fields: make fieldType its own type

Author: julienschmidt

const.go

@@ -87,8 +87,10 @@ const (
 )
 
 // https://dev.mysql.com/doc/internals/en/com-query-response.html#packet-Protocol::ColumnType
+type fieldType byte
+
 const (
-	fieldTypeDecimal byte = iota
+	fieldTypeDecimal fieldType = iota
 	fieldTypeTiny
 	fieldTypeShort
 	fieldTypeLong
@@ -107,7 +109,7 @@ const (
 	fieldTypeBit
 )
 const (
-	fieldTypeJSON byte = iota + 0xf5
+	fieldTypeJSON fieldType = iota + 0xf5
 	fieldTypeNewDecimal
 	fieldTypeEnum
 	fieldTypeSet

fields.go

@@ -41,7 +41,7 @@ type mysqlField struct {
 	tableName string
 	name      string
 	flags     fieldFlag
-	fieldType byte
+	fieldType fieldType
 	decimals  byte
 }
 

packets.go

@@ -676,7 +676,7 @@ func (mc *mysqlConn) readColumns(count int) ([]mysqlField, error) {
 		pos += n + 1 + 2 + 4
 
 		// Field type [uint8]
-		columns[i].fieldType = data[pos]
+		columns[i].fieldType = fieldType(data[pos])
 		pos++
 
 		// Flags [uint16]
@@ -960,15 +960,15 @@ func (stmt *mysqlStmt) writeExecutePacket(args []driver.Value) error {
 			// build NULL-bitmap
 			if arg == nil {
 				nullMask[i/8] |= 1 << (uint(i) & 7)
-				paramTypes[i+i] = fieldTypeNULL
+				paramTypes[i+i] = byte(fieldTypeNULL)
 				paramTypes[i+i+1] = 0x00
 				continue
 			}
 
 			// cache types and values
 			switch v := arg.(type) {
 			case int64:
-				paramTypes[i+i] = fieldTypeLongLong
+				paramTypes[i+i] = byte(fieldTypeLongLong)
 				paramTypes[i+i+1] = 0x00
 
 				if cap(paramValues)-len(paramValues)-8 >= 0 {
@@ -984,7 +984,7 @@ func (stmt *mysqlStmt) writeExecutePacket(args []driver.Value) error {
 				}
 
 			case float64:
-				paramTypes[i+i] = fieldTypeDouble
+				paramTypes[i+i] = byte(fieldTypeDouble)
 				paramTypes[i+i+1] = 0x00
 
 				if cap(paramValues)-len(paramValues)-8 >= 0 {
@@ -1000,7 +1000,7 @@ func (stmt *mysqlStmt) writeExecutePacket(args []driver.Value) error {
 				}
 
 			case bool:
-				paramTypes[i+i] = fieldTypeTiny
+				paramTypes[i+i] = byte(fieldTypeTiny)
 				paramTypes[i+i+1] = 0x00
 
 				if v {
@@ -1012,7 +1012,7 @@ func (stmt *mysqlStmt) writeExecutePacket(args []driver.Value) error {
 			case []byte:
 				// Common case (non-nil value) first
 				if v != nil {
-					paramTypes[i+i] = fieldTypeString
+					paramTypes[i+i] = byte(fieldTypeString)
 					paramTypes[i+i+1] = 0x00
 
 					if len(v) < mc.maxAllowedPacket-pos-len(paramValues)-(len(args)-(i+1))*64 {
@@ -1030,11 +1030,11 @@ func (stmt *mysqlStmt) writeExecutePacket(args []driver.Value) error {
 
 				// Handle []byte(nil) as a NULL value
 				nullMask[i/8] |= 1 << (uint(i) & 7)
-				paramTypes[i+i] = fieldTypeNULL
+				paramTypes[i+i] = byte(fieldTypeNULL)
 				paramTypes[i+i+1] = 0x00
 
 			case string:
-				paramTypes[i+i] = fieldTypeString
+				paramTypes[i+i] = byte(fieldTypeString)
 				paramTypes[i+i+1] = 0x00
 
 				if len(v) < mc.maxAllowedPacket-pos-len(paramValues)-(len(args)-(i+1))*64 {
@@ -1049,7 +1049,7 @@ func (stmt *mysqlStmt) writeExecutePacket(args []driver.Value) error {
 				}
 
 			case time.Time:
-				paramTypes[i+i] = fieldTypeString
+				paramTypes[i+i] = byte(fieldTypeString)
 				paramTypes[i+i+1] = 0x00
 
 				var val []byte