kuvia2/vendor/github.com/go-redis/redis/v8/internal/hscan/structmap.go

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2022-01-14 23:09:03 +00:00
package hscan
import (
"fmt"
"reflect"
"strings"
"sync"
)
// structMap contains the map of struct fields for target structs
// indexed by the struct type.
type structMap struct {
m sync.Map
}
func newStructMap() *structMap {
return new(structMap)
}
func (s *structMap) get(t reflect.Type) *structSpec {
if v, ok := s.m.Load(t); ok {
return v.(*structSpec)
}
spec := newStructSpec(t, "redis")
s.m.Store(t, spec)
return spec
}
//------------------------------------------------------------------------------
// structSpec contains the list of all fields in a target struct.
type structSpec struct {
m map[string]*structField
}
func (s *structSpec) set(tag string, sf *structField) {
s.m[tag] = sf
}
func newStructSpec(t reflect.Type, fieldTag string) *structSpec {
numField := t.NumField()
out := &structSpec{
m: make(map[string]*structField, numField),
}
for i := 0; i < numField; i++ {
f := t.Field(i)
tag := f.Tag.Get(fieldTag)
if tag == "" || tag == "-" {
continue
}
tag = strings.Split(tag, ",")[0]
if tag == "" {
continue
}
// Use the built-in decoder.
out.set(tag, &structField{index: i, fn: decoders[f.Type.Kind()]})
}
return out
}
//------------------------------------------------------------------------------
// structField represents a single field in a target struct.
type structField struct {
index int
fn decoderFunc
}
//------------------------------------------------------------------------------
type StructValue struct {
spec *structSpec
value reflect.Value
}
func (s StructValue) Scan(key string, value string) error {
field, ok := s.spec.m[key]
if !ok {
return nil
}
if err := field.fn(s.value.Field(field.index), value); err != nil {
t := s.value.Type()
return fmt.Errorf("cannot scan redis.result %s into struct field %s.%s of type %s, error-%s",
value, t.Name(), t.Field(field.index).Name, t.Field(field.index).Type, err.Error())
}
return nil
}