94 lines
2.5 KiB
Python
94 lines
2.5 KiB
Python
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#
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# micro_priority.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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import os
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import fdb
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fdb.api_version(300)
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pq = fdb.Subspace(('P',))
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@fdb.transactional
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def push(tr, value, priority):
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tr[pq[priority][_next_count(tr, priority)][os.urandom(20)]] = value
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@fdb.transactional
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def _next_count(tr, priority):
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r = pq[priority].range()
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for key, value in tr.snapshot.get_range(r.start, r.stop, limit=1, reverse=True):
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return pq[priority].unpack(key)[0] + 1
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return 0
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@fdb.transactional
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def pop(tr, max=False):
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r = pq.range()
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for item in tr.get_range(r.start, r.stop, limit=1, reverse=max):
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del tr[item.key]
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return item.value
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@fdb.transactional
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def peek(tr, max=False):
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r = pq.range()
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for item in tr.get_range(r.start, r.stop, limit=1, reverse=max):
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return item.value
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@fdb.transactional
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def clear_subspace(tr, subspace):
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tr.clear_range_startswith(subspace.key())
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def smoke_test():
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print "Peek none:", peek(db)
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push(db, 'a', 1)
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push(db, 'b', 5)
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push(db, 'c', 2)
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push(db, 'd', 4)
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push(db, 'e', 3)
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print "peek in min order"
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print peek(db)
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print peek(db)
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print "pop in min order"
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print pop(db)
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print pop(db)
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print pop(db)
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print pop(db)
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print pop(db)
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print "Peek none:", peek(db, max=True)
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push(db, 'a1', 1)
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push(db, 'a2', 1)
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push(db, 'a3', 1)
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push(db, 'a4', 1)
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push(db, 'b', 5)
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push(db, 'c', 2)
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push(db, 'd', 4)
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push(db, 'e', 3)
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print "peek in max order"
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print peek(db, max=True)
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print peek(db, max=True)
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print "pop in max order"
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print pop(db, max=True)
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print pop(db, max=True)
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print pop(db, max=True)
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print pop(db, max=True)
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print pop(db, max=True)
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print pop(db, max=True)
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if __name__ == "__main__":
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db = fdb.open()
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clear_subspace(db, pq)
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smoke_test()
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