resultify some imap operations

src/configure/mod.rs

@@ -7,6 +7,7 @@ use crate::constants::*;
 use crate::context::Context;
 use crate::dc_tools::*;
 use crate::e2ee;
+use crate::error::*;
 use crate::imap::*;
 use crate::job::*;
 use crate::login_param::LoginParam;
@@ -566,23 +567,23 @@ fn try_smtp_one_param(context: &Context, param: &LoginParam) -> Option<bool> {
 }
 
 /// Connects to the configured account
-pub fn dc_connect_to_configured_imap(context: &Context, imap: &Imap) -> libc::c_int {
+pub fn dc_connect_to_configured_imap(context: &Context, imap: &Imap) -> Result<()> {
-    let mut ret_connected = 0;
-
     if async_std::task::block_on(async move { imap.is_connected().await }) {
-        ret_connected = 1
+        return Ok(());
-    } else if !context.sql.get_raw_config_bool(context, "configured") {
+    }
-        warn!(context, "Not configured, cannot connect.",);
+    if !context.sql.get_raw_config_bool(context, "configured") {
-    } else {
+        return Err(Error::ConnectWithoutConfigure);
+    }
+
     let param = LoginParam::from_database(context, "configured_");
     // the trailing underscore is correct
 
     if imap.connect(context, &param) {
-            ret_connected = 2;
+        return Ok(());
     }
-    }
+    return Err(Error::ImapConnectionFailed(
-
+        format!("{}", param).to_string(),
-    ret_connected
+    ));
 }
 
 /*******************************************************************************

src/error.rs

@@ -34,6 +34,16 @@ pub enum Error {
     BlobError(#[cause] crate::blob::BlobError),
     #[fail(display = "Invalid Message ID.")]
     InvalidMsgId,
+    #[fail(display = "Watch folder not found {:?}", _0)]
+    WatchFolderNotFound(String),
+    #[fail(display = "Connection Failed params: {}", _0)]
+    ImapConnectionFailed(String),
+    #[fail(display = "Cannot idle")]
+    ImapMissesIdle,
+    #[fail(display = "Imap IDLE protocol failed to init/complete")]
+    ImapIdleProtocolFailed(String),
+    #[fail(display = "Connect without configured params")]
+    ConnectWithoutConfigure,
 }
 
 pub type Result<T> = std::result::Result<T, Error>;

src/imap.rs

@@ -34,6 +34,12 @@ pub enum ImapActionResult {
     Success,
 }
 
+#[derive(Debug, Display, Clone, Copy, PartialEq, Eq)]
+pub enum IdlePollMode {
+    Often,
+    Never,
+}
+
 const PREFETCH_FLAGS: &str = "(UID ENVELOPE)";
 const BODY_FLAGS: &str = "(FLAGS BODY.PEEK[])";
 const SELECT_ALL: &str = "1:*";
@@ -746,17 +752,15 @@ impl Imap {
         1
     }
 
-    pub fn idle(&self, context: &Context) {
+    pub fn idle(&self, context: &Context) -> Result<(), Error> {
         task::block_on(async move {
-            if self.config.read().await.selected_folder.is_none() {
+            ensure!(
-                // this probably means that we are in teardown
+                self.config.read().await.selected_folder.is_some(),
-                // in any case we can't perform any idling
+                "no folder selected, probably in teardown?"
-                return;
+            );
-            }
 
             if !self.config.read().await.can_idle {
-                self.fake_idle(context, true).await;
+                return Err(Error::ImapMissesIdle);
-                return;
             }
 
             self.setup_handle_if_needed(context);
@@ -766,13 +770,7 @@ impl Imap {
                 ImapActionResult::Success | ImapActionResult::AlreadyDone => {}
 
                 ImapActionResult::Failed | ImapActionResult::RetryLater => {
-                    warn!(
+                    bail!("IMAP select failed for {:?}", watch_folder.as_ref());
-                        context,
-                        "idle select_folder failed {:?}",
-                        watch_folder.as_ref()
-                    );
-                    self.fake_idle(context, true).await;
-                    return;
                 }
             }
 
@@ -784,9 +782,9 @@ impl Imap {
                     // typically also need to change the Insecure branch.
                     IdleHandle::Secure(mut handle) => {
                         if let Err(err) = handle.init().await {
-                            warn!(context, "Failed to establish IDLE connection: {:?}", err);
+                            bail!("IDLE init failed: {}", err);
-                            return;
                         }
+
                         let (idle_wait, interrupt) = handle.wait_with_timeout(timeout);
                         *self.interrupt.lock().await = Some(interrupt);
 
