From 9155dc0c56d3509dae74d02160592f6c818fd426 Mon Sep 17 00:00:00 2001
From: Barak Michener <me@barakmich.com>
Date: Tue, 23 Jun 2015 14:04:48 -0400
Subject: [PATCH] spec out the interface change

---
 cmd/cayleyupgrade/cayleyupgrade.go | 75 ++++++++++++++++++++++++++++++++++++++
 graph/quadstore.go                 | 40 +++++++++++---------
 2 files changed, 98 insertions(+), 17 deletions(-)
 create mode 100644 cmd/cayleyupgrade/cayleyupgrade.go

diff --git a/cmd/cayleyupgrade/cayleyupgrade.go b/cmd/cayleyupgrade/cayleyupgrade.go
new file mode 100644
index 0000000..e6813c9
--- /dev/null
+++ b/cmd/cayleyupgrade/cayleyupgrade.go
@@ -0,0 +1,75 @@
+// Copyright 2015 The Cayley 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.
+
+// +build !appengine
+
+package main
+
+import (
+	"errors"
+	"flag"
+
+	"github.com/google/cayley/config"
+	_ "github.com/google/cayley/graph"
+
+	// Load all supported backends.
+	"github.com/google/cayley/db"
+	_ "github.com/google/cayley/graph/bolt"
+	_ "github.com/google/cayley/graph/leveldb"
+	_ "github.com/google/cayley/graph/memstore"
+	_ "github.com/google/cayley/graph/mongo"
+	"github.com/google/cayley/internal"
+)
+
+var (
+	configFile      = flag.String("config", "", "Path to an explicit configuration file.")
+	databasePath    = flag.String("dbpath", "/tmp/testdb", "Path to the database.")
+	databaseBackend = flag.String("db", "memstore", "Database Backend.")
+)
+
+func configFrom(file string) *config.Config {
+	if cfg.DatabasePath == "" {
+		cfg.DatabasePath = *databasePath
+	}
+
+	if cfg.DatabaseType == "" {
+		cfg.DatabaseType = *databaseBackend
+	}
+	return cfg
+}
+
+func main() {
+	flag.Parse()
+	cfg := configFrom(*configFile)
+
+	r, registered := storeRegistry[*databaseBackend]
+	if registered {
+		return r.initFunc(dbpath, opts)
+	}
+	return errors.New("quadstore: name '" + name + "' is not registered")
+	if err != nil {
+		break
+	}
+	if *quadFile != "" {
+		handle, err = db.Open(cfg)
+		if err != nil {
+			break
+		}
+		err = internal.Load(handle.QuadWriter, cfg, *quadFile, *quadType)
+		if err != nil {
+			break
+		}
+		handle.Close()
+	}
+}
diff --git a/graph/quadstore.go b/graph/quadstore.go
index 8a89885..ebba912 100644
--- a/graph/quadstore.go
+++ b/graph/quadstore.go
@@ -150,27 +150,24 @@ type BulkLoader interface {
 
 type NewStoreFunc func(string, Options) (QuadStore, error)
 type InitStoreFunc func(string, Options) error
+type UpgradeStoreFunc func(string, Options) error
 type NewStoreForRequestFunc func(QuadStore, Options) (QuadStore, error)
 
-type register struct {
-	newFunc           NewStoreFunc
-	newForRequestFunc NewStoreForRequestFunc
-	initFunc          InitStoreFunc
-	isPersistent      bool
+type QuadStoreRegistration struct {
+	NewFunc           NewStoreFunc
+	NewForRequestFunc NewStoreForRequestFunc
+	UpgradeFunc       UpgradeStoreFunc
+	InitFunc          InitStoreFunc
+	IsPersistent      bool
 }
 
-var storeRegistry = make(map[string]register)
+var storeRegistry = make(map[string]QuadStoreRegistration)
 
-func RegisterQuadStore(name string, persists bool, newFunc NewStoreFunc, initFunc InitStoreFunc, newForRequestFunc NewStoreForRequestFunc) {
+func RegisterQuadStore(name string, register QuadStoreRegistration) {
 	if _, found := storeRegistry[name]; found {
 		panic("already registered QuadStore " + name)
 	}
-	storeRegistry[name] = register{
-		newFunc:           newFunc,
-		initFunc:          initFunc,
-		newForRequestFunc: newForRequestFunc,
-		isPersistent:      persists,
-	}
+	storeRegistry[name] = register
 }
 
 func NewQuadStore(name, dbpath string, opts Options) (QuadStore, error) {
@@ -178,13 +175,13 @@ func NewQuadStore(name, dbpath string, opts Options) (QuadStore, error) {
 	if !registered {
 		return nil, errors.New("quadstore: name '" + name + "' is not registered")
 	}
-	return r.newFunc(dbpath, opts)
+	return r.NewFunc(dbpath, opts)
 }
 
 func InitQuadStore(name, dbpath string, opts Options) error {
 	r, registered := storeRegistry[name]
 	if registered {
-		return r.initFunc(dbpath, opts)
+		return r.InitFunc(dbpath, opts)
 	}
 	return errors.New("quadstore: name '" + name + "' is not registered")
 }
@@ -192,13 +189,22 @@ func InitQuadStore(name, dbpath string, opts Options) error {
 func NewQuadStoreForRequest(qs QuadStore, opts Options) (QuadStore, error) {
 	r, registered := storeRegistry[qs.Type()]
 	if registered {
-		return r.newForRequestFunc(qs, opts)
+		return r.NewForRequestFunc(qs, opts)
 	}
 	return nil, errors.New("QuadStore does not support Per Request construction, check config")
 }
 
+func UpgradeQuadStore(name, dbpath string, opts Options) error {
+	r, registered := storeRegistry[name]
+	if registered {
+		return r.UpgradeFunc(dbpath, opts)
+	}
+	return errors.New("quadstore: name '" + name + "' is not registered")
+
+}
+
 func IsPersistent(name string) bool {
-	return storeRegistry[name].isPersistent
+	return storeRegistry[name].IsPersistent
 }
 
 func QuadStores() []string {