Rewrote casts as a root object collection

Author: Hydrocharged

core/casts/collection.go

@@ -0,0 +1,133 @@
+// Copyright 2026 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 casts
+
+import (
+	"context"
+
+	"github.com/cockroachdb/errors"
+	"github.com/dolthub/dolt/go/libraries/doltcore/doltdb"
+	"github.com/dolthub/dolt/go/libraries/doltcore/merge"
+	"github.com/dolthub/dolt/go/store/hash"
+	"github.com/dolthub/dolt/go/store/prolly"
+	"github.com/dolthub/dolt/go/store/prolly/tree"
+
+	"github.com/dolthub/doltgresql/core/id"
+	"github.com/dolthub/doltgresql/core/rootobject/objinterface"
+	"github.com/dolthub/doltgresql/flatbuffers/gen/serial"
+)
+
+// storage is used to read from and write to the root.
+var storage = objinterface.RootObjectSerializer{
+	Bytes:        (*serial.RootValue).CastsBytes,
+	RootValueAdd: serial.RootValueAddCasts,
+}
+
+// HandleMerge implements the interface objinterface.Collection.
+func (*Collection) HandleMerge(ctx context.Context, mro merge.MergeRootObject) (doltdb.RootObject, *merge.MergeStats, error) {
+	ourCast := mro.OurRootObj.(Cast)
+	theirCast := mro.TheirRootObj.(Cast)
+	// Ensure that they have the same identifier
+	if ourCast.ID != theirCast.ID {
+		return nil, nil, errors.Newf("attempted to merge different casts: `%s` and `%s`",
+			ourCast.Name().String(), theirCast.Name().String())
+	}
+	ourHash, err := ourCast.HashOf(ctx)
+	if err != nil {
+		return nil, nil, err
+	}
+	theirHash, err := theirCast.HashOf(ctx)
+	if err != nil {
+		return nil, nil, err
+	}
+	if ourHash.Equal(theirHash) {
+		return mro.OurRootObj, &merge.MergeStats{
+			Operation:            merge.TableUnmodified,
+			Adds:                 0,
+			Deletes:              0,
+			Modifications:        0,
+			DataConflicts:        0,
+			SchemaConflicts:      0,
+			ConstraintViolations: 0,
+		}, nil
+	}
+	// TODO: figure out a decent merge strategy
+	return nil, nil, errors.Errorf("unable to merge `%s`", theirCast.Name().String())
+}
+
+// LoadCollection implements the interface objinterface.Collection.
+func (*Collection) LoadCollection(ctx context.Context, root objinterface.RootValue) (objinterface.Collection, error) {
+	return LoadCasts(ctx, root)
+}
+
+// LoadCollectionHash implements the interface objinterface.Collection.
+func (*Collection) LoadCollectionHash(ctx context.Context, root objinterface.RootValue) (hash.Hash, error) {
+	m, ok, err := storage.GetProllyMap(ctx, root)
+	if err != nil || !ok {
+		return hash.Hash{}, err
+	}
+	return m.HashOf(), nil
+}
+
+// LoadCasts loads the casts collection from the given root.
+func LoadCasts(ctx context.Context, root objinterface.RootValue) (*Collection, error) {
+	m, ok, err := storage.GetProllyMap(ctx, root)
+	if err != nil {
+		return nil, err
+	}
+	if !ok {
+		m, err = prolly.NewEmptyAddressMap(root.NodeStore())
+		if err != nil {
+			return nil, err
+		}
+	}
+	return NewCollection(ctx, m, root.NodeStore())
+}
+
+// ResolveNameFromObjects implements the interface objinterface.Collection.
+func (*Collection) ResolveNameFromObjects(ctx context.Context, name doltdb.TableName, rootObjects []objinterface.RootObject) (doltdb.TableName, id.Id, error) {
+	// There are root objects to search through, so we'll create a temporary store
+	ns := tree.NewTestNodeStore()
+	addressMap, err := prolly.NewEmptyAddressMap(ns)
+	if err != nil {
+		return doltdb.TableName{}, id.Null, err
+	}
+	tempCollection, err := NewCollection(ctx, addressMap, ns)
+	if err != nil {
+		return doltdb.TableName{}, id.Null, err
+	}
+	for _, rootObject := range rootObjects {
+		if c, ok := rootObject.(Cast); ok {
+			if err = tempCollection.AddCast(ctx, c); err != nil {
+				return doltdb.TableName{}, id.Null, err
+			}
+		}
+	}
+	return tempCollection.ResolveName(ctx, name)
+}
+
+// Serializer implements the interface objinterface.Collection.
+func (*Collection) Serializer() objinterface.RootObjectSerializer {
+	return storage
+}
+
+// UpdateRoot implements the interface objinterface.Collection.
+func (pgc *Collection) UpdateRoot(ctx context.Context, root objinterface.RootValue) (objinterface.RootValue, error) {
+	m, err := pgc.Map(ctx)
+	if err != nil {
+		return nil, err
+	}
+	return storage.WriteProllyMap(ctx, root, m)
+}

