From ba4fcd072a2b071b629ea34eb565e947e04701e1 Mon Sep 17 00:00:00 2001
From: Greg Heartsfield <scsibug@imap.cc>
Date: Wed, 1 Feb 2023 18:09:30 -0600
Subject: [PATCH] improvement: allow queries to be cancelled earlier (before
 SQL execution)

---
 src/repo/sqlite.rs | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/repo/sqlite.rs b/src/repo/sqlite.rs
index 6519abe..83c3ace 100644
--- a/src/repo/sqlite.rs
+++ b/src/repo/sqlite.rs
@@ -344,6 +344,12 @@ impl NostrRepo for SqliteRepo {
                     db_queue_time, client_id, sub.id
                 );
             }
+            // check before getting a DB connection if the client still wants the results
+            if abandon_query_rx.try_recv().is_ok() {
+                debug!("query cancelled by client (before execution) (cid: {}, sub: {:?})", client_id, sub.id);
+                return Ok(());
+            }
+
             let start = Instant::now();
             let mut row_count: usize = 0;
             // cutoff for displaying slow queries