1 files changed, 68 insertions, 0 deletions
diff --git a/cacheDir.go b/cacheDir.go
new file mode 100644
index 0000000..370b619
--- /dev/null
+++ b/cacheDir.go
@@ -0,0 +1,68 @@
+package config
+
+// loads from the users .cache/ dir
+//
+// GOAL: always work. When in doubt, delete things in ~/.cache/
+// RULE: always use raw .pb files, never human readable .text or .json files
+//
+// deletes files when versions don't match
+// deletes files when filenames can't be set
+// deletes anything that doesn't work
+//
+// This is important to avoid unmarshalling garbage protobuf data
+
+import (
+	"errors"
+	"os"
+
+	"go.wit.com/lib/ENV"
+	"go.wit.com/log"
+	"google.golang.org/protobuf/proto"
+)
+
+// loads foo.proto from ~/.cache/<appname>/foo.pb
+func LoadCacheDir(pb proto.Message) error {
+	appname, err := ENV.GetAppname() // already configured by your application
+	if err != nil {
+		return err
+	}
+
+	err = LoadCacheDirByAppname(pb, appname)
+	return err
+}
+
+// loads foo.proto from ~/.cache/<appname>/foo.pb
+func LoadCacheDirByAppname(pb proto.Message, appname string) error {
+	protoname, err := GetProtobufName(pb) // defined in the foo.proto file
+	if err != nil {
+		return err
+	}
+
+	err = CreateCacheDirPB(pb, appname, protoname)
+	return err
+}
+
+// checks the UUID and Version of the .pb file
+func CreateCacheDirPB(pb proto.Message, appname string, protoname string) error {
+	// Get ~/.cache/appname/protoname.text
+	fullname := MakeCacheFilename(appname, protoname)
+
+	_, err := SetFilename(pb, fullname)
+	if err != nil {
+		log.Info("lib/config PB file does not support Filename")
+	}
+	newver, curver, err := VersionCheckFile(pb, fullname)
+	_, _ = newver, curver
+	if err == nil {
+		// everything is fine. Versions match. load file
+		err = LoadFromFilename(pb, fullname)
+		return err
+	}
+	if errors.Is(err, os.ErrNotExist) {
+		// file is new, create the file
+		err = SaveToFilename(pb, fullname)
+		return err
+	}
+	// some other bad error
+	return err
+}