nio2: NIO.2 file API companion code (streaming 5 GB at -Xmx64m, handle leaks, WatchService, mmap)

Co-Authored-By: Claude Sonnet 5.5 <[email protected]> Claude-Session: https://claude.ai/code/session_01KqJyCidz3ZgRyHABv2GVJh
2026-09-30 19:14:31 +00:00
parent f4b732799d
commit 1ac2f6077a
30 changed files with 1072 additions and 0 deletions
@@ -0,0 +1,54 @@
+    final void signalEvent(WatchEvent.Kind<?> kind, Object context) {
+        boolean isModify = (kind == StandardWatchEventKinds.ENTRY_MODIFY);
+        synchronized (this) {
+            int size = events.size();
+            if (size > 0) {
+                // if the previous event is an OVERFLOW event or this is a
+                // repeated event then we simply increment the counter
+                WatchEvent<?> prev = events.get(size-1);
+                if ((prev.kind() == StandardWatchEventKinds.OVERFLOW) ||
+                    ((kind == prev.kind() &&
+                     Objects.equals(context, prev.context()))))
+                {
+                    ((Event<?>)prev).increment();
+                    return;
+                }
+
+                // if this is a modify event and the last entry for the context
+                // is a modify event then we simply increment the count
+                if (!lastModifyEvents.isEmpty()) {
+                    if (isModify) {
+                        WatchEvent<?> ev = lastModifyEvents.get(context);
+                        if (ev != null) {
+                            assert ev.kind() == StandardWatchEventKinds.ENTRY_MODIFY;
+                            ((Event<?>)ev).increment();
+                            return;
+                        }
+                    } else {
+                        // not a modify event so remove from the map as the
+                        // last event will no longer be a modify event.
+                        lastModifyEvents.remove(context);
+                    }
+                }
+
+                // if the list has reached the limit then drop pending events
+                // and queue an OVERFLOW event
+                if (size >= MAX_EVENT_LIST_SIZE) {
+                    kind = StandardWatchEventKinds.OVERFLOW;
+                    isModify = false;
+                    context = null;
+                }
+            }
+
+            // non-repeated event
+            Event<Object> ev =
+                new Event<>((WatchEvent.Kind<Object>)kind, context);
+            if (isModify) {
+                lastModifyEvents.put(context, ev);
+            } else if (kind == StandardWatchEventKinds.OVERFLOW) {
+                // drop all pending events
+                events.clear();
+                lastModifyEvents.clear();
+            }
+            events.add(ev);
+            signal();