From 7ec9c97e46ebc555379d4a95b13a5d8748a4dc16 Mon Sep 17 00:00:00 2001
From: Matt Jaffee <matthew.jaffee@gmail.com>
Date: Mon, 2 Jul 2018 08:29:37 -0500
Subject: [PATCH] fixup nopAttrStore.

Methods no longer take pointer receiver, and NewNopAttrStore always returns a
reference to the same global object (which is no longer exported).
---
 attr.go   | 44 +++++++++++++-------------------------------
 field.go  |  2 +-
 holder.go |  2 +-
 index.go  |  4 ++--
 4 files changed, 17 insertions(+), 35 deletions(-)

diff --git a/attr.go b/attr.go
index 34d14a280..628613172 100644
--- a/attr.go
+++ b/attr.go
@@ -42,57 +42,39 @@ type AttrStore interface {
 	BlockData(i uint64) (map[uint64]map[string]interface{}, error)
 }
 
-func init() {
-	NopAttrStore = &nopAttrStore{}
-}
+// nopStore represents an AttrStore that doesn't do anything.
+var nopStore AttrStore = nopAttrStore{}
 
-// NopAttrStore represents an AttrStore that doesn't do anything.
-var NopAttrStore AttrStore
-
-func NewNopAttrStore(string) AttrStore {
-	return &nopAttrStore{}
-}
+// newNopAttrStore returns an attr store which does nothing. It returns a global
+// object to avoid unecessary allocations.
+func newNopAttrStore(string) AttrStore { return nopStore }
 
 // nopAttrStore represents a no-op implementation of the AttrStore interface.
 type nopAttrStore struct{}
 
 // Path is a no-op implementation of AttrStore Path method.
-func (s *nopAttrStore) Path() string { return "" }
+func (s nopAttrStore) Path() string { return "" }
 
 // Open is a no-op implementation of AttrStore Open method.
-func (s *nopAttrStore) Open() error {
-	return nil
-}
+func (s nopAttrStore) Open() error { return nil }
 
 // Close is a no-op implementation of AttrStore Close method.
-func (s *nopAttrStore) Close() error {
-	return nil
-}
+func (s nopAttrStore) Close() error { return nil }
 
 // Attrs is a no-op implementation of AttrStore Attrs method.
-func (s *nopAttrStore) Attrs(id uint64) (m map[string]interface{}, err error) {
-	return nil, nil
-}
+func (s nopAttrStore) Attrs(id uint64) (m map[string]interface{}, err error) { return nil, nil }
 
 // SetAttrs is a no-op implementation of AttrStore SetAttrs method.
-func (s *nopAttrStore) SetAttrs(id uint64, m map[string]interface{}) error {
-	return nil
-}
+func (s nopAttrStore) SetAttrs(id uint64, m map[string]interface{}) error { return nil }
 
 // SetBulkAttrs is a no-op implementation of AttrStore SetBulkAttrs method.
-func (s *nopAttrStore) SetBulkAttrs(m map[uint64]map[string]interface{}) error {
-	return nil
-}
+func (s nopAttrStore) SetBulkAttrs(m map[uint64]map[string]interface{}) error { return nil }
 
 // Blocks is a no-op implementation of AttrStore Blocks method.
-func (s *nopAttrStore) Blocks() ([]AttrBlock, error) {
-	return nil, nil
-}
+func (s nopAttrStore) Blocks() ([]AttrBlock, error) { return nil, nil }
 
 // BlockData is a no-op implementation of AttrStore BlockData method.
-func (s *nopAttrStore) BlockData(i uint64) (map[uint64]map[string]interface{}, error) {
-	return nil, nil
-}
+func (s nopAttrStore) BlockData(i uint64) (map[uint64]map[string]interface{}, error) { return nil, nil }
 
 // AttrBlock represents a checksummed block of the attribute store.
 type AttrBlock struct {
diff --git a/field.go b/field.go
index 42f607ff9..ed8d1811b 100644
--- a/field.go
+++ b/field.go
@@ -133,7 +133,7 @@ func NewField(path, index, name string, options FieldOptions) (*Field, error) {
 
 		views: make(map[string]*View),
 
-		rowAttrStore: NopAttrStore,
+		rowAttrStore: nopStore,
 
 		broadcaster: NopBroadcaster,
 		Stats:       NopStatsClient,
diff --git a/holder.go b/holder.go
index 0141d365e..e4462519b 100644
--- a/holder.go
+++ b/holder.go
@@ -81,7 +81,7 @@ func NewHolder() *Holder {
 		Broadcaster: NopBroadcaster,
 		Stats:       NopStatsClient,
 
-		NewAttrStore: NewNopAttrStore,
+		NewAttrStore: newNopAttrStore,
 
 		CacheFlushInterval: defaultCacheFlushInterval,
 
diff --git a/index.go b/index.go
index ae6141b90..79ffd69c0 100644
--- a/index.go
+++ b/index.go
@@ -66,8 +66,8 @@ func NewIndex(path, name string) (*Index, error) {
 
 		remoteMaxShard: 0,
 
-		NewAttrStore:    NewNopAttrStore,
-		columnAttrStore: NopAttrStore,
+		NewAttrStore:    newNopAttrStore,
+		columnAttrStore: nopStore,
 
 		broadcaster: NopBroadcaster,
 		Stats:       NopStatsClient,