matrix-org.dendrite/src/github.com/matrix-org/dendrite/common/partition_offset_table.go

84 lines
2.8 KiB
Go

// Copyright 2017 Vector Creations Ltd
//
// 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 common
import "database/sql"
const partitionOffsetsSchema = `
-- The offsets that the server has processed up to.
CREATE TABLE IF NOT EXISTS partition_offsets (
-- The name of the topic.
topic TEXT NOT NULL,
-- The 32-bit partition ID
partition INTEGER NOT NULL,
-- The 64-bit offset.
partition_offset BIGINT NOT NULL,
CONSTRAINT topic_partition_unique UNIQUE (topic, partition)
);
`
const selectPartitionOffsetsSQL = "" +
"SELECT partition, partition_offset FROM partition_offsets WHERE topic = $1"
const upsertPartitionOffsetsSQL = "" +
"INSERT INTO partition_offsets (topic, partition, partition_offset) VALUES ($1, $2, $3)" +
" ON CONFLICT ON CONSTRAINT topic_partition_unique" +
" DO UPDATE SET partition_offset = $3"
// PartitionOffsetStatements represents a set of statements that can be run on a partition_offsets table.
type PartitionOffsetStatements struct {
selectPartitionOffsetsStmt *sql.Stmt
upsertPartitionOffsetStmt *sql.Stmt
}
// Prepare converts the raw SQL statements into prepared statements.
func (s *PartitionOffsetStatements) Prepare(db *sql.DB) (err error) {
_, err = db.Exec(partitionOffsetsSchema)
if err != nil {
return
}
if s.selectPartitionOffsetsStmt, err = db.Prepare(selectPartitionOffsetsSQL); err != nil {
return
}
if s.upsertPartitionOffsetStmt, err = db.Prepare(upsertPartitionOffsetsSQL); err != nil {
return
}
return
}
// SelectPartitionOffsets returns all the partition offsets for the given topic.
func (s *PartitionOffsetStatements) SelectPartitionOffsets(topic string) ([]PartitionOffset, error) {
rows, err := s.selectPartitionOffsetsStmt.Query(topic)
if err != nil {
return nil, err
}
defer rows.Close()
var results []PartitionOffset
for rows.Next() {
var offset PartitionOffset
if err := rows.Scan(&offset.Partition, &offset.Offset); err != nil {
return nil, err
}
results = append(results, offset)
}
return results, nil
}
// UpsertPartitionOffset updates or inserts the partition offset for the given topic.
func (s *PartitionOffsetStatements) UpsertPartitionOffset(topic string, partition int32, offset int64) error {
_, err := s.upsertPartitionOffsetStmt.Exec(topic, partition, offset)
return err
}