2648fb1bb1
Done with: ack '2019+' -l | xargs sed -i -e 's/2019+/2020+/g' Checked manually with: git add -p Hello to future James from 2021, and Happy Hacking!
85 lines
2.5 KiB
Go
85 lines
2.5 KiB
Go
// Mgmt
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// Copyright (C) 2013-2020+ James Shubin and the project contributors
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// Written by James Shubin <james@shubin.ca> and the project contributors
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//
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// This program is free software: you can redistribute it and/or modify
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// it under the terms of the GNU General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// This program is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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//
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// You should have received a copy of the GNU General Public License
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// along with this program. If not, see <http://www.gnu.org/licenses/>.
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package scheduler // TODO: i'd like this to be a separate package, but cycles!
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import (
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"fmt"
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"sort"
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"github.com/purpleidea/mgmt/util"
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)
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func init() {
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Register("rr", func() Strategy { return &rrStrategy{} }) // must register the func and name
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}
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type rrStrategy struct {
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// some stored state
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hosts []string
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}
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// Schedule returns hosts in round robin style from the available hostnames.
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func (obj *rrStrategy) Schedule(hostnames map[string]string, opts *schedulerOptions) ([]string, error) {
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if len(hostnames) <= 0 {
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return nil, fmt.Errorf("strategy: cannot schedule from zero hosts")
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}
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if opts.maxCount <= 0 {
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return nil, fmt.Errorf("strategy: cannot schedule with a max of zero")
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}
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// always get a deterministic list of current hosts first...
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sortedHosts := []string{}
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for key := range hostnames {
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sortedHosts = append(sortedHosts, key)
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}
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sort.Strings(sortedHosts)
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if obj.hosts == nil {
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obj.hosts = []string{} // initialize if needed
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}
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// add any new hosts we learned about, to the end of the list
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for _, x := range sortedHosts {
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if !util.StrInList(x, obj.hosts) {
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obj.hosts = append(obj.hosts, x)
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}
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}
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// remove any hosts we previouly knew about from the list
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for ix := len(obj.hosts) - 1; ix >= 0; ix-- {
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if !util.StrInList(obj.hosts[ix], sortedHosts) {
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// delete entry at this index
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obj.hosts = append(obj.hosts[:ix], obj.hosts[ix+1:]...)
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}
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}
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// get the maximum number of hosts to return
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max := len(obj.hosts) // can't return more than we have
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if opts.maxCount < max { // found a smaller limit
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max = opts.maxCount
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}
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result := []string{}
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// now return the number of needed hosts from the list
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for i := 0; i < max; i++ {
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result = append(result, obj.hosts[i])
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}
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return result, nil
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}
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