refactor: a rusty job

* refactor(jobthread): safe and rusty
* refactor(job): rusty and safe

src/job_thread.rs

@@ -0,0 +1,181 @@
+use std::sync::{Arc, Condvar, Mutex};
+
+use crate::context::Context;
+use crate::dc_configure::*;
+use crate::imap::Imap;
+
+pub struct JobThread {
+    pub name: &'static str,
+    pub folder_config_name: &'static str,
+    pub imap: Imap,
+    pub state: Arc<(Mutex<JobState>, Condvar)>,
+}
+
+#[derive(Clone, Debug, Default)]
+pub struct JobState {
+    idle: bool,
+    jobs_needed: i32,
+    suspended: bool,
+    using_handle: bool,
+}
+
+impl JobThread {
+    pub fn new(name: &'static str, folder_config_name: &'static str, imap: Imap) -> Self {
+        JobThread {
+            name,
+            folder_config_name,
+            imap,
+            state: Arc::new((Mutex::new(Default::default()), Condvar::new())),
+        }
+    }
+
+    pub fn suspend(&self, context: &Context) {
+        info!(context, 0, "Suspending {}-thread.", self.name,);
+        {
+            self.state.0.lock().unwrap().suspended = true;
+        }
+        self.interrupt_idle(context);
+        loop {
+            let using_handle = self.state.0.lock().unwrap().using_handle;
+            if !using_handle {
+                return;
+            }
+            std::thread::sleep(std::time::Duration::from_micros(300 * 1000));
+        }
+    }
+
+    pub fn unsuspend(&self, context: &Context) {
+        info!(context, 0, "Unsuspending {}-thread.", self.name);
+
+        let &(ref lock, ref cvar) = &*self.state.clone();
+        let mut state = lock.lock().unwrap();
+
+        state.suspended = false;
+        state.idle = true;
+        cvar.notify_one();
+    }
+
+    pub fn interrupt_idle(&self, context: &Context) {
+        {
+            self.state.0.lock().unwrap().jobs_needed = 1;
+        }
+
+        info!(context, 0, "Interrupting {}-IDLE...", self.name);
+
+        self.imap.interrupt_idle();
+
+        let &(ref lock, ref cvar) = &*self.state.clone();
+        let mut state = lock.lock().unwrap();
+
+        state.idle = true;
+        cvar.notify_one();
+    }
+
+    pub fn fetch(&mut self, context: &Context, use_network: bool) {
+        {
+            let &(ref lock, _) = &*self.state.clone();
+            let mut state = lock.lock().unwrap();
+
+            if state.suspended {
+                return;
+            }
+
+            state.using_handle = true;
+        }
+
+        if use_network {
+            let start = std::time::Instant::now();
+            if self.connect_to_imap(context) {
+                info!(context, 0, "{}-fetch started...", self.name);
+                self.imap.fetch(context);
+
+                if self.imap.should_reconnect() {
+                    info!(context, 0, "{}-fetch aborted, starting over...", self.name,);
+                    self.imap.fetch(context);
+                }
+                info!(
+                    context,
+                    0,
+                    "{}-fetch done in {:.3} ms.",
+                    self.name,
+                    start.elapsed().as_millis(),
+                );
+            }
+        }
+
+        self.state.0.lock().unwrap().using_handle = false;
+    }
+
+    fn connect_to_imap(&self, context: &Context) -> bool {
+        if self.imap.is_connected() {
+            return true;
+        }
+
+        let mut ret_connected = dc_connect_to_configured_imap(context, &self.imap) != 0;
+
+        if ret_connected {
+            if context
+                .sql
+                .get_config_int(context, "folders_configured")
+                .unwrap_or_default()
+                < 3
+            {
+                self.imap.configure_folders(context, 0x1);
+            }
+
+            if let Some(mvbox_name) = context.sql.get_config(context, self.folder_config_name) {
+                self.imap.set_watch_folder(mvbox_name);
+            } else {
+                self.imap.disconnect(context);
+                ret_connected = false;
+            }
+        }
+
+        ret_connected
+    }
+
+    pub fn idle(&self, context: &Context, use_network: bool) {
+        {
+            let &(ref lock, ref cvar) = &*self.state.clone();
+            let mut state = lock.lock().unwrap();
+
+            if 0 != state.jobs_needed {
+                info!(
+                    context,
+                    0,
+                    "{}-IDLE will not be started as it was interrupted while not ideling.",
+                    self.name,
+                );
+                state.jobs_needed = 0;
+                return;
+            }
+
+            if state.suspended {
+                while !state.idle {
+                    state = cvar.wait(state).unwrap();
+                }
+                state.idle = false;
+                return;
+            }
+
+            state.using_handle = true;
+
+            if !use_network {
+                state.using_handle = false;
+
+                while !state.idle {
+                    state = cvar.wait(state).unwrap();
+                }
+                state.idle = false;
+                return;
+            }
+        }
+
+        self.connect_to_imap(context);
+        info!(context, 0, "{}-IDLE started...", self.name,);
+        self.imap.idle(context);
+        info!(context, 0, "{}-IDLE ended.", self.name);
+
+        self.state.0.lock().unwrap().using_handle = false;
+    }
+}