Impl dynamic netgraph display

The netgraph can now dynamically "resize" to always have the maximum
bytes transferred in an interval be the max value.

src/main.rs

@@ -46,6 +46,7 @@ fn main() {
     let mut net_obj: Option<proc::NetInfo> = None;
     let mut net_width: Option<u16> = Some(10);
     let mut net_graph_max: Option<f64> = None;
+    let mut net_graph_is_dynamic: bool = false;
     let mut interval: Duration = Duration::from_secs(5);
     if args_result.map.contains_key("netdev") {
         net_obj = Some(proc::NetInfo::new(
@@ -67,6 +68,9 @@ fn main() {
         }
     }
     if args_result.map.contains_key("netgraph") {
+        if args_result.map.get("netgraph").as_ref().unwrap() == &"dynamic" {
+            net_graph_is_dynamic = true;
+        } else {
             let graph_max_result: Result<f64, _> = args_result.map.get("netgraph").unwrap().parse();
             if let Ok(graph_max) = graph_max_result {
                 net_graph_max = Some(graph_max);
@@ -82,6 +86,7 @@ fn main() {
                     .ok();
             }
         }
+    }
     if args_result.map.contains_key("interval-sec") {
         let seconds: Result<i64, _> = args_result.map.get("interval-sec").unwrap().parse();
         if let Ok(seconds_value) = seconds {
@@ -126,7 +131,7 @@ fn main() {
     let mut array = SwaybarArray::new();
     let set_net_error = |is_empty: bool, array: &mut SwaybarArray, graph_max_opt: &Option<f64>| {
         if is_empty {
-            if graph_max_opt.is_some() {
+            if graph_max_opt.is_some() || net_graph_is_dynamic {
                 array.push_object(SwaybarObject::from_error_string(
                     "net_graph".to_owned(),
                     "net ERROR".into(),
@@ -140,7 +145,7 @@ fn main() {
             let up_obj = SwaybarObject::from_error_string("net_up".to_owned(), "Net ERROR".into());
             array.push_object(up_obj);
         } else {
-            if graph_max_opt.is_some() {
+            if graph_max_opt.is_some() || net_graph_is_dynamic {
                 if let Some(graph_ref) = array.get_by_name_mut("net_graph") {
                     graph_ref.update_as_error("Net ERROR".to_owned());
                 }
@@ -167,7 +172,7 @@ fn main() {
         let netinfo_parts: Vec<&str> = netinfo_string.split_whitespace().collect();
 
         if is_empty {
-            if net_graph_max.is_some() {
+            if net_graph_max.is_some() || net_graph_is_dynamic {
                 let mut graph_obj =
                     SwaybarObject::from_string("net_graph".to_owned(), graph_string);
                 graph_obj.color = Some("#ffff88".into());
@@ -205,7 +210,7 @@ fn main() {
                 array.push_object(up_object);
             }
         } else {
-            if net_graph_max.is_some() {
+            if net_graph_max.is_some() || net_graph_is_dynamic {
                 if let Some(graph_obj) = array.get_by_name_mut("net_graph") {
                     graph_obj.full_text = graph_string;
                 }

src/proc.rs

@@ -59,10 +59,12 @@ impl std::error::Error for Error {
 pub struct NetInfo {
     dev_name: String,
     graph: String,
+    graph_history: [f64; 10],
     down: u64,
     prev_down: u64,
     up: u64,
     prev_up: u64,
+    first_iteration: bool,
 }
 
 impl NetInfo {
@@ -70,10 +72,12 @@ impl NetInfo {
         Self {
             dev_name,
             graph: String::from("          "),
+            graph_history: [0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0],
             down: 0,
             prev_down: 0,
             up: 0,
             prev_up: 0,
+            first_iteration: true,
         }
     }
 
@@ -98,8 +102,13 @@ impl NetInfo {
                 return Err(format!("NetInfo::update: Failed to parse /proc/net/dev, \"{}\" device line is too short", self.dev_name).into());
             }
 
+            if !self.first_iteration {
                 self.down = entries[1].parse()?;
                 self.up = entries[9].parse()?;
+            } else {
+                self.prev_down = entries[1].parse()?;
+                self.prev_up = entries[9].parse()?;
+            }
         } else {
             return Err(format!(
                 "NetInfo::update: Failed to parse /proc/net/dev, can't find net device \"{}\"",
@@ -108,14 +117,26 @@ impl NetInfo {
             .into());
         }
 
+        self.first_iteration = false;
+
         Ok(())
     }
 
-    pub fn get_netstring(&mut self, graph_max: Option<f64>) -> Result<(String, String), Error> {
+    pub fn get_netstring(&mut self, graph_max_opt: Option<f64>) -> Result<(String, String), Error> {
-        let down_diff: f64 = (self.down - self.prev_down) as f64;
+        let down_diff: f64 = if self.down > self.prev_down {
+            let value = (self.down - self.prev_down) as f64;
             self.prev_down = self.down;
-        let up_diff: f64 = (self.up - self.prev_up) as f64;
+            value
+        } else {
+            0.0
+        };
+        let up_diff: f64 = if self.up > self.prev_up {
+            let value = (self.up - self.prev_up) as f64;
             self.prev_up = self.up;
+            value
+        } else {
+            0.0
+        };
 
         let mut output = String::new();
         if down_diff > 1024.0 * 1024.0 {
@@ -134,12 +155,13 @@ impl NetInfo {
             write!(&mut output, "{:.0} B", up_diff)?;
         }
 
-        if let Some(graph_max) = graph_max {
         let diff_max = if down_diff > up_diff {
             down_diff
         } else {
             up_diff
         };
+
+        if let Some(graph_max) = graph_max_opt {
             let graph_value: u8 = if diff_max > graph_max {
                 8
             } else {
@@ -158,6 +180,36 @@ impl NetInfo {
                 7 => self.graph.push('▇'),
                 _ => self.graph.push('█'),
             }
+        } else {
+            self.graph_history.rotate_left(1);
+            self.graph_history[9] = diff_max;
+
+            let mut history_max: f64 = 0.0;
+            for value in &self.graph_history {
+                if history_max < *value {
+                    history_max = *value;
+                }
+            }
+
+            self.graph.clear();
+            if history_max == 0.0 {
+                self.graph = String::from("          ");
+            } else {
+                for value in &self.graph_history {
+                    match (8.0 * value / history_max).round() as u8 {
+                        0 => self.graph.push(' '),
+                        1 => self.graph.push('▁'),
+                        2 => self.graph.push('▂'),
+                        3 => self.graph.push('▃'),
+                        4 => self.graph.push('▄'),
+                        5 => self.graph.push('▅'),
+                        6 => self.graph.push('▆'),
+                        7 => self.graph.push('▇'),
+                        _ => self.graph.push('█'),
+                    }
+                }
+            }
+            assert_eq!(self.graph_history.len(), 10);
         }
 
         Ok((output, self.graph.clone()))