@@ -810,18 +808,15 @@ impl Imap {
                                 // means that we waited long (with idle_wait)
                                 // but the network went away/changed
                                 self.trigger_reconnect();
-                                warn!(
+                                return Err(Error::ImapIdleProtocolFailed(format!("{}", err)));
-                                    context,
-                                    "Failed to terminate IMAP IDLE connection: {:?}", err
-                                );
                             }
                         }
                     }
                     IdleHandle::Insecure(mut handle) => {
                         if let Err(err) = handle.init().await {
-                            warn!(context, "Failed to establish IDLE connection: {:?}", err);
+                            bail!("IDLE init failed: {}", err);
-                            return;
                         }
+
                         let (idle_wait, interrupt) = handle.wait_with_timeout(timeout);
                         *self.interrupt.lock().await = Some(interrupt);
 
@@ -836,7 +831,6 @@ impl Imap {
                             let res = idle_wait.await;
                             info!(context, "Idle finished wait-on-remote: {:?}", res);
                         }
-
                         match handle.done().await {
                             Ok(session) => {
                                 *self.session.lock().await = Some(Session::Insecure(session));
@@ -846,23 +840,24 @@ impl Imap {
                                 // means that we waited long (with idle_wait)
                                 // but the network went away/changed
                                 self.trigger_reconnect();
-                                warn!(context, "Failed to close IMAP IDLE connection: {:?}", err);
+                                return Err(Error::ImapIdleProtocolFailed(format!("{}", err)));
                             }
                         }
                     }
                 }
             }
-        });
-    }
 
-    pub(crate) async fn fake_idle(&self, context: &Context, use_network: bool) {
+            Ok(())
-        // Idle using timeouts. This is also needed if we're not yet configured -
+        })
-        // in this case, we're waiting for a configure job
+    }
+
+    pub(crate) fn fake_idle(&self, context: &Context, poll_mode: IdlePollMode) {
+        // Idle using polling.
+        task::block_on(async move {
             let fake_idle_start_time = SystemTime::now();
 
             info!(context, "IMAP-fake-IDLEing...");
 
-        task::block_on(async move {
             let interrupt = stop_token::StopSource::new();
 
             // we use 1000 minutes if we are told to not try network
@@ -870,21 +865,29 @@ impl Imap {
             // but clients are still calling us in a loop.
             // if we are to use network, we check every minute if there
             // is new mail -- TODO: make this more flexible
-            let secs = if use_network { 60 } else { 60000 };
+            let secs = match poll_mode {
+                IdlePollMode::Never => 60000,
+                IdlePollMode::Often => 60,
+            };
             let interval = async_std::stream::interval(Duration::from_secs(secs));
             let mut interrupt_interval = interrupt.stop_token().stop_stream(interval);
             *self.interrupt.lock().await = Some(interrupt);
 
+            // loop until we are interrupted or if we fetched something
             while let Some(_) = interrupt_interval.next().await {
-                if !use_network {
+                if poll_mode == IdlePollMode::Never {
                     continue;
                 }
                 if !self.is_connected().await {
                     // try to connect with proper login params
                     // (setup_handle_if_needed might not know about them if we
                     // never successfully connected)
-                    if dc_connect_to_configured_imap(context, &self) != 0 {
+                    match dc_connect_to_configured_imap(context, &self) {
-                        self.interrupt.lock().await.take();
+                        Ok(()) => {}
+                        Err(err) => {
+                            warn!(context, "fake_idle: could not connect: {}", err);
+                            continue;
+                        }
                     }
                 }
                 // we are connected, let's see if fetching messages results
@@ -895,12 +898,11 @@ impl Imap {
                 let watch_folder = self.config.read().await.watch_folder.clone();
                 if let Some(watch_folder) = watch_folder {
                     if 0 != self.fetch_from_single_folder(context, watch_folder).await {
-                        self.interrupt.lock().await.take();
                         break;
                     }
                 }
             }
-        });
+            self.interrupt.lock().await.take();
 
             info!(
                 context,
@@ -911,6 +913,7 @@ impl Imap {
                     .as_millis() as f64
                     / 1000.,
             );
+        })
     }
 
     pub fn interrupt_idle(&self) {
@@ -1052,8 +1055,8 @@ impl Imap {
             if uid == 0 {
                 return Some(ImapActionResult::Failed);
             } else if !self.is_connected().await {
-                connect_to_inbox(context, &self);
+                if let Err(err) = connect_to_inbox(context, &self) {
-                if !self.is_connected().await {
+                    warn!(context, "prepare_imap_op failed: {}", err);
                     return Some(ImapActionResult::RetryLater);
                 }
             }

src/job.rs

@@ -367,14 +367,15 @@ pub fn job_kill_action(context: &Context, action: Action) -> bool {
 }
 
 pub fn perform_imap_fetch(context: &Context) {
+    if !context.get_config_bool(Config::InboxWatch) {
+        info!(context, "INBOX-fetch skipped: INBOX-watch is disabled.");
+        return;
+    }
     let inbox = context.inbox.read().unwrap();
     let start = std::time::Instant::now();
 
