Initial distributor implementation

appengine/cmd/dm/distributor/test_registry.go

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package distributor
+
+import (
+        "fmt"
+
+        "github.com/luci/luci-go/appengine/tumble"
+        "github.com/luci/luci-go/common/api/dm/service/v1"
+        "golang.org/x/net/context"
+)
+
+type testRegistry struct {
+        finishExecutionImpl FinishExecutionFn
+        data                map[string]D
+}
+
+var _ Registry = (*testRegistry)(nil)

[dnj (Google), 2016/06/09 18:00:56]

nit: this isn't necessary, since NewTestingRegistry does this assertion.

[iannucci, 2016/06/15 00:46:01]

I like putting this near every type definition so it's an explicit assertion in
case the implicit assertions elsewhere in the code change.

+
+// NewTestingRegistry returns a new testing registry.
+//
+// The mocks dictionary maps from cfgName to a mock implementation of the
+// distributor.
+func NewTestingRegistry(mocks map[string]D, fFn FinishExecutionFn) Registry {

[iannucci, 2016/06/08 02:54:24]

this evades luci-config/pubsub in tests.

+        return &testRegistry{fFn, mocks}
+}
+
+func (t *testRegistry) FinishExecution(c context.Context, eid *dm.Execution_ID, rslt *TaskResult) ([]tumble.Mutation, error) {
+        return t.finishExecutionImpl(c, eid, rslt)
+}
+
+func (t *testRegistry) MakeDistributor(_ context.Context, cfgName string) (D, string, error) {
+        ret, ok := t.data[cfgName]
+        if !ok {
+                return nil, "", fmt.Errorf("unknown distributor configuration: %q", cfgName)
+        }
+        return ret, "testing", nil
+}