From 6979d88440131da2de1624cc26c6a45c7a6acad1 Mon Sep 17 00:00:00 2001
From: siyul-park <siyual.bak@gmail.com>
Date: Sun, 8 Oct 2023 01:10:27 -0400
Subject: [PATCH] feat: add cache in focus, env

---
 README.md  | 12 ++++++------
 jsonata.go | 56 ++++++++++++++++++++++++++++++++++++++++++------------
 2 files changed, 50 insertions(+), 18 deletions(-)

diff --git a/README.md b/README.md
index c19b1e2..01f1e5c 100644
--- a/README.md
+++ b/README.md
@@ -41,13 +41,13 @@ goos: linux
 goarch: amd64
 pkg: github.com/siyul-park/jsonata-go
 cpu: AMD EPYC 7282 16-Core Processor                
-BenchmarkExpression_Compile-4                        241           4289580 ns/op         1533227 B/op      19943 allocs/op
-BenchmarkExpression_Evaluate-4                      4311            238447 ns/op           62422 B/op        872 allocs/op
-BenchmarkExpression_Assign-4                      627997              1706 ns/op             522 B/op          9 allocs/op
-BenchmarkExpression_RegisterFunction-4            296378              4030 ns/op            1845 B/op         23 allocs/op
-BenchmarkExpression_Ast-4                          15912             76499 ns/op           29610 B/op        413 allocs/op
+BenchmarkExpression_Compile-4            	     207	   5672824 ns/op	 1533080 B/op	   19941 allocs/op
+BenchmarkExpression_Evaluate-4           	    3902	    260193 ns/op	   62461 B/op	     873 allocs/op
+BenchmarkExpression_Assign-4             	  822211	      1542 ns/op	     521 B/op	       9 allocs/op
+BenchmarkExpression_RegisterFunction-4   	  243468	      4395 ns/op	    1846 B/op	      23 allocs/op
+BenchmarkExpression_Ast-4                	   14838	     80954 ns/op	   29617 B/op	     413 allocs/op
 PASS
-ok      github.com/siyul-park/jsonata-go        6.962s
+ok  	github.com/siyul-park/jsonata-go	8.251s
 ```
 
 ## More information
diff --git a/jsonata.go b/jsonata.go
index 2c05f27..39247e8 100644
--- a/jsonata.go
+++ b/jsonata.go
@@ -32,13 +32,19 @@ type (
 	}
 
 	Environment struct {
-		vm    *goja.Runtime
-		value *goja.Object
+		async     bool
+		timestamp time.Time
+		vm        *goja.Runtime
+		value     *goja.Object
+		mu        sync.Mutex
 	}
 
 	Focus struct {
-		vm    *goja.Runtime
-		value *goja.Object
+		environment *Environment
+		input       any
+		vm          *goja.Runtime
+		value       *goja.Object
+		mu          sync.Mutex
 	}
 
 	Expression struct {
@@ -103,7 +109,6 @@ func Compile(str string, opts ...Options) (*Expression, error) {
 		return &Expression{
 			vm:    vm,
 			value: exp.ToObject(vm),
-			mu:    sync.Mutex{},
 		}, nil
 	}
 }
@@ -181,22 +186,49 @@ func (e *Expression) Ast() (*ExprNode, error) {
 }
 
 func (f *Focus) Environment() *Environment {
-	return &Environment{
-		value: f.vm.Get("environment").ToObject(f.vm),
-		vm:    f.vm,
+	f.mu.Lock()
+	defer f.mu.Unlock()
+
+	if f.environment == nil {
+		f.environment = &Environment{
+			value: f.vm.Get("environment").ToObject(f.vm),
+			vm:    f.vm,
+		}
 	}
+
+	return f.environment
 }
 
 func (f *Focus) Input() any {
-	return f.vm.Get("input").Export()
+	f.mu.Lock()
+	defer f.mu.Unlock()
+
+	if f.input == nil {
+		f.input = f.vm.Get("input").Export()
+	}
+	return f.input
 }
 
 func (e *Environment) Async() bool {
-	return e.value.Get("async").ToBoolean()
+	e.mu.Lock()
+	defer e.mu.Unlock()
+
+	if !e.async {
+		e.async = e.value.Get("async").ToBoolean()
+	}
+
+	return e.async
 }
 
 func (e *Environment) Timestamp() time.Time {
-	return e.value.Get("timestamp").Export().(time.Time)
+	e.mu.Lock()
+	defer e.mu.Unlock()
+
+	if e.timestamp == (time.Time{}) {
+		e.timestamp = e.value.Get("timestamp").Export().(time.Time)
+	}
+
+	return e.timestamp
 }
 
 func (e *Environment) Bind(s string, a any) error {
@@ -205,7 +237,7 @@ func (e *Environment) Bind(s string, a any) error {
 	return err
 }
 
-func (e Environment) Lookup(s string) (any, error) {
+func (e *Environment) Lookup(s string) (any, error) {
 	lookup, _ := goja.AssertFunction(e.value.Get("lookup"))
 	if v, err := lookup(goja.Undefined(), e.vm.ToValue(s)); err != nil {
 		return nil, err