server/config: Generic caching backend.

server/config/caching/proccache_test.go

Index: server/config/caching/proccache_test.go
diff --git a/server/config/caching/proccache_test.go b/server/config/caching/proccache_test.go
new file mode 100644
index 0000000000000000000000000000000000000000..ab51db4525442e2c6f9b9bbce2f6913cbb58fad5
--- /dev/null
+++ b/server/config/caching/proccache_test.go
@@ -0,0 +1,80 @@
+// Copyright 2015 The LUCI Authors. All rights reserved.
+// Use of this source code is governed under the Apache License, Version 2.0
+// that can be found in the LICENSE file.
+
+package caching
+
+import (
+	"testing"
+	"time"
+
+	"github.com/luci/luci-go/common/clock/testclock"
+	"github.com/luci/luci-go/common/config/impl/memory"
+	"github.com/luci/luci-go/common/data/caching/proccache"
+	"github.com/luci/luci-go/server/config"
+	"github.com/luci/luci-go/server/config/testconfig"
+
+	"golang.org/x/net/context"
+
+	//. "github.com/luci/luci-go/common/testing/assertions"
+	. "github.com/smartystreets/goconvey/convey"
+)
+
+func TestProcCache(t *testing.T) {
+	t.Parallel()
+
+	Convey(`A testing setup`, t, func() {
+		c := context.Background()
+		c, tc := testclock.UseTime(c, testclock.TestTimeLocal)
+
+		mbase := map[string]memory.ConfigSet{
+			"projects/foo": {
+				"file": "content",
+			},
+		}
+
+		var pc proccache.Cache
+		c = proccache.Use(c, &pc)
+
+		// Install our backend: memory backed by cache backed by force error.
+		var backend config.Backend
+		lcp := testconfig.LocalClientProvider{
+			Base: memory.New(mbase),
+		}
+		backend = &config.ClientBackend{
+			Provider: &lcp,
+		}
+		backend = ProcCache(backend, time.Hour)
+		c = config.WithBackend(c, backend)
+
+		Convey(`Will store and cache a value.`, func() {
+			var s string
+			So(config.Get(c, config.AsService, "projects/foo", "file", config.String(&s), nil), ShouldBeNil)
+			So(s, ShouldEqual, "content")
+
+			delete(mbase, "projects/foo")
+
+			// Cached.
+			So(config.Get(c, config.AsService, "projects/foo", "file", config.String(&s), nil), ShouldBeNil)
+			So(s, ShouldEqual, "content")
+
+			// Expires, records lack of config.
+			tc.Add(time.Hour)
+
+			So(config.Get(c, config.AsService, "projects/foo", "file", config.String(&s), nil),
+				ShouldEqual, config.ErrNoConfig)
+
+			// Re-add, still no config.
+			mbase["projects/foo"] = memory.ConfigSet{
+				"file": "content",
+			}
+			So(config.Get(c, config.AsService, "projects/foo", "file", config.String(&s), nil),
+				ShouldEqual, config.ErrNoConfig)
+
+			// "No config" expires, config is back.
+			tc.Add(time.Hour)
+			So(config.Get(c, config.AsService, "projects/foo", "file", config.String(&s), nil), ShouldBeNil)
+			So(s, ShouldEqual, "content")
+		})
+	})
+}