v0.0.32

dataext/structHash.go

@@ -0,0 +1,254 @@
+package dataext
+
+import (
+	"bytes"
+	"crypto/sha256"
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"gogs.mikescher.com/BlackForestBytes/goext/langext"
+	"hash"
+	"io"
+	"reflect"
+	"sort"
+)
+
+type StructHashOptions struct {
+	HashAlgo    hash.Hash
+	Tag         *string
+	SkipChannel bool
+	SkipFunc    bool
+}
+
+func StructHash(dat any, opt ...StructHashOptions) (r []byte, err error) {
+	defer func() {
+		if rec := recover(); rec != nil {
+			r = nil
+			err = errors.New(fmt.Sprintf("recovered panic: %v", rec))
+		}
+	}()
+
+	shopt := StructHashOptions{}
+	if len(opt) > 1 {
+		return nil, errors.New("multiple options supplied")
+	} else if len(opt) == 1 {
+		shopt = opt[0]
+	}
+
+	if shopt.HashAlgo == nil {
+		shopt.HashAlgo = sha256.New()
+	}
+
+	writer := new(bytes.Buffer)
+
+	if langext.IsNil(dat) {
+		shopt.HashAlgo.Reset()
+		shopt.HashAlgo.Write(writer.Bytes())
+		res := shopt.HashAlgo.Sum(nil)
+		return res, nil
+	}
+
+	err = binarize(writer, reflect.ValueOf(dat), shopt)
+	if err != nil {
+		return nil, err
+	}
+
+	shopt.HashAlgo.Reset()
+	shopt.HashAlgo.Write(writer.Bytes())
+	res := shopt.HashAlgo.Sum(nil)
+
+	return res, nil
+}
+
+func writeBinarized(writer io.Writer, dat any) error {
+	tmp := bytes.Buffer{}
+	err := binary.Write(&tmp, binary.LittleEndian, dat)
+	if err != nil {
+		return err
+	}
+	err = binary.Write(writer, binary.LittleEndian, uint64(tmp.Len()))
+	if err != nil {
+		return err
+	}
+	_, err = writer.Write(tmp.Bytes())
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func binarize(writer io.Writer, dat reflect.Value, opt StructHashOptions) error {
+	var err error
+
+	err = binary.Write(writer, binary.LittleEndian, uint8(dat.Kind()))
+	switch dat.Kind() {
+	case reflect.Ptr, reflect.Map, reflect.Array, reflect.Chan, reflect.Slice, reflect.Interface:
+		if dat.IsNil() {
+			err = binary.Write(writer, binary.LittleEndian, uint64(0))
+			if err != nil {
+				return err
+			}
+			return nil
+		}
+	}
+
+	err = binary.Write(writer, binary.LittleEndian, uint64(len(dat.Type().String())))
+	if err != nil {
+		return err
+	}
+	_, err = writer.Write([]byte(dat.Type().String()))
+	if err != nil {
+		return err
+	}
+
+	switch dat.Type().Kind() {
+	case reflect.Invalid:
+		return errors.New("cannot binarize value of kind <Invalid>")
+	case reflect.Bool:
+		return writeBinarized(writer, dat.Bool())
+	case reflect.Int:
+		return writeBinarized(writer, int64(dat.Int()))
+	case reflect.Int8:
+		fallthrough
+	case reflect.Int16:
+		fallthrough
+	case reflect.Int32:
+		fallthrough
+	case reflect.Int64:
+		return writeBinarized(writer, dat.Interface())
+	case reflect.Uint:
+		return writeBinarized(writer, uint64(dat.Int()))
+	case reflect.Uint8:
+		fallthrough
+	case reflect.Uint16:
+		fallthrough
+	case reflect.Uint32:
+		fallthrough
+	case reflect.Uint64:
+		return writeBinarized(writer, dat.Interface())
+	case reflect.Uintptr:
+		return errors.New("cannot binarize value of kind <Uintptr>")
+	case reflect.Float32:
+		fallthrough
+	case reflect.Float64:
+		return writeBinarized(writer, dat.Interface())
+	case reflect.Complex64:
