debugcommands: add debugwireproto command
We currently don't have a low-level mechanism for sending
arbitrary wire protocol commands. Having a generic and robust
mechanism for sending wire protocol commands, examining wire
data, etc would make it vastly easier to test the wire protocol
and debug server operation. This is a problem I've wanted a
solution for numerous times, especially recently as I've been
hacking on a new version of the wire protocol.
This commit establishes a `hg debugwireproto` command for sending
data to a peer.
The command invents a mini language for specifying actions to take.
This will enable a lot of flexibility for issuing commands and testing
variations for how commands are sent.
Right now, we only support low-level raw sends and receives. These
are probably the least valuable commands to intended users of this
command. But they are the most useful commands to implement to
bootstrap the feature (I've chosen to reimplement test-ssh-proto.t
using this command to prove its usefulness).
My eventual goal of `hg debugwireproto` is to allow calling wire
protocol commands with a human-friendly interface. Essentially,
people can type in a command name and arguments and
`hg debugwireproto` will figure out how to send that on the wire.
I'd love to eventually be able to save the server's raw response
to a file. This would allow us to e.g. call "getbundle" wire
protocol commands easily.
test-ssh-proto.t has been updated to use the new command in lieu
of piping directly to a server process. As part of the transition,
test behavior improved. Before, we piped all request data to the
server at once. Now, we have explicit control over the ordering of
operations. e.g. we can send one command, receive its response,
then send another command. This will allow us to more robustly
test race conditions, buffering behavior, etc.
There were some subtle changes in test behavior. For example,
previous behavior would often send trailing newlines to the server.
The new mechanism doesn't treat literal newlines specially and
requires newlines be escaped in the payload.
Because the new logging code is very low level, it is easy to
introduce race conditions in tests. For example, the number of bytes
returned by a read() may vary depending on load. This is why tests
make heavy use of "readline" for consuming data: the result of
that operation should be deterministic and not subject to race
conditions. There are still some uses of "readavailable." However,
those are only for reading from stderr. I was able to reproduce
timing issues with my system under load when using "readavailable"
globally. But if I "readline" to grab stdout, "readavailable"
appears to work deterministically for stderr. I think this is
because the server writes to stderr first. As long as the OS
delivers writes to pipes in the same order they were made, this
should work. If there are timing issues, we can introduce a
mechanism to readline from stderr.
Differential Revision: https://phab.mercurial-scm.org/D2392
# formatter.py - generic output formatting for mercurial
#
# Copyright 2012 Matt Mackall <mpm@selenic.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
"""Generic output formatting for Mercurial
The formatter provides API to show data in various ways. The following
functions should be used in place of ui.write():
- fm.write() for unconditional output
- fm.condwrite() to show some extra data conditionally in plain output
- fm.context() to provide changectx to template output
- fm.data() to provide extra data to JSON or template output
- fm.plain() to show raw text that isn't provided to JSON or template output
To show structured data (e.g. date tuples, dicts, lists), apply fm.format*()
beforehand so the data is converted to the appropriate data type. Use
fm.isplain() if you need to convert or format data conditionally which isn't
supported by the formatter API.
To build nested structure (i.e. a list of dicts), use fm.nested().
See also https://www.mercurial-scm.org/wiki/GenericTemplatingPlan
fm.condwrite() vs 'if cond:':
In most cases, use fm.condwrite() so users can selectively show the data
in template output. If it's costly to build data, use plain 'if cond:' with
fm.write().
fm.nested() vs fm.formatdict() (or fm.formatlist()):
fm.nested() should be used to form a tree structure (a list of dicts of
lists of dicts...) which can be accessed through template keywords, e.g.
"{foo % "{bar % {...}} {baz % {...}}"}". On the other hand, fm.formatdict()
exports a dict-type object to template, which can be accessed by e.g.
"{get(foo, key)}" function.
