocol. If not, it sends an empty response, which is how all Mercurial SSH servers from the beginning of time reacted to unknown commands. The upgrade request is effectively ignored and the client continues to use the existing version of the protocol as if nothing happened. The new version of the SSH protocol is completely identical to version 1 aside from the upgrade dance and the bytes that follow. The immediate bytes that follow the protocol switch are defined to be a length framed "capabilities: " line containing the remote's advertised capabilities. In reality, this looks very similar to what the "hello" response would look like. But it will evolve quickly. The methodology by which the protocol will evolve is important. I'm not going to introduce the new protocol all at once. That would likely lead to endless bike shedding and forward progress would stall. Instead, I intend to tricle out new features and diversions from the existing protocol in small, incremental changes. To support the gradual evolution of the protocol, the on-the-wire advertised protocol name contains an "exp" to denote "experimental" and a 4 digit field to capture the sub-version of the protocol. Whenever we make a BC change to the wire protocol, we can increment this version and lock out all older clients because it will appear as a completely different protocol version. This means we can incur as many breaking changes as we want. We don't have to commit to supporting any one feature or idea for a long period of time. We can even evolve the handshake mechanism, because that is defined as being an implementation detail of the negotiated protocol version! Hopefully this lowers the barrier to accepting changes to the protocol and for experimenting with "radical" ideas during its development. In core, sshpeer received most of the attention. We haven't even implemented the server bits for the new protocol in core yet. Instead, we add very primitive support to our test server, mainly just to exercise the added code paths in sshpeer. Differential Revision: https://phab.mercurial-scm.org/D2061 # no-check-commit because of required foo_bar naming

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test-imports-checker.t
159 lines | 5.1 KiB | text/troff | Tads3Lexer
/ tests / test-imports-checker.t
#require test-repo
$ . "$TESTDIR/helpers-testrepo.sh"
$ testrepohgenv
$ import_checker="$TESTDIR"/../contrib/import-checker.py
Run the doctests from the import checker, and make sure
it's working correctly.
$ TERM=dumb
$ export TERM
$ $PYTHON -m doctest $import_checker
Run additional tests for the import checker
$ mkdir testpackage
$ touch testpackage/__init__.py
$ cat > testpackage/multiple.py << EOF
> from __future__ import absolute_import
> import os, sys
> EOF
$ cat > testpackage/unsorted.py << EOF
> from __future__ import absolute_import
> import sys
> import os
> EOF
$ cat > testpackage/stdafterlocal.py << EOF
> from __future__ import absolute_import
> from . import unsorted
> import os
> EOF
$ cat > testpackage/requirerelative.py << EOF
> from __future__ import absolute_import
> import testpackage.unsorted
> EOF
$ cat > testpackage/importalias.py << EOF
> from __future__ import absolute_import
> import ui
> EOF
$ cat > testpackage/relativestdlib.py << EOF
> from __future__ import absolute_import
> from .. import os
> EOF
$ cat > testpackage/symbolimport.py << EOF
> from __future__ import absolute_import
> from .unsorted import foo
> EOF
$ cat > testpackage/latesymbolimport.py << EOF
> from __future__ import absolute_import
> from . import unsorted
> from mercurial.node import hex
> EOF
$ cat > testpackage/multiplegroups.py << EOF
> from __future__ import absolute_import
> from . import unsorted
> from . import more
> EOF
$ mkdir testpackage/subpackage
$ cat > testpackage/subpackage/levelpriority.py << EOF
> from __future__ import absolute_import
> from . import foo
> from .. import parent
> EOF
$ touch testpackage/subpackage/foo.py
$ cat > testpackage/subpackage/__init__.py << EOF
> from __future__ import absolute_import
> from . import levelpriority # should not cause cycle
> EOF
$ cat > testpackage/subpackage/localimport.py << EOF
> from __future__ import absolute_import
> from . import foo
> def bar():
> # should not cause "higher-level import should come first"
> from .. import unsorted
> # but other errors should be detected
> from .. import more
> import testpackage.subpackage.levelpriority
> EOF
$ cat > testpackage/importmodulefromsub.py << EOF
> from __future__ import absolute_import
> from .subpackage import foo # not a "direct symbol import"
> EOF
$ cat > testpackage/importsymbolfromsub.py << EOF
> from __future__ import absolute_import
> from .subpackage import foo, nonmodule
> EOF
$ cat > testpackage/sortedentries.py << EOF
> from __future__ import absolute_import
> from . import (
> foo,
> bar,
> )
> EOF
$ cat > testpackage/importfromalias.py << EOF
> from __future__ import absolute_import
> from . import ui
> EOF
$ cat > testpackage/importfromrelative.py << EOF
> from __future__ import absolute_import
> from testpackage.unsorted import foo
> EOF
$ mkdir testpackage2
$ touch testpackage2/__init__.py
$ cat > testpackage2/latesymbolimport.py << EOF
> from __future__ import absolute_import
> from testpackage import unsorted
> from mercurial.node import hex
> EOF
# Shadowing a stdlib module to test "relative import of stdlib module" is
# allowed if the module is also being checked
$ mkdir email
$ touch email/__init__.py
$ touch email/errors.py
$ cat > email/utils.py << EOF
> from __future__ import absolute_import
> from . import errors
> EOF
$ $PYTHON "$import_checker" testpackage*/*.py testpackage/subpackage/*.py \
> email/*.py
testpackage/importalias.py:2: ui module must be "as" aliased to uimod
testpackage/importfromalias.py:2: ui from testpackage must be "as" aliased to uimod
testpackage/importfromrelative.py:2: import should be relative: testpackage.unsorted
testpackage/importfromrelative.py:2: direct symbol import foo from testpackage.unsorted
testpackage/importsymbolfromsub.py:2: direct symbol import nonmodule from testpackage.subpackage
testpackage/latesymbolimport.py:3: symbol import follows non-symbol import: mercurial.node
testpackage/multiple.py:2: multiple imported names: os, sys
testpackage/multiplegroups.py:3: multiple "from . import" statements
testpackage/relativestdlib.py:2: relative import of stdlib module
testpackage/requirerelative.py:2: import should be relative: testpackage.unsorted
testpackage/sortedentries.py:2: imports from testpackage not lexically sorted: bar < foo
testpackage/stdafterlocal.py:3: stdlib import "os" follows local import: testpackage
testpackage/subpackage/levelpriority.py:3: higher-level import should come first: testpackage
testpackage/subpackage/localimport.py:7: multiple "from .. import" statements
testpackage/subpackage/localimport.py:8: import should be relative: testpackage.subpackage.levelpriority
testpackage/symbolimport.py:2: direct symbol import foo from testpackage.unsorted
testpackage/unsorted.py:3: imports not lexically sorted: os < sys
testpackage2/latesymbolimport.py:3: symbol import follows non-symbol import: mercurial.node
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