mirror of
https://gitlab.com/pulsechaincom/go-pulse.git
synced 2024-12-24 20:37:17 +00:00
129 lines
3.5 KiB
Go
129 lines
3.5 KiB
Go
// Copyright 2020 The go-ethereum Authors
|
|
// This file is part of the go-ethereum library.
|
|
//
|
|
// The go-ethereum library is free software: you can redistribute it and/or modify
|
|
// it under the terms of the GNU Lesser General Public License as published by
|
|
// the Free Software Foundation, either version 3 of the License, or
|
|
// (at your option) any later version.
|
|
//
|
|
// The go-ethereum library is distributed in the hope that it will be useful,
|
|
// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
// GNU Lesser General Public License for more details.
|
|
//
|
|
// You should have received a copy of the GNU Lesser General Public License
|
|
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
package client
|
|
|
|
import (
|
|
"sync"
|
|
|
|
"github.com/ethereum/go-ethereum/les/utils"
|
|
"github.com/ethereum/go-ethereum/p2p/enode"
|
|
"github.com/ethereum/go-ethereum/p2p/nodestate"
|
|
)
|
|
|
|
// WrsIterator returns nodes from the specified selectable set with a weighted random
|
|
// selection. Selection weights are provided by a callback function.
|
|
type WrsIterator struct {
|
|
lock sync.Mutex
|
|
cond *sync.Cond
|
|
|
|
ns *nodestate.NodeStateMachine
|
|
wrs *utils.WeightedRandomSelect
|
|
nextNode *enode.Node
|
|
closed bool
|
|
}
|
|
|
|
// NewWrsIterator creates a new WrsIterator. Nodes are selectable if they have all the required
|
|
// and none of the disabled flags set. When a node is selected the selectedFlag is set which also
|
|
// disables further selectability until it is removed or times out.
|
|
func NewWrsIterator(ns *nodestate.NodeStateMachine, requireFlags, disableFlags nodestate.Flags, weightField nodestate.Field) *WrsIterator {
|
|
wfn := func(i interface{}) uint64 {
|
|
n := ns.GetNode(i.(enode.ID))
|
|
if n == nil {
|
|
return 0
|
|
}
|
|
wt, _ := ns.GetField(n, weightField).(uint64)
|
|
return wt
|
|
}
|
|
|
|
w := &WrsIterator{
|
|
ns: ns,
|
|
wrs: utils.NewWeightedRandomSelect(wfn),
|
|
}
|
|
w.cond = sync.NewCond(&w.lock)
|
|
|
|
ns.SubscribeField(weightField, func(n *enode.Node, state nodestate.Flags, oldValue, newValue interface{}) {
|
|
if state.HasAll(requireFlags) && state.HasNone(disableFlags) {
|
|
w.lock.Lock()
|
|
w.wrs.Update(n.ID())
|
|
w.lock.Unlock()
|
|
w.cond.Signal()
|
|
}
|
|
})
|
|
|
|
ns.SubscribeState(requireFlags.Or(disableFlags), func(n *enode.Node, oldState, newState nodestate.Flags) {
|
|
oldMatch := oldState.HasAll(requireFlags) && oldState.HasNone(disableFlags)
|
|
newMatch := newState.HasAll(requireFlags) && newState.HasNone(disableFlags)
|
|
if newMatch == oldMatch {
|
|
return
|
|
}
|
|
|
|
w.lock.Lock()
|
|
if newMatch {
|
|
w.wrs.Update(n.ID())
|
|
} else {
|
|
w.wrs.Remove(n.ID())
|
|
}
|
|
w.lock.Unlock()
|
|
w.cond.Signal()
|
|
})
|
|
return w
|
|
}
|
|
|
|
// Next selects the next node.
|
|
func (w *WrsIterator) Next() bool {
|
|
w.nextNode = w.chooseNode()
|
|
return w.nextNode != nil
|
|
}
|
|
|
|
func (w *WrsIterator) chooseNode() *enode.Node {
|
|
w.lock.Lock()
|
|
defer w.lock.Unlock()
|
|
|
|
for {
|
|
for !w.closed && w.wrs.IsEmpty() {
|
|
w.cond.Wait()
|
|
}
|
|
if w.closed {
|
|
return nil
|
|
}
|
|
// Choose the next node at random. Even though w.wrs is guaranteed
|
|
// non-empty here, Choose might return nil if all items have weight
|
|
// zero.
|
|
if c := w.wrs.Choose(); c != nil {
|
|
id := c.(enode.ID)
|
|
w.wrs.Remove(id)
|
|
return w.ns.GetNode(id)
|
|
}
|
|
}
|
|
|
|
}
|
|
|
|
// Close ends the iterator.
|
|
func (w *WrsIterator) Close() {
|
|
w.lock.Lock()
|
|
w.closed = true
|
|
w.lock.Unlock()
|
|
w.cond.Signal()
|
|
}
|
|
|
|
// Node returns the current node.
|
|
func (w *WrsIterator) Node() *enode.Node {
|
|
w.lock.Lock()
|
|
defer w.lock.Unlock()
|
|
return w.nextNode
|
|
}
|