Doctest helper:
>>> def show(fn, verbose=False, **opts):
... import sys
... from . import ui as uimod
... ui = uimod.ui()
... ui.verbose = verbose
... ui.pushbuffer()
... try:
... return fn(ui, ui.formatter(pycompat.sysbytes(fn.__name__),
... pycompat.byteskwargs(opts)))
... finally:
... print(pycompat.sysstr(ui.popbuffer()), end='')
Basic example:
>>> def files(ui, fm):
... files = [(b'foo', 123, (0, 0)), (b'bar', 456, (1, 0))]
... for f in files:
... fm.startitem()
... fm.write(b'path', b'%s', f[0])
... fm.condwrite(ui.verbose, b'date', b' %s',
... fm.formatdate(f[2], b'%Y-%m-%d %H:%M:%S'))
... fm.data(size=f[1])
... fm.plain(b'\\n')
... fm.end()
>>> show(files)
foo
bar
>>> show(files, verbose=True)
foo 1970-01-01 00:00:00
bar 1970-01-01 00:00:01
>>> show(files, template=b'json')
[
{
"date": [0, 0],
"path": "foo",
"size": 123
},
{
"date": [1, 0],
"path": "bar",
"size": 456
}
]
>>> show(files, template=b'path: {path}\\ndate: {date|rfc3339date}\\n')
path: foo
date: 1970-01-01T00:00:00+00:00
path: bar
date: 1970-01-01T00:00:01+00:00
Nested example:
>>> def subrepos(ui, fm):
... fm.startitem()
... fm.write(b'reponame', b'[%s]\\n', b'baz')
... files(ui, fm.nested(b'files'))
... fm.end()
>>> show(subrepos)
[baz]
foo
bar
>>> show(subrepos, template=b'{reponame}: {join(files % "{path}", ", ")}\\n')
baz: foo, bar
"""
from __future__ import absolute_import, print_function
import collections
import contextlib
import itertools
import os
from .i18n import _
from .node import (
hex,
short,
)
from . import (
error,
pycompat,
templatefilters,
templatekw,
templater,
util,
)
pickle = util.pickle
class _nullconverter(object):
'''convert non-primitive data types to be processed by formatter'''
# set to True if context object should be stored as item
storecontext = False
@staticmethod
def formatdate(date, fmt):
'''convert date tuple to appropriate format'''
return date
@staticmethod
def formatdict(data, key, value, fmt, sep):
'''convert dict or key-value pairs to appropriate dict format'''
# use plain dict instead of util.sortdict so that data can be
# serialized as a builtin dict in pickle output
return dict(data)
@staticmethod
def formatlist(data, name, fmt, sep):
'''convert iterable to appropriate list format'''
return list(data)
class baseformatter(object):
def __init__(self, ui, topic, opts, converter):
self._ui = ui
self._topic = topic
self._style = opts.get("style")
self._template = opts.get("template")
self._converter = converter
self._item = None
# function to convert node to string suitable for this output
self.hexfunc = hex
def __enter__(self):
return self
def __exit__(self, exctype, excvalue, traceback):
if exctype is None:
self.end()
def _showitem(self):
'''show a formatted item once all data is collected'''
def startitem(self):
'''begin an item in the format list'''
if self._item is not None:
self._showitem()
self._item = {}
def formatdate(self, date, fmt='%a %b %d %H:%M:%S %Y %1%2'):
'''convert date tuple to appropriate format'''
return self._converter.formatdate(date, fmt)
def formatdict(self, data, key='key', value='value', fmt='%s=%s', sep=' '):
'''convert dict or key-value pairs to appropriate dict format'''
return self._converter.formatdict(data, key, value, fmt, sep)
def formatlist(self, data, name, fmt='%s', sep=' '):
'''convert iterable to appropriate list format'''
# name is mandatory argument for now, but it could be optional if
# we have default template keyword, e.g. {item}
return self._converter.formatlist(data, name, fmt, sep)
def context(self, **ctxs):
'''insert context objects to be used to render template keywords'''
ctxs = pycompat.byteskwargs(ctxs)
assert all(k == 'ctx' for k in ctxs)
if self._converter.storecontext:
self._item.update(ctxs)
def data(self, **data):
'''insert data into item that's not shown in default output'''
data = pycompat.byteskwargs(data)
self._item.update(data)
def write(self, fields, deftext, *fielddata, **opts):
'''do default text output while assigning data to item'''
fieldkeys = fields.split()
assert len(fieldkeys) == len(fielddata)
self._item.update(zip(fieldkeys, fielddata))
def condwrite(self, cond, fields, deftext, *fielddata, **opts):
'''do conditional write (primarily for plain formatter)'''
fieldkeys = fields.split()
assert len(fieldkeys) == len(fielddata)
self._item.update(zip(fieldkeys, fielddata))
def plain(self, text, **opts):
'''show raw text for non-templated mode'''
def isplain(self):
'''check for plain formatter usage'''
return False
def nested(self, field):
'''sub formatter to store nested data in the specified field'''
self._item[field] = data = []
return _nestedformatter(self._ui, self._converter, data)
def end(self):
'''end output for the formatter'''
if self._item is not None:
self._showitem()
def nullformatter(ui, topic):
'''formatter that prints nothing'''
return baseformatter(ui, topic, opts={}, converter=_nullconverter)
class _nestedformatter(baseformatter):
'''build sub items and store them in the parent formatter'''
def __init__(self, ui, converter, data):
baseformatter.__init__(self, ui, topic='', opts={}, converter=converter)
self._data = data
def _showitem(self):
self._data.append(self._item)
def _iteritems(data):
'''iterate key-value pairs in stable order'''