-    if 0 == connect_to_inbox(context, &inbox) {
+    if let Err(err) = connect_to_inbox(context, &inbox) {
-        return;
+        warn!(context, "could not connect to inbox: {:?}", err);
-    }
-    if !context.get_config_bool(Config::InboxWatch) {
-        info!(context, "INBOX-watch disabled.",);
         return;
     }
     info!(context, "INBOX-fetch started...",);
@@ -391,10 +392,6 @@ pub fn perform_imap_fetch(context: &Context) {
 }
 
 pub fn perform_imap_idle(context: &Context) {
-    let inbox = context.inbox.read().unwrap();
-
-    connect_to_inbox(context, &inbox);
-
     if *context.perform_inbox_jobs_needed.clone().read().unwrap() {
         info!(
             context,
@@ -402,9 +399,48 @@ pub fn perform_imap_idle(context: &Context) {
         );
         return;
     }
-    info!(context, "INBOX-IDLE started...");
+    let inbox = context.inbox.read().unwrap();
-    inbox.idle(context);
+    let poll_mode = if !context.get_config_bool(Config::InboxWatch) {
+        Some(IdlePollMode::Never)
+    } else {
+        match connect_to_inbox(context, &inbox) {
+            Err(Error::ImapConnectionFailed(param)) => {
+                warn!(context, "perform_imap_idle could not connect {:?}", param);
+                Some(IdlePollMode::Often)
+            }
+            Err(err) => {
+                warn!(context, "perform_imap_idle error: {}", err);
+                // anything else than a plain connection error
+                // hints at configuration issues.
+                Some(IdlePollMode::Never)
+            }
+
+            Ok(()) => {
+                info!(context, "INBOX-IDLE starting...");
+                let res = inbox.idle(context);
                 info!(context, "INBOX-IDLE ended.");
+
+                match res {
+                    Ok(()) => None,
+                    Err(Error::ImapConnectionFailed(param)) => {
+                        warn!(
+                            context,
+                            "perform_imap_idle IDLE could not connect {:?}", param
+                        );
+                        Some(IdlePollMode::Often)
+                    }
+                    Err(err) => {
+                        warn!(context, "perform_imap_idle IDLE error: {}", err);
+                        Some(IdlePollMode::Never)
+                    }
+                }
+            }
+        }
+    };
+
+    if let Some(poll_mode) = poll_mode {
+        inbox.fake_idle(context, poll_mode);
+    }
 }
 
 pub fn perform_mvbox_fetch(context: &Context) {
@@ -724,7 +760,9 @@ fn job_perform(context: &Context, thread: Thread, probe_network: bool) {
         params_probe
     };
 
-    let jobs: Result<Vec<Job>, _> = context.sql.query_map(
+    let jobs: Result<Vec<Job>, _> = context
+        .sql
+        .query_map(
             query,
             params,
             |row| {
@@ -743,13 +781,10 @@ fn job_perform(context: &Context, thread: Thread, probe_network: bool) {
                 Ok(job)
             },
             |jobs| jobs.collect::<Result<Vec<Job>, _>>().map_err(Into::into),
-    );
+        )
-    match jobs {
+        .map_err(|err| {
-        Ok(ref _res) => {}
+            warn!(context, "query failed: {:?}", err);
-        Err(ref err) => {
+        });
-            info!(context, "query failed: {:?}", err);
-        }
-    }
 
     for mut job in jobs.unwrap_or_default() {
         info!(
@@ -928,12 +963,10 @@ fn suspend_smtp_thread(context: &Context, suspend: bool) {
     }
 }
 
