vbox: Handle different array representations of XPCOM and MSCOM

Add a vboxArray to hide the details from the general driver code.

src/vbox/vbox_MSCOMGlue.c

@@ -646,3 +646,110 @@ void
 VBoxCGlueTerm(void)
 {
 }
+
+
+
+/*
+ * In MSCOM an array is represented by a SAFEARRAY pointer. To access the items
+ * in the array the SafeArrayAccessData function is used to lock the array and
+ * get its contents. When the items aren't needed anymore the
+ * SafeArrayUnaccessData function is used to unlock the array. The pointer
+ * retuned by SafeArrayAccessData function becomes invalid. Finally the
+ * SafeArrayDestroy function is called to destroy the array, it also releases
+ * or frees all items in the array according to their type.
+ */
+
+typedef HRESULT __stdcall (*SafeArrayGetter)(void *self, SAFEARRAY **array);
+typedef HRESULT __stdcall (*SafeArrayGetterWithArg)(void *self, void *arg, SAFEARRAY **array);
+
+/*
+ * Call the getter with self as first argument and fill the array with the
+ * returned items.
+ */
+nsresult
+vboxArrayGet(vboxArray *array, void *self, void *getter)
+{
+    HRESULT hrc;
+    SAFEARRAY *safeArray = NULL;
+    void **items = NULL;
+
+    array->items = NULL;
+    array->count = 0;
+    array->handle = NULL;
+
+    hrc = ((SafeArrayGetter)getter)(self, &safeArray);
+
+    if (FAILED(hrc)) {
+        return hrc;
+    }
+
+    hrc = SafeArrayAccessData(safeArray, (void **)&items);
+
+    if (FAILED(hrc)) {
+        SafeArrayDestroy(safeArray);
+        return hrc;
+    }
+
+    array->items = items;
+    array->count = safeArray->rgsabound[0].cElements;
+    array->handle = safeArray;
+
+    return hrc;
+}
+
+/*
+ * Call the getter with self as first argument and arg as second argument
+ * and fill the array with the returned items.
+ */
+nsresult
+vboxArrayGetWithArg(vboxArray *array, void *self, void *getter, void *arg)
+{
+    HRESULT hrc;
+    SAFEARRAY *safeArray = NULL;
+    void **items = NULL;
+
+    array->items = NULL;
+    array->count = 0;
+    array->handle = NULL;
+
+    hrc = ((SafeArrayGetterWithArg)getter)(self, arg, &safeArray);
+
+    if (FAILED(hrc)) {
+        return hrc;
+    }
+
+    hrc = SafeArrayAccessData(safeArray, (void **)&items);
+
+    if (FAILED(hrc)) {
+        SafeArrayDestroy(safeArray);
+        return hrc;
+    }
+
+    array->items = items;
+    array->count = safeArray->rgsabound[0].cElements;
+    array->handle = safeArray;
+
+    return hrc;
+}
+
+/*
+ * Release all items in the array and reset it.
+ *
+ * SafeArrayDestroy is aware of the item's type and calls release or free
+ * for each item according to its type. Therefore, vboxArrayUnalloc and
+ * vboxArrayRelease are the same for MSCOM.
+ */
+void
+vboxArrayRelease(vboxArray *array)
+{
+    if (array->handle == NULL) {
+        return;
+    }
+
+    SafeArrayUnaccessData(array->handle);
+    SafeArrayDestroy(array->handle);
+
+    array->items = NULL;
+    array->count = 0;
+    array->handle = NULL;
+}

src/vbox/vbox_MSCOMGlue.h

@@ -30,4 +30,19 @@ extern PFNVBOXGETXPCOMCFUNCTIONS g_pfnGetFunctions;
 int VBoxCGlueInit(unsigned int *version);
 void VBoxCGlueTerm(void);
 
