Version 1.8 of gecko-sdk. Downloaded from here:...

gecko-sdk/include/nsMemory.h

+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is mozilla.org code.
+ *
+ * The Initial Developer of the Original Code is
+ * Netscape Communications Corporation.
+ * Portions created by the Initial Developer are Copyright (C) 1998
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either of the GNU General Public License Version 2 or later (the "GPL"),
+ * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+#ifndef nsMemory_h__
+#define nsMemory_h__
+
+#include "nsXPCOM.h"
+#include "nsIMemory.h"
+
+#define NS_MEMORY_CONTRACTID "@mozilla.org/xpcom/memory-service;1"
+#define NS_MEMORY_CLASSNAME  "Global Memory Service"
+#define NS_MEMORY_CID                                \
+{ /* 30a04e40-38e7-11d4-8cf5-0060b0fc14a3 */         \
+    0x30a04e40,                                      \
+    0x38e7,                                          \
+    0x11d4,                                          \
+    {0x8c, 0xf5, 0x00, 0x60, 0xb0, 0xfc, 0x14, 0xa3} \
+}
+
+
+/**
+ * Static helper routines to manage memory. These routines allow easy access
+ * to xpcom's built-in (global) nsIMemory implementation, without needing
+ * to go through the service manager to get it. However this requires clients
+ * to link with the xpcom DLL. 
+ *
+ * This class is not threadsafe and is intented for use only on the main
+ * thread.
+ */
+class nsMemory
+{
+public:
+    static NS_HIDDEN_(void*) Alloc(size_t size)
+        { return NS_Alloc(size); }
+
+    static NS_HIDDEN_(void*) Realloc(void* ptr, PRSize size)
+        { return NS_Realloc(ptr, size); }
+
+    static NS_HIDDEN_(void) Free(void* ptr)
+        { NS_Free(ptr); }
+
+    static NS_COM_GLUE nsresult   HeapMinimize(PRBool aImmediate);
+    static NS_COM_GLUE void*      Clone(const void* ptr, PRSize size);
+    static NS_COM_GLUE nsIMemory* GetGlobalMemoryService();       // AddRefs
+};
+
+/** 
+ * Macro to free all elements of an XPCOM array of a given size using
+ * freeFunc, then frees the array itself using nsMemory::Free().  
+ *
+ * Note that this macro (and its wrappers) can be used to deallocate a
+ * partially- or completely-built array while unwinding an error
+ * condition inside the XPCOM routine that was going to return the
+ * array.  For this to work on a partially-built array, your code
+ * needs to be building the array from index 0 upwards, and simply
+ * pass the number of elements that have already been built (and thus
+ * need to be freed) as |size|.
+ *
+ * Thanks to <alecf@netscape.com> for suggesting this form, which
+ * allows the macro to be used with NS_RELEASE / NS_RELEASE_IF in
+ * addition to nsMemory::Free.
+ * 
+ * @param size      Number of elements in the array.  If not a constant, this 
+ *                  should be a PRInt32.  Note that this means this macro 
+ *                  will not work if size >= 2^31.
+ * @param array     The array to be freed.
+ * @param freeFunc  The function or macro to be used to free it. 
+ *                  For arrays of nsISupports (or any class derived
+ *                  from it), NS_IF_RELEASE (or NS_RELEASE) should be
+ *                  passed as freeFunc.  For most (all?) other pointer
+ *                  types (including XPCOM strings and wstrings),
+ *                  nsMemory::Free should be used, since the
+ *                  shared-allocator (nsMemory) is what will have been
+ *                  used to allocate the memory.  
+ */
+#define NS_FREE_XPCOM_POINTER_ARRAY(size, array, freeFunc)                    \
+    PR_BEGIN_MACRO                                                            \
+        PRInt32 iter_ = PRInt32(size);                                        \
+        while (--iter_ >= 0)                                                  \
+            freeFunc((array)[iter_]);                                         \
+        NS_Free((array));                                                     \
+    PR_END_MACRO
+
+// convenience macros for commonly used calls.  mmmmm.  syntactic sugar.
+
+/** 
+ * Macro to free arrays of non-refcounted objects allocated by the
+ * shared allocator (nsMemory) such as strings and wstrings.  A
+ * convenience wrapper around NS_FREE_XPCOM_POINTER_ARRAY.
+ *
+ * @param size      Number of elements in the array.  If not a constant, this 
+ *                  should be a PRInt32.  Note that this means this macro 
+ *                  will not work if size >= 2^31.
+ * @param array     The array to be freed.
+ */
+#define NS_FREE_XPCOM_ALLOCATED_POINTER_ARRAY(size, array)                    \
+    NS_FREE_XPCOM_POINTER_ARRAY((size), (array), NS_Free)
+
+/**
+ * Macro to free an array of pointers to nsISupports (or classes
+ * derived from it).  A convenience wrapper around
+ * NS_FREE_XPCOM_POINTER_ARRAY.
+ *
+ * Note that if you know that none of your nsISupports pointers are
+ * going to be 0, you can gain a bit of speed by calling
+ * NS_FREE_XPCOM_POINTER_ARRAY directly and using NS_RELEASE as your
+ * free function.
+ *
+ * @param size      Number of elements in the array.  If not a constant, this 
+ *                  should be a PRInt32.  Note that this means this macro 
+ *                  will not work if size >= 2^31.
+ * @param array     The array to be freed.
+ */
+#define NS_FREE_XPCOM_ISUPPORTS_POINTER_ARRAY(size, array)                    \
+    NS_FREE_XPCOM_POINTER_ARRAY((size), (array), NS_IF_RELEASE)
+
+/**
+ * Helpful array length function for calculating the length of a
+ * statically declared array.
+ */
+
+#define NS_ARRAY_LENGTH(array_) \
+  (sizeof(array_)/sizeof(array_[0]))
+
+
+#endif // nsMemory_h__
+