From 14357f2c96cf4dada922f25f8181177e108f0155 Mon Sep 17 00:00:00 2001
From: alexpasmantier <alex.pasmant@gmail.com>
Date: Tue, 22 Oct 2024 14:50:35 +0200
Subject: [PATCH] caching for git repos and max_lines_in_memory for text

---
 crates/television/channels/git_repos.rs | 13 +++++++++----
 crates/television/channels/text.rs      | 13 ++++++++++++-
 2 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/crates/television/channels/git_repos.rs b/crates/television/channels/git_repos.rs
index 3d953b1..de59ee6 100644
--- a/crates/television/channels/git_repos.rs
+++ b/crates/television/channels/git_repos.rs
@@ -30,9 +30,9 @@ pub struct Channel {
     running: bool,
     icon: FileIcon,
     crawl_handle: JoinHandle<()>,
-    entry_cache: Arc<Mutex<HashSet<String>>>,
+    git_dirs_cache: Arc<Mutex<HashSet<String>>>,
     // TODO: implement cache validation/invalidation
-    cache_valid: bool,
+    cache_valid: Arc<Mutex<bool>>,
 }
 
 impl Channel {
@@ -44,12 +44,14 @@ impl Channel {
             1,
         );
         let entry_cache = Arc::new(Mutex::new(HashSet::new()));
+        let cache_valid = Arc::new(Mutex::new(false));
         // start loading files in the background
         // PERF: store the results somewhere in a cache
         let crawl_handle = tokio::spawn(crawl_for_repos(
             std::env::home_dir().expect("Could not get home directory"),
             matcher.injector(),
             entry_cache.clone(),
+            cache_valid.clone(),
         ));
         Channel {
             matcher,
@@ -59,8 +61,8 @@ impl Channel {
             running: false,
             icon: FileIcon::from("git"),
             crawl_handle,
-            entry_cache,
-            cache_valid: false,
+            git_dirs_cache: entry_cache,
+            cache_valid,
         }
     }
 
@@ -157,6 +159,7 @@ async fn crawl_for_repos(
     starting_point: std::path::PathBuf,
     injector: nucleo::Injector<DirEntry>,
     entry_cache: Arc<Mutex<HashSet<String>>>,
+    cache_valid: Arc<Mutex<bool>>,
 ) {
     let mut walker_overrides_builder = OverrideBuilder::new(&starting_point);
     walker_overrides_builder.add(".git").unwrap();
@@ -199,4 +202,6 @@ async fn crawl_for_repos(
             ignore::WalkState::Continue
         })
     });
+
+    *cache_valid.lock() = true;
 }
diff --git a/crates/television/channels/text.rs b/crates/television/channels/text.rs
index 0ea8527..1c1ee88 100644
--- a/crates/television/channels/text.rs
+++ b/crates/television/channels/text.rs
@@ -7,7 +7,7 @@ use std::{
     fs::File,
     io::{BufRead, Read, Seek},
     path::{Path, PathBuf},
-    sync::Arc,
+    sync::{atomic::AtomicUsize, Arc},
 };
 
 use tracing::{debug, info};
@@ -172,16 +172,24 @@ impl OnAir for Channel {
 /// a lot of files (e.g. starting tv in $HOME).
 const MAX_FILE_SIZE: u64 = 4 * 1024 * 1024;
 
+const MAX_IN_MEMORY_LINES: usize = 5_000_000;
+
 #[allow(clippy::unused_async)]
 async fn load_candidates(path: PathBuf, injector: Injector<CandidateLine>) {
     let current_dir = std::env::current_dir().unwrap();
     let walker =
         walk_builder(&path, *DEFAULT_NUM_THREADS, None).build_parallel();
 
+    let lines_in_mem = Arc::new(AtomicUsize::new(0));
+
     walker.run(|| {
         let injector = injector.clone();
         let current_dir = current_dir.clone();
+        let lines_in_mem = lines_in_mem.clone();
         Box::new(move |result| {
+            if lines_in_mem.load(std::sync::atomic::Ordering::Relaxed) > MAX_IN_MEMORY_LINES {
+                return ignore::WalkState::Quit;
+            }
             if let Ok(entry) = result {
                 if entry.file_type().unwrap().is_file() {
                     if let Ok(m) = entry.metadata() {
@@ -192,6 +200,7 @@ async fn load_candidates(path: PathBuf, injector: Injector<CandidateLine>) {
                     // iterate over the lines of the file
                     match File::open(entry.path()) {
                         Ok(file) => {
+                            // is the file a text-based file?
                             let mut reader = std::io::BufReader::new(&file);
                             let mut buffer = [0u8; 128];
                             match reader.read(&mut buffer) {
@@ -212,6 +221,7 @@ async fn load_candidates(path: PathBuf, injector: Injector<CandidateLine>) {
                                     return ignore::WalkState::Continue;
                                 }
                             }
+                            // read the lines of the file
                             let mut line_number = 0;
                             for maybe_line in reader.lines() {
                                 match maybe_line {
@@ -238,6 +248,7 @@ async fn load_candidates(path: PathBuf, injector: Injector<CandidateLine>) {
                                                     c.line.clone().into();
                                             },
                                         );
+                                        lines_in_mem.fetch_add(1, std::sync::atomic::Ordering::Relaxed);
                                     }
                                     Err(e) => {
                                         info!("Error reading line: {:?}", e);