chore: import upstream snapshot with attribution

server/functions/dolt_recordtrim.go

@@ -0,0 +1,53 @@
+// Copyright 2024 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 functions
+
+import (
+	"github.com/cockroachdb/errors"
+	"github.com/dolthub/go-mysql-server/sql"
+
+	"github.com/dolthub/doltgresql/server/functions/framework"
+	pgtypes "github.com/dolthub/doltgresql/server/types"
+)
+
+// initDoltRecordTrim registers the functions to the catalog.
+func initDoltRecordTrim() {
+	framework.RegisterFunction(dolt_recordTrim)
+}
+
+// dolt_recordTrim is used to remove a specific column within a composite type. This will generally lead to an invalid
+// value for the composite type, however this is used within the DROP COLUMN table hook to fix data for all columns that
+// reference the type, as that is the only time when the data is invalid. This is why this is a "dolt_" function as
+// well, as it's not intended for general use.
+var dolt_recordTrim = framework.Function2{
+	Name:       "dolt_recordtrim",
+	Return:     pgtypes.AnyElement,
+	Parameters: [2]*pgtypes.DoltgresType{pgtypes.AnyElement, pgtypes.Int32},
+	Strict:     true,
+	Callable: func(ctx *sql.Context, types [3]*pgtypes.DoltgresType, val1 any, val2 any) (any, error) {
+		if !types[0].IsCompositeType() {
+			return val1, nil
+		}
+		trimVal := val2.(int32)
+		recordVals := val1.([]pgtypes.RecordValue)
+		if trimVal < 0 || int(trimVal) >= len(recordVals) {
+			return nil, errors.New("record trim index is out of bounds")
+		}
+		newRecordVals := make([]pgtypes.RecordValue, len(recordVals)-1)
+		copy(newRecordVals, recordVals[:trimVal])
+		copy(newRecordVals[trimVal:], recordVals[trimVal+1:])
+		return newRecordVals, nil
+	},
+}