chore: import upstream snapshot with attribution

server/ast/copy_from.go

@@ -0,0 +1,79 @@
+// Copyright 2023 Dolthub, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ast
+
+import (
+	"github.com/cockroachdb/errors"
+
+	"github.com/dolthub/dolt/go/libraries/doltcore/doltdb"
+	vitess "github.com/dolthub/vitess/go/vt/sqlparser"
+
+	"github.com/dolthub/doltgresql/postgres/parser/sem/tree"
+	pgnodes "github.com/dolthub/doltgresql/server/node"
+)
+
+// nodeCopyFrom handles *tree.CopyFrom nodes.
+func nodeCopyFrom(ctx *Context, node *tree.CopyFrom) (vitess.Statement, error) {
+	if node == nil {
+		return nil, nil
+	}
+	if node.Options.CopyFormat == tree.CopyFormatBinary {
+		return nil, errors.Errorf("COPY FROM does not support format BINARY")
+	}
+
+	// We start by creating a stub insert statement for the COPY FROM statement, which we will use to build a basic
+	// INSERT plan for. At runtime we will swap out the bogus row values for our actual data read from STDIN.
+	var columns []vitess.ColIdent
+	if len(node.Columns) > 0 {
+		columns = make([]vitess.ColIdent, len(node.Columns))
+		for i := range node.Columns {
+			columns[i] = vitess.NewColIdent(string(node.Columns[i]))
+		}
+	}
+
+	tableName, err := nodeTableName(ctx, &node.Table)
+	if err != nil {
+		return nil, err
+	}
+
+	stubValues := make(vitess.Values, 1)
+	stubValues[0] = make(vitess.ValTuple, len(columns))
+	for i := range columns {
+		stubValues[0][i] = &vitess.NullVal{}
+	}
+
+	return vitess.InjectedStatement{
+		Statement: pgnodes.NewCopyFrom(
+			node.Table.Catalog(),
+			doltdb.TableName{
+				Name:   node.Table.Object(),
+				Schema: node.Table.Schema(),
+			},
+			node.Options,
+			node.File,
+			node.Stdin,
+			node.Columns,
+			&vitess.Insert{
+				Action:  vitess.InsertStr,
+				Table:   tableName,
+				Columns: columns,
+				Rows: &vitess.AliasedValues{
+					Values: stubValues,
+				},
+			},
+		),
+		Children: nil,
+	}, nil
+}