view tests/test-propertycache.py @ 37048:fc5e261915b9

wireproto: require POST for all HTTPv2 requests

Wire protocol version 1 transfers argument data via request
headers by default. This has historically caused problems because
servers institute limits on the length of individual HTTP headers
as well as the total size of all request headers. Mercurial servers
can advertise the maximum length of an individual header. But
there's no guarantee any intermediate HTTP agents will accept
headers up to that length.

In the existing wire protocol, server operators typically also
key off the HTTP request method to implement authentication.
For example, GET requests translate to read-only requests and
can be allowed. But read-write commands must use POST and require
authentication. This has typically worked because the only wire
protocol commands that use POST modify the repo (e.g. the
"unbundle" command).

There is an experimental feature to enable clients to transmit
argument data via POST request bodies. This is technically a
better and more robust solution. But we can't enable it by default
because of servers assuming POST means write access.

In version 2 of the wire protocol, the permissions of a request
are encoded in the URL. And with it being a new protocol in a new
URL space, we're not constrained by backwards compatibility
requirements.

This commit adopts the technically superior mechanism of using
HTTP request bodies to send argument data by requiring POST for
all commands. Strictly speaking, it may be possible to send
request bodies on GET requests. But my experience is that not all
HTTP stacks support this. POST pretty much always works. Using POST
for read-only operations does sacrifice some RESTful design
purity. But this API cares about practicality, not about being
in Roy T. Fielding's REST ivory tower.

There's a chance we may relax this restriction in the future. But
for now, I want to see how far we can get with a POST only API.

Differential Revision: https://phab.mercurial-scm.org/D2837

"""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'))