API/JSWeakObjectMapRefPrivate.h

   1 /*
   2  * Copyright (C) 2010 Apple Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
  14  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  15  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  16  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
  17  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  18  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  19  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  20  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  21  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  22  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
  23  * THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #ifndef JSWeakObjectMapRefPrivate_h
  27 #define JSWeakObjectMapRefPrivate_h
  28
  29 #include <JavaScriptCore/JSContextRef.h>
  30 #include <JavaScriptCore/JSValueRef.h>
  31
  32 #ifdef __cplusplus
  33 extern "C" {
  34 #endif
  35
  36 /*! @typedef JSWeakObjectMapRef A weak map for storing JSObjectRefs */
  37 typedef struct OpaqueJSWeakObjectMap* JSWeakObjectMapRef;
  38
  39 /*!
  40  @typedef JSWeakMapDestroyedCallback
  41  @abstract The callback invoked when a JSWeakObjectMapRef is being destroyed.
  42  @param map The map that is being destroyed.
  43  @param data The private data (if any) that was associated with the map instance.
  44  */
  45 typedef void (*JSWeakMapDestroyedCallback)(JSWeakObjectMapRef map, void* data);
  46
  47 /*!
  48  @function
  49  @abstract Creates a weak value map that can be used to reference user defined objects without preventing them from being collected.
  50  @param ctx The execution context to use.
  51  @param data A void* to set as the map's private data. Pass NULL to specify no private data.
  52  @param destructor A function to call when the weak map is destroyed.
  53  @result A JSWeakObjectMapRef bound to the given context, data and destructor.
  54  @discussion The JSWeakObjectMapRef can be used as a storage mechanism to hold custom JS objects without forcing those objects to
  55  remain live as JSValueProtect would.
  56  */
  57 JS_EXPORT JSWeakObjectMapRef JSWeakObjectMapCreate(JSContextRef ctx, void* data, JSWeakMapDestroyedCallback destructor);
  58
  59 /*!
  60  @function
  61  @abstract Associates a JSObjectRef with the given key in a JSWeakObjectMap.
  62  @param ctx The execution context to use.
  63  @param map The map to operate on.
  64  @param key The key to associate a weak reference with.
  65  @param object The user defined object to associate with the key.
  66  */
  67 JS_EXPORT void JSWeakObjectMapSet(JSContextRef ctx, JSWeakObjectMapRef map, void* key, JSObjectRef);
  68
  69 /*!
  70  @function
  71  @abstract Retrieves the JSObjectRef associated with a key.
  72  @param ctx The execution context to use.
  73  @param map The map to query.
  74  @param key The key to search for.
  75  @result Either the live object associated with the provided key, or NULL.
  76  */
  77 JS_EXPORT JSObjectRef JSWeakObjectMapGet(JSContextRef ctx, JSWeakObjectMapRef map, void* key);
  78
  79 /*!
  80  @function
  81  @abstract Removes the entry for the given key if the key is present, otherwise it has no effect.
  82  @param ctx The execution context to use.
  83  @param map The map to use.
  84  @param key The key to remove.
  85  */
  86 JS_EXPORT void JSWeakObjectMapRemove(JSContextRef ctx, JSWeakObjectMapRef map, void* key);
  87
  88 #ifdef __cplusplus
  89 }
  90 #endif
  91
  92 #endif // JSWeakObjectMapPrivate_h