Add sync => go-sync

sync/lock/etcd/etcd.go

@@ -0,0 +1,115 @@
+// Package etcd is an etcd implementation of lock
+package etcd
+
+import (
+	"context"
+	"errors"
+	"log"
+	"path"
+	"strings"
+	"sync"
+
+	"github.com/micro/go-micro/sync/lock"
+	client "go.etcd.io/etcd/clientv3"
+	cc "go.etcd.io/etcd/clientv3/concurrency"
+)
+
+type etcdLock struct {
+	opts   lock.Options
+	path   string
+	client *client.Client
+
+	sync.Mutex
+	locks map[string]*elock
+}
+
+type elock struct {
+	s *cc.Session
+	m *cc.Mutex
+}
+
+func (e *etcdLock) Acquire(id string, opts ...lock.AcquireOption) error {
+	var options lock.AcquireOptions
+	for _, o := range opts {
+		o(&options)
+	}
+
+	// make path
+	path := path.Join(e.path, strings.Replace(e.opts.Prefix+id, "/", "-", -1))
+
+	var sopts []cc.SessionOption
+	if options.TTL > 0 {
+		sopts = append(sopts, cc.WithTTL(int(options.TTL.Seconds())))
+	}
+
+	s, err := cc.NewSession(e.client, sopts...)
+	if err != nil {
+		return err
+	}
+
+	m := cc.NewMutex(s, path)
+
+	ctx, _ := context.WithCancel(context.Background())
+
+	if err := m.Lock(ctx); err != nil {
+		return err
+	}
+
+	e.Lock()
+	e.locks[id] = &elock{
+		s: s,
+		m: m,
+	}
+	e.Unlock()
+	return nil
+}
+
+func (e *etcdLock) Release(id string) error {
+	e.Lock()
+	defer e.Unlock()
+	v, ok := e.locks[id]
+	if !ok {
+		return errors.New("lock not found")
+	}
+	err := v.m.Unlock(context.Background())
+	delete(e.locks, id)
+	return err
+}
+
+func (e *etcdLock) String() string {
+	return "etcd"
+}
+
+func NewLock(opts ...lock.Option) lock.Lock {
+	var options lock.Options
+	for _, o := range opts {
+		o(&options)
+	}
+
+	var endpoints []string
+
+	for _, addr := range options.Nodes {
+		if len(addr) > 0 {
+			endpoints = append(endpoints, addr)
+		}
+	}
+
+	if len(endpoints) == 0 {
+		endpoints = []string{"http://127.0.0.1:2379"}
+	}
+
+	// TODO: parse addresses
+	c, err := client.New(client.Config{
+		Endpoints: endpoints,
+	})
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	return &etcdLock{
+		path:   "/micro/lock",
+		client: c,
+		opts:   options,
+		locks:  make(map[string]*elock),
+	}
+}