chore: import upstream snapshot with attribution

core/sequences/serialization.go

@@ -0,0 +1,89 @@
+// 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 sequences
+
+import (
+	"context"
+
+	"github.com/cockroachdb/errors"
+
+	"github.com/dolthub/doltgresql/core/id"
+	"github.com/dolthub/doltgresql/utils"
+)
+
+// Serialize returns the Sequence as a byte slice. If the Sequence is nil, then this returns a nil slice.
+func (sequence *Sequence) Serialize(ctx context.Context) ([]byte, error) {
+	if sequence == nil {
+		return nil, nil
+	}
+
+	// Create the writer
+	writer := utils.NewWriter(256)
+	writer.VariableUint(1) // Version
+	// Write the sequence data
+	writer.Id(sequence.Id.AsId())
+	writer.Id(sequence.DataTypeID.AsId())
+	writer.Uint8(uint8(sequence.Persistence))
+	writer.Int64(sequence.Start)
+	writer.Int64(sequence.Current)
+	writer.Int64(sequence.Increment)
+	writer.Int64(sequence.Minimum)
+	writer.Int64(sequence.Maximum)
+	writer.Int64(sequence.Cache)
+	writer.Bool(sequence.Cycle)
+	writer.Bool(sequence.IsAtEnd)
+	writer.Bool(sequence.HasBeenCalled)
+	writer.Id(sequence.OwnerTable.AsId())
+	writer.String(sequence.OwnerColumn)
+	// Returns the data
+	return writer.Data(), nil
+}
+
+// DeserializeSequence returns the Sequence that was serialized in the byte slice. Returns an empty Sequence if data is
+// nil or empty.
+func DeserializeSequence(_ context.Context, data []byte) (*Sequence, error) {
+	if len(data) == 0 {
+		return nil, nil
+	}
+	reader := utils.NewReader(data)
+	version := reader.VariableUint()
+	if version > 1 {
+		return nil, errors.Errorf("version %d of sequences is not supported, please upgrade the server", version)
+	}
+
+	// Read from the reader
+	sequence := &Sequence{}
+	sequence.Id = id.Sequence(reader.Id())
+	sequence.DataTypeID = id.Type(reader.Id())
+	sequence.Persistence = Persistence(reader.Uint8())
+	sequence.Start = reader.Int64()
+	sequence.Current = reader.Int64()
+	sequence.Increment = reader.Int64()
+	sequence.Minimum = reader.Int64()
+	sequence.Maximum = reader.Int64()
+	sequence.Cache = reader.Int64()
+	sequence.Cycle = reader.Bool()
+	sequence.IsAtEnd = reader.Bool()
+	if version >= 1 {
+		sequence.HasBeenCalled = reader.Bool()
+	}
+	sequence.OwnerTable = id.Table(reader.Id())
+	sequence.OwnerColumn = reader.String()
+	if !reader.IsEmpty() {
+		return nil, errors.Errorf("extra data found while deserializing a sequence")
+	}
+	// Return the deserialized object
+	return sequence, nil
+}