Factor out database checks into a separate module.

src/index.rs

@@ -0,0 +1,40 @@
+use std::{
+    os::unix::prelude::CommandExt,
+    process::Command,
+    time::{Duration, SystemTime},
+};
+
+/// Update the local nix-index database.
+pub fn update_database() {
+    println!("Updating nix-index database, takes around 5 minutes.");
+    Command::new("nix-index").exec();
+}
+
+/// Prints warnings if the nix-index database is non-existent or out of date.
+pub fn check_database() {
+    let base = xdg::BaseDirectories::with_prefix("nix-index").unwrap();
+    let cache_dir = base.get_cache_home();
+    let database_file = cache_dir.join("files");
+    if !database_file.exists() {
+        println!("Warning: Nix-index database does not exist, try updating with `--update`.");
+    } else if is_database_old(database_file) {
+        println!(
+            "Warning: Nix-index database is older than 30 days, try updating with `--update`."
+        );
+    }
+}
+
+/// Test whether the database is more than 30 days old
+fn is_database_old(database_file: std::path::PathBuf) -> bool {
+    let modified = match database_file.metadata() {
+        Ok(metadata) => metadata.modified().unwrap_or_else(|_| SystemTime::now()),
+        Err(_) => return false,
+    };
+    let time_since_modified = SystemTime::now()
+        .duration_since(modified)
+        .unwrap_or(Duration::new(0, 0));
+    if time_since_modified > Duration::from_secs(30 * 24 * 60 * 60) {
+        return true;
+    }
+    false
+}

src/main.rs

@@ -1,3 +1,4 @@
+mod index;
 use std::{
     env,
     io::Write,
@@ -7,7 +8,6 @@ use std::{
 
 use clap::crate_version;
 use clap::Parser;
-use std::time::{Duration, SystemTime};
 
 fn pick(picker: &str, derivations: &[&str]) -> Option<String> {
     let mut picker_process = Command::new(&picker)
@@ -55,35 +55,6 @@ fn run_command(use_channel: bool, choice: &str, command: &str, trail: &[String])
     run_cmd.exec();
 }
 
-/// Test whether the database is more than 30 days old
-fn is_database_old(database_file: std::path::PathBuf) -> bool {
-    let modified = match database_file.metadata() {
-        Ok(metadata) => metadata.modified().unwrap_or_else(|_| SystemTime::now()),
-        Err(_) => return false,
-    };
-    let time_since_modified = SystemTime::now()
-        .duration_since(modified)
-        .unwrap_or(Duration::new(0, 0));
-    if time_since_modified > Duration::from_secs(30 * 24 * 60 * 60) {
-        return true;
-    }
-    false
-}
-
-/// Prints warnings if the nix-index database is non-existent or out of date.
-fn check_database() {
-    let base = xdg::BaseDirectories::with_prefix("nix-index").unwrap();
-    let cache_dir = base.get_cache_home();
-    let database_file = cache_dir.join("files");
-    if !database_file.exists() {
-        println!("Warning: Nix-index database does not exist, try updating with `--update`.");
-    } else if is_database_old(database_file) {
-        println!(
-            "Warning: Nix-index database is older than 30 days, try updating with `--update`."
-        );
-    }
-}
-
 fn main() -> ExitCode {
     let args = Opt::parse();
 
@@ -92,10 +63,10 @@ fn main() -> ExitCode {
 
     if args.update {
         println!("Updating nix-index database, takes around 5 minutes.");
-        Command::new("nix-index").exec();
+        index::update_database();
     }
 
-    check_database();
+    index::check_database();
 
     let attrs = Command::new("nix-locate")
         .args(["--top-level", "--minimal", "--at-root", "--whole-name"])