Pg to bun (#148)

* start moving to bun

* changing more stuff

* more

* and yet more

* tests passing

* seems stable now

* more big changes

* small fix

* little fixes

vendor/github.com/uptrace/bun/model_slice.go

@@ -0,0 +1,82 @@
+package bun
+
+import (
+	"context"
+	"database/sql"
+	"reflect"
+
+	"github.com/uptrace/bun/internal"
+	"github.com/uptrace/bun/schema"
+)
+
+type sliceInfo struct {
+	nextElem func() reflect.Value
+	scan     schema.ScannerFunc
+}
+
+type sliceModel struct {
+	dest      []interface{}
+	values    []reflect.Value
+	scanIndex int
+	info      []sliceInfo
+}
+
+var _ model = (*sliceModel)(nil)
+
+func newSliceModel(db *DB, dest []interface{}, values []reflect.Value) *sliceModel {
+	return &sliceModel{
+		dest:   dest,
+		values: values,
+	}
+}
+
+func (m *sliceModel) Value() interface{} {
+	return m.dest
+}
+
+func (m *sliceModel) ScanRows(ctx context.Context, rows *sql.Rows) (int, error) {
+	columns, err := rows.Columns()
+	if err != nil {
+		return 0, err
+	}
+
+	m.info = make([]sliceInfo, len(m.values))
+	for i, v := range m.values {
+		if v.IsValid() && v.Len() > 0 {
+			v.Set(v.Slice(0, 0))
+		}
+
+		m.info[i] = sliceInfo{
+			nextElem: internal.MakeSliceNextElemFunc(v),
+			scan:     schema.Scanner(v.Type().Elem()),
+		}
+	}
+
+	if len(columns) == 0 {
+		return 0, nil
+	}
+	dest := makeDest(m, len(columns))
+
+	var n int
+
+	for rows.Next() {
+		m.scanIndex = 0
+		if err := rows.Scan(dest...); err != nil {
+			return 0, err
+		}
+		n++
+	}
+	if err := rows.Err(); err != nil {
+		return 0, err
+	}
+
+	return n, nil
+}
+
+func (m *sliceModel) Scan(src interface{}) error {
+	info := m.info[m.scanIndex]
+	m.scanIndex++
+
+	dest := info.nextElem()
+	return info.scan(dest, src)
+}