Merge pull request #2451 from secondlife/lua-resultset

Give certain `LLInventoryListener` queries an API based on result sets.

1 files changed, 43 insertions, 0 deletions

diff --git a/indra/llcommon/llinttracker.h b/indra/llcommon/llinttracker.h
new file mode 100644
index 0000000000..fd6d24d0fd
--- /dev/null
+++ b/indra/llcommon/llinttracker.h
@@ -0,0 +1,43 @@
+/**
+ * @file   llinttracker.h
+ * @author Nat Goodspeed
+ * @date   2024-08-30
+ * @brief  LLIntTracker isa LLInstanceTracker with generated int keys.
+ *
+ * $LicenseInfo:firstyear=2024&license=viewerlgpl$
+ * Copyright (c) 2024, Linden Research, Inc.
+ * $/LicenseInfo$
+ */
+
+#if ! defined(LL_LLINTTRACKER_H)
+#define LL_LLINTTRACKER_H
+
+#include "llinstancetracker.h"
+
+template <typename T>
+class LLIntTracker: public LLInstanceTracker<T, int>
+{
+    using super = LLInstanceTracker<T, int>;
+public:
+    LLIntTracker():
+        super(getUniqueKey())
+    {}
+
+private:
+    static int getUniqueKey()
+    {
+        // Find a random key that does NOT already correspond to an instance.
+        // Passing a duplicate key to LLInstanceTracker would do Bad Things.
+        int key;
+        do
+        {
+            key = std::rand();
+        } while (super::getInstance(key));
+        // This could be racy, if we were instantiating new LLIntTracker<T>s
+        // on multiple threads. If we need that, have to lock between checking
+        // getInstance() and constructing the new super.
+        return key;
+    }
+};
+
+#endif /* ! defined(LL_LLINTTRACKER_H) */