From 4a62feb5240b603b0531aa937429b2eb432b6460 Mon Sep 17 00:00:00 2001
From: alexpasmantier <alex.pasmant@gmail.com>
Date: Sun, 12 Jan 2025 22:08:03 +0100
Subject: [PATCH] perf: trying things with the preview

---
 .../television-previewers/src/previewers.rs   | 64 ++++++++++---------
 .../src/previewers/files.rs                   | 10 +--
 crates/television/television.rs               | 12 ++++
 3 files changed, 51 insertions(+), 35 deletions(-)

diff --git a/crates/television-previewers/src/previewers.rs b/crates/television-previewers/src/previewers.rs
index 132a703..e6fe199 100644
--- a/crates/television-previewers/src/previewers.rs
+++ b/crates/television-previewers/src/previewers.rs
@@ -156,39 +156,43 @@ impl Previewer {
             debug!("Preview already in cache");
             return Some(preview);
         }
-        // if we've already acknowledged the request
-        if let Some(initial_request) = self.requests.get(entry) {
-            debug!("Request already acknowledged");
-            // and we're past the debounce duration
-            if initial_request.elapsed() > DEBOUNCE_DURATION {
-                debug!("Past debounce duration");
-                // forward the request to the appropriate previewer
-                let preview = match &entry.preview_type {
-                    PreviewType::Basic => Some(self.basic.preview(entry)),
-                    PreviewType::EnvVar => Some(self.env_var.preview(entry)),
-                    PreviewType::Files => self.file.preview(entry),
-                    PreviewType::Command(cmd) => {
-                        self.command.preview(entry, cmd)
-                    }
-                    PreviewType::None => Some(Arc::new(Preview::default())),
-                };
-                // if we got a preview, cache it
-                if let Some(preview) = preview {
-                    self.cache.lock().insert(entry.name.clone(), &preview);
-                    Some(preview)
-                } else {
-                    None
-                }
+        // if we haven't acknowledged the request yet, acknowledge it
+        if !self.requests.contains_key(entry) {
+            self.requests.insert(entry.clone(), Instant::now());
+        }
+
+        let initial_request = self.requests.get(entry).unwrap();
+        // if we're past the debounce duration
+        if initial_request.elapsed() > DEBOUNCE_DURATION {
+            debug!("Past debounce duration");
+            // forward the request to the appropriate previewer
+            let preview = match &entry.preview_type {
+                PreviewType::Basic => Some(self.basic.preview(entry)),
+                PreviewType::EnvVar => Some(self.env_var.preview(entry)),
+                PreviewType::Files => self.file.preview(entry),
+                PreviewType::Command(cmd) => self.command.preview(entry, cmd),
+                PreviewType::None => Some(Arc::new(Preview::default())),
+            };
+            // if we got a preview, cache it
+            if let Some(preview) = preview {
+                self.cache.lock().insert(entry.name.clone(), &preview);
+                Some(preview)
             } else {
-                debug!("Not past debounce duration");
                 None
             }
-        }
-        // if we haven't acknowledged the request yet
-        else {
-            debug!("Request not acknowledged, acknowledging");
-            self.requests.insert(entry.clone(), Instant::now());
-            None
+        } else {
+            debug!("Not past debounce duration");
+            // partial preview
+            let preview = match &entry.preview_type {
+                PreviewType::Basic => Some(self.basic.preview(entry)),
+                PreviewType::EnvVar => Some(self.env_var.preview(entry)),
+                PreviewType::Files => self.file.preview(entry),
+                PreviewType::Command(cmd) => {
+                    self.command.partial_preview(entry, cmd)
+                }
+                PreviewType::None => Some(Arc::new(Preview::default())),
+            };
+            Some(preview)
         }
     }
 
diff --git a/crates/television-previewers/src/previewers/files.rs b/crates/television-previewers/src/previewers/files.rs
index a7f14bc..63749b7 100644
--- a/crates/television-previewers/src/previewers/files.rs
+++ b/crates/television-previewers/src/previewers/files.rs
@@ -150,10 +150,11 @@ pub fn try_preview(
             Ok(file) => {
                 // compute the highlighted version in the background
                 let mut reader = BufReader::new(file);
+
                 reader.seek(std::io::SeekFrom::Start(0)).unwrap();
                 let preview = compute_highlighted_text_preview(
                     entry,
-                    reader,
+                    reader.lines().map_while(Result::ok).collect(),
                     syntax_set,
                     syntax_theme,
                 );
@@ -176,7 +177,7 @@ pub fn try_preview(
 
 fn compute_highlighted_text_preview(
     entry: &entry::Entry,
-    reader: BufReader<File>,
+    lines: Vec<&str>,
     syntax_set: &SyntaxSet,
     syntax_theme: &Theme,
 ) -> Arc<Preview> {
@@ -184,9 +185,8 @@ fn compute_highlighted_text_preview(
         "Computing highlights in the background for {:?}",
         entry.name
     );
-    let lines: Vec<String> = reader
-        .lines()
-        .map_while(Result::ok)
+    let lines: Vec<String> = lines
+        .iter()
         // we need to add a newline here because sublime syntaxes expect one
         // to be present at the end of each line
         .map(|line| preprocess_line(&line).0 + "\n")
diff --git a/crates/television/television.rs b/crates/television/television.rs
index 69bec66..eb489be 100644
--- a/crates/television/television.rs
+++ b/crates/television/television.rs
@@ -561,6 +561,18 @@ impl Television {
         {
             // preview content
             let maybe_preview = self.previewer.preview(&selected_entry);
+            //// preload the next 3 previews
+            //if let Some(i) = self.results_picker.selected() {
+            //    for j in 1..=5 {
+            //        if let Some(entry) =
+            //            self.channel.get_result((i + j).try_into().unwrap())
+            //        {
+            //            let _ = self.previewer.preview(&entry);
+            //        }
+            //    }
+            //}
+
+            let _ = self.previewer.preview(&selected_entry);
 
             if let Some(preview) = &maybe_preview {
                 self.current_preview_total_lines = preview.total_lines();