couchbase session provider

+package session
+
+import (
+	"github.com/couchbaselabs/go-couchbase"
+	"net/http"
+	"strings"
+	"sync"
+)
+
+var couchbpder = &CouchbaseProvider{}
+
+type CouchbaseSessionStore struct {
+	b           *couchbase.Bucket
+	sid         string
+	lock        sync.RWMutex
+	values      map[interface{}]interface{}
+	maxlifetime int64
+}
+
+type CouchbaseProvider struct {
+	maxlifetime int64
+	savePath    string
+	pool        string
+	bucket      string
+	b           *couchbase.Bucket
+}
+
+func (cs *CouchbaseSessionStore) Set(key, value interface{}) error {
+	cs.lock.Lock()
+	defer cs.lock.Unlock()
+	cs.values[key] = value
+	return nil
+}
+
+func (cs *CouchbaseSessionStore) Get(key interface{}) interface{} {
+	cs.lock.RLock()
+	defer cs.lock.RUnlock()
+	if v, ok := cs.values[key]; ok {
+		return v
+	} else {
+		return nil
+	}
+	return nil
+}
+
+func (cs *CouchbaseSessionStore) Delete(key interface{}) error {
+	cs.lock.Lock()
+	defer cs.lock.Unlock()
+	delete(cs.values, key)
+	return nil
+}
+
+func (cs *CouchbaseSessionStore) Flush() error {
+	cs.lock.Lock()
+	defer cs.lock.Unlock()
+	cs.values = make(map[interface{}]interface{})
+	return nil
+}
+
+func (cs *CouchbaseSessionStore) SessionID() string {
+	return cs.sid
+}
+
+func (cs *CouchbaseSessionStore) SessionRelease(w http.ResponseWriter) {
+	defer cs.b.Close()
+
+	// if rs.values is empty, return directly
+	if len(cs.values) < 1 {
+		cs.b.Delete(cs.sid)
+		return
+	}
+
+	bo, err := encodeGob(cs.values)
+	if err != nil {
+		return
+	}
+
+	cs.b.Set(cs.sid, int(cs.maxlifetime), bo)
+}
+
+func (cp *CouchbaseProvider) getBucket() *couchbase.Bucket {
+	c, err := couchbase.Connect(cp.savePath)
+	if err != nil {
+		return nil
+	}
+
+	pool, err := c.GetPool(cp.pool)
+	if err != nil {
+		return nil
+	}
+
+	bucket, err := pool.GetBucket(cp.bucket)
+	if err != nil {
+		return nil
+	}
+
+	return bucket
+}
+
+// init couchbase session
+// savepath like couchbase server REST/JSON URL
+// e.g. http://host:port/, Pool, Bucket
+func (cp *CouchbaseProvider) SessionInit(maxlifetime int64, savePath string) error {
+	cp.maxlifetime = maxlifetime
+	configs := strings.Split(savePath, ",")
+	if len(configs) > 0 {
+		cp.savePath = configs[0]
+	}
+	if len(configs) > 1 {
+		cp.pool = configs[1]
+	}
+	if len(configs) > 2 {
+		cp.bucket = configs[2]
+	}
+
+	return nil
+}
+
+// read couchbase session by sid
+func (cp *CouchbaseProvider) SessionRead(sid string) (SessionStore, error) {
+	cp.b = cp.getBucket()
+
+	var doc []byte
+
+	err := cp.b.Get(sid, &doc)
+	var kv map[interface{}]interface{}
+	if doc == nil {
+		kv = make(map[interface{}]interface{})
+	} else {
+		kv, err = decodeGob(doc)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	cs := &CouchbaseSessionStore{b: cp.b, sid: sid, values: kv, maxlifetime: cp.maxlifetime}
+	return cs, nil
+}
+
+func (cp *CouchbaseProvider) SessionExist(sid string) bool {
+	cp.b = cp.getBucket()
+	defer cp.b.Close()
+
+	var doc []byte
+
+	if err := cp.b.Get(sid, &doc); err != nil || doc == nil {
+		return false
+	} else {
+		return true
+	}
+}
+
+func (cp *CouchbaseProvider) SessionRegenerate(oldsid, sid string) (SessionStore, error) {
+	cp.b = cp.getBucket()
+
+	var doc []byte
+	if err := cp.b.Get(oldsid, &doc); err != nil || doc == nil {
+		cp.b.Set(sid, int(cp.maxlifetime), "")
+	} else {
+		err := cp.b.Delete(oldsid)
+		if err != nil {
+			return nil, err
+		}
+		_, _ = cp.b.Add(sid, int(cp.maxlifetime), doc)
+	}
+
+	err := cp.b.Get(sid, &doc)
+	if err != nil {
+		return nil, err
+	}
+	var kv map[interface{}]interface{}
+	if doc == nil {
+		kv = make(map[interface{}]interface{})
+	} else {
+		kv, err = decodeGob(doc)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	cs := &CouchbaseSessionStore{b: cp.b, sid: sid, values: kv, maxlifetime: cp.maxlifetime}
+	return cs, nil
+}
+
+func (cp *CouchbaseProvider) SessionDestroy(sid string) error {
+	cp.b = cp.getBucket()
+	defer cp.b.Close()
+
+	cp.b.Delete(sid)
+	return nil
+}
+
+func (cp *CouchbaseProvider) SessionGC() {
+	return
+}
+
+func (cp *CouchbaseProvider) SessionAll() int {
+	return 0
+}
+
+func init() {
+	Register("couchbase", couchbpder)
+}