2010-04-05 Oliver Hunt <oliver@apple.com>
Reviewed by Gavin Barraclough.
Support weak maps in JSC
https://bugs.webkit.org/show_bug.cgi?id=37132
Expose an API to allow creation of a map for storing
weak JS references.
* API/JSWeakObjectMapRefInternal.h: Added.
(OpaqueJSWeakObjectMap::create):
(OpaqueJSWeakObjectMap::map):
(OpaqueJSWeakObjectMap::~OpaqueJSWeakObjectMap):
(OpaqueJSWeakObjectMap::OpaqueJSWeakObjectMap):
* API/JSWeakObjectMapRefPrivate.cpp: Added.
* API/JSWeakObjectMapRefPrivate.h: Added.
* JavaScriptCore.exp:
* JavaScriptCore.xcodeproj/project.pbxproj:
* runtime/JSGlobalObject.h:
(JSC::JSGlobalObject::registerWeakMap):
(JSC::JSGlobalObject::deregisterWeakMap):
git-svn-id: http://svn.webkit.org/repository/webkit/trunk@57120 268f45cc-cd09-0410-ab3c-d52691b4dbfc
diff --git a/JavaScriptCore/API/JSWeakObjectMapRefPrivate.h b/JavaScriptCore/API/JSWeakObjectMapRefPrivate.h
new file mode 100644
index 0000000..d36111c
--- /dev/null
+++ b/JavaScriptCore/API/JSWeakObjectMapRefPrivate.h
@@ -0,0 +1,95 @@
+/*
+ * Copyright (C) 2010 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
+ * THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef JSWeakObjectMapRefPrivate_h
+#define JSWeakObjectMapRefPrivate_h
+
+#include <JavaScriptCore/JSContextRef.h>
+#include <JavaScriptCore/JSValueRef.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*! @typedef JSWeakObjectMapRef A weak map for storing JSObjectRefs */
+typedef struct OpaqueJSWeakObjectMap* JSWeakObjectMapRef;
+
+/*!
+ @typedef JSWeakMapDestroyedCallback
+ @abstract The callback invoked when a JSWeakObjectMapRef is being destroyed.
+ @param map The map that is being destroyed.
+ @param data The private data (if any) that was associated with the map instance.
+ */
+typedef void (*JSWeakMapDestroyedCallback)(JSWeakObjectMapRef map, void* data);
+
+/*!
+ @function
+ @abstract Creates a weak value map that can be used to reference user defined objects without preventing them from being collected.
+ @param ctx The execution context to use.
+ @param data A void* to set as the map's private data. Pass NULL to specify no private data.
+ @param destructor A function to call when the weak map is destroyed.
+ @result A JSWeakObjectMapRef bound to the given context, data and destructor.
+ @discussion The JSWeakObjectMapRef can be used as a storage mechanism to hold custom JS objects without forcing those objects to
+ remain live as JSValueProtect would. Any objects that are intended to be stored in a weak map must be user defined objects that
+ remove themselves from the map in their finalizer.
+ */
+JS_EXPORT JSWeakObjectMapRef JSWeakObjectMapCreate(JSContextRef ctx, void* data, JSWeakMapDestroyedCallback destructor);
+
+/*!
+ @function
+ @abstract Associates a JSObjectRef with the given key in a JSWeakObjectMap.
+ @param ctx The execution context to use.
+ @param map The map to operate on.
+ @param key The key to associate a weak reference with.
+ @param object The user defined object to associate with the key.
+ */
+JS_EXPORT void JSWeakObjectMapSet(JSContextRef ctx, JSWeakObjectMapRef map, void* key, JSObjectRef);
+
+/*!
+ @function
+ @abstract Retrieves the JSObjectRef associated with a key.
+ @param ctx The execution context to use.
+ @param map The map to query.
+ @param key The key to search for.
+ @result Either the live object associated with the provided key, or NULL.
+ */
+JS_EXPORT JSObjectRef JSWeakObjectMapGet(JSContextRef ctx, JSWeakObjectMapRef map, void* key);
+
+/*!
+ @function
+ @abstract Clears the association between a key and an object in a JSWeakObjectMapRef
+ @param ctx The execution context to use.
+ @param map The map to clear the key association from.
+ @param key The key to use.
+ @param object The old object value.
+ @result Returns true if the key/object association was present in map, and has been removed.
+ */
+JS_EXPORT bool JSWeakObjectMapClear(JSContextRef ctx, JSWeakObjectMapRef map, void* key, JSObjectRef object);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // JSWeakObjectMapPrivate_h
