view tests/test-symlink-os-yes-fs-no.py @ 36367:043e77f3be09

sshpeer: return framed file object when needed

Currently, wireproto.wirepeer has a default implementation of
_submitbatch() and sshv1peer has a very similar implementation.
The main difference is that sshv1peer is aware of the total amount
of bytes it can read whereas the default implementation reads the
stream until no more data is returned. The default implementation
works for HTTP, since there is a known end to HTTP responses (either
Content-Length or 0 sized chunk).

This commit teaches sshv1peer to use our just-introduced "cappedreader"
class for wrapping a file object to limit the number of bytes that
can be read. We do this by introducing an argument to specify whether
the response is framed. If set, we returned a cappedreader instance
instead of the raw pipe.

_call() always has framed responses. So we set this argument
unconditionally and then .read() the entirety of the result.
Strictly speaking, we don't need to use cappedreader in this case
and can inline frame decoding/read logic. But I like when things
are consistent. The overhead should be negligible.

_callstream() and _callcompressable() are special: whether framing
is used depends on the specific command. So, we define a set
of commands that have framed response. It currently only
contains "batch."

As a result of this change, the one-off implementation of
_submitbatch() in sshv1peer can be removed since it is now
safe to .read() the response's file object until end of stream.
cappedreader takes care of not overrunning the frame.

Differential Revision: https://phab.mercurial-scm.org/D2380

from __future__ import absolute_import

import os
import sys
import time
from mercurial import (
    commands,
    hg,
    ui as uimod,
    util,
)

TESTDIR = os.environ["TESTDIR"]
BUNDLEPATH = os.path.join(TESTDIR, 'bundles', 'test-no-symlinks.hg')

# only makes sense to test on os which supports symlinks
if not getattr(os, "symlink", False):
    sys.exit(80) # SKIPPED_STATUS defined in run-tests.py

u = uimod.ui.load()
# hide outer repo
hg.peer(u, {}, '.', create=True)

# clone with symlink support
hg.clone(u, {}, BUNDLEPATH, 'test0')

repo = hg.repository(u, 'test0')

# wait a bit, or the status call wont update the dirstate
time.sleep(1)
commands.status(u, repo)

# now disable symlink support -- this is what os.symlink would do on a
# non-symlink file system
def symlink_failure(src, dst):
    raise OSError(1, "Operation not permitted")
os.symlink = symlink_failure
def islink_failure(path):
    return False
os.path.islink = islink_failure

# dereference links as if a Samba server has exported this to a
# Windows client
for f in 'test0/a.lnk', 'test0/d/b.lnk':
    os.unlink(f)
    fp = open(f, 'wb')
    fp.write(util.readfile(f[:-4]))
    fp.close()

# reload repository
u = uimod.ui.load()
repo = hg.repository(u, 'test0')
commands.status(u, repo)

# try cloning a repo which contains symlinks
u = uimod.ui.load()
hg.clone(u, {}, BUNDLEPATH, 'test1')