gprc: define CANCEL_RETRIEVE request to aboirt staging

src/main/proto/cta_dcache.proto

@@ -52,7 +52,7 @@ message ArchiveRequest {
 }
 
 /*
- * ARCHIVE request.
+ * RETRIEVE request.
  */
 message RetrieveRequest {
   cta.common.Service instance = 1;  // client instance ID
@@ -62,6 +62,9 @@ message RetrieveRequest {
   uint64 archiveId = 5; // tape system unique file ID
 }
 
+/*
+ * DELETE request.
+ */
 message DeleteRequest {
   cta.common.Service instance = 1;  // client instance ID
   cta.eos.Client cli = 2;      // requester information
@@ -69,11 +72,22 @@ message DeleteRequest {
   uint64 archiveId = 4; // tape system unique file ID
 }
 
+/*
+ * CANCEL RETRIEVE request.
+ */
+message CancelRetrieveRequest {
+  cta.common.Service instance = 1;  // client instance ID
+  cta.eos.Client cli = 2;      // requester information
+  uint64 fid = 3; // tape system unique file ID
+  string reqId = 4; // tape request scheduler ID, used to cancel the request
+}
+
 service CtaRpc {
   rpc Version (google.protobuf.Empty) returns (cta.admin.Version) {}
 
   rpc Archive (ArchiveRequest) returns (ArchiveResponse) {}
   rpc Retrieve (RetrieveRequest) returns (RetrieveResponse) {}
   rpc Delete (DeleteRequest) returns (google.protobuf.Empty) {}
+  rpc CancelRetrieve (CancelRetrieveRequest) returns (google.protobuf.Empty) {}
 
 }
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