chore: import upstream snapshot with attribution

server/functions/regproc.go

@@ -0,0 +1,142 @@
+// 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 (
+	"strconv"
+
+	"github.com/cockroachdb/errors"
+	"github.com/dolthub/go-mysql-server/sql"
+
+	"github.com/dolthub/doltgresql/core/id"
+	"github.com/dolthub/doltgresql/server/functions/framework"
+	pgtypes "github.com/dolthub/doltgresql/server/types"
+	"github.com/dolthub/doltgresql/utils"
+)
+
+// initRegproc registers the functions to the catalog.
+func initRegproc() {
+	framework.RegisterFunction(regprocin)
+	framework.RegisterFunction(regprocout)
+	framework.RegisterFunction(regprocrecv)
+	framework.RegisterFunction(regprocsend)
+}
+
+// regprocin represents the PostgreSQL function of regproc type IO input.
+var regprocin = framework.Function1{
+	Name:       "regprocin",
+	Return:     pgtypes.Regproc,
+	Parameters: [1]*pgtypes.DoltgresType{pgtypes.Cstring},
+	Strict:     true,
+	Callable: func(ctx *sql.Context, _ [2]*pgtypes.DoltgresType, val any) (any, error) {
+		// If the string just represents a number, then we return it.
+		input := val.(string)
+		if parsedOid, err := strconv.ParseUint(input, 10, 32); err == nil {
+			if internalID := id.Cache().ToInternal(uint32(parsedOid)); internalID.IsValid() {
+				return internalID, nil
+			}
+			return id.NewOID(uint32(parsedOid)).AsId(), nil
+		}
+		sections, err := ioInputSections(input)
+		if err != nil {
+			return id.Null, err
+		}
+		if err = regproc_IoInputValidation(ctx, input, sections); err != nil {
+			return id.Null, err
+		}
+		switch len(sections) {
+		case 1:
+			// TODO: handle procedures, aggregate functions, and window functions
+			// TODO: this only handles built-in functions
+			funcInterfaces := framework.Catalog[sections[0]]
+			if len(funcInterfaces) == 1 {
+				return funcInterfaces[0].InternalID(), nil
+			}
+			return id.Null, errors.Errorf(`"function "%s" does not exist"`, input)
+		default:
+			return id.Null, errors.Errorf("regproc failed validation")
+		}
+	},
+}
+
+// regprocout represents the PostgreSQL function of regproc type IO output.
+var regprocout = framework.Function1{
+	Name:       "regprocout",
+	Return:     pgtypes.Cstring,
+	Parameters: [1]*pgtypes.DoltgresType{pgtypes.Regproc},
+	Strict:     true,
+	Callable: func(ctx *sql.Context, _ [2]*pgtypes.DoltgresType, val any) (any, error) {
+		input := val.(id.Id)
+		if input.Section() == id.Section_OID {
+			return input.Segment(0), nil
+		}
+		return val.(id.Id).Segment(1), nil
+	},
+}
+
+// regprocrecv represents the PostgreSQL function of regproc type IO receive.
+var regprocrecv = framework.Function1{
+	Name:       "regprocrecv",
+	Return:     pgtypes.Regproc,
+	Parameters: [1]*pgtypes.DoltgresType{pgtypes.Internal},
+	Strict:     true,
+	Callable: func(ctx *sql.Context, _ [2]*pgtypes.DoltgresType, val any) (any, error) {
+		data := val.([]byte)
+		if data == nil {
+			return nil, nil
+		}
+		reader := utils.NewWireReader(data)
+		cachedID := id.Cache().ToInternal(reader.ReadUint32())
+		return cachedID, nil
+	},
+}
+
+// regprocsend represents the PostgreSQL function of regproc type IO send.
+var regprocsend = framework.Function1{
+	Name:       "regprocsend",
+	Return:     pgtypes.Bytea,
+	Parameters: [1]*pgtypes.DoltgresType{pgtypes.Regproc},
+	Strict:     true,
+	Callable: func(ctx *sql.Context, _ [2]*pgtypes.DoltgresType, val any) (any, error) {
+		writer := utils.NewWireWriter()
+		writer.WriteUint32(id.Cache().ToOID(val.(id.Id)))
+		return writer.BufferData(), nil
+	},
+}
+
+// regproc_IoInputValidation handles the validation for the parsed sections in regproc_IoInput.
+func regproc_IoInputValidation(ctx *sql.Context, input string, sections []string) error {
+	switch len(sections) {
+	case 1:
+		return nil
+	case 3:
+		if sections[1] != "." {
+			return errors.Errorf("invalid name syntax")
+		}
+		return errors.Errorf("functions are not yet implemented in terms of the schema")
+	case 5:
+		if sections[1] != "." || sections[3] != "." {
+			return errors.Errorf("invalid name syntax")
+		}
+		return errors.Errorf("cross-database references are not implemented: %s", input)
+	case 7:
+		if sections[1] != "." || sections[3] != "." || sections[5] != "." {
+			return errors.Errorf("invalid name syntax")
+		}
+		return errors.Errorf("improper qualified name (too many dotted names): %s", input)
+	default:
+		return errors.Errorf("invalid name syntax")
+	}
+}