-pub fn connect_to_inbox(context: &Context, inbox: &Imap) -> libc::c_int {
+pub fn connect_to_inbox(context: &Context, imap: &Imap) -> Result<(), Error> {
-    let ret_connected = dc_connect_to_configured_imap(context, inbox);
+    dc_connect_to_configured_imap(context, imap)?;
-    if 0 != ret_connected {
+    imap.set_watch_folder("INBOX".into());
-        inbox.set_watch_folder("INBOX".into());
+    Ok(())
-    }
-    ret_connected
 }
 
 fn send_mdn(context: &Context, msg_id: MsgId) -> Result<(), Error> {

src/job_thread.rs

@@ -2,7 +2,8 @@ use std::sync::{Arc, Condvar, Mutex};
 
 use crate::configure::*;
 use crate::context::Context;
-use crate::imap::Imap;
+use crate::error::Error;
+use crate::imap::{IdlePollMode, Imap};
 
 #[derive(Debug)]
 pub struct JobThread {
@@ -86,39 +87,49 @@ impl JobThread {
 
         if use_network {
             let start = std::time::Instant::now();
-            if self.connect_to_imap(context) {
+            let prefix = format!("{}-fetch", self.name);
-                info!(context, "{}-fetch started...", self.name);
+            match self.connect_to_imap(context) {
+                Ok(()) => {
+                    info!(context, "{} started...", prefix);
                     self.imap.fetch(context);
 
                     if self.imap.should_reconnect() {
-                    info!(context, "{}-fetch aborted, starting over...", self.name,);
+                        info!(context, "{} aborted, starting over...", prefix);
                         self.imap.fetch(context);
                     }
                     info!(
                         context,
-                    "{}-fetch done in {:.3} ms.",
+                        "{} done in {:.3} ms.",
-                    self.name,
+                        prefix,
                         start.elapsed().as_millis(),
                     );
                 }
+                Err(err) => {
+                    warn!(
+                        context,
+                        "{} skipped, could not connect to imap {:?}", prefix, err
+                    );
+                }
+            }
         }
 
         self.state.0.lock().unwrap().using_handle = false;
     }
 
-    fn connect_to_imap(&self, context: &Context) -> bool {
+    fn connect_to_imap(&self, context: &Context) -> Result<(), Error> {
         if async_std::task::block_on(async move { self.imap.is_connected().await }) {
-            return true;
+            return Ok(());
         }
         let watch_folder_name = match context.sql.get_raw_config(context, self.folder_config_name) {
             Some(name) => name,
             None => {
-                return false;
+                return Err(Error::WatchFolderNotFound(
+                    self.folder_config_name.to_string(),
+                ));
             }
         };
 
-        let ret_connected = dc_connect_to_configured_imap(context, &self.imap) != 0;
+        dc_connect_to_configured_imap(context, &self.imap)?;
-        if ret_connected {
         if context
             .sql
             .get_raw_config_int(context, "folders_configured")
@@ -127,11 +138,9 @@ impl JobThread {
         {
             self.imap.configure_folders(context, 0x1);
         }
-
         self.imap.set_watch_folder(watch_folder_name);
-        }
 
-        ret_connected
+        Ok(())
     }
 
     pub fn idle(&self, context: &Context, use_network: bool) {
@@ -170,17 +179,30 @@ impl JobThread {
             }
         }
 
-        if self.connect_to_imap(context) {
+        let poll_mode = match self.connect_to_imap(context) {
+            Ok(()) => {
                 info!(context, "{}-IDLE started...", self.name,);
-            self.imap.idle(context);
+                let res = self.imap.idle(context);
                 info!(context, "{}-IDLE ended.", self.name);
-        } else {
+                match res {
-            // It's probably wrong that the thread even runs
+                    Ok(()) => None,
-            // but let's call fake_idle and tell it to not try network at all.
+                    Err(Error::ImapConnectionFailed(err)) => {
-            // (once we move to rust-managed threads this problem goes away)
+                        warn!(context, "idle connection failed: {}", err);
-            info!(context, "{}-IDLE not connected, fake-idling", self.name);
+                        Some(IdlePollMode::Often)
-            async_std::task::block_on(async move { self.imap.fake_idle(context, false).await });
+                    }
-            info!(context, "{}-IDLE fake-idling finished", self.name);
+                    Err(err) => {
+                        warn!(context, "idle failed: {}", err);
+                        Some(IdlePollMode::Never)
+                    }
+                }
+            }
+            Err(err) => {
+                info!(context, "{}-IDLE fail: {:?}", self.name, err);
+                Some(IdlePollMode::Never)
+            }
+        };
+        if let Some(poll_mode) = poll_mode {
+            self.imap.fake_idle(context, poll_mode);
         }
 
         self.state.0.lock().unwrap().using_handle = false;