Expose functions for zero related grpc APIs (#254)

Add wrappers for zero related grpc APIs

Author: mangalaman93

zero.go

@@ -0,0 +1,48 @@
+/*
+ * SPDX-FileCopyrightText: © Hypermode Inc. <[email protected]>
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package dgo
+
+import (
+	"context"
+
+	apiv25 "github.com/dgraph-io/dgo/v250/protos/api.v25"
+)
+
+// AllocateUIDs allocates a given number of Node UIDs in the Graph and returns a start and end UIDs,
+// end excluded. The UIDs in the range [start, end) can then be used by the client in the mutations
+// going forward. Note that, each node in a Graph is assigned a UID in Dgraph. Dgraph ensures that
+// these UIDs are not allocated anywhere else throughout the operation of this cluster. This is useful
+// in bulk loader or live loader or similar applications.
+func (d *Dgraph) AllocateUIDs(ctx context.Context, howMany uint64) (uint64, uint64, error) {
+	return d.allocateIDs(ctx, howMany, apiv25.LeaseType_UID)
+}
+
+// AllocateTimestamps gets a sequence of timestamps allocated from Dgraph. These timestamps can be
+// used in bulk loader and similar applications.
+func (d *Dgraph) AllocateTimestamps(ctx context.Context, howMany uint64) (uint64, uint64, error) {
+	return d.allocateIDs(ctx, howMany, apiv25.LeaseType_TS)
+}
+
+// AllocateNamespaces allocates a given number of namespaces in the Graph and returns a start and end
+// namespaces, end excluded. The namespaces in the range [start, end) can then be used by the client.
+// Dgraph ensures that these namespaces are NOT allocated anywhere else throughout the operation of
+// this cluster. This is useful in bulk loader or live loader or similar applications.
+func (d *Dgraph) AllocateNamespaces(ctx context.Context, howMany uint64) (uint64, uint64, error) {
+	return d.allocateIDs(ctx, howMany, apiv25.LeaseType_NS)
+}
+
+func (d *Dgraph) allocateIDs(ctx context.Context, howMany uint64,
+	leaseType apiv25.LeaseType) (uint64, uint64, error) {
+
+	req := &apiv25.AllocateIDsRequest{HowMany: howMany, LeaseType: leaseType}
+	resp, err := doWithRetryLogin(ctx, d, func(dc apiv25.DgraphClient) (*apiv25.AllocateIDsResponse, error) {
+		return dc.AllocateIDs(d.getContext(ctx), req)
+	})
+	if err != nil {
+		return 0, 0, err
+	}
+	return resp.Start, resp.End, nil
+}