major refactor

grain-pool.go

@@ -3,6 +3,7 @@ package main
 import (
 	"fmt"
 	"log"
+	"net/http"
 	"sync"
 	"time"
 
@@ -47,11 +48,16 @@ type GrainPool interface {
 	Apply(id CartId, mutation interface{}) (*CartGrain, error)
 	Get(id CartId) (*CartGrain, error)
 	// OwnerHost returns the primary owner host for a given cart id.
-	OwnerHost(id CartId) string
+	OwnerHost(id CartId) (Host, bool)
 	// Hostname returns the hostname of the local pool implementation.
 	Hostname() string
 }
 
+type Host interface {
+	Name() string
+	Proxy(id CartId, w http.ResponseWriter, r *http.Request) (bool, error)
+}
+
 // Ttl keeps expiry info
 type Ttl struct {
 	Expires time.Time
@@ -269,8 +275,8 @@ func (p *GrainLocalPool) UnsafePointerToLegacyMap() uintptr {
 // OwnerHost implements the extended GrainPool interface for the standalone
 // local pool. Since the local pool has no concept of multi-host ownership,
 // it returns an empty string. Callers can treat empty as "local host".
-func (p *GrainLocalPool) OwnerHost(id CartId) string {
-	return ""
+func (p *GrainLocalPool) OwnerHost(id CartId) (Host, bool) {
+	return nil, false
 }
 
 // Hostname returns a blank string because GrainLocalPool does not track a node