keyfork-qrcode: prefer Instant over SystemTime for infallible time comparison

Cargo.lock

@@ -1818,7 +1818,7 @@ dependencies = [
 
 [[package]]
 name = "keyfork-qrcode"
-version = "0.1.0"
+version = "0.1.1"
 dependencies = [
  "image",
  "keyfork-bug",

crates/qrcode/keyfork-qrcode/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "keyfork-qrcode"
-version = "0.1.0"
+version = "0.1.1"
 repository = "https://git.distrust.co/public/keyfork"
 edition = "2021"
 license = "MIT"

crates/qrcode/keyfork-qrcode/src/lib.rs

@@ -5,7 +5,7 @@ use keyfork_bug as bug;
 use image::io::Reader as ImageReader;
 use std::{
     io::{Cursor, Write},
-    time::{Duration, SystemTime},
+    time::{Duration, Instant},
     process::{Command, Stdio},
 };
 use v4l::{
@@ -110,11 +110,10 @@ pub fn scan_camera(timeout: Duration, index: usize) -> Result<Option<String>, QR
     fmt.fourcc = FourCC::new(b"MPG1");
     device.set_format(&fmt)?;
     let mut stream = Stream::with_buffers(&device, Type::VideoCapture, 4)?;
-    let start = SystemTime::now();
+    let start = Instant::now();
 
-    while SystemTime::now()
+    while Instant::now()
         .duration_since(start)
-        .unwrap_or(Duration::from_secs(0))
         < timeout
     {
         let (buffer, _) = stream.next()?;
@@ -141,12 +140,11 @@ pub fn scan_camera(timeout: Duration, index: usize) -> Result<Option<String>, QR
     fmt.fourcc = FourCC::new(b"MPG1");
     device.set_format(&fmt)?;
     let mut stream = Stream::with_buffers(&device, Type::VideoCapture, 4)?;
-    let start = SystemTime::now();
+    let start = Instant::now();
     let mut scanner = keyfork_zbar::image_scanner::ImageScanner::new();
 
-    while SystemTime::now()
+    while Instant::now()
         .duration_since(start)
-        .unwrap_or(Duration::from_secs(0))
         < timeout
     {
         let (buffer, _) = stream.next()?;