Naveen Sampath | 04696f7 | 2022-06-13 15:19:14 +0530 | [diff] [blame] | 1 | package hscan |
| 2 | |
| 3 | import ( |
| 4 | "fmt" |
| 5 | "reflect" |
| 6 | "strings" |
| 7 | "sync" |
| 8 | ) |
| 9 | |
| 10 | // structMap contains the map of struct fields for target structs |
| 11 | // indexed by the struct type. |
| 12 | type structMap struct { |
| 13 | m sync.Map |
| 14 | } |
| 15 | |
| 16 | func newStructMap() *structMap { |
| 17 | return new(structMap) |
| 18 | } |
| 19 | |
| 20 | func (s *structMap) get(t reflect.Type) *structSpec { |
| 21 | if v, ok := s.m.Load(t); ok { |
| 22 | return v.(*structSpec) |
| 23 | } |
| 24 | |
| 25 | spec := newStructSpec(t, "redis") |
| 26 | s.m.Store(t, spec) |
| 27 | return spec |
| 28 | } |
| 29 | |
| 30 | //------------------------------------------------------------------------------ |
| 31 | |
| 32 | // structSpec contains the list of all fields in a target struct. |
| 33 | type structSpec struct { |
| 34 | m map[string]*structField |
| 35 | } |
| 36 | |
| 37 | func (s *structSpec) set(tag string, sf *structField) { |
| 38 | s.m[tag] = sf |
| 39 | } |
| 40 | |
| 41 | func newStructSpec(t reflect.Type, fieldTag string) *structSpec { |
| 42 | numField := t.NumField() |
| 43 | out := &structSpec{ |
| 44 | m: make(map[string]*structField, numField), |
| 45 | } |
| 46 | |
| 47 | for i := 0; i < numField; i++ { |
| 48 | f := t.Field(i) |
| 49 | |
| 50 | tag := f.Tag.Get(fieldTag) |
| 51 | if tag == "" || tag == "-" { |
| 52 | continue |
| 53 | } |
| 54 | |
| 55 | tag = strings.Split(tag, ",")[0] |
| 56 | if tag == "" { |
| 57 | continue |
| 58 | } |
| 59 | |
| 60 | // Use the built-in decoder. |
| 61 | out.set(tag, &structField{index: i, fn: decoders[f.Type.Kind()]}) |
| 62 | } |
| 63 | |
| 64 | return out |
| 65 | } |
| 66 | |
| 67 | //------------------------------------------------------------------------------ |
| 68 | |
| 69 | // structField represents a single field in a target struct. |
| 70 | type structField struct { |
| 71 | index int |
| 72 | fn decoderFunc |
| 73 | } |
| 74 | |
| 75 | //------------------------------------------------------------------------------ |
| 76 | |
| 77 | type StructValue struct { |
| 78 | spec *structSpec |
| 79 | value reflect.Value |
| 80 | } |
| 81 | |
| 82 | func (s StructValue) Scan(key string, value string) error { |
| 83 | field, ok := s.spec.m[key] |
| 84 | if !ok { |
| 85 | return nil |
| 86 | } |
| 87 | if err := field.fn(s.value.Field(field.index), value); err != nil { |
| 88 | t := s.value.Type() |
| 89 | return fmt.Errorf("cannot scan redis.result %s into struct field %s.%s of type %s, error-%s", |
| 90 | value, t.Name(), t.Field(field.index).Name, t.Field(field.index).Type, err.Error()) |
| 91 | } |
| 92 | return nil |
| 93 | } |