migrate to upstream libcompose in one and a half go

vendor/github.com/docker/libnetwork/endpoint_cnt.go

@@ -0,0 +1,162 @@
+package libnetwork
+
+import (
+	"encoding/json"
+	"fmt"
+	"sync"
+
+	"github.com/docker/libnetwork/datastore"
+)
+
+type endpointCnt struct {
+	n        *network
+	Count    uint64
+	dbIndex  uint64
+	dbExists bool
+	sync.Mutex
+}
+
+const epCntKeyPrefix = "endpoint_count"
+
+func (ec *endpointCnt) Key() []string {
+	ec.Lock()
+	defer ec.Unlock()
+
+	return []string{epCntKeyPrefix, ec.n.id}
+}
+
+func (ec *endpointCnt) KeyPrefix() []string {
+	ec.Lock()
+	defer ec.Unlock()
+
+	return []string{epCntKeyPrefix, ec.n.id}
+}
+
+func (ec *endpointCnt) Value() []byte {
+	ec.Lock()
+	defer ec.Unlock()
+
+	b, err := json.Marshal(ec)
+	if err != nil {
+		return nil
+	}
+	return b
+}
+
+func (ec *endpointCnt) SetValue(value []byte) error {
+	ec.Lock()
+	defer ec.Unlock()
+
+	return json.Unmarshal(value, &ec)
+}
+
+func (ec *endpointCnt) Index() uint64 {
+	ec.Lock()
+	defer ec.Unlock()
+	return ec.dbIndex
+}
+
+func (ec *endpointCnt) SetIndex(index uint64) {
+	ec.Lock()
+	ec.dbIndex = index
+	ec.dbExists = true
+	ec.Unlock()
+}
+
+func (ec *endpointCnt) Exists() bool {
+	ec.Lock()
+	defer ec.Unlock()
+	return ec.dbExists
+}
+
+func (ec *endpointCnt) Skip() bool {
+	ec.Lock()
+	defer ec.Unlock()
+	return !ec.n.persist
+}
+
+func (ec *endpointCnt) New() datastore.KVObject {
+	ec.Lock()
+	defer ec.Unlock()
+
+	return &endpointCnt{
+		n: ec.n,
+	}
+}
+
+func (ec *endpointCnt) CopyTo(o datastore.KVObject) error {
+	ec.Lock()
+	defer ec.Unlock()
+
+	dstEc := o.(*endpointCnt)
+	dstEc.n = ec.n
+	dstEc.Count = ec.Count
+	dstEc.dbExists = ec.dbExists
+	dstEc.dbIndex = ec.dbIndex
+
+	return nil
+}
+
+func (ec *endpointCnt) DataScope() string {
+	return ec.n.DataScope()
+}
+
+func (ec *endpointCnt) EndpointCnt() uint64 {
+	ec.Lock()
+	defer ec.Unlock()
+
+	return ec.Count
+}
+
+func (ec *endpointCnt) updateStore() error {
+	store := ec.n.getController().getStore(ec.DataScope())
+	if store == nil {
+		return fmt.Errorf("store not found for scope %s on endpoint count update", ec.DataScope())
+	}
+	for {
+		if err := ec.n.getController().updateToStore(ec); err == nil || err != datastore.ErrKeyModified {
+			return err
+		}
+		if err := store.GetObject(datastore.Key(ec.Key()...), ec); err != nil {
+			return fmt.Errorf("could not update the kvobject to latest on endpoint count update: %v", err)
+		}
+	}
+}
+
+func (ec *endpointCnt) atomicIncDecEpCnt(inc bool) error {
+retry:
+	ec.Lock()
+	if inc {
+		ec.Count++
+	} else {
+		ec.Count--
+	}
+	ec.Unlock()
+
+	store := ec.n.getController().getStore(ec.DataScope())
+	if store == nil {
+		return fmt.Errorf("store not found for scope %s", ec.DataScope())
+	}
+
+	if err := ec.n.getController().updateToStore(ec); err != nil {
+		if err == datastore.ErrKeyModified {
+			if err := store.GetObject(datastore.Key(ec.Key()...), ec); err != nil {
+				return fmt.Errorf("could not update the kvobject to latest when trying to atomic add endpoint count: %v", err)
+			}
+
+			goto retry
+		}
+
+		return err
+	}
+
+	return nil
+}
+
+func (ec *endpointCnt) IncEndpointCnt() error {
+	return ec.atomicIncDecEpCnt(true)
+}
+
+func (ec *endpointCnt) DecEndpointCnt() error {
+	return ec.atomicIncDecEpCnt(false)
+}