Move datetime to widgets subdir and import i3monkit network.

src/widgets/mod.rs

@@ -0,0 +1,2 @@
+pub mod datetime;
+pub mod network;

src/widgets/network.rs

@@ -0,0 +1,138 @@
+use i3monkit::Block;
+use i3monkit::{Widget, WidgetUpdate};
+
+use std::path::PathBuf;
+
+use std::fs::File;
+use std::io::{BufRead, BufReader, Error, ErrorKind, Result};
+use std::time::SystemTime;
+
+const NETWORK_PATH_PREFIX: &'static str = "/sys/class/net";
+const NETWORK_STAT_SUFFIX: &'static str = "statistics/dummy";
+
+struct TransferStat {
+    rx: u64,
+    tx: u64,
+    ts: SystemTime,
+}
+
+impl TransferStat {
+    fn read_stat(interface: &str) -> Result<Self> {
+        let mut path = PathBuf::new();
+        path.push(format!(
+            "{}/{}/{}",
+            NETWORK_PATH_PREFIX, interface, NETWORK_STAT_SUFFIX
+        ));
+
+        let mut read_stat_file = move |what: &str| {
+            path.set_file_name(what);
+
+            let reader = BufReader::new(File::open(path.as_path())?);
+
+            if let Some(line) = reader.lines().next() {
+                return line;
+            }
+
+            return Err(Error::new(ErrorKind::Other, "Empty file"));
+        };
+
+        let rx = u64::from_str_radix(&(read_stat_file("rx_bytes")?), 10).unwrap();
+        let tx = u64::from_str_radix(&(read_stat_file("tx_bytes")?), 10).unwrap();
+        let ts = SystemTime::now();
+
+        return Ok(Self { rx, tx, ts });
+    }
+
+    fn duration(&self, earlier: &Self) -> f64 {
+        let duration = self.ts.duration_since(earlier.ts).unwrap();
+        let secs = duration.as_secs() as f64 + duration.subsec_nanos() as f64 / 1_000_000_000.0;
+        return secs;
+    }
+
+    fn rx_rate(&self, earlier: &Self) -> f64 {
+        let duration = self.duration(earlier);
+        if duration < 1e-5 {
+            return std::f64::NAN;
+        }
+
+        return (self.rx - earlier.rx) as f64 / duration;
+    }
+
+    fn tx_rate(&self, earlier: &Self) -> f64 {
+        let duration = self.duration(earlier);
+        if duration < 1e-5 {
+            return std::f64::NAN;
+        }
+
+        return (self.tx - earlier.tx) as f64 / duration;
+    }
+}
+
+/// A widget that shows the network speed realtimely
+pub struct NetworkSpeedWidget {
+    interface: String,
+    last_stat: TransferStat,
+}
+
+impl NetworkSpeedWidget {
+    /// Create the widget, for given interface.
+    ///
+    /// **interface** The interface to monitor
+    pub fn new(interface: &str) -> Self {
+        let last_stat = TransferStat::read_stat(interface).unwrap();
+        let interface = interface.to_string();
+        Self {
+            last_stat,
+            interface,
+        }
+    }
+
+    fn format_rate(rate: f64) -> String {
+        if rate.is_nan() {
+            return "N/A".to_string();
+        }
+
+        const UNIT_NAME: [&'static str; 6] = [" B/s", "KB/s", "MB/s", "GB/s", "TB/s", "PB/s"];
+
+        let mut best_unit = UNIT_NAME[0];
+        let mut best_multiplier = 1.0;
+
+        for unit in UNIT_NAME[1..].iter() {
+            if best_multiplier > rate / 1024.0 {
+                break;
+            }
+            best_unit = unit;
+            best_multiplier *= 1024.0
+        }
+
+        let ret = format!("{:6.1}{}", rate / best_multiplier, best_unit);
+
+        return ret;
+    }
+
+    fn get_human_readable_stat(&mut self) -> Result<(String, String)> {
+        let cur_stat = TransferStat::read_stat(&self.interface)?;
+
+        let rx_rate = cur_stat.rx_rate(&self.last_stat);
+        let tx_rate = cur_stat.tx_rate(&self.last_stat);
+
+        self.last_stat = cur_stat;
+
+        return Ok((Self::format_rate(rx_rate), Self::format_rate(tx_rate)));
+    }
+}
+
+impl Widget for NetworkSpeedWidget {
+    fn update(&mut self) -> Option<WidgetUpdate> {
+        if let Ok((rx, tx)) = self.get_human_readable_stat() {
+            let mut data = Block::new();
+            data.use_pango();
+            data.append_full_text(&format!("Rx:<tt>{}</tt> Tx:<tt>{}</tt>", rx, tx));
+            return Some(WidgetUpdate {
+                refresh_interval: std::time::Duration::new(1, 0),
+                data: Some(data),
+            });
+        }
+        None
+    }
+}