add driver package to encapsulate storage backends

pkg/storage/driver/driver.go

@@ -0,0 +1,53 @@
+/*
+Copyright 2016 The Kubernetes Authors 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 driver // import "k8s.io/helm/pkg/storage/driver"
+
+import (
+	"errors"
+	rspb "k8s.io/helm/pkg/proto/hapi/release"
+)
+
+var (
+	// ErrReleaseNotFound indicates that a release is not found.
+	ErrReleaseNotFound = errors.New("release not found")
+	// Temporary error while WIP.
+	ErrNotImplemented  = errors.New("not implemented")
+)
+
+type Creator interface {
+	Create(*rspb.Release) error
+}
+
+type Updator interface {
+	Update(*rspb.Release) error
+}
+
+type Deletor interface {
+	Delete(string) (*rspb.Release, error)
+}
+
+type Queryor interface {
+	Get(string) (*rspb.Release, error)
+
+	All(string, ...interface{}) ([]*rspb.Release, error)
+}
+
+type Driver interface {
+	Creator
+	Updator
+	Deletor
+	Queryor
+}

pkg/storage/driver/memory.go

@@ -0,0 +1,106 @@
+/*
+Copyright 2016 The Kubernetes Authors 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 driver // import "k8s.io/helm/pkg/storage/driver"
+
+import (
+	"sync"
+
+	rspb "k8s.io/helm/pkg/proto/hapi/release"
+)
+
+// Memory is an in-memory storage driver implementation.
+type Memory struct {
+	sync.RWMutex
+	cache map[string]*rspb.Release
+}
+
+func NewMemory() *Memory {
+	return &Memory{cache: map[string]*rspb.Release{}}
+}
+
+// Get returns the release named by key.
+func (mem *Memory) Get(key string) (*rspb.Release, error) {
+	defer unlock(mem.rlock())
+
+	if rls, ok := mem.cache[key]; ok {
+		return rls, nil
+	}
+	return nil, ErrReleaseNotFound
+}
+
+// All returns all releases whose status is not Status_DELETED.
+func (mem *Memory) All(key string, opts ...interface{}) ([]*rspb.Release, error) {
+	defer unlock(mem.rlock())
+
+	var releases []*rspb.Release
+	for _, rls := range mem.cache {
+		if rls.Info.Status.Code != rspb.Status_DELETED {
+			releases = append(releases, rls)
+		}
+	}
+	return releases, nil
+}
+
+// Create creates a new release or error.
+func (mem *Memory) Create(rls *rspb.Release) error {
+	defer unlock(mem.wlock())
+
+	mem.cache[rls.Name] = rls
+	return nil
+}
+
+// Update updates a release or error.
+func (mem *Memory) Update(rls *rspb.Release) error {
+	defer unlock(mem.wlock())
+
+	if old, ok := mem.cache[rls.Name]; ok {
+		// FIXME: when release update is complete, old release should
+		// be marked as superseded, creating the new release.
+		_ = old
+
+		mem.cache[rls.Name] = rls
+		return nil
+	}
+	return ErrReleaseNotFound
+}
+
+// Delete deletes a release or error.
+func (mem *Memory) Delete(key string) (*rspb.Release, error) {
+	defer unlock(mem.wlock())
+
+	if old, ok := mem.cache[key]; ok {
+		old.Info.Status.Code = rspb.Status_DELETED
+		delete(mem.cache, key)
+		return old, nil
+	}
+	return nil, ErrReleaseNotFound
+}
+
+func (mem *Memory) wlock() func() {
+	mem.Lock()
+	return func() {
+		mem.Unlock()
+	}
+}
+
+func (mem *Memory) rlock() func() {
+	mem.RLock()
+	return func() {
+		mem.RUnlock()
+	}
+}
+
+func unlock(fn func()) { fn() }

pkg/storage/driver/memory_test.go

@@ -0,0 +1,92 @@
+/*
+Copyright 2016 The Kubernetes Authors 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 driver // import "k8s.io/helm/pkg/storage/driver"
+
+import (
+	"testing"
+	rspb "k8s.io/helm/pkg/proto/hapi/release"
+)
+
+func TestMemoryGet(t *testing.T) {
+	key := "test-1"
+	rls := &rspb.Release{Name: key}
+
+	mem := NewMemory()
+	mem.Create(rls)
+
+	res, err := mem.Get(key)
+	switch {
+	case err != nil:
+		t.Errorf("Could not get %s: %s", key, err)
+	case res.Name != key:
+		t.Errorf("Expected %s, got %s", key, res.Name)
+	}
+}
+
+func TestMemoryAll(t *testing.T) {
+	t.Skip("MemoryAll")
+}
+
+func TestMemoryCreate(t *testing.T) {
+	key := "test-1"
+	rls := &rspb.Release{Name: key}
+
+	mem := NewMemory()
+	err := mem.Create(rls)
+
+	switch {
+	case err != nil:
+		t.Fatalf("Failed create: %s", err)
+	case mem.cache[key].Name != key:
+		t.Errorf("Unexpected release name: %s", mem.cache[key].Name)
+	}
+}
+
+func TestMemoryUpdate(t *testing.T) {
+	key := "test-1"
+	rls := &rspb.Release{Name: key}
+
+	mem := NewMemory()
+	if err := mem.Create(rls); err != nil {
+		t.Fatalf("Failed create: %s", err)
+	}
+	if err := mem.Update(rls); err != nil {
+		t.Fatalf("Failed update: %s", err)
+	}
+	if mem.cache[key].Name != key {
+		t.Errorf("Unexpected release name: %s", mem.cache[key].Name)
+	}
+}
+
+func TestMemoryDelete(t *testing.T) {
+	key := "test-1"
+	rls := &rspb.Release{Name: key}
+
+	mem := NewMemory()
+	if err := mem.Create(rls); err != nil {
+		t.Fatalf("Failed create: %s", err)
+	}
+	
+	res, err := mem.Delete(key)
+	switch {
+	case err != nil:
+		t.Fatalf("Failed delete: %s", err)
+	case mem.cache[key] != nil:
+		t.Errorf("Expected nil, got %s", mem.cache[key])
+	case res.Info.Status.Code != release.Status_DELETED:
+		t.Errorf("Expected Status_DELETED, got %s", res.Info.Status.Code)
+	}
+}