lib/spf: realign struct for better size allocation

The realignment reduce the cost of the following struct,

* directive: from 32 to 24 bytes (-8)
* macro: from 64 to 56 bytes (-8)
* Result: from 224 to 216 bytes (-8)

3 files changed, 16 insertions, 9 deletions

diff --git a/lib/spf/directive.go b/lib/spf/directive.go
index 417384f1..45a0c66a 100644
--- a/lib/spf/directive.go
+++ b/lib/spf/directive.go
@@ -25,7 +25,7 @@ const (
 )
 
 type directive struct {
-	qual  byte
 	mech  string
 	value []byte
+	qual  byte
 }
diff --git a/lib/spf/macro.go b/lib/spf/macro.go
index f41f2e32..825be51a 100644
--- a/lib/spf/macro.go
+++ b/lib/spf/macro.go
@@ -34,14 +34,18 @@ const (
 
 type macro struct {
 	ref *Result
-	out []byte
 
 	// mode is either mechanism "include", modifier "redirect", or
 	// modifier "exp".
-	mode       string
-	nright     int
-	dels       []byte
-	letter     byte
+	mode string
+
+	out  []byte
+	dels []byte
+
+	nright int
+
+	letter byte
+
 	isReversed bool
 }
 
diff --git a/lib/spf/result.go b/lib/spf/result.go
index 34f98430..48ecb1db 100644
--- a/lib/spf/result.go
+++ b/lib/spf/result.go
@@ -16,18 +16,21 @@ import (
 
 // Result contains the output of CheckHost function.
 type Result struct {
-	IP       net.IP // The IP address of sender.
+	IP net.IP // The IP address of sender.
+
+	Err string
+
 	Domain   []byte // The domain address of sender from SMTP EHLO or MAIL FROM command.
 	Sender   []byte // The email address of sender.
 	Hostname []byte
-	Code     byte // Result of check host.
-	Err      string
 
 	senderLocal  []byte // The local part of sender.
 	senderDomain []byte // The domain part of sender.
 	terms        []byte // terms contains raw DNS RR that have SPF record.
 	dirs         []*directive
 	mods         []*modifier
+
+	Code byte // Result of check host.
 }
 
 // newResult initialize new SPF result on single domain.