chore: import upstream snapshot with attribution

server/functions/enum.go

@@ -0,0 +1,169 @@
+// 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/core"
+	"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"
+)
+
+// initEnum registers the functions to the catalog.
+func initEnum() {
+	framework.RegisterFunction(enum_in)
+	framework.RegisterFunction(enum_out)
+	framework.RegisterFunction(enum_recv)
+	framework.RegisterFunction(enum_send)
+	framework.RegisterFunction(enum_cmp)
+}
+
+// enum_in represents the PostgreSQL function of enum type IO input.
+var enum_in = framework.Function2{
+	Name:       "enum_in",
+	Return:     pgtypes.AnyEnum,
+	Parameters: [2]*pgtypes.DoltgresType{pgtypes.Cstring, pgtypes.Oid},
+	Strict:     true,
+	Callable: func(ctx *sql.Context, _ [3]*pgtypes.DoltgresType, val1, val2 any) (any, error) {
+		typ, err := getDoltgresTypeFromId(ctx, val2.(id.Id))
+		if err != nil {
+			return nil, err
+		}
+		if typ.TypCategory != pgtypes.TypeCategory_EnumTypes {
+			return nil, errors.Errorf(`"%s" is not an enum type`, typ.Name())
+		}
+
+		value := val1.(string)
+		if _, exists := typ.EnumLabels[value]; !exists {
+			return nil, pgtypes.ErrInvalidInputValueForEnum.New(typ.Name(), value)
+		}
+		// TODO: should return the index instead of label?
+		return value, nil
+	},
+}
+
+// enum_out represents the PostgreSQL function of enum type IO output.
+var enum_out = framework.Function1{
+	Name:       "enum_out",
+	Return:     pgtypes.Cstring,
+	Parameters: [1]*pgtypes.DoltgresType{pgtypes.AnyEnum},
+	Strict:     true,
+	Callable: func(ctx *sql.Context, _ [2]*pgtypes.DoltgresType, val any) (any, error) {
+		// TODO: should receive the index instead of label?
+		return val.(string), nil
+	},
+}
+
+// enum_recv represents the PostgreSQL function of enum type IO receive.
+var enum_recv = framework.Function2{
+	Name:       "enum_recv",
+	Return:     pgtypes.AnyEnum,
+	Parameters: [2]*pgtypes.DoltgresType{pgtypes.Internal, pgtypes.Oid},
+	Strict:     true,
+	Callable: func(ctx *sql.Context, _ [3]*pgtypes.DoltgresType, val1, val2 any) (any, error) {
+		data := val1.([]byte)
+		if data == nil {
+			return nil, nil
+		}
+		return string(data), nil
+	},
+}
+
+// enum_send represents the PostgreSQL function of enum type IO send.
+var enum_send = framework.Function1{
+	Name:       "enum_send",
+	Return:     pgtypes.Bytea,
+	Parameters: [1]*pgtypes.DoltgresType{pgtypes.AnyEnum},
+	Strict:     true,
+	Callable: func(ctx *sql.Context, _ [2]*pgtypes.DoltgresType, val any) (any, error) {
+		if wrapper, ok := val.(sql.AnyWrapper); ok {
+			var err error
+			val, err = wrapper.UnwrapAny(ctx)
+			if err != nil {
+				return nil, err
+			}
+			if val == nil {
+				return nil, nil
+			}
+		}
+		writer := utils.NewWireWriter()
+		writer.WriteString(val.(string))
+		return writer.BufferData(), nil
+	},
+}
+
+// enum_cmp represents the PostgreSQL function of enum type compare.
+var enum_cmp = framework.Function2{
+	Name:       "enum_cmp",
+	Return:     pgtypes.Int32,
+	Parameters: [2]*pgtypes.DoltgresType{pgtypes.AnyEnum, pgtypes.AnyEnum},
+	Strict:     true,
+	Callable: func(ctx *sql.Context, t [3]*pgtypes.DoltgresType, val1, val2 any) (any, error) {
+		ab := val1.(string)
+		bb := val2.(string)
+		enumType := t[0]
+		if enumType.EnumLabels == nil {
+			return nil, errors.Errorf(`enum label lookup failed for type %s`, enumType.Name())
+		}
+		abLabel, ok := enumType.EnumLabels[ab]
+		if !ok {
+			return nil, pgtypes.ErrInvalidInputValueForEnum.New(enumType.Name(), ab)
+		}
+		bbLabel, ok := enumType.EnumLabels[bb]
+		if !ok {
+			return nil, pgtypes.ErrInvalidInputValueForEnum.New(enumType.Name(), bb)
+		}
+		if abLabel.SortOrder == bbLabel.SortOrder {
+			return int32(0), nil
+		} else if abLabel.SortOrder < bbLabel.SortOrder {
+			return int32(-1), nil
+		} else {
+			return int32(1), nil
+		}
+	},
+}
+
+// getDoltgresTypeFromId takes internal ID and returns the DoltgresType associated to it. It allows retrieving a
+// user-defined type, and it requires a valid sql.Context.
+func getDoltgresTypeFromId(ctx *sql.Context, rawId id.Id) (*pgtypes.DoltgresType, error) {
+	typCol, err := core.GetTypesCollectionFromContext(ctx, "")
+	if err != nil {
+		return nil, err
+	}
+	typID := id.Type(rawId)
+
+	schName := typID.SchemaName()
+	if schName == "" {
+		schName, err = core.GetCurrentSchema(ctx)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	typName := typID.TypeName()
+	typ, err := typCol.GetType(ctx, id.NewType(schName, typName))
+	if err != nil {
+		return nil, err
+	}
+	if typ == nil {
+		return nil, pgtypes.ErrTypeDoesNotExist.New(typName)
+	}
+	return typ, nil
+}