Add transform to deduplicate entities in CDI spec

Signed-off-by: Evan Lezar <elezar@nvidia.com>

pkg/nvcdi/transform/remove.go

@@ -0,0 +1,105 @@
+/**
+# Copyright (c) NVIDIA CORPORATION.  All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+**/
+
+package transform
+
+import (
+	"fmt"
+
+	"github.com/container-orchestrated-devices/container-device-interface/specs-go"
+)
+
+type remove map[string]bool
+
+func newRemover(ids ...string) Transformer {
+	r := make(remove)
+	for _, id := range ids {
+		r[id] = true
+	}
+	return r
+}
+
+// Transform remove the specified entities from the spec.
+func (r remove) Transform(spec *specs.Spec) error {
+	if spec == nil {
+		return nil
+	}
+
+	for _, device := range spec.Devices {
+		if err := r.transformEdits(&device.ContainerEdits); err != nil {
+			return fmt.Errorf("failed to remove edits from device %q: %w", device.Name, err)
+		}
+	}
+
+	return r.transformEdits(&spec.ContainerEdits)
+}
+
+func (r remove) transformEdits(edits *specs.ContainerEdits) error {
+	if edits == nil {
+		return nil
+	}
+
+	var deviceNodes []*specs.DeviceNode
+	for _, entity := range edits.DeviceNodes {
+		id, err := deviceNode(*entity).id()
+		if err != nil {
+			return err
+		}
+		if r[id] {
+			continue
+		}
+		deviceNodes = append(deviceNodes, entity)
+	}
+	edits.DeviceNodes = deviceNodes
+
+	var envs []string
+	for _, entity := range edits.Env {
+		id := entity
+		if r[id] {
+			continue
+		}
+		envs = append(envs, entity)
+	}
+	edits.Env = envs
+
+	var hooks []*specs.Hook
+	for _, entity := range edits.Hooks {
+		id, err := hook(*entity).id()
+		if err != nil {
+			return err
+		}
+		if r[id] {
+			continue
+		}
+		hooks = append(hooks, entity)
+	}
+	edits.Hooks = hooks
+
+	var mounts []*specs.Mount
+	for _, entity := range edits.Mounts {
+		id, err := mount(*entity).id()
+		if err != nil {
+			return err
+		}
+		if r[id] {
+			continue
+		}
+		mounts = append(mounts, entity)
+	}
+	edits.Mounts = mounts
+
+	return nil
+}