akka.persistence.postgresql.snapshot.PostgreSqlSnapshotStoreDao.scala Maven / Gradle / Ivy

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Reactive Akka Journal, Snapshot Store, and Persistence Query plugin for PostgreSQL
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/*
 * Copyright 2020-2021 Borislav Borisov.
 *
 * 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
 *
 *     https://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 akka.persistence.postgresql.snapshot

import akka.NotUsed
import akka.persistence.SnapshotSelectionCriteria
import akka.persistence.r2dbc.client.R2dbc
import akka.persistence.r2dbc.snapshot.ResultUtils.entryOf
import akka.persistence.r2dbc.snapshot.{SnapshotEntry, SnapshotStoreDao}
import akka.stream.scaladsl.Source
import io.netty.buffer.ByteBufUtil

private[snapshot] object PostgreSqlSnapshotStoreDao {

  // Note, the two criterion - minSeqNr and minTs - do not appear to be used anywhere. But we've
  // added them in case they are used in the future.
  def fetchSnapshotQuery(persistenceId: String, criteria: SnapshotSelectionCriteria): String =
    "SELECT persistence_id, sequence_nr, instant, snapshot FROM snapshot " +
        "WHERE persistence_id = '" + persistenceId + "'" + selectionCriteria(criteria) +
        " ORDER BY sequence_nr DESC LIMIT 1"

  def upsertSnapshotQuery(entry: SnapshotEntry): String = {
    val snapshotHex = "\\x" + ByteBufUtil.hexDump(entry.snapshot)
    "INSERT INTO snapshot (persistence_id, sequence_nr, instant, snapshot) VALUES " +
        s"('${entry.persistenceId}', ${entry.sequenceNr}, ${entry.instant}, '$snapshotHex')" +
        s" ON CONFLICT (persistence_id, sequence_nr) DO UPDATE SET instant = ${entry.instant}, snapshot = '$snapshotHex'"
  }

  def deleteSnapshotQuery(persistenceId: String, seqNr: Long): String =
    "DELETE FROM snapshot WHERE persistence_id = '" + persistenceId + "' " + "AND sequence_nr = " + seqNr

  def deleteSnapshotQuery(persistenceId: String, criteria: SnapshotSelectionCriteria): String =
    "DELETE FROM snapshot WHERE persistence_id = '" + persistenceId + "'" + selectionCriteria(criteria)

  private def selectionCriteria(criteria: SnapshotSelectionCriteria) = {
    var query = ""
    if (criteria.maxSequenceNr != Long.MaxValue) query += " AND sequence_nr <= " + criteria.maxSequenceNr
    if (criteria.maxTimestamp != Long.MaxValue) query += " AND instant <= " + criteria.maxTimestamp
    if (criteria.minSequenceNr != 0L) query += " AND sequence_nr => " + criteria.minSequenceNr
    if (criteria.minTimestamp != 0L) query += " AND instant => " + criteria.minTimestamp
    query
  }

}

private[snapshot] final class PostgreSqlSnapshotStoreDao(val r2dbc: R2dbc) extends SnapshotStoreDao {
  import PostgreSqlSnapshotStoreDao._

  override def fetchSnapshot(persistenceId: String, criteria: SnapshotSelectionCriteria): Source[SnapshotEntry, NotUsed] =
    Source.fromPublisher(r2dbc.withHandle(_.executeQuery(fetchSnapshotQuery(persistenceId, criteria), entryOf)))

  override def save(entry: SnapshotEntry): Source[Int, NotUsed] = Source.fromPublisher(
    r2dbc.withHandle(_.executeQuery(upsertSnapshotQuery(entry), _.getRowsUpdated))
  ).map(_.toInt)

  override def deleteSnapshot(persistenceId: String, seqNr: Long): Source[Int, NotUsed] = Source.fromPublisher(
    r2dbc.withHandle(_.executeQuery(deleteSnapshotQuery(persistenceId, seqNr), _.getRowsUpdated))
  ).map(_.toInt)

  override def deleteSnapshot(persistenceId: String, criteria: SnapshotSelectionCriteria): Source[Int, NotUsed] =
    Source.fromPublisher(r2dbc.withHandle(_.executeQuery(deleteSnapshotQuery(persistenceId, criteria), _.getRowsUpdated)))
        .map(_.toInt)

}