alittle splitted mstorectl code; etc

app/imageoper/delblob.go

@@ -0,0 +1,71 @@
+/*
+ * Copyright 2026 Oleg Borodin <onborodin@gmail.com>
+ *
+ * This work is published and licensed under a Creative Commons
+ * Attribution-NonCommercial-NoDerivatives 4.0 International License.
+ *
+ * Distribution of this work is permitted, but commercial use and
+ * modifications are strictly prohibited.
+ */
+package imageoper
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+)
+
+type DeleteBlobParams struct {
+	Name   string
+	Digest string
+}
+type DeleteBlobResult struct{}
+
+// Removing an individual layer is very probably to compromise data integrity.
+// - If the data layers are to be reused, this is like shooting yourself in the foot.
+// - It also prevents the manifest from being issued, as one
+// of the layers is missing.
+
+func (oper *Operator) DeleteBlob(ctx context.Context, operatorID string, params *DeleteBlobParams) (*DeleteBlobResult, int, error) {
+	var err error
+	res := &DeleteBlobResult{}
+
+	if params.Digest == "" {
+		err = fmt.Errorf("Empty digest")
+		return res, http.StatusBadRequest, err
+	}
+	if params.Name == "" {
+		err = fmt.Errorf("Empty name")
+		return res, http.StatusBadRequest, err
+	}
+
+	resName := params.Name
+	oper.iLock.WaitAndLock(resName)
+	defer oper.iLock.Done(resName)
+
+	// Check namespace record
+	descrExists, _, err := oper.mdb.GetBlobByNameDigest(ctx, params.Name, params.Digest)
+	if err != nil {
+		return res, http.StatusInternalServerError, err
+	}
+
+	if !descrExists {
+		return res, http.StatusNotFound, err
+	}
+	// Deleting blob record
+	oper.logg.Warningf("Deleting blob record %s:%s", params.Name, params.Digest)
+	err = oper.mdb.DeleteBlobByNameDigest(ctx, params.Name, params.Digest)
+	if err != nil {
+		return res, http.StatusInternalServerError, err
+	}
+	// Removing the blob binary if usage == 0
+	blobUsage, err := oper.mdb.GetBlobUsage(ctx, params.Digest)
+	if err != nil {
+		return res, http.StatusInternalServerError, err
+	}
+	if blobUsage == 0 {
+		oper.logg.Warningf("Deleting useless blob binary %s", params.Digest)
+		oper.store.DeleteBlob(params.Digest)
+	}
+	return res, http.StatusOK, err
+}