1 files changed, 48 insertions, 0 deletions
diff --git a/vendor/github.com/sjtug/cerberus/core/pool.go b/vendor/github.com/sjtug/cerberus/core/pool.go
new file mode 100644
index 0000000..5d6268a
--- /dev/null
+++ b/vendor/github.com/sjtug/cerberus/core/pool.go
@@ -0,0 +1,48 @@
+package core
+
+import (
+	"sync"
+
+	"go.uber.org/zap"
+)
+
+var (
+	lock     sync.RWMutex
+	instance *Instance
+)
+
+// GetInstance returns an instance of given config.
+// If there already exists an instance (during server reload), it will be updated with the new config.
+// Otherwise, a new instance will be created.
+// User can pass in an optional logger to log basic metrics about the initialized state.
+func GetInstance(config Config, logger *zap.Logger) (*Instance, error) {
+	lock.Lock()
+	defer lock.Unlock()
+
+	if instance == nil {
+		// Initialize a new instance.
+		state, pendingElems, blocklistElems, approvalElems, err := NewInstanceState(config)
+		if err != nil {
+			return nil, err
+		}
+
+		logger.Info("cerberus state initialized",
+			zap.Int64("pending_elems", pendingElems),
+			zap.Int64("blocklist_elems", blocklistElems),
+			zap.Int64("approval_elems", approvalElems),
+		)
+		instance = &Instance{
+			Config:        config,
+			InstanceState: state,
+		}
+		return instance, nil
+	}
+
+	// Update the existing instance with the new config.
+	err := instance.UpdateWithConfig(config, logger)
+	if err != nil {
+		return nil, err
+	}
+
+	return instance, nil
+}