1/* File: swi/paxos.pl 2 Author: Roy Ratcliffe 3 WWW: https://github.com/royratcliffe 4 Created: Jun 12 2021 5 Purpose: SWI Paxos 6 7Copyright (c) 2021, Roy Ratcliffe, United Kingdom 8 9Permission is hereby granted, free of charge, to any person obtaining a 10copy of this software and associated documentation files (the 11"Software"), to deal in the Software without restriction, including 12without limitation the rights to use, copy, modify, merge, publish, 13distribute, sublicense, and/or sell copies of the Software, and to 14permit persons to whom the Software is furnished to do so, subject to 15the following conditions: 16 17 The above copyright notice and this permission notice shall be 18 included in all copies or substantial portions of the Software. 19 20THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS 21OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 22MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 23IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY 24CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, 25TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE 26SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. 27 28*/ 29 30:- module(swi_paxos, 31 [ paxos_quorum_nodes/1, % -Nodes:list(nonneg) 32 paxos_quorum_nth1/1 % ?Nth1 33 ]). 34:- autoload(library(lists), [nth1/3]). 35:- autoload(library(paxos), [paxos_property/1]). 36:- use_module(library(canny/pop)).
45paxos_quorum_nodes(Nodes) :- 46 paxos_property(quorum(Quorum)), 47 pop_lsbs(Quorum, Nodes).
55paxos_quorum_nth1(Nth1) :- 56 paxos_property(node(Node)), 57 paxos_quorum_nodes(Nodes), 58 once(nth1(Nth1, Nodes, Node))