variable length hex

datatype.go

@@ -1,10 +1,11 @@
 package envconf
 
 import (
+	"fmt"
 	"time"
 )
 
-type DataType int
+type DataType uint
 
 const (
 	TypeNone      DataType = iota
@@ -17,6 +18,18 @@ const (
 	TypeHex       DataType = iota
 )
 
+func FixedHex(size uint) DataType {
+	return (DataType)(size<<16) | TypeHex
+}
+
+func (dtype DataType) baseType() DataType {
+	return dtype & 0xffff
+}
+
+func (dtype DataType) typeAndSize() (DataType, uint) {
+	return (dtype & 0xffff), uint(dtype >> 16)
+}
+
 type cValue struct {
 	dtype   DataType
 	intval  int64
@@ -28,18 +41,24 @@ type cValue struct {
 }
 
 func (dtype DataType) parse(key string, str string) (ret cValue) {
-	info, ok := tInfo[dtype]
+	rdtype, size := dtype.typeAndSize()
+	info, ok := tInfo[rdtype]
 	if ok {
-		ret = info.parser(key, str)
+		ret = info.parser(key, str, size)
 		if len(ret.binval) == 0 {
 			ret.binval = make([]byte, 0, 0)
 		}
 	}
 	return
 }
+
 func (dtype DataType) String() string {
-	info, ok := tInfo[dtype]
+	rdtype, size := dtype.typeAndSize()
+	info, ok := tInfo[rdtype]
 	if ok {
+		if size > 0 {
+			return fmt.Sprintf("%s%d", info.name, size)
+		}
 		return info.name
 	}
 	return "invalid"

envconf.go

@@ -283,10 +283,11 @@ func keySplit(key string) (left string, right string, ok bool) {
 
 func (c *Config) getRaw(key string, dtype DataType) (val cValue) {
 	val.dtype = TypeNone
+	val.binval = make([]byte, 0, 0)
 	if c.parsed {
 		key = cleanKey(key)
 		entry, ok := c.env[key]
-		if ok && (entry.dtype == dtype) {
+		if ok && (entry.dtype.baseType() == dtype.baseType()) {
 			return entry.parsed
 		}
 	}
@@ -302,7 +303,7 @@ func (c *Config) getRawMap(key string, dtype DataType) (empty map[string]cValue)
 
 		if ok {
 			for k, v := range entries {
-				if (v.dtype == dtype) && (v.parsed.err == nil) {
+				if (v.dtype.baseType() == dtype.baseType()) && (v.parsed.err == nil) {
 					retval[k] = v.parsed
 				} else {
 					return

parsers.go

@@ -11,7 +11,7 @@ import (
 	"time"
 )
 
-func parseInt(key string, str string) (ret cValue) {
+func parseInt(key string, str string, _ uint) (ret cValue) {
 	val, err := strconv.ParseInt(str, 10, 64)
 	if err == nil {
 		ret.intval = val
@@ -21,7 +21,7 @@ func parseInt(key string, str string) (ret cValue) {
 	return
 }
 
-func parseMetric(key string, str string) (ret cValue) {
+func parseMetric(key string, str string, _ uint) (ret cValue) {
 	mod := int64(1)
 	str = strings.ToUpper(str)
 	if strings.HasSuffix(str, "K") {
@@ -46,7 +46,7 @@ func parseMetric(key string, str string) (ret cValue) {
 	return
 }
 
-func parseDuration(key string, str string) (ret cValue) {
+func parseDuration(key string, str string, _ uint) (ret cValue) {
 	val, err := time.ParseDuration(str)
 	if err == nil {
 		ret.durval = val
@@ -56,7 +56,7 @@ func parseDuration(key string, str string) (ret cValue) {
 	return
 }
 
-func parseBool(key string, str string) (ret cValue) {
+func parseBool(key string, str string, _ uint) (ret cValue) {
 	val, err := strconv.ParseBool(str)
 	if err == nil {
 		ret.boolval = val
@@ -66,17 +66,21 @@ func parseBool(key string, str string) (ret cValue) {
 	return
 }
 
-func parseHex(key string, str string) (ret cValue) {
+func parseHex(key string, str string, size uint) (ret cValue) {
 	val, err := hex.DecodeString(str)
-	if err == nil {
+	if err == nil && (size == 0 || size == uint(len(val))) {
 		ret.binval = val
 	} else {
-		ret.err = errors.New(fmt.Sprintf(`Environment variable "%s" is not of type hex.`, key))
+		if size == 0 {
+			ret.err = errors.New(fmt.Sprintf(`Environment variable "%s" is not of type hex.`, key))
+		} else {
+			ret.err = errors.New(fmt.Sprintf(`Environment variable "%s" is not of type hex%d.`, key, size))
+		}
 	}
 	return
 }
 
-func parseDirectory(_ string, str string) (ret cValue) {
+func parseDirectory(_ string, str string, _ uint) (ret cValue) {
 	wd, err := os.Getwd()
 	if err == nil {
 		if path.IsAbs(str) {
@@ -90,7 +94,7 @@ func parseDirectory(_ string, str string) (ret cValue) {
 	return
 }
 
-func parseString(_ string, str string) (ret cValue) {
+func parseString(_ string, str string, _ uint) (ret cValue) {
 	ret.strval = str
 	return
 }

typeinfo.go

@@ -1,7 +1,7 @@
 package envconf
 
 type dataTypeInfo struct {
-	parser func(string, string) cValue
+	parser func(string, string, uint) cValue
 	name   string
 }
 
@@ -15,6 +15,7 @@ func init() {
 	var strInfo dataTypeInfo
 	var dirInfo dataTypeInfo
 	var hexInfo dataTypeInfo
+
 	var boolInfo dataTypeInfo
 
 	intInfo.name = "int"
@@ -30,6 +31,7 @@ func init() {
 	durInfo.parser = parseDuration
 	dirInfo.parser = parseDirectory
 	strInfo.parser = parseString
+
 	hexInfo.parser = parseHex
 	boolInfo.parser = parseBool