if isinstance(data, dict):
return sorted(data.iteritems())
return data
class _plainconverter(object):
'''convert non-primitive data types to text'''
storecontext = False
@staticmethod
def formatdate(date, fmt):
'''stringify date tuple in the given format'''
return util.datestr(date, fmt)
@staticmethod
def formatdict(data, key, value, fmt, sep):
'''stringify key-value pairs separated by sep'''
return sep.join(fmt % (k, v) for k, v in _iteritems(data))
@staticmethod
def formatlist(data, name, fmt, sep):
'''stringify iterable separated by sep'''
return sep.join(fmt % e for e in data)
class plainformatter(baseformatter):
'''the default text output scheme'''
def __init__(self, ui, out, topic, opts):
baseformatter.__init__(self, ui, topic, opts, _plainconverter)
if ui.debugflag:
self.hexfunc = hex
else:
self.hexfunc = short
if ui is out:
self._write = ui.write
else:
self._write = lambda s, **opts: out.write(s)
def startitem(self):
pass
def data(self, **data):
pass
def write(self, fields, deftext, *fielddata, **opts):
self._write(deftext % fielddata, **opts)
def condwrite(self, cond, fields, deftext, *fielddata, **opts):
'''do conditional write'''
if cond:
self._write(deftext % fielddata, **opts)
def plain(self, text, **opts):
self._write(text, **opts)
def isplain(self):
return True
def nested(self, field):
# nested data will be directly written to ui
return self
def end(self):
pass
class debugformatter(baseformatter):
def __init__(self, ui, out, topic, opts):
baseformatter.__init__(self, ui, topic, opts, _nullconverter)
self._out = out
self._out.write("%s = [\n" % self._topic)
def _showitem(self):
self._out.write(' %s,\n' % pycompat.byterepr(self._item))
def end(self):
baseformatter.end(self)
self._out.write("]\n")
class pickleformatter(baseformatter):
def __init__(self, ui, out, topic, opts):
baseformatter.__init__(self, ui, topic, opts, _nullconverter)
self._out = out
self._data = []
def _showitem(self):
self._data.append(self._item)
def end(self):
baseformatter.end(self)
self._out.write(pickle.dumps(self._data))
class jsonformatter(baseformatter):
def __init__(self, ui, out, topic, opts):
baseformatter.__init__(self, ui, topic, opts, _nullconverter)
self._out = out
self._out.write("[")
self._first = True
def _showitem(self):
if self._first:
self._first = False
else:
self._out.write(",")
self._out.write("\n {\n")
first = True
for k, v in sorted(self._item.items()):
if first:
first = False
else:
self._out.write(",\n")
u = templatefilters.json(v, paranoid=False)
self._out.write(' "%s": %s' % (k, u))
self._out.write("\n }")
def end(self):
baseformatter.end(self)
self._out.write("\n]\n")
class _templateconverter(object):
'''convert non-primitive data types to be processed by templater'''
storecontext = True
@staticmethod
def formatdate(date, fmt):
'''return date tuple'''
return date
@staticmethod
def formatdict(data, key, value, fmt, sep):
'''build object that can be evaluated as either plain string or dict'''
data = util.sortdict(_iteritems(data))
def f():
yield _plainconverter.formatdict(data, key, value, fmt, sep)
return templatekw.hybriddict(data, key=key, value=value, fmt=fmt, gen=f)
@staticmethod
def formatlist(data, name, fmt, sep):
'''build object that can be evaluated as either plain string or list'''
data = list(data)
def f():
yield _plainconverter.formatlist(data, name, fmt, sep)
return templatekw.hybridlist(data, name=name, fmt=fmt, gen=f)
class templateformatter(baseformatter):
def __init__(self, ui, out, topic, opts):
baseformatter.__init__(self, ui, topic, opts, _templateconverter)
self._out = out
spec = lookuptemplate(ui, topic, opts.get('template', ''))
self._tref = spec.ref
self._t = loadtemplater(ui, spec, defaults=templatekw.keywords,
resources=templateresources(ui),
cache=templatekw.defaulttempl)
self._parts = templatepartsmap(spec, self._t,
['docheader', 'docfooter', 'separator'])
self._counter = itertools.count()
self._renderitem('docheader', {})
def _showitem(self):
item = self._item.copy()
item['index'] = index = next(self._counter)
if index > 0:
self._renderitem('separator', {})
self._renderitem(self._tref, item)
def _renderitem(self, part, item):
if part not in self._parts:
return
ref = self._parts[part]
# TODO: add support for filectx
props = {}
# explicitly-defined fields precede templatekw
props.update(item)
if 'ctx' in item:
# but template resources must be always available
props['repo'] = props['ctx'].repo()
props['revcache'] = {}
props = pycompat.strkwargs(props)
g = self._t(ref, **props)
self._out.write(templater.stringify(g))
def end(self):
baseformatter.end(self)
self._renderitem('docfooter', {})
templatespec = collections.namedtuple(r'templatespec',
r'ref tmpl mapfile')
def lookuptemplate(ui, topic, tmpl):
"""Find the template matching the given -T/--template spec 'tmpl'
'tmpl' can be any of the following:
- a literal template (e.g. '{rev}')
- a map-file name or path (e.g. 'changelog')
- a reference to [templates] in config file
- a path to raw template file
A map file defines a stand-alone template environment. If a map file
selected, all templates defined in the file will be loaded, and the
template matching the given topic will be rendered. Aliases won't be
loaded from user config, but from the map file.