core/casts/collection_funcs.go

@@ -0,0 +1,22 @@
+// 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 casts
+
+import "github.com/dolthub/doltgresql/core/id"
+
+// Init initializes this package.
+func Init() map[id.Cast]Cast {
+	return builtInCasts
+}

core/casts/init.go

@@ -0,0 +1,149 @@
+// Copyright 2026 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 casts
+
+import (
+	"context"
+	"io"
+
+	"github.com/cockroachdb/errors"
+	"github.com/dolthub/dolt/go/libraries/doltcore/doltdb"
+	"github.com/dolthub/dolt/go/store/hash"
+
+	"github.com/dolthub/doltgresql/core/id"
+	"github.com/dolthub/doltgresql/core/rootobject/objinterface"
+	pgtypes "github.com/dolthub/doltgresql/server/types"
+)
+
+// DeserializeRootObject implements the interface objinterface.Collection.
+func (pgc *Collection) DeserializeRootObject(ctx context.Context, data []byte) (objinterface.RootObject, error) {
+	return DeserializeCast(ctx, data)
+}
+
+// DiffRootObjects implements the interface objinterface.Collection.
+func (pgc *Collection) DiffRootObjects(ctx context.Context, fromHash string, ours objinterface.RootObject, theirs objinterface.RootObject, ancestor objinterface.RootObject) ([]objinterface.RootObjectDiff, objinterface.RootObject, error) {
+	return nil, nil, errors.New("cast conflict detection has not yet been implemented")
+}
+
+// DropRootObject implements the interface objinterface.Collection.
+func (pgc *Collection) DropRootObject(ctx context.Context, identifier id.Id) error {
+	if identifier.Section() != id.Section_Cast {
+		return errors.Errorf(`cast %s does not exist`, identifier.String())
+	}
+	return pgc.DropCast(ctx, id.Cast(identifier))
+}
+
+// GetFieldType implements the interface objinterface.Collection.
+func (pgc *Collection) GetFieldType(ctx context.Context, fieldName string) *pgtypes.DoltgresType {
+	return nil
+}
+
+// GetID implements the interface objinterface.Collection.
+func (pgc *Collection) GetID() objinterface.RootObjectID {
+	return objinterface.RootObjectID_Casts
+}
+
+// GetRootObject implements the interface objinterface.Collection.
+func (pgc *Collection) GetRootObject(ctx context.Context, identifier id.Id) (objinterface.RootObject, bool, error) {
+	if identifier.Section() != id.Section_Cast {
+		return nil, false, nil
+	}
+	c, err := pgc.getCast(ctx, id.Cast(identifier), nil, nil, CastType_Explicit)
+	return c, err == nil && c.ID.IsValid(), err
+}
+
+// HasRootObject implements the interface objinterface.Collection.
+func (pgc *Collection) HasRootObject(ctx context.Context, identifier id.Id) (bool, error) {
+	if identifier.Section() != id.Section_Cast {
+		return false, nil
+	}
+	return pgc.HasCast(ctx, id.Cast(identifier)), nil
+}
+
+// IDToTableName implements the interface objinterface.Collection.
+func (pgc *Collection) IDToTableName(identifier id.Id) doltdb.TableName {
+	if identifier.Section() != id.Section_Cast {
+		return doltdb.TableName{}
+	}
+	return CastIDToTableName(id.Cast(identifier))
+}
+
+// IterAll implements the interface objinterface.Collection.
+func (pgc *Collection) IterAll(ctx context.Context, callback func(rootObj objinterface.RootObject) (stop bool, err error)) error {
+	return pgc.IterateCasts(ctx, func(c Cast) (stop bool, err error) {
+		return callback(c)
+	})
+}
+
+// IterIDs implements the interface objinterface.Collection.
+func (pgc *Collection) IterIDs(ctx context.Context, callback func(identifier id.Id) (stop bool, err error)) error {
+	err := pgc.underlyingMap.IterAll(ctx, func(k string, _ hash.Hash) error {
+		stop, err := callback(id.Id(k))
+		if err != nil {
+			return err
+		} else if stop {
+			return io.EOF
+		} else {
+			return nil
+		}
+	})
+	return err
+}
+
+// PutRootObject implements the interface objinterface.Collection.
+func (pgc *Collection) PutRootObject(ctx context.Context, rootObj objinterface.RootObject) error {
+	c, ok := rootObj.(Cast)
+	if !ok {
+		return errors.Newf("invalid cast root object: %T", rootObj)
+	}
+	return pgc.AddCast(ctx, c)
+}
+
+// RenameRootObject implements the interface objinterface.Collection.
+func (pgc *Collection) RenameRootObject(ctx context.Context, oldName id.Id, newName id.Id) error {
+	if !oldName.IsValid() || !newName.IsValid() || oldName.Section() != newName.Section() || oldName.Section() != id.Section_Cast {
+		return errors.New("cannot rename cast due to invalid id")
+	}
+	oldCastName := id.Cast(oldName)
+	newCastName := id.Cast(newName)
+	c, err := pgc.getCast(ctx, oldCastName, nil, nil, CastType_Explicit)
+	if err != nil {
+		return err
+	}
+	if err = pgc.DropCast(ctx, newCastName); err != nil {
+		return err
+	}
+	c.ID = newCastName
+	return pgc.AddCast(ctx, c)
+}
+
+// ResolveName implements the interface objinterface.Collection.
+func (pgc *Collection) ResolveName(ctx context.Context, name doltdb.TableName) (doltdb.TableName, id.Id, error) {
+	rawID, err := pgc.resolveName(ctx, name.Schema, name.Name)
+	if err != nil || !rawID.IsValid() {
+		return doltdb.TableName{}, id.Null, err
+	}
+	return CastIDToTableName(rawID), rawID.AsId(), nil
+}
+
+// TableNameToID implements the interface objinterface.Collection.
+func (pgc *Collection) TableNameToID(name doltdb.TableName) id.Id {
+	return pgc.tableNameToID(name.Schema, name.Name).AsId()
+}
+
+// UpdateField implements the interface objinterface.Collection.
+func (pgc *Collection) UpdateField(ctx context.Context, rootObject objinterface.RootObject, fieldName string, newValue any) (objinterface.RootObject, error) {
+	return nil, errors.New("updating through the conflicts table for this object type is not yet supported")
+}

