merge api/redis_common and api/redis_pubsub to api/redis

api/redis/namespace.go

@@ -0,0 +1,47 @@
+package redis
+
+import (
+	"strings"
+
+	"thalos/api"
+)
+
+const (
+	// Default prefix to use when none is set.
+	defaultPrefix = "ship"
+
+	// We need to have some chain_id, so if no one is specified.
+	// we use a "null" id that is all zeros.
+	nullChain = "0000000000000000000000000000000000000000000000000000000000000000"
+)
+
+// Namespace type.
+//
+// Contains a prefix and chain_id to guard keys against collision.
+// Prefix should be sufficient to not collide with other application using the same redis database.
+// chain_id should be ok to not let multiple reader with different chains to write to the same channels.
+
+type Namespace struct {
+	Prefix  string
+	ChainID string
+}
+
+// Create a new key with this namespace.
+func (ns Namespace) NewKey(ch api.Channel) Key {
+	return Key{NS: ns, Channel: ch}
+}
+
+func (ns Namespace) String() string {
+	// No Chain id, set to "nullChain"
+	if len(ns.ChainID) < 1 {
+		ns.ChainID = nullChain
+	}
+
+	// Set default prefix if empty.
+	if len(ns.Prefix) < 1 {
+		ns.Prefix = defaultPrefix
+	}
+
+	// Otherwise. return both.
+	return strings.Join([]string{ns.Prefix, ns.ChainID}, "::")
+}