wireproto: define and implement HTTP handshake to upgrade protocol
When clients connect to repositories over HTTP, they issue a request
to the well-known URL "?cmd=capabilities" to fetch the repository
capabilities. This is the handshake portion of the HTTP protocol.
This commit defines a mechanism to use that HTTP request to return
information about modern server features.
If a client sends an X-HgUpgrade-* header containing a list of
client-supported API names, the server responds with a response
containing information about available services. This includes
the normal capabilities string. So if the server doesn't support
any newer services, the client can easily fall back.
By advertising supported services from clients, server operators
can see and log what client support exists in the wild. This will
also help with debugging.
The response contains the base path to API services. We know there
are potential issues with the <repo>/api/ URL space conflicting with
hgwebdir and subrepos. By making the API URL dynamic from the
perspective of the client, the URL for APIs is not subject to backwards
compatibility concerns - at least as long as a ?cmd=capabilities request
is made.
We've also defined the ``cbor`` client capability for the X-HgProto-*
header. This MUST be sent in order to get the modern response from
"?cmd=capabilities". During implementation, I initially always sent
an application/mercurial-cbor response. However, the handshake
mechanism will be more future compatible if the client is in charge
of which formats to request. We already perform content negotiation
from X-HgProto-*, so keying off this for the capabilities response
feels appropriate.
In addition, I initially used application/cbor. However, it is
conceivable that a non-Mercurial server could serve application/cbor.
To rule out this possibility, I've invented a new media type that
is Mercurial specific and can't be confused for generic CBOR.
Differential Revision: https://phab.mercurial-scm.org/D3242
"""test behavior of propertycache and unfiltered propertycache
The repoview overlay is quite complex. We test the behavior of
property cache of both localrepo and repoview to prevent
regression."""
from __future__ import absolute_import, print_function
import os
import subprocess
from mercurial import (
hg,
localrepo,
ui as uimod,
util,
)
# create some special property cache that trace they call
calllog = []
@util.propertycache
def testcachedfoobar(repo):
name = repo.filtername
if name is None:
name = ''
val = len(name)
calllog.append(val)
return val
unficalllog = []
@localrepo.unfilteredpropertycache
def testcachedunfifoobar(repo):
name = repo.filtername
if name is None:
name = ''
val = 100 + len(name)
unficalllog.append(val)
return val
#plug them on repo
localrepo.localrepository.testcachedfoobar = testcachedfoobar
localrepo.localrepository.testcachedunfifoobar = testcachedunfifoobar
# Create an empty repo and instantiate it. It is important to run
# these tests on the real object to detect regression.
repopath = os.path.join(os.environ['TESTTMP'], 'repo')
assert subprocess.call(['hg', 'init', repopath]) == 0
ui = uimod.ui.load()
repo = hg.repository(ui, path=repopath).unfiltered()
print('')
print('=== property cache ===')
print('')
print('calllog:', calllog)
print('cached value (unfiltered):',
vars(repo).get('testcachedfoobar', 'NOCACHE'))
print('')
print('= first access on unfiltered, should do a call')
print('access:', repo.testcachedfoobar)
print('calllog:', calllog)
print('cached value (unfiltered):',
vars(repo).get('testcachedfoobar', 'NOCACHE'))
print('')
print('= second access on unfiltered, should not do call')
print('access', repo.testcachedfoobar)
print('calllog:', calllog)
print('cached value (unfiltered):',
vars(repo).get('testcachedfoobar', 'NOCACHE'))
print('')
print('= first access on "visible" view, should do a call')
visibleview = repo.filtered('visible')
print('cached value ("visible" view):',
vars(visibleview).get('testcachedfoobar', 'NOCACHE'))
print('access:', visibleview.testcachedfoobar)
print('calllog:', calllog)
print('cached value (unfiltered):',
