70 lines
2.0 KiB
Python
70 lines
2.0 KiB
Python
#!/usr/bin/python -i
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#
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# ps_tutorial.py
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#
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# This source file is part of the FoundationDB open source project
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#
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# Copyright 2013-2018 Apple Inc. and the FoundationDB project authors
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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#
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"""
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This document is a brief tutorial of the publish/subscription layer.
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The key concepts are:
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- Feeds: A feed is a source of messages.
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- Inbox: An inbox receives messages posted to feeds
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- Subscriptions: A subscription connects an inbox to a feed
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Simply put, an inbox receives receives all messages posted to the feeds it subscribes to.
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The pub/sub layer allows management of feeds, inboxes, and subscriptions, as well as the
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actual delivery of messages.
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"""
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# Prerequisites
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import os
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import sys
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import fdb
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from pubsub_bigdoc import PubSub
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fdb.api_version(14)
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# Start by opening the default FoundationDB database (see documentation)
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db = fdb.open()
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# Clear all data from the database, so that this simple test starts fresh each time
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# del db[:]
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# Create a "new" PubSub layer that will use the opened database
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ps = PubSub(db)
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# Create a single feed (for Alice)
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feed_a = ps.create_feed('alice_feed')
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# Create an inbox for Bob
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inbox_b = ps.create_inbox('bob_inbox')
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# Subscribe bob to alice's feed
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assert ps.create_subscription(feed_a, inbox_b)
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# Post a couple of messages to alice's feed
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ps.post_message(feed_a, 'hi from alice')
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ps.post_message(feed_a, 'hi from alice again!')
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# Print all the messages in bob's inbox (which subscribes to alice's feed)
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print "Messages to Bob:"
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for m in ps.get_inbox_messages(inbox_b):
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print " ->", m
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