+		return errors.New("cannot binarize value of kind <Complex64>")
+	case reflect.Complex128:
+		return errors.New("cannot binarize value of kind <Complex128>")
+	case reflect.Slice:
+		fallthrough
+	case reflect.Array:
+		return binarizeArrayOrSlice(writer, dat, opt)
+	case reflect.Chan:
+		if opt.SkipChannel {
+			return nil
+		}
+		return errors.New("cannot binarize value of kind <Chan>")
+	case reflect.Func:
+		if opt.SkipFunc {
+			return nil
+		}
+		return errors.New("cannot binarize value of kind <Func>")
+	case reflect.Interface:
+		return binarize(writer, dat.Elem(), opt)
+	case reflect.Map:
+		return binarizeMap(writer, dat, opt)
+	case reflect.Pointer:
+		return binarize(writer, dat.Elem(), opt)
+	case reflect.String:
+		v := dat.String()
+		err = binary.Write(writer, binary.LittleEndian, uint64(len(v)))
+		if err != nil {
+			return err
+		}
+		_, err = writer.Write([]byte(v))
+		if err != nil {
+			return err
+		}
+		return nil
+	case reflect.Struct:
+		return binarizeStruct(writer, dat, opt)
+	case reflect.UnsafePointer:
+		return errors.New("cannot binarize value of kind <UnsafePointer>")
+	default:
+		return errors.New("cannot binarize value of unknown kind <" + dat.Type().Kind().String() + ">")
+	}
+}
+
+func binarizeStruct(writer io.Writer, dat reflect.Value, opt StructHashOptions) error {
+	err := binary.Write(writer, binary.LittleEndian, uint64(dat.NumField()))
+	if err != nil {
+		return err
+	}
+
+	for i := 0; i < dat.NumField(); i++ {
+
+		if opt.Tag != nil {
+			if _, ok := dat.Type().Field(i).Tag.Lookup(*opt.Tag); !ok {
+				continue
+			}
+		}
+
+		err = binary.Write(writer, binary.LittleEndian, uint64(len(dat.Type().Field(i).Name)))
+		if err != nil {
+			return err
+		}
+		_, err = writer.Write([]byte(dat.Type().Field(i).Name))
+		if err != nil {
+			return err
+		}
+
+		err = binarize(writer, dat.Field(i), opt)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func binarizeArrayOrSlice(writer io.Writer, dat reflect.Value, opt StructHashOptions) error {
+	err := binary.Write(writer, binary.LittleEndian, uint64(dat.Len()))
+	if err != nil {
+		return err
+	}
+
+	for i := 0; i < dat.Len(); i++ {
+		err := binarize(writer, dat.Index(i), opt)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func binarizeMap(writer io.Writer, dat reflect.Value, opt StructHashOptions) error {
+	err := binary.Write(writer, binary.LittleEndian, uint64(dat.Len()))
+	if err != nil {
+		return err
+	}
+
+	sub := make([][]byte, 0, dat.Len())
+
+	for _, k := range dat.MapKeys() {
+		tmp := bytes.Buffer{}
+		err = binarize(&tmp, dat.MapIndex(k), opt)
+		if err != nil {
+			return err
+		}
+		sub = append(sub, tmp.Bytes())
+	}
+
+	sort.Slice(sub, func(i1, i2 int) bool { return bytes.Compare(sub[i1], sub[i2]) < 0 })
+
+	for _, v := range sub {
+		_, err = writer.Write(v)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}

dataext/structHash_test.go

@@ -0,0 +1,143 @@
+package dataext
+
+import (
+	"encoding/hex"
+	"gogs.mikescher.com/BlackForestBytes/goext/langext"
+	"testing"
+)
+
+func noErrStructHash(t *testing.T, dat any, opt ...StructHashOptions) []byte {
+	res, err := StructHash(dat, opt...)
