From 352f7505fcbcb92581124dcfdff4a30e7c274fe4 Mon Sep 17 00:00:00 2001
From: Manos Pitsidianakis <el13635@mail.ntua.gr>
Date: Sun, 13 Sep 2020 00:24:26 +0300
Subject: [PATCH] melib/imap: don't poll \Noselect mailboxes for updates

---
 melib/src/backends/imap/connection.rs | 40 +++++++++++++++++++--------
 melib/src/backends/imap/watch.rs      | 26 +++++++++--------
 2 files changed, 44 insertions(+), 22 deletions(-)

diff --git a/melib/src/backends/imap/connection.rs b/melib/src/backends/imap/connection.rs
index 6a205bef8..5c17a9163 100644
--- a/melib/src/backends/imap/connection.rs
+++ b/melib/src/backends/imap/connection.rs
@@ -781,10 +781,21 @@ impl ImapConnection {
         {
             return Ok(None);
         }
-        let (imap_path, permissions) = {
+        let (imap_path, no_select, permissions) = {
             let m = &self.uid_store.mailboxes.lock().await[&mailbox_hash];
-            (m.imap_path().to_string(), m.permissions.clone())
+            (
+                m.imap_path().to_string(),
+                m.no_select,
+                m.permissions.clone(),
+            )
         };
+        if no_select {
+            return Err(MeliError::new(format!(
+                "Trying to select a \\NoSelect mailbox: {}",
+                &imap_path
+            ))
+            .set_kind(crate::error::ErrorKind::Bug));
+        }
         self.send_command(format!("SELECT \"{}\"", imap_path).as_bytes())
             .await?;
         self.read_response(ret, RequiredResponses::SELECT_REQUIRED)
@@ -856,18 +867,25 @@ impl ImapConnection {
         {
             return Ok(None);
         }
-        self.send_command(
-            format!(
-                "EXAMINE \"{}\"",
-                self.uid_store.mailboxes.lock().await[&mailbox_hash].imap_path()
-            )
-            .as_bytes(),
-        )
-        .await?;
+        let (imap_path, no_select) = {
+            let m = &self.uid_store.mailboxes.lock().await[&mailbox_hash];
+            (m.imap_path().to_string(), m.no_select)
+        };
+        if no_select {
+            return Err(MeliError::new(format!(
+                "Trying to examine a \\NoSelect mailbox: {}",
+                &imap_path
+            ))
+            .set_kind(crate::error::ErrorKind::Bug));
+        }
+        self.send_command(format!("EXAMINE \"{}\"", &imap_path).as_bytes())
+            .await?;
         self.read_response(ret, RequiredResponses::EXAMINE_REQUIRED)
             .await?;
         debug!("examine response {}", ret);
-        let select_response = protocol_parser::select_response(&ret)?;
+        let select_response = protocol_parser::select_response(&ret).chain_err_summary(|| {
+            format!("Could not parse select response for mailbox {}", imap_path)
+        })?;
         self.stream.as_mut()?.current_mailbox = MailboxSelection::Examine(mailbox_hash);
         if !self
             .uid_store
diff --git a/melib/src/backends/imap/watch.rs b/melib/src/backends/imap/watch.rs
index 786b32c70..aaba948ff 100644
--- a/melib/src/backends/imap/watch.rs
+++ b/melib/src/backends/imap/watch.rs
@@ -37,14 +37,16 @@ pub async fn poll_with_examine(kit: ImapWatchKit) -> Result<()> {
         uid_store,
     } = kit;
     conn.connect().await?;
+    let mailboxes: HashMap<MailboxHash, ImapMailbox> = {
+        let mailboxes_lck = timeout(uid_store.timeout, uid_store.mailboxes.lock()).await?;
+        mailboxes_lck.clone()
+    };
     loop {
-        let mailboxes: HashMap<MailboxHash, ImapMailbox> = {
-            let mailboxes_lck = timeout(uid_store.timeout, uid_store.mailboxes.lock()).await?;
-            mailboxes_lck.clone()
-        };
-        for (_, mailbox) in mailboxes {
+        for (_, mailbox) in mailboxes.clone() {
             examine_updates(mailbox, &mut conn, &uid_store).await?;
         }
+        //FIXME: make sleep duration configurable
+        smol::Timer::after(std::time::Duration::from_secs(3 * 60)).await;
     }
 }
 
@@ -105,6 +107,10 @@ pub async fn idle(kit: ImapWatchKit) -> Result<()> {
             uidvalidities.insert(mailbox_hash, select_response.uidvalidity);
         }
     }
+    let mailboxes: HashMap<MailboxHash, ImapMailbox> = {
+        let mailboxes_lck = timeout(uid_store.timeout, uid_store.mailboxes.lock()).await?;
+        mailboxes_lck.clone()
+    };
     conn.send_command(b"IDLE").await?;
     let mut blockn = ImapBlockingConnection::from(conn);
     let mut beat = std::time::Instant::now();
@@ -134,12 +140,7 @@ pub async fn idle(kit: ImapWatchKit) -> Result<()> {
         if now.duration_since(watch) >= _5_MINS {
             /* Time to poll all inboxes */
             let mut conn = timeout(uid_store.timeout, main_conn.lock()).await?;
-            let mailboxes: HashMap<MailboxHash, ImapMailbox> = {
-                let mailboxes_lck =
-                    timeout(uid_store.timeout, uid_store.mailboxes.lock()).await?;
-                mailboxes_lck.clone()
-            };
-            for (h, mailbox) in mailboxes {
+            for (h, mailbox) in mailboxes.clone() {
                 if mailbox_hash == h {
                     continue;
                 }
@@ -193,6 +194,9 @@ pub async fn examine_updates(
     conn: &mut ImapConnection,
     uid_store: &Arc<UIDStore>,
 ) -> Result<()> {
+    if mailbox.no_select {
+        return Ok(());
+    }
     let mailbox_hash = mailbox.hash();
     debug!("examining mailbox {} {}", mailbox_hash, mailbox.path());
     if let Some(new_envelopes) = conn.resync(mailbox_hash).await? {