From d8725b3d7c0d45ea95c7a80743dd06ff6ef35dec Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E4=B8=89=E5=92=B2=E9=9B=85=20=C2=B7=20Misaki=20Masa?=
 <sxyazi@gmail.com>
Date: Thu, 27 Jul 2023 11:17:51 +0800
Subject: [PATCH] feat: avoid duplicating the same task of precaching the size
 (#11)

---
 src/core/tasks/precache.rs  | 14 ++++++++++++--
 src/core/tasks/scheduler.rs | 10 ++++++++--
 2 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/src/core/tasks/precache.rs b/src/core/tasks/precache.rs
index f8641010..8f9ccd07 100644
--- a/src/core/tasks/precache.rs
+++ b/src/core/tasks/precache.rs
@@ -1,7 +1,8 @@
-use std::{collections::BTreeMap, path::{Path, PathBuf}, sync::Arc};
+use std::{collections::{BTreeMap, BTreeSet}, path::{Path, PathBuf}, sync::Arc};
 
 use anyhow::{Error, Result};
 use image::{imageops::FilterType, ImageFormat};
+use parking_lot::Mutex;
 use tokio::{fs, sync::mpsc};
 
 use super::TaskOp;
@@ -12,6 +13,8 @@ pub struct Precache {
 	tx: async_channel::Sender<PrecacheOp>,
 
 	sch: mpsc::UnboundedSender<TaskOp>,
+
+	pub(super) size_handing: Mutex<BTreeSet<PathBuf>>,
 }
 
 #[derive(Debug)]
@@ -48,7 +51,7 @@ pub(super) struct PrecacheOpVideo {
 impl Precache {
 	pub(super) fn new(sch: mpsc::UnboundedSender<TaskOp>) -> Self {
 		let (tx, rx) = async_channel::unbounded();
-		Self { tx, rx, sch }
+		Self { tx, rx, sch, size_handing: Default::default() }
 	}
 
 	#[inline]
@@ -115,9 +118,16 @@ impl Precache {
 		if let Ok(mut file) = File::from(&task.target).await {
 			file.length = length;
 			task.throttle.done((task.target, file), |buf| {
+				let mut handing = self.size_handing.lock();
+				for (path, _) in &buf {
+					handing.remove(path);
+				}
+
 				let parent = buf[0].0.parent().unwrap().to_path_buf();
 				emit!(Files(FilesOp::Sort(parent, BTreeMap::from_iter(buf))));
 			});
+		} else {
+			self.size_handing.lock().remove(&task.target);
 		};
 
 		self.sch.send(TaskOp::Adv(task.id, 1, 0))?;
diff --git a/src/core/tasks/scheduler.rs b/src/core/tasks/scheduler.rs
index 14eac7b4..a07aea2d 100644
--- a/src/core/tasks/scheduler.rs
+++ b/src/core/tasks/scheduler.rs
@@ -383,11 +383,17 @@ impl Scheduler {
 
 	pub(super) fn precache_size(&self, targets: Vec<PathBuf>) {
 		let throttle = Arc::new(Throttle::new(targets.len(), Duration::from_millis(300)));
+		let mut handing = self.precache.size_handing.lock();
+		let mut running = self.running.write();
 
 		for target in targets {
-			let name = format!("Calculate the size of {:?}", target);
-			let id = self.running.write().add(name);
+			if !handing.contains(&target) {
+				handing.insert(target.clone());
+			} else {
+				continue;
+			}
 
+			let id = running.add(format!("Calculate the size of {:?}", target));
 			let _ = self.todo.send_blocking({
 				let precache = self.precache.clone();
 				let throttle = throttle.clone();