Merge 28eaaa5 into 7ddbcb2

snapshot/src/main/scala/com/evolutiongaming/kafka/journal/SnapshotSelectionCriteria.scala

@@ -0,0 +1,19 @@
+package com.evolutiongaming.kafka.journal
+
+import java.time.Instant
+
+final case class SnapshotSelectionCriteria(
+  maxSeqNr: SeqNr = SeqNr.max,
+  maxTimestamp: Instant = Instant.MAX,
+  minSeqNr: SeqNr = SeqNr.min,
+  minTimestamp: Instant = Instant.MIN
+)
+
+object SnapshotSelectionCriteria {
+
+  val All: SnapshotSelectionCriteria = SnapshotSelectionCriteria()
+
+  def one(seqNr: SeqNr): SnapshotSelectionCriteria =
+    SnapshotSelectionCriteria(maxSeqNr = seqNr, minSeqNr = seqNr)
+
+}

snapshot/src/main/scala/com/evolutiongaming/kafka/journal/SnapshotStoreFlat.scala

@@ -0,0 +1,58 @@
+package com.evolutiongaming.kafka.journal
+
+import com.evolutiongaming.kafka.journal.eventual.EventualPayloadAndType
+
+/** Snapshot storage for Kafka Journal.
+  *
+  * Uses `Key` instead of `persistenceId`, similar to [[ReplicatedJournalFlat]]
+  * and [[EventualJournal]].
+  */
+trait SnapshotStoreFlat[F[_]] {
+
+  /** Save snapshot for a specific key.
+    *
+    * @param key
+    *   Unique identifier of a journal snapshot is done for.
+    * @param snapshot
+    *   Journal snapshot including sequence number and some metadata.
+    */
+  def save(key: Key, snapshot: SnapshotRecord[EventualPayloadAndType]): F[Unit]
+
+  /** Loads a snapshot for a given key and selection criteria.
+    *
+    * If several snapshots are found using a passed selection criteria for a
+    * specific key, then the last one (i.e. with a latest `SeqNr`) is returned.
+    *
+    * @param key
+    *   Unique identifier of a journal snapshot was done for.
+    * @param criteria
+    *   Criteria to use.
+    */
+  def load(key: Key, criteria: SnapshotSelectionCriteria): F[Option[SnapshotRecord[EventualPayloadAndType]]]
+
+  /** Deletes all snapshots for a given key and selection criteria.
+    *
+    * If several snapshots are found using a passed selection criteria for a
+    * specific key, then all of them are deleted.
+    *
+    * @param key
+    *   Unique identifier of a journal snapshot was done for.
+    * @param criteria
+    *   Criteria to use.
+    */
+  def delete(key: Key, criteria: SnapshotSelectionCriteria): F[Unit]
+
+  /** Deletes a snapshot for a given key and sequence number.
+    *
+    * The method returns the same as
+    * `load(key, SnapshotSelectionCriteria.one(seqNr))`,
+    * but additional optimizations might be possible.
+    *
+    * @param key
+    *   Unique identifier of a journal snapshot was done for.
+    * @param seqNr
+    *   Sequence number to be deleted.
+    */
+  def delete(key: Key, seqNr: SeqNr): F[Unit]
+
+}