Initial commit.

Author: rand0x0m

README.md

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+# chord-dfs : Minimal DFS implementing part of the Chord algorithm
+
+## Overview
+
+Aims to fully implement the algorithm but for the time it still lacks a lot of features other implementations have. And most notably it doesn't support fingers thus has worst time O(n) time complexity for any call. 
+
+## Install
+
+```
+go get github.com/rand0x0m/chord-dfs
+```
+
+## License
+
+MIT.
+

client.go

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+package chord
+
+func remotePut(server *Info, value string) error {
+	con, err := setupConnection(server)
+
+	if err == nil {
+		err = con.Call("Node.Put", value, nil)
+	}
+
+	return err
+}
+
+func remoteGet(server *Info, key string) (string, error) {
+	var res string
+
+	con, err := setupConnection(server)
+	if err == nil {
+		err = con.Call("Node.Get", key, &res)
+	}
+
+	return res, err
+}
+
+func remoteDelete(server *Info, key string) error {
+	con, err := setupConnection(server)
+
+	if err == nil {
+		err = con.Call("Node.Delete", key, nil)
+	}
+
+	return err
+}
+
+func remoteSucc(server *Info) (*Info, error) {
+	var res Info
+
+	con, err := setupConnection(server)
+	if err == nil {
+		err = con.Call("Node.Successor", struct{}{}, &res)
+	}
+
+	return &res, err
+}
+
+func remotePred(server *Info) (*Info, error) {
+	var res Info
+
+	con, err := setupConnection(server)
+	if err == nil {
+		err = con.Call("Node.Predecessor", struct{}{}, &res)
+	}
+
+	return &res, err
+}
+
+func remoteNotify(server *Info, newPred Info) error {
+	con, err := setupConnection(server)
+
+	if err == nil {
+		err = con.Call("Node.Notify", newPred, nil)
+	}
+
+	return err
+}
+
+func remoteFindPred(server *Info, id string) (*Info, error) {
+	var pred Info
+
+	con, err := setupConnection(server)
+	if err == nil {
+		err = con.Call("Node.FindPred", id, &pred)
+	}
+
+	return &pred, err
+}
+
+func remoteFindSucc(server *Info, id string) (*Info, error) {
+	var succ Info
+
+	con, err := setupConnection(server)
+	if err == nil {
+		err = con.Call("Node.FindSucc", id, &succ)
+	}
+
+	return &succ, err
+}

db.go

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+package chord
+
+type Db map[string]string
+
+func newDb() Db {
+	var s Db = make(map[string]string)
+
+	return s
+}

dfs.go

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+package chord
+
+import (
+	"errors"
+	"net"
+)
+
+type DFS struct {
+	N      *Node
+	Config *Config
+}
+
+type Config struct {
+	BindAddr      *net.TCPAddr
+	BootstrapAddr *net.TCPAddr
+}
+
+func (dfs *DFS) Put(value string) error {
+	if dfs.N.isBootstrap() {
+		return errors.New("disconnected")
+	} else {
+		succ, err := remoteFindSucc(dfs.N.Info, hashData(value))
+		if err != nil {
+			return err
+		}
+		return remotePut(succ, value)
+	}
+}
+
+func (dfs *DFS) Get(value string) (string, error) {
+	key := hashData(value)
+	if dfs.N.isBootstrap() {
+		return "", errors.New("disconnected")
+	} else {
+		succ, err := remoteFindSucc(dfs.N.Info, key)
+		if err != nil {
+			return "", err
+		}
+
+		return remoteGet(succ, key)
+	}
+}
+
+func (dfs *DFS) Delete(value string) error {
+	key := hashData(value)
+	if dfs.N.isBootstrap() {
+		return errors.New("disconnected")
+	} else {
+		succ, err := remoteFindSucc(dfs.N.Info, key)
+		if err != nil {
+			return err
+		}
+
+		return remoteDelete(succ, key)
+	}
+}
+
+func (dfs *DFS) Shutdown() {
+	dfs.N.shutdown()
+}
+
+func (dfs *DFS) Connect() error {
+	err := dfs.N.join(*dfs.Config.BootstrapAddr)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func NewDFS(config *Config) (*DFS, error) {
+	dfs := new(DFS)
+	dfs.N = NewNode(*config.BindAddr)
+	dfs.Config = config
+
+	if err := dfs.N.listen(); err != nil {
+		return nil, err
+	}
+
+	return dfs, nil
+}

examples/three-nodes-network/main.go

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+package main
+
+import (
+	"fmt"
+	"net"
+	"time"
+
+	"github.com/rand0x0m/chord"
+)
+
+var dfs1, dfs2, dfs3 chord.DFS
+
+var testAddrs = [6]net.TCPAddr{
+	{IP: net.ParseIP("127.0.0.1"), Port: 5483},
+	{IP: net.ParseIP("127.0.0.1"), Port: 5484},
+	{IP: net.ParseIP("127.0.0.1"), Port: 5485},
+}
+
+var testValues = [6]string{
+	"TestValue",
+	"TestValue87",
+	"TestValue90",
+	"TestValue20",
+	"TestValue6",
+	"TestValue65",
+}
+
+func main() {
+
+	dfs1, err := chord.NewDFS(&chord.Config{&testAddrs[0], nil})
+	if err != nil {
+		panic(err)
+	}
+
+	dfs2, err := chord.NewDFS(&chord.Config{&testAddrs[1], &testAddrs[0]})
+	if err != nil {
+		panic(err)
+	}
+
+	dfs3, err := chord.NewDFS(&chord.Config{&testAddrs[2], &testAddrs[0]})
+	if err != nil {
+		panic(err)
+	}
+
+	if err := dfs2.Connect(); err != nil {
+		panic(0)
+	}
+
+	time.Sleep(5 * time.Second)
+
+	if err := dfs3.Connect(); err != nil {
+		panic(0)
+	}
+
+	time.Sleep(5 * time.Second)
+
+	for _, v := range testValues {
+		err := dfs1.Put(v)
+		if err != nil {
+			panic(err)
+		}
+	}
+
+	for _, v := range testValues {
+		v, err := dfs1.Get(v)
+		fmt.Println(v)
+		if err != nil {
+			panic(err)
+		}
+	}
+
+	dfs1.Shutdown()
+
+	time.Sleep(3 * time.Second)
+
+	dfs2.Shutdown()
+
+	time.Sleep(3 * time.Second)
+
+	dfs3.Shutdown()
+}

info.go

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+package chord
+
+import (
+	"fmt"
+	"net"
+)
+
+type Info struct {
+	Addr net.TCPAddr
+	Id   string
+}
+
+func (i *Info) equal(o *Info) bool {
+	return i.Id == o.Id
+}
+
+func (i *Info) String() string {
+	return fmt.Sprintf("Network:%v:%v Id:%v", i.Addr.Network(), i.Addr.String(), i.Id)
+}
+
+func newNodeInfo(addr net.TCPAddr) *Info {
+	i := new(Info)
+	i.Addr = addr
+	i.Id = hashAddr(addr)
+
+	return i
+}