drafty types refactor with simple ascii packagergdd/sketch

types.go compiles but that is about it, here be dragons.  Pushing so
that we can get an idea of what this refactor would roughly look like.

1 files changed, 0 insertions, 306 deletions

diff --git a/pkg/ascii/ascii.go b/pkg/ascii/ascii.go
deleted file mode 100644
index d91a240..0000000
--- a/pkg/ascii/ascii.go
+++ /dev/null
@@ -1,306 +0,0 @@
-// package ascii implements an ASCII key-value parser.
-//
-// The top-most (de)serialize must operate on a struct pointer.  A struct may
-// contain other structs, in which case all tag names should be unique.  Public
-// fields without tag names are ignored.  Private fields are also ignored.
-//
-// The supported field types are:
-// - struct
-// - string (no empty strings)
-// - uint64 (only digits in ASCII representation)
-// - byte array (only lower-case hex in ASCII representation)
-// - slice of uint64 (no empty slices)
-// - slice of byte array (no empty slices)
-//
-// A key must not contain an encoding's end-of-key value.
-// A value must not contain an encoding's end-of-value value.
-//
-// For additional details, please refer to the Sigsum v0 API documentation.
-//
-package ascii
-
-import (
-	"bytes"
-	"fmt"
-	"io"
-	"io/ioutil"
-	"reflect"
-	"strconv"
-	"strings"
-
-	"git.sigsum.org/sigsum-go/pkg/hex"
-)
-
-var StdEncoding = NewEncoding("ascii", "=", "\n")
-
-type Encoding struct {
-	identifier string
-	endOfKey   string
-	endOfValue string
-}
-
-func NewEncoding(id, eok, eov string) *Encoding {
-	return &Encoding{
-		identifier: id,
-		endOfKey:   eok,
-		endOfValue: eov,
-	}
-}
-
-type someValue struct {
-	v  reflect.Value
-	ok bool
-}
-
-// Serialize tries to serialize an interface as ASCII key-value pairs
-func (e *Encoding) Serialize(w io.Writer, i interface{}) error {
-	v, err := dereferenceStructPointer(i)
-	if err != nil {
-		return err
-	}
-
-	t := v.Type()
-	for i := 0; i < t.NumField(); i++ {
-		switch v.Field(i).Type().Kind() {
-		case reflect.Struct:
-			if err := e.Serialize(w, v.Field(i).Addr().Interface()); err != nil {
-				return err
-			}
-		default:
-			if t.Field(i).PkgPath != "" {
-				continue // skip private field
-			}
-			key, ok := t.Field(i).Tag.Lookup(e.identifier)
-			if !ok {
-				continue // skip public field without tag
-			}
-
-			if strings.Contains(key, e.endOfKey) {
-				return fmt.Errorf("ascii: key %q contains end-of-key character", key)
-			}
-			if err := e.write(w, key, v.Field(i)); err != nil {
-				return err
-			}
-		}
-	}
-	return nil
-}
-
-func (e *Encoding) write(w io.Writer, key string, v reflect.Value) error {
-	t := v.Type()
-	switch t {
-	case reflect.TypeOf(uint64(0)):
-		val := fmt.Sprintf("%d", v.Uint())
-		return e.writeOne(w, key, val)
-	}
-
-	k := t.Kind()
-	switch k {
-	case reflect.Array:
-		if kind := t.Elem().Kind(); kind != reflect.Uint8 {
-			return fmt.Errorf("ascii: array kind not supported: %v", kind)
-		}
-
-		arrayLen := v.Len()
-		array := make([]byte, arrayLen, arrayLen)
-		for i := 0; i < arrayLen; i++ {
-			array[i] = uint8(v.Index(i).Uint())
-		}
-
-		val := hex.Serialize(array)
-		return e.writeOne(w, key, val)
-
-	case reflect.Slice:
-		kind := t.Elem().Kind()
-		if kind != reflect.Array && kind != reflect.Uint64 {
-			return fmt.Errorf("ascii: slice kind not supported: %v", kind)
-		}
-		if v.Len() == 0 {
-			return fmt.Errorf("ascii: slice must not be empty")
-		}
-
-		var err error
-		for i := 0; i < v.Len(); i++ {
-			err = e.write(w, key, v.Index(i))
-		}
-		return err
-
-	case reflect.String:
-		if v.Len() == 0 {
-			return fmt.Errorf("ascii: string must not be empty")
-		}
-		return e.writeOne(w, key, v.String())
-	}
-
-	return fmt.Errorf("ascii: unsupported type %v and kind %v", t, k)
-}
-
-func (e *Encoding) writeOne(w io.Writer, key, value string) error {
-	_, err := w.Write([]byte(key + e.endOfKey + value + e.endOfValue))
-	return err
-}
-
