From bb80d168af2c5e36903dd61473fdbd3840846d7f Mon Sep 17 00:00:00 2001
From: dec05eba <dec05eba@protonmail.com>
Date: Wed, 27 Oct 2021 15:20:30 +0200
Subject: Stop download of thumbnail if the thumbnail is no longer visible on
 the screen

---
 TODO                         |  4 +++-
 include/AsyncImageLoader.hpp | 20 +++++++++++---------
 src/AsyncImageLoader.cpp     | 37 +++++++++++++++++++++++++++++--------
 3 files changed, 43 insertions(+), 18 deletions(-)

diff --git a/TODO b/TODO
index 08ae2ee..35594ab 100644
--- a/TODO
+++ b/TODO
@@ -201,4 +201,6 @@ Add keybindings for image control for 4chan.
 Fix youtube videos that are age restricted AND do not allow embedding. Is that even possible?
 Use local lbry instead of odysee when I figure out the incorrect instructions of to use lighthouse locally.
 ffmpeg (and mpv) is very slow at playing streams (mostly affects lbry and certain peertube videos) for some reason.
-Allow specifying start/end range for video/music downloads.
\ No newline at end of file
+Allow specifying start/end range for video/music downloads.
+Limit text input length for 4chan posts to the server limit.
+Allow creating a new thread on 4chan.
\ No newline at end of file
diff --git a/include/AsyncImageLoader.hpp b/include/AsyncImageLoader.hpp
index 77fd5b4..94b225d 100644
--- a/include/AsyncImageLoader.hpp
+++ b/include/AsyncImageLoader.hpp
@@ -54,6 +54,15 @@ namespace QuickMedia {
         // Note: this method is not thread-safe
         void update();
     private:
+        struct Download {
+            ReadProgram read_program;
+            int64_t download_start = 0;
+            Path thumbnail_path;
+            std::shared_ptr<ThumbnailData> thumbnail_data;
+            sf::Vector2i resize_target_size;
+            std::string url;
+        };
+
         AsyncImageLoader();
         ~AsyncImageLoader();
         AsyncImageLoader(AsyncImageLoader &other) = delete;
@@ -65,16 +74,9 @@ namespace QuickMedia {
 
         // Returns -1 if all threads are busy
         int get_free_load_index() const;
-    private:
-        struct Download {
-            ReadProgram read_program;
-            int64_t download_start = 0;
-            Path thumbnail_path;
-            std::shared_ptr<ThumbnailData> thumbnail_data;
-            sf::Vector2i resize_target_size;
-            std::string url;
-        };
 
+        void reset_download(Download &download);
+    private:
         std::mutex download_mutex;
         // TODO: Use curl single-threaded multi-download feature instead
         Download downloads[NUM_IMAGE_LOAD_PARALLEL];
diff --git a/src/AsyncImageLoader.cpp b/src/AsyncImageLoader.cpp
index f926a8d..762408c 100644
--- a/src/AsyncImageLoader.cpp
+++ b/src/AsyncImageLoader.cpp
@@ -236,14 +236,7 @@ namespace QuickMedia {
                         } else {
                             fprintf(stderr, "Thumbnail download failed for %s\n", download.url.c_str());
                         }
-
-                        std::lock_guard<std::mutex> lock(download_mutex);
-                        close(download.read_program.read_fd);
-                        download.read_program.pid = -1;
-                        download.read_program.read_fd = -1;
-                        download.thumbnail_path.data.clear();
-                        download.url.c_str();
-                        download.thumbnail_data = nullptr;
+                        reset_download(download);
                     }
                 }
 
@@ -336,6 +329,19 @@ namespace QuickMedia {
         bool loaded_textures_changed = false;
         for(auto it = thumbnails.begin(); it != thumbnails.end();) {
             if(it->second->counter != counter) {
+                {
+                    for(int i = 0; i < NUM_IMAGE_LOAD_PARALLEL; ++i) {
+                        Download &download = downloads[i];
+                        if(download.read_program.pid == -1)
+                            continue;
+
+                        if(download.url == it->first) {
+                            reset_download(download);
+                            break;
+                        }
+                    }
+                }
+
                 image_load_queue.erase_if([&it](ThumbnailLoadData &load_data) {
                     return load_data.path.data == it->first;
                 });
@@ -358,4 +364,19 @@ namespace QuickMedia {
         }
         return -1;
     }
+
+    void AsyncImageLoader::reset_download(Download &download) {
+        std::lock_guard<std::mutex> lock(download_mutex);
+        if(download.read_program.pid != -1) {
+            kill(download.read_program.pid, SIGTERM);
+            download.read_program.pid = -1;
+        }
+        if(download.read_program.read_fd != -1) {
+            close(download.read_program.read_fd);
+            download.read_program.read_fd = -1;
+        }
+        download.thumbnail_path.data.clear();
+        download.url.c_str();
+        download.thumbnail_data = nullptr;
+    }
 }
-- 
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