Initial QSfera import

Server/vendor/go-micro.dev/v4/config/source/source.go

@@ -0,0 +1,35 @@
+// Package source is the interface for sources
+package source
+
+import (
+	"errors"
+	"time"
+)
+
+var (
+	// ErrWatcherStopped is returned when source watcher has been stopped.
+	ErrWatcherStopped = errors.New("watcher stopped")
+)
+
+// Source is the source from which config is loaded.
+type Source interface {
+	Read() (*ChangeSet, error)
+	Write(*ChangeSet) error
+	Watch() (Watcher, error)
+	String() string
+}
+
+// ChangeSet represents a set of changes from a source.
+type ChangeSet struct {
+	Timestamp time.Time
+	Checksum  string
+	Format    string
+	Source    string
+	Data      []byte
+}
+
+// Watcher watches a source for changes.
+type Watcher interface {
+	Next() (*ChangeSet, error)
+	Stop() error
+}