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package rlp
import (
"reflect"
"sync"
)
var (
typeCacheMutex sync.RWMutex
typeCache = make(map[reflect.Type]*typeinfo)
)
type typeinfo struct {
decoder
writer
}
type decoder func(*Stream, reflect.Value) error
type writer func(reflect.Value, *encbuf) error
func cachedTypeInfo(typ reflect.Type) (*typeinfo, error) {
typeCacheMutex.RLock()
info := typeCache[typ]
typeCacheMutex.RUnlock()
if info != nil {
return info, nil
}
// not in the cache, need to generate info for this type.
typeCacheMutex.Lock()
defer typeCacheMutex.Unlock()
return cachedTypeInfo1(typ)
}
func cachedTypeInfo1(typ reflect.Type) (*typeinfo, error) {
info := typeCache[typ]
if info != nil {
// another goroutine got the write lock first
return info, nil
}
// put a dummmy value into the cache before generating.
// if the generator tries to lookup itself, it will get
// the dummy value and won't call itself recursively.
typeCache[typ] = new(typeinfo)
info, err := genTypeInfo(typ)
if err != nil {
// remove the dummy value if the generator fails
delete(typeCache, typ)
return nil, err
}
*typeCache[typ] = *info
return typeCache[typ], err
}
func structFields(typ reflect.Type) (fields []field, err error) {
for i := 0; i < typ.NumField(); i++ {
if f := typ.Field(i); f.PkgPath == "" { // exported
info, err := cachedTypeInfo1(f.Type)
if err != nil {
return nil, err
}
fields = append(fields, field{i, info})
}
}
return fields, nil
}
func genTypeInfo(typ reflect.Type) (info *typeinfo, err error) {
info = new(typeinfo)
if info.decoder, err = makeDecoder(typ); err != nil {
return nil, err
}
if info.writer, err = makeWriter(typ); err != nil {
return nil, err
}
return info, nil
}
func isUint(k reflect.Kind) bool {
return k >= reflect.Uint && k <= reflect.Uintptr
}