core/casts/root_object.go

@@ -0,0 +1,67 @@
+// Copyright 2026 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 casts
+
+import (
+	"context"
+
+	"github.com/cockroachdb/errors"
+
+	"github.com/dolthub/doltgresql/core/id"
+	"github.com/dolthub/doltgresql/utils"
+)
+
+// Serialize returns the Cast as a byte slice. If the Cast is invalid, then this returns a nil slice.
+func (cast Cast) Serialize(ctx context.Context) ([]byte, error) {
+	if !cast.ID.IsValid() {
+		return nil, nil
+	}
+
+	// Initialize the writer and version
+	writer := utils.NewWriter(256)
+	writer.VariableUint(0) // Version
+	// Write the cast data
+	writer.Id(cast.ID.AsId())
+	writer.Uint8(uint8(cast.CastType))
+	writer.Id(cast.Function.AsId())
+	writer.Bool(cast.UseInOut)
+	// Returns the data
+	return writer.Data(), nil
+}
+
+// DeserializeCast returns the Cast that was serialized in the byte slice. Returns an empty Cast (invalid ID) if data is
+// nil or empty.
+func DeserializeCast(ctx context.Context, data []byte) (Cast, error) {
+	if len(data) == 0 {
+		return Cast{}, nil
+	}
+	reader := utils.NewReader(data)
+	version := reader.VariableUint()
+	if version != 0 {
+		return Cast{}, errors.Errorf("version %d of casts is not supported, please upgrade the server", version)
+	}
+
+	// Read from the reader
+	t := Cast{}
+	t.ID = id.Cast(reader.Id())
+	t.CastType = CastType(reader.Uint8())
+	t.Function = id.Function(reader.Id())
+	t.UseInOut = reader.Bool()
+	if !reader.IsEmpty() {
+		return Cast{}, errors.Errorf("extra data found while deserializing a cast")
+	}
+	// Return the deserialized object
+	return t, nil
+}