Ensure CPU frequency gets dynamically updated

- Fix state refresh logic for sysinfo system
- Let each module refresh happen when needed. This requires mutable
  System instance to be passed around though.

src/cpu.rs

@@ -18,17 +18,19 @@ this program.  If not, see <https://www.gnu.org/licenses/>.
 use super::colors::colorize;
 use super::config::Config;
 use colored::*;
-use sysinfo::{CpuExt, System, SystemExt};
+use sysinfo::{CpuExt, CpuRefreshKind, System, SystemExt};
+
+pub fn overview(config: &Config, system: &mut System) -> String {
+    system.refresh_cpu_specifics(CpuRefreshKind::everything());
 
-pub fn overview(config: &Config, system: &System) -> String {
     if config.frequency {
         format!("{} {}", usage(config, system), frequency(system))
     } else {
         usage(config, system)
     }
 }
 
-fn usage(config: &Config, system: &System) -> String {
+fn usage(config: &Config, system: &mut System) -> String {
     let usage = system.global_cpu_info().cpu_usage();
 
     colorize(

src/main.rs

@@ -40,18 +40,17 @@ struct State {
     ping: ping::PingManager,
 }
 
-fn line(state: &State) -> String {
+fn line(state: &mut State) -> String {
     [
-        memory::usage(&state.config, &state.system),
-        cpu::overview(&state.config, &state.system),
-        sensors::temperature(&state.config, &state.system),
+        memory::usage(&state.config, &mut state.system),
+        cpu::overview(&state.config, &mut state.system),
+        sensors::temperature(&state.config, &mut state.system),
         state.ping.current(),
     ]
     .join(" ")
 }
 
 fn render_line(delimiter: char, state: &mut State) -> () {
-    state.system.refresh_all();
     print!("{}{}", line(state), delimiter);
     ()
 }

src/memory.rs

@@ -19,7 +19,9 @@ use super::colors::colorize;
 use super::config::Config;
 use sysinfo::{System, SystemExt};
 
-pub fn usage(config: &Config, system: &System) -> String {
+pub fn usage(config: &Config, system: &mut System) -> String {
+    system.refresh_memory();
+
     let total = system.total_memory() as f32;
     let available = system.available_memory() as f32;
     let usage = (100.0 * (total - available) / total).round();

src/sensors.rs

@@ -19,14 +19,15 @@ use super::colors::colorize;
 use super::config::Config;
 use sysinfo::{ComponentExt, System, SystemExt};
 
-fn max_temperature(system: &System) -> f32 {
+fn max_temperature(system: &mut System) -> f32 {
+    system.refresh_components();
     system
         .components()
         .iter()
         .rfold(0.0, |acc, x| acc.max(x.temperature()))
 }
 
-pub fn temperature(config: &Config, system: &System) -> String {
+pub fn temperature(config: &Config, system: &mut System) -> String {
     let temp = max_temperature(system);
 
     colorize(