vars(repo).get('testcachedfoobar', 'NOCACHE'))
print('cached value ("visible" view):',
vars(visibleview).get('testcachedfoobar', 'NOCACHE'))
print('')
print('= second access on "visible view", should not do call')
print('access:', visibleview.testcachedfoobar)
print('calllog:', calllog)
print('cached value (unfiltered):',
vars(repo).get('testcachedfoobar', 'NOCACHE'))
print('cached value ("visible" view):',
vars(visibleview).get('testcachedfoobar', 'NOCACHE'))
print('')
print('= no effect on other view')
immutableview = repo.filtered('immutable')
print('cached value ("immutable" view):',
vars(immutableview).get('testcachedfoobar', 'NOCACHE'))
print('access:', immutableview.testcachedfoobar)
print('calllog:', calllog)
print('cached value (unfiltered):',
vars(repo).get('testcachedfoobar', 'NOCACHE'))
print('cached value ("visible" view):',
vars(visibleview).get('testcachedfoobar', 'NOCACHE'))
print('cached value ("immutable" view):',
vars(immutableview).get('testcachedfoobar', 'NOCACHE'))
# unfiltered property cache test
print('')
print('')
print('=== unfiltered property cache ===')
print('')
print('unficalllog:', unficalllog)
print('cached value (unfiltered): ',
vars(repo).get('testcachedunfifoobar', 'NOCACHE'))
print('cached value ("visible" view): ',
vars(visibleview).get('testcachedunfifoobar', 'NOCACHE'))
print('cached value ("immutable" view):',
vars(immutableview).get('testcachedunfifoobar', 'NOCACHE'))
print('')
print('= first access on unfiltered, should do a call')
print('access (unfiltered):', repo.testcachedunfifoobar)
print('unficalllog:', unficalllog)
print('cached value (unfiltered): ',
vars(repo).get('testcachedunfifoobar', 'NOCACHE'))
print('')
print('= second access on unfiltered, should not do call')
print('access (unfiltered):', repo.testcachedunfifoobar)
print('unficalllog:', unficalllog)
print('cached value (unfiltered): ',
vars(repo).get('testcachedunfifoobar', 'NOCACHE'))
print('')
print('= access on view should use the unfiltered cache')
print('access (unfiltered): ', repo.testcachedunfifoobar)
print('access ("visible" view): ', visibleview.testcachedunfifoobar)
print('access ("immutable" view):', immutableview.testcachedunfifoobar)
print('unficalllog:', unficalllog)
print('cached value (unfiltered): ',
vars(repo).get('testcachedunfifoobar', 'NOCACHE'))
print('cached value ("visible" view): ',
vars(visibleview).get('testcachedunfifoobar', 'NOCACHE'))
print('cached value ("immutable" view):',
vars(immutableview).get('testcachedunfifoobar', 'NOCACHE'))
print('')
print('= even if we clear the unfiltered cache')
del repo.__dict__['testcachedunfifoobar']
print('cached value (unfiltered): ',
vars(repo).get('testcachedunfifoobar', 'NOCACHE'))
print('cached value ("visible" view): ',
vars(visibleview).get('testcachedunfifoobar', 'NOCACHE'))
print('cached value ("immutable" view):',
vars(immutableview).get('testcachedunfifoobar', 'NOCACHE'))
print('unficalllog:', unficalllog)
print('access ("visible" view): ', visibleview.testcachedunfifoobar)
print('unficalllog:', unficalllog)
print('cached value (unfiltered): ',
vars(repo).get('testcachedunfifoobar', 'NOCACHE'))
print('cached value ("visible" view): ',
vars(visibleview).get('testcachedunfifoobar', 'NOCACHE'))
print('cached value ("immutable" view):',
vars(immutableview).get('testcachedunfifoobar', 'NOCACHE'))
print('access ("immutable" view):', immutableview.testcachedunfifoobar)
print('unficalllog:', unficalllog)
print('cached value (unfiltered): ',
vars(repo).get('testcachedunfifoobar', 'NOCACHE'))
print('cached value ("visible" view): ',
vars(visibleview).get('testcachedunfifoobar', 'NOCACHE'))
print('cached value ("immutable" view):',
vars(immutableview).get('testcachedunfifoobar', 'NOCACHE'))
print('access (unfiltered): ', repo.testcachedunfifoobar)
print('unficalllog:', unficalllog)
print('cached value (unfiltered): ',
vars(repo).get('testcachedunfifoobar', 'NOCACHE'))
print('cached value ("visible" view): ',
vars(visibleview).get('testcachedunfifoobar', 'NOCACHE'))
print('cached value ("immutable" view):',
vars(immutableview).get('testcachedunfifoobar', 'NOCACHE'))