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# -*- coding: utf-8 -*-
"""
helloworld
~~~~~~~~~~
A minimal working example, showing :mod:`pyxs` API usage.
:copyright: (c) 2016 by pyxs authors and contributors,
see AUTHORS for more details.
"""
from __future__ import print_function
from pyxs import Client, PyXSError
if __name__ == "__main__":
with Client() as c:
# a) write-read.
c[b"/foo/bar"] = b"baz"
print(c[b"/foo/bar"]) # ==> "baz"
# b) exceptions! let's try to read a non-existant path.
try:
c[b"/path/to/something/useless"]
except PyXSError as e:
print(e)
# c) okay, time to delete that /foo/bar path.
del c[b"/foo/bar"]
try:
c[b"/foo/bar"]
except PyXSError as e:
print("`/foo/bar` is no moar!")
# d) directory listing and permissions.
c.mkdir(b"/foo/bar")
c.mkdir(b"/foo/baz")
c.mkdir(b"/foo/boo")
print("Here's what `/foo` has: ", c.list(b"/foo"))
print(c.get_perms(b"/foo"))
# e) let's watch some paths!
c.write(b"/foo/bar", b"baz")
with c.monitor() as m:
m.watch(b"/foo/bar", b"baz")
print("Watching ... do ``xenstore-write /foo/bar <anything>``.")
print(next(m.wait())) # 1st.
print(next(m.wait())) # 2nd.
m.unwatch(b"/foo/bar", b"baz")
# f) domain management commands.
print(c.get_domain_path(0))
print("domain 0 introduced: ", c.is_domain_introduced(0))
# g) transactions.
print("Creating a `/bar/foo` within a transaction.")
while True:
c.transaction()
c[b"/bar/foo"] = b"baz"
if c.commit():
break
print("Transaction committed. Let's check it: "
"/bar/foo =", c[b"/bar/foo"])
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