From 20c89c6e56a6135e1e0bbe143536a3b3515c9e9d Mon Sep 17 00:00:00 2001
From: Greg <gmp@wow.st>
Date: Thu, 30 Aug 2018 09:23:21 -0400
Subject: [PATCH] Functional options to persist.Init().

---
 generate/template.go |  4 +--
 persist.go           | 75 +++++++++++++++++++++++++-------------------
 test/tidy/main.go    |  9 +++---
 3 files changed, 48 insertions(+), 40 deletions(-)

diff --git a/generate/template.go b/generate/template.go
index a8f1173..17101a8 100644
--- a/generate/template.go
+++ b/generate/template.go
@@ -12,9 +12,9 @@ import (
 
 type Var_N persist.Var
 
-func New(name string, x _T, opt ...persist.Option) *Var_N {
+func New(name string, x _T, ps ...bool) *Var_N {
 	gob.Register(x)
-	ptr := persist.New(name, x, opt...)
+	ptr := persist.New(name, x, ps...)
 	ret := (*Var_N)(unsafe.Pointer(ptr))
 	return ret
 }
diff --git a/persist.go b/persist.go
index f1d8ef4..cbea4a2 100644
--- a/persist.go
+++ b/persist.go
@@ -25,16 +25,14 @@ type Var struct {
 	X interface{}
 	Time time.Time
 	name string
-	opt Option
+	permanent bool
 }
 
 type encVar struct {
 	X interface{}
 }
 
-type Option struct {
-	Permanent bool
-}
+type Option func(*Config)
 
 type Config struct {
 	configured bool
@@ -43,42 +41,47 @@ type Config struct {
 	Tidy TidyConfig
 }
 
-func Init(x ...Config) {
+func MaxVars(i int) Option {
+	return func(c *Config) {
+		c.MaxVars = i
+	}
+}
+
+func DBPath(s string) Option {
+	return func(c *Config) {
+		c.DBPath = s
+	}
+}
+
+func TidyInterval(d time.Duration) Option {
+	return func(c *Config) {
+		c.Tidy.Interval = d
+	}
+}
+
+func Init(confs ...Option) {
 	mux.Lock()
-	c := Config {
+	tc := TidyConfig {
+		Interval: 10 * time.Second,
+	}
+	conf = Config { // default config
 		configured: true,
-		MaxVars: 64, // default config
+		MaxVars: 64,
 		DBPath: "db",
-	}
-	conf = c
-	if len(x) > 0 {
-		c = x[0]
-	}
-	if c.MaxVars != 0 {
-		conf.MaxVars = c.MaxVars
-	}
-	if c.DBPath != "" {
-		conf.DBPath = c.DBPath
+		Tidy: tc,
 	}
 
-	if c.Tidy.Interval == 0 {
-		conf.Tidy.Interval = 10 * time.Second
-	} else {
-		fmt.Println("Setting conf.Tidy.Interval to",c.Tidy.Interval)
-		conf.Tidy.Interval = c.Tidy.Interval
+	for _,f := range(confs) {
+		f(&conf)
 	}
 
-	if c.Tidy.Func == nil {
-		conf.Tidy.Func = ExpireAfter(24 * time.Hour)
-	} else {
-		fmt.Println("Setting conf.Tidy.Func")
-		conf.Tidy.Func = c.Tidy.Func
+	if conf.Tidy.Func == nil {
+		conf.Tidy.Func = ExpireAfterFunc(24 * time.Hour)
 	}
-
 	mux.Unlock()
 }
 
-func New(name string, x interface{},opt ...Option) *Var {
+func New(name string, x interface{},ps ...bool) *Var {
 	start()
 	mux.Lock()
 	if vars == nil {
@@ -89,8 +92,8 @@ func New(name string, x interface{},opt ...Option) *Var {
 		ret = &Var{X: x, name: name}
 		vars[name] = ret
 	}
-	if len(opt) == 1 {
-		ret.opt = opt[0]
+	if len(ps) > 1 {
+		ret.permanent = ps[0]
 	}
 	mux.Unlock()
 	err := ret.Load()
@@ -450,7 +453,13 @@ type TidyConfig struct {
 	Func TidyFunc
 }
 
-func ExpireAfter(exp time.Duration) TidyFunc {
+func ExpireAfter(exp time.Duration) Option {
+	return func(c *Config) {
+		c.Tidy.Func = ExpireAfterFunc(exp)
+	}
+}
+
+func ExpireAfterFunc(exp time.Duration) TidyFunc {
 	if exp > 0 {
 		exp = -1 * exp
 	}
@@ -485,7 +494,7 @@ func tidyThread() {
 		}
 		for {
 			for p := range loaded {
-				if p.opt.Permanent == false {
+				if p.permanent == false {
 					lchan<- p.name
 					loaded<- p // put it back in the queue
 				}
diff --git a/test/tidy/main.go b/test/tidy/main.go
index 25a6d48..18dfab2 100644
--- a/test/tidy/main.go
+++ b/test/tidy/main.go
@@ -7,11 +7,10 @@ import (
 )
 
 func main() {
-	tc := persist.TidyConfig{
-		Interval: 2 * time.Second,
-		Func: persist.ExpireAfter(-5 * time.Second),
-	}
-	persist.Init(persist.Config{Tidy: tc})
+	persist.Init(
+		persist.TidyInterval(2 * time.Second),
+		persist.ExpireAfter(-5 * time.Second),
+	)
 
 	x := persistInt("x",0)
 	persist.Commit()