alittle splitted mstorectl code; etc

app/imageoper/blobexist.go

@@ -0,0 +1,69 @@
+/*
+ * 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"
+	"strconv"
+)
+
+type BlobExistsParams struct {
+	Name   string
+	Digest string
+}
+type BlobExistsResult struct {
+	DockerContentDigest string
+	ContentLength       string
+	ContentType         string
+	//Exists              bool
+}
+
+func (oper *Operator) BlobExists(ctx context.Context, operatorID string, params *BlobExistsParams) (*BlobExistsResult, int, error) {
+	var err error
+	res := &BlobExistsResult{}
+
+	if params.Digest == "" {
+		err = fmt.Errorf("Empty reference")
+		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 blob descriptor
+	descrExists, blobDescr, err := oper.mdb.GetBlobByNameDigest(ctx, params.Digest, params.Digest)
+	if err != nil {
+		return res, http.StatusInternalServerError, err
+	}
+	if !descrExists {
+		return res, http.StatusNotFound, err
+	}
+	// Check blob file
+	blobExists, _, err := oper.store.BlobExists(params.Digest)
+	if err != nil {
+		return res, http.StatusInternalServerError, err
+	}
+	if !blobExists {
+		return res, http.StatusNotFound, err
+	}
+
+	res.ContentLength = strconv.FormatInt(blobDescr.Size, 10)
+	res.DockerContentDigest = blobDescr.Digest
+	res.ContentType = blobDescr.MediaType
+
+	return res, http.StatusOK, err
+}