Make blob storage constructors take a blobserver.Loader

lib/go/camli/blobserver/localdisk/localdisk.go

@@ -54,7 +54,7 @@ func New(root string) (storage *DiskStorage, err os.Error) {
 	return
 }
 
-func newFromConfig(config jsonconfig.Obj) (storage blobserver.Storage, err os.Error) {
+func newFromConfig(_ blobserver.Loader, config jsonconfig.Obj) (storage blobserver.Storage, err os.Error) {
 	sto := &DiskStorage{
 		SimpleBlobHubPartitionMap: &blobserver.SimpleBlobHubPartitionMap{},
 		root:                      config.RequiredString("path"),

lib/go/camli/blobserver/registry.go

@@ -25,7 +25,16 @@ import (
 	"camli/jsonconfig"
 )
 
-type StorageConstructor func(config jsonconfig.Obj) (Storage, os.Error)
+type Loader interface {
+	GetStorage(prefix string) (Storage, os.Error)
+}
+
+type StorageConstructor func(Loader, jsonconfig.Obj) (Storage, os.Error)
+
+// TODO: HandlerConstructor never ended up being used, but that was from
+// before the Loader interface was introduced. Perhaps camlistored server
+// could have all its non-Storage handlers simplified and no longer
+// special-cased by using HandlerConstructor with a Loader parameter.
 type HandlerConstructor func(config jsonconfig.Obj) (http.Handler, os.Error)
 
 var mapLock sync.Mutex
@@ -41,14 +50,14 @@ func RegisterStorageConstructor(typ string, ctor StorageConstructor) {
 	storageConstructors[typ] = ctor
 }
 
-func CreateStorage(typ string, config jsonconfig.Obj) (Storage, os.Error) {
+func CreateStorage(typ string, loader Loader, config jsonconfig.Obj) (Storage, os.Error) {
 	mapLock.Lock()
 	ctor, ok := storageConstructors[typ]
 	mapLock.Unlock()
 	if !ok {
 		return nil, fmt.Errorf("Storage type %q not known or loaded", typ)
 	}
-	return ctor(config)
+	return ctor(loader, config)
 }
 
 func RegisterHandlerConstrutor(typ string, ctor HandlerConstructor) {

lib/go/camli/blobserver/remote/remote.go

@@ -35,7 +35,7 @@ type remoteStorage struct {
 
 var _ = blobserver.Storage((*remoteStorage)(nil))
 
-func newFromConfig(config jsonconfig.Obj) (storage blobserver.Storage, err os.Error) {
+func newFromConfig(_ blobserver.Loader, config jsonconfig.Obj) (storage blobserver.Storage, err os.Error) {
 	url := config.RequiredString("url")
 	password := config.RequiredString("password")
 	skipStartupCheck := config.OptionalBool("skipStartupCheck", false)

lib/go/camli/blobserver/s3/s3.go

@@ -32,7 +32,7 @@ type s3Storage struct {
 	bucket   string
 }
 
-func newFromConfig(config jsonconfig.Obj) (storage blobserver.Storage, err os.Error) {
+func newFromConfig(_ blobserver.Loader, config jsonconfig.Obj) (storage blobserver.Storage, err os.Error) {
 	client := &s3.Client{
 		Auth: &s3.Auth{
 			AccessKey:       config.RequiredString("aws_access_key"),

lib/go/camli/blobserver/shard/shard.go

@@ -36,7 +36,7 @@ func (ss *shardStorage) GetBlobHub() blobserver.BlobHub {
 	return ss.SimpleBlobHubPartitionMap.GetBlobHub()
 }
 
-func newFromConfig(config jsonconfig.Obj) (storage blobserver.Storage, err os.Error) {
+func newFromConfig(_ blobserver.Loader, config jsonconfig.Obj) (storage blobserver.Storage, err os.Error) {
 	sto := &shardStorage{
 		SimpleBlobHubPartitionMap: &blobserver.SimpleBlobHubPartitionMap{},
 		NoImplStorage:             &blobserver.NoImplStorage{},

lib/go/camli/mysqlindexer/mysqlindexer.go

@@ -43,7 +43,7 @@ type Indexer struct {
 	cachedClients []*mysql.Client
 }
 
-func newFromConfig(config jsonconfig.Obj) (blobserver.Storage, os.Error) {
+func newFromConfig(_ blobserver.Loader, config jsonconfig.Obj) (blobserver.Storage, os.Error) {
 	indexer := &Indexer{
 		SimpleBlobHubPartitionMap: &blobserver.SimpleBlobHubPartitionMap{},
 		Host:                      config.OptionalString("host", "localhost"),

server/go/camlistored/camlistored.go

@@ -39,6 +39,7 @@ import (
 
 	// Storage options:
 	_ "camli/blobserver/localdisk"
+	_ "camli/blobserver/remote"
 	_ "camli/blobserver/s3"
 	_ "camli/blobserver/shard"
 	_ "camli/mysqlindexer" // indexer, but uses storage interface
@@ -148,7 +149,7 @@ type handlerLoader struct {
 	ws      *webserver.Server
 	baseURL string
 	config  map[string]*handlerConfig // prefix -> config
-	handler map[string]interface{}    // prefix -> http.Handler / func
+	handler map[string]interface{}    // prefix -> http.Handler / func / blobserver.Storage
 }
 
 func main() {
@@ -260,6 +261,14 @@ func (hl *handlerLoader) getOrSetup(prefix string) interface{} {
 	return hl.handler[prefix]
 }
 
+func (hl *handlerLoader) GetStorage(prefix string) (blobserver.Storage, os.Error) {
+	hl.setupHandler(prefix)
+	if s, ok := hl.handler[prefix].(blobserver.Storage); ok {
+		return s, nil
+	}
+	return nil, fmt.Errorf("bogus storage handler referenced as %q", prefix)
+}
+
 func (hl *handlerLoader) setupHandler(prefix string) {
 	h, ok := hl.config[prefix]
 	if !ok {
@@ -338,7 +347,7 @@ func (hl *handlerLoader) setupHandler(prefix string) {
 		hl.ws.Handle(prefix, synch)
 	default:
 		// Assume a storage interface
-		pstorage, err := blobserver.CreateStorage(h.htype, h.conf)
+		pstorage, err := blobserver.CreateStorage(h.htype, hl, h.conf)
 		if err != nil {
 			exitFailure("error instantiating storage for prefix %q, type %q: %v",
 				h.prefix, h.htype, err)