108 lines
3.1 KiB
Go
108 lines
3.1 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/p2p/enode"
|
||
|
|
"github.com/ethereum/go-ethereum/p2p/nodestate"
|
||
|
|
)
|
||
|
|
|
||
|
|
// FillSet tries to read nodes from an input iterator and add them to a node set by
|
||
|
|
// setting the specified node state flag(s) until the size of the set reaches the target.
|
||
|
|
// Note that other mechanisms (like other FillSet instances reading from different inputs)
|
||
|
|
// can also set the same flag(s) and FillSet will always care about the total number of
|
||
|
|
// nodes having those flags.
|
||
|
|
type FillSet struct {
|
||
|
|
lock sync.Mutex
|
||
|
|
cond *sync.Cond
|
||
|
|
ns *nodestate.NodeStateMachine
|
||
|
|
input enode.Iterator
|
||
|
|
closed bool
|
||
|
|
flags nodestate.Flags
|
||
|
|
count, target int
|
||
|
|
}
|
||
|
|
|
||
|
|
// NewFillSet creates a new FillSet
|
||
|
|
func NewFillSet(ns *nodestate.NodeStateMachine, input enode.Iterator, flags nodestate.Flags) *FillSet {
|
||
|
|
fs := &FillSet{
|
||
|
|
ns: ns,
|
||
|
|
input: input,
|
||
|
|
flags: flags,
|
||
|
|
}
|
||
|
|
fs.cond = sync.NewCond(&fs.lock)
|
||
|
|
|
||
|
|
ns.SubscribeState(flags, func(n *enode.Node, oldState, newState nodestate.Flags) {
|
||
|
|
fs.lock.Lock()
|
||
|
|
if oldState.Equals(flags) {
|
||
|
|
fs.count--
|
||
|
|
}
|
||
|
|
if newState.Equals(flags) {
|
||
|
|
fs.count++
|
||
|
|
}
|
||
|
|
if fs.target > fs.count {
|
||
|
|
fs.cond.Signal()
|
||
|
|
}
|
||
|
|
fs.lock.Unlock()
|
||
|
|
})
|
||
|
|
|
||
|
|
go fs.readLoop()
|
||
|
|
return fs
|
||
|
|
}
|
||
|
|
|
||
|
|
// readLoop keeps reading nodes from the input and setting the specified flags for them
|
||
|
|
// whenever the node set size is under the current target
|
||
|
|
func (fs *FillSet) readLoop() {
|
||
|
|
for {
|
||
|
|
fs.lock.Lock()
|
||
|
|
for fs.target <= fs.count && !fs.closed {
|
||
|
|
fs.cond.Wait()
|
||
|
|
}
|
||
|
|
|
||
|
|
fs.lock.Unlock()
|
||
|
|
if !fs.input.Next() {
|
||
|
|
return
|
||
|
|
}
|
||
|
|
fs.ns.SetState(fs.input.Node(), fs.flags, nodestate.Flags{}, 0)
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// SetTarget sets the current target for node set size. If the previous target was not
|
||
|
|
// reached and FillSet was still waiting for the next node from the input then the next
|
||
|
|
// incoming node will be added to the set regardless of the target. This ensures that
|
||
|
|
// all nodes coming from the input are eventually added to the set.
|
||
|
|
func (fs *FillSet) SetTarget(target int) {
|
||
|
|
fs.lock.Lock()
|
||
|
|
defer fs.lock.Unlock()
|
||
|
|
|
||
|
|
fs.target = target
|
||
|
|
if fs.target > fs.count {
|
||
|
|
fs.cond.Signal()
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// Close shuts FillSet down and closes the input iterator
|
||
|
|
func (fs *FillSet) Close() {
|
||
|
|
fs.lock.Lock()
|
||
|
|
defer fs.lock.Unlock()
|
||
|
|
|
||
|
|
fs.closed = true
|
||
|
|
fs.input.Close()
|
||
|
|
fs.cond.Signal()
|
||
|
|
}
|