v0.4.28: wipe video_player_cache on game shutdown

Add ClientLifecycleEvents.CLIENT_STOPPING handler that deletes every
file under <gameDir>/video_player_cache/. Quieter sibling of clearAll()
- no chat notify and no concurrent-download race handling needed since
at shutdown no other code is touching the directory.

Cache repopulation on next launch is already handled: the server's
ServerPlayConnectionEvents.JOIN handler re-broadcasts a PreloadPayload
for every preload_urls and cache_entries entry on every join, so a
freshly wiped cache auto-refills from the server's named entries
without any user action.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

gradle.properties

@@ -5,7 +5,7 @@ org.gradle.configuration-cache=false
 
 # Mod
 mod_id=video_player
-mod_version=0.4.26
+mod_version=0.4.28
 maven_group=com.ejclaw.videoplayer
 archives_base_name=video_player
 

src/main/java/com/ejclaw/videoplayer/VideoPlayerClient.java

@@ -3,6 +3,7 @@ package com.ejclaw.videoplayer;
 import com.ejclaw.videoplayer.block.VideoAnchorBlockEntity;
 import com.ejclaw.videoplayer.client.MusicQuizClient;
 import com.ejclaw.videoplayer.client.net.ClientNetworking;
+import com.ejclaw.videoplayer.client.playback.VideoCache;
 import com.ejclaw.videoplayer.client.playback.VideoPlayback;
 import com.ejclaw.videoplayer.client.render.VideoAnchorRenderer;
 import com.ejclaw.videoplayer.item.VideoStickItem;
@@ -12,6 +13,7 @@ import net.fabricmc.api.ClientModInitializer;
 import net.fabricmc.api.EnvType;
 import net.fabricmc.api.Environment;
 import net.fabricmc.fabric.api.client.event.lifecycle.v1.ClientBlockEntityEvents;
+import net.fabricmc.fabric.api.client.event.lifecycle.v1.ClientLifecycleEvents;
 import net.fabricmc.fabric.api.client.event.lifecycle.v1.ClientTickEvents;
 import net.fabricmc.fabric.api.client.networking.v1.ClientPlayNetworking;
 import net.fabricmc.fabric.api.client.rendering.v1.BlockEntityRendererRegistry;
@@ -82,6 +84,11 @@ public class VideoPlayerClient implements ClientModInitializer {
             }
         });
 
+        // Wipe video_player_cache/ on game exit so preloaded clips don't pile up across
+        // sessions. Cache entries are re-broadcast by the server on every JOIN, so a freshly
+        // started game will repopulate the cache automatically.
+        ClientLifecycleEvents.CLIENT_STOPPING.register(client -> VideoCache.wipeOnShutdown());
+
         VideoPlayerMod.LOG.info("[{}] client initialized", VideoPlayerMod.MOD_ID);
     }
 

src/main/java/com/ejclaw/videoplayer/client/playback/JavaCvBackend.java

@@ -180,27 +180,24 @@ public class JavaCvBackend implements VideoBackend {
         // stale srcAddr — closing the grabber there frees the av_frame plane and the next
         // memcpy crashes inside StubRoutines::jbyte_disjoint_arraycopy (exactly the 4K-delete
         // crash dump we saw). So the safe rule is: only the decoder thread touches the
-        // grabber. External stop signals `running=false`, stops the audio line, interrupts the
-        // worker, and joins briefly; the worker's own `finally` calls grabber.close(). Inside
-        // the loop, grab() unblocks via the rw_timeout/timeout options (3 s, set in runLoop)
-        // even on a stuck HTTP read, so the join below normally returns within a frame.
+        // grabber. External stop signals `running=false`, stops the audio line, interrupts
+        // the worker, and returns immediately; the worker's own `finally` calls
+        // grabber.close() whenever grab()/start() eventually returns.
+        //
+        // We deliberately do NOT join the worker. close() runs on the client tick thread (via
+        // VideoPlayback.tick → Entry.close), and the worker can spend several seconds inside
+        // the native FFmpeg probe at the top of runLoop — probesize=8 MB and
+        // analyzeduration=2 s do not honor the `running` flag and Thread.interrupt() doesn't
+        // unblock native I/O. A bounded join() there (the old 2 s) is exactly the "place then
+        // immediately delete freezes the game for a moment" symptom: the worker hasn't
+        // entered the grab() loop yet, so flipping running=false has no effect on it until
+        // start() returns. The worker is a daemon, the audio line is already silenced above,
+        // and Entry has been removed from the active map by the caller — nothing observable
+        // depends on the grabber having been closed before this method returns.
         Thread t = worker;
         worker = null;
         if (t != null) {
             t.interrupt();
-            try {
-                t.join(2000);
-            } catch (InterruptedException ie) {
-                Thread.currentThread().interrupt();
-            }
-            if (t.isAlive()) {
-                // Worker still blocked in native grab() — let it finish on its own. Its
-                // finally still closes the grabber when grab() eventually returns / throws.
-                // No native pointers leak in the meantime because we don't touch them here.
-                VideoPlayerMod.LOG.warn(
-                    "[{}] decoder did not exit within 2 s of stop; orphaning until next grab() returns",
-                    VideoPlayerMod.MOD_ID);
-            }
         }
         ready = false;
     }

src/main/java/com/ejclaw/videoplayer/client/playback/VideoCache.java

@@ -226,6 +226,40 @@ public final class VideoCache {
         IN_FLIGHT.clear();
     }
 
+    /**
+     * Wipe the cache directory at game shutdown so the user doesn't accumulate disk usage
+     * across sessions. Distinct from {@link #clearAll()}: at shutdown there are no concurrent
+     * downloads to race and no player to chat-notify, so we skip the chat ping but still bump
+     * the epoch (defensive — any straggler write inside the in-flight {@code .part} stream
+     * will detect the bump and self-clean) and drop indexes.
+     */
+    public static void wipeOnShutdown() {
+        CACHE_EPOCH.incrementAndGet();
+        READY.clear();
+        IN_FLIGHT.clear();
+        int deleted = 0;
+        int failed  = 0;
+        try {
+            Path dir = cacheDir();
+            if (dir != null && Files.isDirectory(dir)) {
+                try (var stream = Files.newDirectoryStream(dir)) {
+                    for (Path p : stream) {
+                        try {
+                            if (Files.isRegularFile(p) && Files.deleteIfExists(p)) deleted++;
+                        } catch (Throwable t) {
+                            failed++;
+                        }
+                    }
+                }
+            }
+        } catch (Throwable t) {
+            VideoPlayerMod.LOG.warn("[{}] wipeOnShutdown failed: {}",
+                VideoPlayerMod.MOD_ID, t.toString());
+        }
+        VideoPlayerMod.LOG.info("[{}] wipeOnShutdown: deleted={} failed={}",
+            VideoPlayerMod.MOD_ID, deleted, failed);
+    }
+
     /** Caller-supplied: current set of URLs that are fully cached, for diagnostics. */
     public static Set<String> readyUrls() {
         return new HashSet<>(READY.keySet());