path: root/swarm/network/simulation/connect.go

// Copyright 2018 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 simulation

import (
    "strings"

    "github.com/ethereum/go-ethereum/p2p/enode"
)

// ConnectToPivotNode connects the node with provided NodeID
// to the pivot node, already set by Simulation.SetPivotNode method.
// It is useful when constructing a star network topology
// when simulation adds and removes nodes dynamically.
func (s *Simulation) ConnectToPivotNode(id enode.ID) (err error) {
    pid := s.PivotNodeID()
    if pid == nil {
        return ErrNoPivotNode
    }
    return s.connect(*pid, id)
}

// ConnectToLastNode connects the node with provided NodeID
// to the last node that is up, and avoiding connection to self.
// It is useful when constructing a chain network topology
// when simulation adds and removes nodes dynamically.
func (s *Simulation) ConnectToLastNode(id enode.ID) (err error) {
    ids := s.UpNodeIDs()
    l := len(ids)
    if l < 2 {
        return nil
    }
    lid := ids[l-1]
    if lid == id {
        lid = ids[l-2]
    }
    return s.connect(lid, id)
}

// ConnectToRandomNode connects the node with provieded NodeID
// to a random node that is up.
func (s *Simulation) ConnectToRandomNode(id enode.ID) (err error) {
    n := s.RandomUpNode(id)
    if n == nil {
        return ErrNodeNotFound
    }
    return s.connect(n.ID, id)
}

// ConnectNodesFull connects all nodes one to another.
// It provides a complete connectivity in the network
// which should be rarely needed.
func (s *Simulation) ConnectNodesFull(ids []enode.ID) (err error) {
    if ids == nil {
        ids = s.UpNodeIDs()
    }
    l := len(ids)
    for i := 0; i < l; i++ {
        for j := i + 1; j < l; j++ {
            err = s.connect(ids[i], ids[j])
            if err != nil {
                return err
            }
        }
    }
    return nil
}

// ConnectNodesChain connects all nodes in a chain topology.
// If ids argument is nil, all nodes that are up will be connected.
func (s *Simulation) ConnectNodesChain(ids []enode.ID) (err error) {
    if ids == nil {
        ids = s.UpNodeIDs()
    }
    l := len(ids)
    for i := 0; i < l-1; i++ {
        err = s.connect(ids[i], ids[i+1])
        if err != nil {
            return err
        }
    }
    return nil
}

// ConnectNodesRing connects all nodes in a ring topology.
// If ids argument is nil, all nodes that are up will be connected.
func (s *Simulation) ConnectNodesRing(ids []enode.ID) (err error) {
    if ids == nil {
        ids = s.UpNodeIDs()
    }
    l := len(ids)
    if l < 2 {
        return nil
    }
    for i := 0; i < l-1; i++ {
        err = s.connect(ids[i], ids[i+1])
        if err != nil {
            return err
        }
    }
    return s.connect(ids[l-1], ids[0])
}

// ConnectNodesStar connects all nodes in a star topology
// with the center at provided NodeID.
// If ids argument is nil, all nodes that are up will be connected.
func (s *Simulation) ConnectNodesStar(id enode.ID, ids []enode.ID) (err error) {
    if ids == nil {
        ids = s.UpNodeIDs()
    }
    l := len(ids)
    for i := 0; i < l; i++ {
        if id == ids[i] {
            continue
        }
        err = s.connect(id, ids[i])
        if err != nil {
            return err
        }
    }
    return nil
}

// ConnectNodesStarPivot connects all nodes in a star topology
// with the center at already set pivot node.
// If ids argument is nil, all nodes that are up will be connected.
func (s *Simulation) ConnectNodesStarPivot(ids []enode.ID) (err error) {
    id := s.PivotNodeID()
    if id == nil {
        return ErrNoPivotNode
    }
    return s.ConnectNodesStar(*id, ids)
}

// connect connects two nodes but ignores already connected error.
func (s *Simulation) connect(oneID, otherID enode.ID) error {
    return ignoreAlreadyConnectedErr(s.Net.Connect(oneID, otherID))
}

func ignoreAlreadyConnectedErr(err error) error {
    if err == nil || strings.Contains(err.Error(), "already connected") {
        return nil
    }
    return err
}