postgres_driver: delete partitions in time retention policy (#2679)

waku/waku_archive/driver/postgres_driver/postgres_driver.nim

@@ -741,16 +741,6 @@ method getNewestMessageTimestamp*(
 
   return ok(Timestamp(intRes.get()))
 
-method deleteMessagesOlderThanTimestamp*(
-    s: PostgresDriver, ts: Timestamp
-): Future[ArchiveDriverResult[void]] {.async.} =
-  let execRes =
-    await s.writeConnPool.pgQuery("DELETE FROM messages WHERE storedAt < " & $ts)
-  if execRes.isErr():
-    return err("error in deleteMessagesOlderThanTimestamp: " & execRes.error)
-
-  return ok()
-
 method deleteOldestMessagesNotWithinLimit*(
     s: PostgresDriver, limit: int
 ): Future[ArchiveDriverResult[void]] {.async.} =
@@ -953,6 +943,54 @@ proc getTableSize*(
 
   return ok(tableSize)
 
+proc removePartition(
+    self: PostgresDriver, partitionName: string
+): Future[ArchiveDriverResult[void]] {.async.} =
+  var partSize = ""
+  let partSizeRes = await self.getTableSize(partitionName)
+  if partSizeRes.isOk():
+    partSize = partSizeRes.get()
+
+  ## Detach and remove the partition concurrently to not block the parent table (messages)
+  let detachPartitionQuery =
+    "ALTER TABLE messages DETACH PARTITION " & partitionName & " CONCURRENTLY;"
+  debug "removeOldestPartition", query = detachPartitionQuery
+  (await self.performWriteQuery(detachPartitionQuery)).isOkOr:
+    return err(fmt"error in {detachPartitionQuery}: " & $error)
+
+  ## Drop the partition
+  let dropPartitionQuery = "DROP TABLE " & partitionName
+  debug "removeOldestPartition drop partition", query = dropPartitionQuery
+  (await self.performWriteQuery(dropPartitionQuery)).isOkOr:
+    return err(fmt"error in {dropPartitionQuery}: " & $error)
+
+  debug "removed partition", partition_name = partitionName, partition_size = partSize
+  self.partitionMngr.removeOldestPartitionName()
+
+  return ok()
+
+proc removePartitionsOlderThan(
+    self: PostgresDriver, tsInNanoSec: Timestamp
+): Future[ArchiveDriverResult[void]] {.async.} =
+  ## Removes old partitions that don't contain the specified timestamp
+
+  let tsInSec = Timestamp(float(tsInNanoSec) / 1_000_000_000)
+
+  var oldestPartition = self.partitionMngr.getOldestPartition().valueOr:
+    return err("could not get oldest partition in removePartitionOlderThan: " & $error)
+
+  while not oldestPartition.containsMoment(tsInSec):
+    (await self.removePartition(oldestPartition.getName())).isOkOr:
+      return err("issue in removePartitionsOlderThan: " & $error)
+
+    oldestPartition = self.partitionMngr.getOldestPartition().valueOr:
+      return err(
+        "could not get partition in removePartitionOlderThan in while loop: " & $error
+      )
+
+  ## We reached the partition that contains the target timestamp plus don't want to remove it
+  return ok()
+
 proc removeOldestPartition(
     self: PostgresDriver, forceRemoval: bool = false, ## To allow cleanup in tests
 ): Future[ArchiveDriverResult[void]] {.async.} =
@@ -971,31 +1009,7 @@ proc removeOldestPartition(
         debug "Skipping to remove the current partition"
         return ok()
 
-  var partSize = ""
-  let partSizeRes = await self.getTableSize(oldestPartition.getName())
-  if partSizeRes.isOk():
-    partSize = partSizeRes.get()
-
-  ## In the following lines is where the partition removal happens.
-  ## Detach and remove the partition concurrently to not block the parent table (messages)
-  let detachPartitionQuery =
-    "ALTER TABLE messages DETACH PARTITION " & oldestPartition.getName() &
-    " CONCURRENTLY;"
-  debug "removeOldestPartition", query = detachPartitionQuery
-  (await self.performWriteQuery(detachPartitionQuery)).isOkOr:
-    return err(fmt"error in {detachPartitionQuery}: " & $error)
-
-  ## Drop the partition
-  let dropPartitionQuery = "DROP TABLE " & oldestPartition.getName()
-  debug "removeOldestPartition drop partition", query = dropPartitionQuery
-  (await self.performWriteQuery(dropPartitionQuery)).isOkOr:
-    return err(fmt"error in {dropPartitionQuery}: " & $error)
-
-  debug "removed partition",
-    partition_name = oldestPartition.getName(), partition_size = partSize
-  self.partitionMngr.removeOldestPartitionName()
-
-  return ok()
+  return await self.removePartition(oldestPartition.getName())
 
 proc containsAnyPartition*(self: PostgresDriver): bool =
   return not self.partitionMngr.isEmpty()
@@ -1079,3 +1093,16 @@ proc getCurrentVersion*(
     return err("error in getMessagesCount: " & $error)
 
   return ok(res)
+
+method deleteMessagesOlderThanTimestamp*(
+    s: PostgresDriver, tsNanoSec: Timestamp
+): Future[ArchiveDriverResult[void]] {.async.} =
+  ## First of all, let's remove the older partitions so that we can reduce
+  ## the database size.
+  (await s.removePartitionsOlderThan(tsNanoSec)).isOkOr:
+    return err("error while removing older partitions: " & $error)
+
+  (await s.writeConnPool.pgQuery("DELETE FROM messages WHERE storedAt < " & $tsNanoSec)).isOkOr:
+    return err("error in deleteMessagesOlderThanTimestamp: " & $error)
+
+  return ok()