plumbed through child add/delete subcommands

children/db.go

@@ -0,0 +1,43 @@
+package children
+
+import (
+	"encoding/json"
+	"errors"
+	"os"
+	"sync"
+
+	"mcquay.me/fs"
+)
+
+var mut sync.Mutex
+
+type DB map[string]int
+
+func Load(filename string) (children DB, err error) {
+	db := DB{}
+	if !fs.Exists(filename) {
+		return db, errors.New("db file doesn't exist")
+	}
+	f, err := os.Open(filename)
+	if err != nil {
+		return nil, err
+	}
+	if err := json.NewDecoder(f).Decode(&db); err != nil {
+		return nil, err
+	}
+	return db, nil
+}
+
+func (db DB) Save(filename string) error {
+	mut.Lock()
+	defer mut.Unlock()
+	f, err := os.Create(filename)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+	if err := json.NewEncoder(f).Encode(db); err != nil {
+		return err
+	}
+	return nil
+}