Microsoft SQL Server driver and prep

vendor/github.com/denisenkom/go-mssqldb/tvp_go19.go

@@ -0,0 +1,167 @@
+// +build go1.9
+
+package mssql
+
+import (
+	"bytes"
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"reflect"
+	"time"
+)
+
+var (
+	ErrorEmptyTVPName        = errors.New("TVPTypeName must not be empty")
+	ErrorTVPTypeSlice        = errors.New("TVPType must be slice type")
+	ErrorTVPTypeSliceIsEmpty = errors.New("TVPType mustn't be null value")
+)
+
+//TVPType is driver type, which allows supporting Table Valued Parameters (TVP) in SQL Server
+type TVPType struct {
+	//TVP param name, mustn't be default value
+	TVPTypeName string
+	//TVP scheme name
+	TVPScheme string
+	//TVP Value. Param must be the slice, mustn't be nil
+	TVPValue interface{}
+}
+
+func (tvp TVPType) check() error {
+	if len(tvp.TVPTypeName) == 0 {
+		return ErrorEmptyTVPName
+	}
+	valueOf := reflect.ValueOf(tvp.TVPValue)
+	if valueOf.Kind() != reflect.Slice {
+		return ErrorTVPTypeSlice
+	}
+	if valueOf.IsNil() {
+		return ErrorTVPTypeSliceIsEmpty
+	}
+	if reflect.TypeOf(tvp.TVPValue).Elem().Kind() != reflect.Struct {
+		return ErrorTVPTypeSlice
+	}
+	return nil
+}
+
+func (tvp TVPType) encode() ([]byte, error) {
+	columnStr, err := tvp.columnTypes()
+	if err != nil {
+		return nil, err
+	}
+	preparedBuffer := make([]byte, 0, 20+(10*len(columnStr)))
+	buf := bytes.NewBuffer(preparedBuffer)
+	err = writeBVarChar(buf, "")
+	if err != nil {
+		return nil, err
+	}
+	writeBVarChar(buf, tvp.TVPScheme)
+	writeBVarChar(buf, tvp.TVPTypeName)
+
+	binary.Write(buf, binary.LittleEndian, uint16(len(columnStr)))
+
+	for i, column := range columnStr {
+		binary.Write(buf, binary.LittleEndian, uint32(column.UserType))
+		binary.Write(buf, binary.LittleEndian, uint16(column.Flags))
+		writeTypeInfo(buf, &columnStr[i].ti)
+		writeBVarChar(buf, "")
+	}
+	buf.WriteByte(_TVP_END_TOKEN)
+	conn := new(Conn)
+	conn.sess = new(tdsSession)
+	conn.sess.loginAck = loginAckStruct{TDSVersion: verTDS73}
+	stmt := &Stmt{
+		c: conn,
+	}
+
+	val := reflect.ValueOf(tvp.TVPValue)
+	for i := 0; i < val.Len(); i++ {
+		refStr := reflect.ValueOf(val.Index(i).Interface())
+		buf.WriteByte(_TVP_ROW_TOKEN)
+		for j := 0; j < refStr.NumField(); j++ {
+			field := refStr.Field(j)
+			tvpVal := field.Interface()
+			valOf := reflect.ValueOf(tvpVal)
+			elemKind := field.Kind()
+			if elemKind == reflect.Ptr && valOf.IsNil() {
+				switch tvpVal.(type) {
+				case *bool, *time.Time, *int8, *int16, *int32, *int64, *float32, *float64:
+					binary.Write(buf, binary.LittleEndian, uint8(0))
+					continue
+				default:
+					binary.Write(buf, binary.LittleEndian, uint64(_PLP_NULL))
+					continue
+				}
+			}
+			if elemKind == reflect.Slice && valOf.IsNil() {
+				binary.Write(buf, binary.LittleEndian, uint64(_PLP_NULL))
+				continue
+			}
+
+			cval, err := convertInputParameter(tvpVal)
+			if err != nil {
+				return nil, fmt.Errorf("failed to convert tvp parameter row col: %s", err)
+			}
+			param, err := stmt.makeParam(cval)
+			if err != nil {
+				return nil, fmt.Errorf("failed to make tvp parameter row col: %s", err)
+			}
+			columnStr[j].ti.Writer(buf, param.ti, param.buffer)
+		}
+	}
+	buf.WriteByte(_TVP_END_TOKEN)
+	return buf.Bytes(), nil
+}
+
+func (tvp TVPType) columnTypes() ([]columnStruct, error) {
+	val := reflect.ValueOf(tvp.TVPValue)
+	var firstRow interface{}
+	if val.Len() != 0 {
+		firstRow = val.Index(0).Interface()
+	} else {
+		firstRow = reflect.New(reflect.TypeOf(tvp.TVPValue).Elem()).Elem().Interface()
+	}
+
+	tvpRow := reflect.TypeOf(firstRow)
+	columnCount := tvpRow.NumField()
+	defaultValues := make([]interface{}, 0, columnCount)
+
+	for i := 0; i < columnCount; i++ {
+		typeField := tvpRow.Field(i).Type
+		if typeField.Kind() == reflect.Ptr {
+			v := reflect.New(typeField.Elem())
+			defaultValues = append(defaultValues, v.Interface())
+			continue
+		}
+		defaultValues = append(defaultValues, reflect.Zero(typeField).Interface())
+	}
+
+	conn := new(Conn)
+	conn.sess = new(tdsSession)
+	conn.sess.loginAck = loginAckStruct{TDSVersion: verTDS73}
+	stmt := &Stmt{
+		c: conn,
+	}
+
+	columnConfiguration := make([]columnStruct, 0, columnCount)
+	for index, val := range defaultValues {
+		cval, err := convertInputParameter(val)
+		if err != nil {
+			return nil, fmt.Errorf("failed to convert tvp parameter row %d col %d: %s", index, val, err)
+		}
+		param, err := stmt.makeParam(cval)
+		if err != nil {
+			return nil, err
+		}
+		column := columnStruct{
+			ti: param.ti,
+		}
+		switch param.ti.TypeId {
+		case typeNVarChar, typeBigVarBin:
+			column.ti.Size = 0
+		}
+		columnConfiguration = append(columnConfiguration, column)
+	}
+
+	return columnConfiguration, nil
+}