Reduce amount of blocking in blocks

Replaced `exists` with `try_exists`

src/blocks/amd_gpu.rs

@@ -63,7 +63,7 @@ pub async fn run(config: &Config, api: &CommonApi) -> Result<()> {
     };
 
     let device = match &config.device {
-        Some(name) => Device::new(name)?,
+        Some(name) => Device::new(name).await?,
         None => Device::default_card()
             .await
             .error("failed to get default GPU")?
@@ -121,10 +121,13 @@ struct GpuInfo {
 }
 
 impl Device {
-    fn new(name: &str) -> Result<Self, Error> {
+    async fn new(name: &str) -> Result<Self, Error> {
         let path = PathBuf::from(format!("/sys/class/drm/{name}/device"));
 
-        if !path.exists() {
+        if !tokio::fs::try_exists(&path)
+            .await
+            .error("Unable to stat file")?
+        {
             Err(Error::new(format!("Device {name} not found")))
         } else {
             Ok(Self { path })
@@ -185,9 +188,9 @@ impl Device {
 mod tests {
     use super::*;
 
-    #[test]
-    fn test_non_existing_gpu_device() {
-        let device = Device::new("/nope");
+    #[tokio::test]
+    async fn test_non_existing_gpu_device() {
+        let device = Device::new("/nope").await;
         assert!(device.is_err());
     }
 }

src/blocks/calendar.rs

@@ -295,7 +295,7 @@ pub async fn run(config: &Config, api: &CommonApi) -> Result<()> {
     let warning_threshold = Duration::try_seconds(config.warning_threshold.into())
         .error("Invalid warning threshold configuration")?;
 
-    let mut source = Source::new(source_config.clone()).await?;
+    let mut source = Source::new(source_config.to_owned()).await?;
 
     let mut timer = config.fetch_interval.timer();
 
@@ -424,7 +424,8 @@ impl Source {
                 credentials_path,
             }) => {
                 let credentials = if let Some(path) = credentials_path {
-                    util::deserialize_toml_file(path.expand()?.to_string())
+                    util::async_deserialize_toml_file(path.expand()?.to_string())
+                        .await
                         .error("Failed to read basic credentials file")?
                 } else {
                     credentials.clone()
@@ -440,7 +441,8 @@ impl Source {
             }
             AuthConfig::OAuth2(oauth2) => {
                 let credentials = if let Some(path) = &oauth2.credentials_path {
-                    util::deserialize_toml_file(path.expand()?.to_string())
+                    util::async_deserialize_toml_file(path.expand()?.to_string())
+                        .await
                         .error("Failed to read oauth2 credentials file")?
                 } else {
                     oauth2.credentials.clone()

src/blocks/packages/apt.rs

@@ -50,7 +50,10 @@ impl Apt {
     async fn setup(&mut self) -> Result<()> {
         let mut cache_dir = env::temp_dir();
         cache_dir.push("i3rs-apt");
-        if !cache_dir.exists() {
+        if !tokio::fs::try_exists(&cache_dir)
+            .await
+            .error("Unable to stat file")?
+        {
             create_dir_all(&cache_dir)
                 .await
                 .error("Failed to create temp dir")?;

src/blocks/packages/pacman.rs

@@ -72,7 +72,10 @@ impl Backend for Pacman {
 
         // Create symlink to local cache in `checkup-db` if required
         let local_cache = PACMAN_UPDATES_DB.join("local");
-        if !local_cache.exists() {
+        if !tokio::fs::try_exists(&local_cache)
+            .await
+            .error("Unable to stat file")?
+        {
             symlink(PACMAN_DB.join("local"), local_cache)
                 .await
                 .error("Failed to created required symlink")?;

src/icons.rs

@@ -121,7 +121,7 @@ impl Icons {
         if file == "none" {
             Ok(Icons::default())
         } else {
-            let file = util::find_file(file, Some("icons"), Some("toml"))
+            let file = util::find_file(file, Some("icons"), Some("toml"))?
                 .or_error(|| format!("Icon set '{file}' not found"))?;
             Ok(Icons(util::deserialize_toml_file(file)?))
         }

src/main.rs

@@ -31,7 +31,7 @@ fn main() {
         .build()
         .unwrap()
         .block_on(async move {
-            let config_path = util::find_file(&args.config, None, Some("toml"))
+            let config_path = util::find_file(&args.config, None, Some("toml"))?
                 .or_error(|| format!("Configuration file '{}' not found", args.config))?;
             let mut config: Config = util::deserialize_toml_file(&config_path)?;
             let blocks = std::mem::take(&mut config.blocks);