-// Deserialize tries to deserialize a buffer of ASCII key-value pairs
-func (e *Encoding) Deserialize(r io.Reader, i interface{}) error {
-	m := make(map[string]*someValue)
-	if err := e.mapKeys(i, m); err != nil {
-		return err
-	}
-
-	buf, err := ioutil.ReadAll(r)
-	if err != nil {
-		return fmt.Errorf("ascii: failed reading incoming buffer")
-	}
-
-	// trim end of buffer so that loop does not run on an empty line
-	if len(buf) <= len(e.endOfValue) {
-		return fmt.Errorf("ascii: buffer contains no key-value pair")
-	}
-	offset := len(buf) - len(e.endOfValue)
-	if !bytes.Equal(buf[offset:], []byte(e.endOfValue)) {
-		return fmt.Errorf("ascii: buffer must end with endOfValue")
-	}
-	buf = buf[:offset]
-
-	for _, kv := range bytes.Split(buf, []byte(e.endOfValue)) {
-		split := bytes.Split(kv, []byte(e.endOfKey))
-		if len(split) == 1 {
-			return fmt.Errorf("ascii: missing key-value pair in %q", string(kv))
-		}
-
-		key := string(split[0])
-		value := string(bytes.Join(split[1:], nil))
-		ref, ok := m[key]
-		if !ok {
-			return fmt.Errorf("ascii: unexpected key %q", key)
-		}
-		if len(value) == 0 {
-			fmt.Errorf("ascii: missing value for key %q", key)
-		}
-		if err := setKey(ref, key, value); err != nil {
-			return err
-		}
-	}
-	return requireValues(m)
-}
-
-func (e *Encoding) mapKeys(i interface{}, m map[string]*someValue) error {
-	v, err := dereferenceStructPointer(i)
-	if err != nil {
-		return err
-	}
-
-	t := v.Type()
-	for i := 0; i < t.NumField(); i++ {
-		switch v.Field(i).Type().Kind() {
-		case reflect.Struct:
-			i := v.Field(i).Addr().Interface()
-			e.mapKeys(i, m) // return is always nil
-		default:
-			if t.Field(i).PkgPath != "" {
-				continue // skip private field
-			}
-			key, ok := t.Field(i).Tag.Lookup(e.identifier)
-			if !ok {
-				continue // skip public field without tag
-			}
-			m[key] = &someValue{
-				v: v.Field(i),
-			}
-		}
-	}
-	return nil
-}
-
-func setKey(ref *someValue, key, value string) error {
-	v := ref.v
-	if v.Kind() == reflect.Ptr && !v.IsNil() {
-		v = v.Elem()
-	}
-
-	t := v.Type()
-	switch t {
-	case reflect.TypeOf(uint64(0)):
-		num, err := strconv.ParseUint(value, 10, 64)
-		if err != nil {
-			return err
-		}
-
-		ref.ok = true
-		v.SetUint(num)
-		return nil
-	}
-
-	k := t.Kind()
-	switch k {
-	case reflect.Array:
-		arrayLen := v.Len()
-		b, err := hex.Deserialize(value)
-		if err != nil {
-			return err
-		}
-		if len(b) != arrayLen {
-			return fmt.Errorf("ascii: invalid array size for key %q", key)
-		}
-
-		ref.ok = true
-		reflect.Copy(v, reflect.ValueOf(b))
-		return nil
-
-	case reflect.Slice:
-		sliceType := t
-		kind := sliceType.Elem().Kind()
-		if kind != reflect.Array && kind != reflect.Uint64 {
-			return fmt.Errorf("ascii: slice kind not supported: %v", kind)
-		}
-
-		if v.IsNil() {
-			v.Set(reflect.MakeSlice(sliceType, 0, 0))
-		}
-		sv := &someValue{
-			v: reflect.New(sliceType.Elem()),
-		}
-		if err := setKey(sv, key, value); err != nil {
-			return err
-		}
-
-		ref.ok = true
-		v.Set(reflect.Append(v, sv.v.Elem()))
-		return nil
-
-	case reflect.String:
-		if len(value) == 0 {
-			return fmt.Errorf("ascii: string must not be empty")
-		}
-
-		ref.ok = true
-		v.SetString(value)
-		return nil
-	}
-
-	return fmt.Errorf("ascii: unsupported type %v and kind %v", t, k)
-}
-
-func requireValues(m map[string]*someValue) error {
-	for k, v := range m {
-		if !v.ok {
-			return fmt.Errorf("ascii: missing value for key %q", k)
-		}
-	}
-	return nil
-}
-
-func dereferenceStructPointer(i interface{}) (*reflect.Value, error) {
-	v := reflect.ValueOf(i)
-	if v.Kind() != reflect.Ptr {
-		return nil, fmt.Errorf("ascii: interface value must be pointer")
-	}
-	if v.IsNil() {
-		return nil, fmt.Errorf("ascii: interface value must be non-nil pointer")
-	}
-	v = v.Elem()
-	if v.Type().Kind() != reflect.Struct {
-		return nil, fmt.Errorf("ascii: interface value must point to struct")
-	}
-	return &v, nil
-}