Add a cache to avoid unnecessary parsing of type strings when constructing values

R=rsc
DELTA=12  (9 added, 0 deleted, 3 changed)
OCL=18916
CL=18921

diff --git a/src/lib/reflect/value.go b/src/lib/reflect/value.go
index c7089b1580f2eb2fe5e0915da6567c78e3a6edc2..fe41e3f92687f825d5e909c3ddca9e410193e4ad 100644 (file)
--- a/src/lib/reflect/value.go
+++ b/src/lib/reflect/value.go
@@ -695,6 +695,7 @@ func FuncCreator(typ Type, addr Addr) Value {
 }
 
 var creator *map[int] Creator
+var typecache *map[string] *Type
 
 func init() {
        creator = new(map[int] Creator);
@@ -722,6 +723,8 @@ func init() {
        creator[StructKind] = &StructCreator;
        creator[InterfaceKind] = &InterfaceCreator;
        creator[FuncKind] = &FuncCreator;
+
+       typecache = new(map[string] *Type);
 }
 
 func NewValueAddr(typ Type, addr Addr) Value {
@@ -752,10 +755,16 @@ export func NewInitValue(typ Type) Value {
 
 export func NewValue(e Empty) Value {
        value, typestring  := sys.reflect(e);
-       typ := ParseTypeString("", typestring);
+       p, ok := typecache[typestring];
+       if !ok {
+               typ := ParseTypeString("", typestring);
+               p = new(Type);
+               *p = typ;
+               typecache[typestring] = p;
+       }
        // Content of interface is a value; need a permanent copy to take its address
        // so we can modify the contents. Values contain pointers to 'values'.
        ap := new(uint64);
        *ap = value;
-       return NewValueAddr(typ, PtrUint64ToAddr(ap));
+       return NewValueAddr(*p, PtrUint64ToAddr(ap));
 }