+	if err != nil {
+		t.Error(err)
+		t.FailNow()
+		return nil
+	}
+	return res
+}
+
+func TestStructHashSimple(t *testing.T) {
+
+	assertEqual(t, "209bf774af36cc3a045c152d9f1269ef3684ad819c1359ee73ff0283a308fefa", noErrStructHash(t, "Hello"))
+	assertEqual(t, "c32f3626b981ae2997db656f3acad3f1dc9d30ef6b6d14296c023e391b25f71a", noErrStructHash(t, 0))
+	assertEqual(t, "01b781b03e9586b257d387057dfc70d9f06051e7d3c1e709a57e13cc8daf3e35", noErrStructHash(t, []byte{}))
+	assertEqual(t, "93e1dcd45c732fe0079b0fb3204c7c803f0921835f6bfee2e6ff263e73eed53c", noErrStructHash(t, []int{}))
+	assertEqual(t, "54f637a376aad55b3160d98ebbcae8099b70d91b9400df23fb3709855d59800a", noErrStructHash(t, []int{1, 2, 3}))
+	assertEqual(t, "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855", noErrStructHash(t, nil))
+	assertEqual(t, "349a7db91aa78fd30bbaa7c7f9c7bfb2fcfe72869b4861162a96713a852f60d3", noErrStructHash(t, []any{1, "", nil}))
+	assertEqual(t, "ca51aab87808bf0062a4a024de6aac0c2bad54275cc857a4944569f89fd245ad", noErrStructHash(t, struct{}{}))
+
+}
+
+func TestStructHashSimpleStruct(t *testing.T) {
+
+	type t0 struct {
+		F1 int
+		F2 []string
+		F3 *int
+	}
+
+	assertEqual(t, "a90bff751c70c738bb5cfc9b108e783fa9c19c0bc9273458e0aaee6e74aa1b92", noErrStructHash(t, t0{
+		F1: 10,
+		F2: []string{"1", "2", "3"},
+		F3: nil,
+	}))
+
+	assertEqual(t, "5d09090dc34ac59dd645f197a255f653387723de3afa1b614721ea5a081c675f", noErrStructHash(t, t0{
+		F1: 10,
+		F2: []string{"1", "2", "3"},
+		F3: langext.Ptr(99),
+	}))
+
+}
+
+func TestStructHashLayeredStruct(t *testing.T) {
+
+	type t1_1 struct {
+		F10 float32
+		F12 float64
+		F15 bool
+	}
+	type t1_2 struct {
+		SV1 *t1_1
+		SV2 *t1_1
+		SV3 t1_1
+	}
+
+	assertEqual(t, "fd4ca071fb40a288fee4b7a3dfdaab577b30cb8f80f81ec511e7afd72dc3b469", noErrStructHash(t, t1_2{
+		SV1: nil,
+		SV2: nil,
+		SV3: t1_1{
+			F10: 1,
+			F12: 2,
+			F15: false,
+		},
+	}))
+	assertEqual(t, "3fbf7c67d8121deda075cc86319a4e32d71744feb2cebf89b43bc682f072a029", noErrStructHash(t, t1_2{
+		SV1: nil,
+		SV2: &t1_1{},
+		SV3: t1_1{
+			F10: 3,
+			F12: 4,
+			F15: true,
+		},
+	}))
+	assertEqual(t, "b1791ccd1b346c3ede5bbffda85555adcd8216b93ffca23f14fe175ec47c5104", noErrStructHash(t, t1_2{
+		SV1: &t1_1{},
+		SV2: &t1_1{},
+		SV3: t1_1{
+			F10: 5,
+			F12: 6,
+			F15: false,
+		},
+	}))
+
+}
+
+func TestStructHashMap(t *testing.T) {
+
+	type t0 struct {
+		F1 int
+		F2 map[string]int
+	}
+
+	assertEqual(t, "d50c53ad1fafb448c33fddd5aca01a86a2edf669ce2ecab07ba6fe877951d824", noErrStructHash(t, t0{
+		F1: 10,
+		F2: map[string]int{
+			"x": 1,
+			"0": 2,
+			"a": 99,
+		},
+	}))
+
+	assertEqual(t, "d50c53ad1fafb448c33fddd5aca01a86a2edf669ce2ecab07ba6fe877951d824", noErrStructHash(t, t0{
+		F1: 10,
+		F2: map[string]int{
+			"a": 99,
+			"x": 1,
+			"0": 2,
+		},
+	}))
+
+	m3 := make(map[string]int, 99)
+	m3["a"] = 0
+	m3["x"] = 0
+	m3["0"] = 0
+
+	m3["0"] = 99
+	m3["x"] = 1
+	m3["a"] = 2
+
+	assertEqual(t, "d50c53ad1fafb448c33fddd5aca01a86a2edf669ce2ecab07ba6fe877951d824", noErrStructHash(t, t0{
+		F1: 10,
+		F2: m3,
+	}))
+
+}
+
+func assertEqual(t *testing.T, expected string, actual []byte) {
+	actualStr := hex.EncodeToString(actual)
+	if actualStr != expected {
+		t.Errorf("values differ: Actual: '%v', Expected: '%v'", actualStr, expected)
+	}
+}