63 lines
1.6 KiB
Go
63 lines
1.6 KiB
Go
// Copyright (C) 2014 The Syncthing Authors.
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//
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// This program is free software: you can redistribute it and/or modify it
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// under the terms of the GNU General Public License as published by the Free
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// Software Foundation, either version 3 of the License, or (at your option)
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// any later version.
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//
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// This program is distributed in the hope that it will be useful, but WITHOUT
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// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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// more details.
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//
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// You should have received a copy of the GNU General Public License along
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// with this program. If not, see <http://www.gnu.org/licenses/>.
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package model
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import (
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"sync"
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"github.com/syncthing/syncthing/internal/protocol"
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)
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// deviceActivity tracks the number of outstanding requests per device and can
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// answer which device is least busy. It is safe for use from multiple
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// goroutines.
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type deviceActivity struct {
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act map[protocol.DeviceID]int
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mut sync.Mutex
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}
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func newDeviceActivity() *deviceActivity {
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return &deviceActivity{
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act: make(map[protocol.DeviceID]int),
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}
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}
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func (m deviceActivity) leastBusy(availability []protocol.DeviceID) protocol.DeviceID {
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m.mut.Lock()
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var low int = 2<<30 - 1
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var selected protocol.DeviceID
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for _, device := range availability {
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if usage := m.act[device]; usage < low {
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low = usage
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selected = device
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}
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}
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m.mut.Unlock()
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return selected
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}
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func (m deviceActivity) using(device protocol.DeviceID) {
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m.mut.Lock()
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defer m.mut.Unlock()
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m.act[device]++
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}
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func (m deviceActivity) done(device protocol.DeviceID) {
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m.mut.Lock()
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defer m.mut.Unlock()
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m.act[device]--
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}
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