Added mechanism to skip updates in a module

* This is useful in modules where HTTP API calls are made. Updating them
  every second is expensive, network intensive and can cause rate limits
  to be hit
* Added get_name() function to modules for easier debug statements

src/main.rs

@@ -2,6 +2,7 @@ use std::str;
 use std::thread;
 use std::time::Duration;
 use clap::Parser;
+use crate::common::UpdateResult;
 
 // Common utilities/types
 mod common;
@@ -17,7 +18,7 @@ mod bar_modules;
  suitable to use in a status bar")]
 struct CommandlineArgs {
     /// Update interval in seconds
-    #[arg(short = 'i', long, default_value = "5")]
+    #[arg(short = 'i', long, default_value = "1")]
     interval: u64,
 
     /// Name of the weather station
@@ -40,6 +41,11 @@ struct CommandlineArgs {
     /// but before output is printed
     #[arg(short = 'M', long)]
     debug_modules: bool,
+
+    /// Show module debug information after all modules are evaluated
+    /// but before output is printed
+    #[arg(short = 'U', long)]
+    debug_update: bool,
 }
 
 //
@@ -95,8 +101,17 @@ impl Unibar {
             //
             // Following generates ICON+CONTENT string for a module to be displayed
             // in the bar
-            md.clear();
-            md.generate_data();
+            match md.should_update() {
+                UpdateResult::Update => {
+                    md.clear();
+                    md.generate_data();
+                }
+                UpdateResult::Skip => {
+                    if self.opts.debug_update {
+                        println!("Skipping module {}", md.get_name());
+                    }
+                }
+            }
             mod_parts.push(md.get_icon());
             mod_parts.push(md.get_content());
 
@@ -162,6 +177,7 @@ fn main() {
             music_progress: cmd_args.music_progress,
             debug: cmd_args.debug,
             debug_modules: cmd_args.debug_modules,
+            debug_update: cmd_args.debug_update,
         },
         bar_modules_enabled: Vec::new(),
         debug_modules_done: false,