+typedef struct _vboxArray vboxArray;
+
+struct _vboxArray {
+    void **items;
+    size_t count;
+    void *handle;
+};
+
+# define VBOX_ARRAY_INITIALIZER { NULL, 0, NULL }
+
+nsresult vboxArrayGet(vboxArray *array, void *self, void *getter);
+nsresult vboxArrayGetWithArg(vboxArray *array, void *self, void *getter, void *arg);
+void vboxArrayRelease(vboxArray *array);
+# define vboxArrayUnalloc vboxArrayRelease
+
 #endif /* __VBOX_MSCOMGLUE_H__ */

src/vbox/vbox_XPCOMCGlue.c

@@ -253,3 +253,118 @@ VBoxCGlueTerm(void)
     pVBoxFuncs_v2_2 = NULL;
     g_pfnGetFunctions = NULL;
 }
+
+
+
+/*
+ * In XPCOM an array is represented by 1) a pointer to an array of pointers
+ * that point to the items and 2) an unsigned int representing the number of
+ * items in the array. When the items aren't needed anymore they are released
+ * or freed according to their type.
+ */
+
+typedef nsresult (*ArrayGetter)(void *self, PRUint32 *count, void ***items);
+typedef nsresult (*ArrayGetterWithArg)(void *self, void *arg, PRUint32 *count, void ***items);
+
+/*
+ * Call the getter with self as first argument and fill the array with the
+ * returned items.
+ */
+nsresult
+vboxArrayGet(vboxArray *array, void *self, void *getter)
+{
+    nsresult nsrc;
+    void **items = NULL;
+    PRUint32 count = 0;
+
+    array->items = NULL;
+    array->count = 0;
+
+    nsrc = ((ArrayGetter)getter)(self, &count, &items);
+
+    if (NS_FAILED(nsrc)) {
+        return nsrc;
+    }
+
+    array->items = items;
+    array->count = count;
+
+    return nsrc;
+}
+
+/*
+ * Call the getter with self as first argument and arg as second argument
+ * and fill the array with the returned items.
+ */
+nsresult
+vboxArrayGetWithArg(vboxArray *array, void *self, void *getter, void *arg)
+{
+    nsresult nsrc;
+    void **items = NULL;
+    PRUint32 count = 0;
+
+    array->items = NULL;
+    array->count = 0;
+
+    nsrc = ((ArrayGetterWithArg)getter)(self, arg, &count, &items);
+
+    if (NS_FAILED(nsrc)) {
+        return nsrc;
+    }
+
+    array->items = items;
+    array->count = count;
+
+    return nsrc;
+}
+
+/*
+ * Release all items in the array and reset it.
+ */
+void
+vboxArrayRelease(vboxArray *array)
+{
+    int i;
+    nsISupports *supports;
+
+    if (array->items == NULL) {
+        return;
+    }
+
+    for (i = 0; i < array->count; ++i) {
+        supports = array->items[i];
+
+        if (supports != NULL) {
+            supports->vtbl->Release(supports);
+        }
+    }
+
+    array->items = NULL;
+    array->count = 0;
+}
+
+
+/*
+ * Unalloc all items in the array and reset it.
+ */
+void
+vboxArrayUnalloc(vboxArray *array)
+{
+    int i;
+    void *item;
+
+    if (array->items == NULL) {
+        return;
+    }
+
+    for (i = 0; i < array->count; ++i) {
+        item = array->items[i];
+
+        if (item != NULL) {
+            pVBoxFuncs_v2_2->pfnComUnallocMem(item);
+        }
+    }
+
+    array->items = NULL;
+    array->count = 0;
+}

src/vbox/vbox_XPCOMCGlue.h

@@ -38,4 +38,18 @@ extern PFNVBOXGETXPCOMCFUNCTIONS g_pfnGetFunctions;
 int VBoxCGlueInit(unsigned int *version);
 void VBoxCGlueTerm(void);
 
+typedef struct _vboxArray vboxArray;
+
+struct _vboxArray {
+    void **items;
+    size_t count;
+};
+
+# define VBOX_ARRAY_INITIALIZER { NULL, 0 }
+
+nsresult vboxArrayGet(vboxArray *array, void *self, void *getter);
+nsresult vboxArrayGetWithArg(vboxArray *array, void *self, void *getter, void *arg);
+void vboxArrayRelease(vboxArray *array);
+void vboxArrayUnalloc(vboxArray *array);
+
 #endif