633746b87d
Currently snitch drivers register themselves in class-registry with all sorts of construction options possible. All those different constuctors are in fact "config options". When later snitch will declare its dependencies (gossiper and system keyspace), it will require patching all this registrations, which's very inconvenient. This patch introduces the snitch_config struct and replaces all the snitch constructors with the snitch_driver(snitch_config cfg) one. Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
69 lines
1.9 KiB
C++
69 lines
1.9 KiB
C++
/*
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*
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* Modified by ScyllaDB
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* Copyright (C) 2015-present ScyllaDB
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*/
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/*
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* SPDX-License-Identifier: (AGPL-3.0-or-later and Apache-2.0)
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*/
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#pragma once
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#include "snitch_base.hh"
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#include "utils/fb_utilities.hh"
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#include <memory>
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namespace locator {
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/**
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* A simple endpoint snitch implementation that treats Strategy order as
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* proximity, allowing non-read-repaired reads to prefer a single endpoint,
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* which improves cache locality.
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*/
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struct simple_snitch : public snitch_base {
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simple_snitch(const snitch_config& cfg) {
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_my_dc = get_datacenter(utils::fb_utilities::get_broadcast_address());
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_my_rack = get_rack(utils::fb_utilities::get_broadcast_address());
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// This snitch is ready on creation
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set_snitch_ready();
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}
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virtual sstring get_rack(inet_address endpoint) override {
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return "rack1";
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}
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virtual sstring get_datacenter(inet_address endpoint) override {
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return "datacenter1";
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}
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virtual void sort_by_proximity(
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inet_address address, inet_address_vector_replica_set& addresses) override {
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// Optimization to avoid walking the list
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}
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virtual int compare_endpoints(inet_address& target, inet_address& a1,
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inet_address& a2) override {
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//
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// "Making all endpoints equal ensures we won't change the original
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// ordering." - quote from C* code.
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//
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// Effectively this would return 0 even in the following case:
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//
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// compare_endpoints(NodeA, NodeA, NodeB) // -1 should be returned
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//
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// The snitch_base implementation would handle the above case correctly.
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//
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// I'm leaving the this implementation anyway since it's the C*'s
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// implementation and some installations may depend on it.
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//
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return 0;
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}
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virtual sstring get_name() const override {
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return "org.apache.cassandra.locator.SimpleSnitch";
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}
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};
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}
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