If no map file selected, all templates in [templates] section will be
available as well as aliases in [templatealias].
"""
# looks like a literal template?
if '{' in tmpl:
return templatespec('', tmpl, None)
# perhaps a stock style?
if not os.path.split(tmpl)[0]:
mapname = (templater.templatepath('map-cmdline.' + tmpl)
or templater.templatepath(tmpl))
if mapname and os.path.isfile(mapname):
return templatespec(topic, None, mapname)
# perhaps it's a reference to [templates]
if ui.config('templates', tmpl):
return templatespec(tmpl, None, None)
if tmpl == 'list':
ui.write(_("available styles: %s\n") % templater.stylelist())
raise error.Abort(_("specify a template"))
# perhaps it's a path to a map or a template
if ('/' in tmpl or '\\' in tmpl) and os.path.isfile(tmpl):
# is it a mapfile for a style?
if os.path.basename(tmpl).startswith("map-"):
return templatespec(topic, None, os.path.realpath(tmpl))
with util.posixfile(tmpl, 'rb') as f:
tmpl = f.read()
return templatespec('', tmpl, None)
# constant string?
return templatespec('', tmpl, None)
def templatepartsmap(spec, t, partnames):
"""Create a mapping of {part: ref}"""
partsmap = {spec.ref: spec.ref} # initial ref must exist in t
if spec.mapfile:
partsmap.update((p, p) for p in partnames if p in t)
elif spec.ref:
for part in partnames:
ref = '%s:%s' % (spec.ref, part) # select config sub-section
if ref in t:
partsmap[part] = ref
return partsmap
def loadtemplater(ui, spec, defaults=None, resources=None, cache=None):
"""Create a templater from either a literal template or loading from
a map file"""
assert not (spec.tmpl and spec.mapfile)
if spec.mapfile:
frommapfile = templater.templater.frommapfile
return frommapfile(spec.mapfile, defaults=defaults, resources=resources,
cache=cache)
return maketemplater(ui, spec.tmpl, defaults=defaults, resources=resources,
cache=cache)
def maketemplater(ui, tmpl, defaults=None, resources=None, cache=None):
"""Create a templater from a string template 'tmpl'"""
aliases = ui.configitems('templatealias')
t = templater.templater(defaults=defaults, resources=resources,
cache=cache, aliases=aliases)
t.cache.update((k, templater.unquotestring(v))
for k, v in ui.configitems('templates'))
if tmpl:
t.cache[''] = tmpl
return t
def templateresources(ui, repo=None):
"""Create a dict of template resources designed for the default templatekw
and function"""
return {
'cache': {}, # for templatekw/funcs to store reusable data
'ctx': None,
'repo': repo,
'revcache': None, # per-ctx cache; set later
'ui': ui,
}
def formatter(ui, out, topic, opts):
template = opts.get("template", "")
if template == "json":
return jsonformatter(ui, out, topic, opts)
elif template == "pickle":
return pickleformatter(ui, out, topic, opts)
elif template == "debug":
return debugformatter(ui, out, topic, opts)
elif template != "":
return templateformatter(ui, out, topic, opts)
# developer config: ui.formatdebug
elif ui.configbool('ui', 'formatdebug'):
return debugformatter(ui, out, topic, opts)
# deprecated config: ui.formatjson
elif ui.configbool('ui', 'formatjson'):
return jsonformatter(ui, out, topic, opts)
return plainformatter(ui, out, topic, opts)
@contextlib.contextmanager
def openformatter(ui, filename, topic, opts):
"""Create a formatter that writes outputs to the specified file
Must be invoked using the 'with' statement.
"""
with util.posixfile(filename, 'wb') as out:
with formatter(ui, out, topic, opts) as fm:
yield fm
@contextlib.contextmanager
def _neverending(fm):
yield fm
def maybereopen(fm, filename, opts):
"""Create a formatter backed by file if filename specified, else return
the given formatter
Must be invoked using the 'with' statement. This will never call fm.end()
of the given formatter.
"""
if filename:
return openformatter(fm._ui, filename, fm._topic, opts)
else:
return _neverending(fm)