Deduplicate peerstates during housekeeping

src/peerstate.rs

@@ -496,6 +496,30 @@ impl Peerstate {
     }
 }
 
+/// Removes duplicate peerstates from `acpeerstates` database table.
+///
+/// Normally there should be no more than one peerstate per address.
+/// However, the database does not enforce this condition.
+///
+/// Previously there were bugs that caused creation of additional
+/// peerstates when existing peerstate could not be read due to a
+/// temporary database error or a failure to parse stored data.  This
+/// procedure fixes the problem by removing duplicate records.
+pub(crate) async fn deduplicate_peerstates(sql: &Sql) -> Result<()> {
+    sql.execute(
+        "DELETE FROM acpeerstates
+         WHERE id NOT IN (
+         SELECT MIN(id)
+         FROM acpeerstates
+         GROUP BY addr
+         )",
+        paramsv![],
+    )
+    .await?;
+
+    Ok(())
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

src/sql.rs

@@ -20,7 +20,7 @@ use crate::dc_tools::{dc_delete_file, time};
 use crate::ephemeral::start_ephemeral_timers;
 use crate::message::Message;
 use crate::param::{Param, Params};
-use crate::peerstate::Peerstate;
+use crate::peerstate::{deduplicate_peerstates, Peerstate};
 use crate::stock_str;
 
 #[macro_export]
@@ -598,6 +598,10 @@ pub async fn housekeeping(context: &Context) -> Result<()> {
         );
     }
 
+    if let Err(err) = deduplicate_peerstates(&context.sql).await {
+        warn!(context, "Failed to deduplicate peerstates: {}", err)
+    }
+
     context.schedule_quota_update().await?;
 
     if let Err(e) = context