src/netlink.rs

@@ -77,7 +77,9 @@ impl NetDevice {
         let path = Path::new("/sys/class/net").join(&iface.name);
         let tun = iface.name.starts_with("tun")
             || iface.name.starts_with("tap")
-            || path.join("tun_flags").exists();
+            || tokio::fs::try_exists(path.join("tun_flags"))
+                .await
+                .error("Unable to stat file")?;
         let (wg, ppp) = util::read_file(path.join("uevent"))
             .await
             .map_or((false, false), |c| {

src/themes.rs

@@ -140,7 +140,7 @@ impl TryFrom<ThemeUserConfig> for Theme {
 
     fn try_from(user_config: ThemeUserConfig) -> Result<Self, Self::Error> {
         let name = user_config.theme.as_deref().unwrap_or("plain");
-        let file = util::find_file(name, Some("themes"), Some("toml"))
+        let file = util::find_file(name, Some("themes"), Some("toml"))?
             .or_error(|| format!("Theme '{name}' not found"))?;
         let theme: ThemeInner = util::deserialize_toml_file(file)?;
         let mut theme = Theme(theme);

src/util.rs

@@ -14,11 +14,15 @@ use crate::errors::*;
 /// - Then try `/usr/share/`
 ///
 /// Automatically append an extension if not presented.
-pub fn find_file(file: &str, subdir: Option<&str>, extension: Option<&str>) -> Option<PathBuf> {
+pub fn find_file(
+    file: &str,
+    subdir: Option<&str>,
+    extension: Option<&str>,
+) -> Result<Option<PathBuf>> {
     let file = Path::new(file);
 
-    if file.is_absolute() && file.exists() {
-        return Some(file.to_path_buf());
+    if file.is_absolute() && file.try_exists().error("Unable to stat file")? {
+        return Ok(Some(file.to_path_buf()));
     }
 
     // Try XDG_CONFIG_HOME (e.g. `~/.config`)
@@ -28,8 +32,8 @@ pub fn find_file(file: &str, subdir: Option<&str>, extension: Option<&str>) -> O
             xdg_config.push(subdir);
         }
         xdg_config.push(file);
-        if let Some(file) = exists_with_opt_extension(&xdg_config, extension) {
-            return Some(file);
+        if let Some(file) = exists_with_opt_extension(&xdg_config, extension)? {
+            return Ok(Some(file));
         }
     }
 
@@ -40,8 +44,8 @@ pub fn find_file(file: &str, subdir: Option<&str>, extension: Option<&str>) -> O
             xdg_data.push(subdir);
         }
         xdg_data.push(file);
-        if let Some(file) = exists_with_opt_extension(&xdg_data, extension) {
-            return Some(file);
+        if let Some(file) = exists_with_opt_extension(&xdg_data, extension)? {
+            return Ok(Some(file));
         }
     }
 
@@ -51,26 +55,26 @@ pub fn find_file(file: &str, subdir: Option<&str>, extension: Option<&str>) -> O
         usr_share_path.push(subdir);
     }
     usr_share_path.push(file);
-    if let Some(file) = exists_with_opt_extension(&usr_share_path, extension) {
-        return Some(file);
+    if let Some(file) = exists_with_opt_extension(&usr_share_path, extension)? {
+        return Ok(Some(file));
     }
 
-    None
+    Ok(None)
 }
 
-fn exists_with_opt_extension(file: &Path, extension: Option<&str>) -> Option<PathBuf> {
-    if file.exists() {
-        return Some(file.into());
+fn exists_with_opt_extension(file: &Path, extension: Option<&str>) -> Result<Option<PathBuf>> {
+    if file.try_exists().error("Unable to stat file")? {
+        return Ok(Some(file.into()));
     }
     // If file has no extension, test with given extension
     if let (None, Some(extension)) = (file.extension(), extension) {
         let file = file.with_extension(extension);
         // Check again with extension added
-        if file.exists() {
-            return Some(file);
+        if file.try_exists().error("Unable to stat file")? {
+            return Ok(Some(file));
         }
     }
-    None
+    Ok(None)
 }
 
 pub async fn new_dbus_connection() -> Result<zbus::Connection> {
@@ -95,6 +99,27 @@ where
     let contents = std::fs::read_to_string(path)
         .or_error(|| format!("Failed to read file: {}", path.display()))?;
 
+    deserialize_toml_file_string(contents, path)
+}
+
+pub async fn async_deserialize_toml_file<T, P>(path: P) -> Result<T>
+where
+    T: DeserializeOwned,
+    P: AsRef<Path>,
+{
+    let path = path.as_ref();
+
+    let contents = read_file(path)
+        .await
+        .or_error(|| format!("Failed to read file: {}", path.display()))?;
+
+    deserialize_toml_file_string(contents, path)
+}
+
+fn deserialize_toml_file_string<T>(contents: String, path: &Path) -> Result<T>
+where
+    T: DeserializeOwned,
+{
     toml::from_str(&contents).map_err(|err| {
         let location_msg = err
             .span()