ICU-20249 An internal helper class for stack allocated UResourceBundle.

icu4c/source/common/locavailable.cpp

@@ -125,7 +125,6 @@ static UBool U_CALLCONV uloc_cleanup(void) {
 //   via the initOnce mechanism.
 
 static void U_CALLCONV loadInstalledLocales() {
-    UResourceBundle installed;
     UErrorCode status = U_ZERO_ERROR;
     int32_t i = 0;
     int32_t localeCount;
@@ -134,22 +133,19 @@ static void U_CALLCONV loadInstalledLocales() {
     U_ASSERT(_installedLocalesCount == 0);
 
     _installedLocalesCount = 0;
-    ures_initStackObject(&installed);
 
     icu::LocalUResourceBundlePointer indexLocale(ures_openDirect(NULL, _kIndexLocaleName, &status));
+    icu::StackUResourceBundle installed;
 
-    // Automatically call ures_close() on this when it goes out of scope.
-    icu::LocalUResourceBundlePointer installedCloser(&installed);
-
-    ures_getByKey(indexLocale.getAlias(), _kIndexTag, &installed, &status);
+    ures_getByKey(indexLocale.getAlias(), _kIndexTag, installed.getAlias(), &status);
 
     if(U_SUCCESS(status)) {
-        localeCount = ures_getSize(&installed);
+        localeCount = ures_getSize(installed.getAlias());
         _installedLocales = (char **) uprv_malloc(sizeof(char*) * (localeCount+1));
         if (_installedLocales != NULL) {
-            ures_resetIterator(&installed);
-            while(ures_hasNext(&installed)) {
-                ures_getNextString(&installed, NULL, (const char **)&_installedLocales[i++], &status);
+            ures_resetIterator(installed.getAlias());
+            while(ures_hasNext(installed.getAlias())) {
+                ures_getNextString(installed.getAlias(), NULL, (const char **)&_installedLocales[i++], &status);
             }
             _installedLocales[i] = NULL;
             _installedLocalesCount = localeCount;

icu4c/source/common/locresdata.cpp

@@ -49,7 +49,6 @@ uloc_getTableStringWithFallback(const char *path, const char *locale,
                               UErrorCode *pErrorCode)
 {
 /*    char localeBuffer[ULOC_FULLNAME_CAPACITY*4];*/
-    UResourceBundle table, subTable;
     const UChar *item=NULL;
     UErrorCode errorCode;
     char explicitFallbackName[ULOC_FULLNAME_CAPACITY] = {0};
@@ -61,10 +60,6 @@ uloc_getTableStringWithFallback(const char *path, const char *locale,
     errorCode=U_ZERO_ERROR;
     icu::LocalUResourceBundlePointer rb(ures_open(path, locale, &errorCode));
 
-    // Automatically call ures_close() on these when they go out of scope.
-    icu::LocalUResourceBundlePointer tableCloser(&table);
-    icu::LocalUResourceBundlePointer subTableCloser(&subTable);
-
     if(U_FAILURE(errorCode)) {
         /* total failure, not even root could be opened */
         *pErrorCode=errorCode;
@@ -77,24 +72,24 @@ uloc_getTableStringWithFallback(const char *path, const char *locale,
     }
 
     for(;;){
-        ures_initStackObject(&table);
-        ures_initStackObject(&subTable);
-        ures_getByKeyWithFallback(rb.getAlias(), tableKey, &table, &errorCode);
+        icu::StackUResourceBundle table;
+        icu::StackUResourceBundle subTable;
+        ures_getByKeyWithFallback(rb.getAlias(), tableKey, table.getAlias(), &errorCode);
 
         if (subTableKey != NULL) {
             /*
-            ures_getByKeyWithFallback(&table,subTableKey, &subTable, &errorCode);
-            item = ures_getStringByKeyWithFallback(&subTable, itemKey, pLength, &errorCode);
+            ures_getByKeyWithFallback(table.getAlias(), subTableKey, subTable.getAlias(), &errorCode);
+            item = ures_getStringByKeyWithFallback(subTable.getAlias(), itemKey, pLength, &errorCode);
             if(U_FAILURE(errorCode)){
                 *pErrorCode = errorCode;
             }
             
             break;*/
             
-            ures_getByKeyWithFallback(&table,subTableKey, &table, &errorCode);
+            ures_getByKeyWithFallback(table.getAlias(), subTableKey, table.getAlias(), &errorCode);
         }
         if(U_SUCCESS(errorCode)){
-            item = ures_getStringByKeyWithFallback(&table, itemKey, pLength, &errorCode);
+            item = ures_getStringByKeyWithFallback(table.getAlias(), itemKey, pLength, &errorCode);
             if(U_FAILURE(errorCode)){
                 const char* replacement = NULL;
                 *pErrorCode = errorCode; /*save the errorCode*/
@@ -107,7 +102,7 @@ uloc_getTableStringWithFallback(const char *path, const char *locale,
                 }
                 /*pointer comparison is ok since uloc_getCurrentCountryID & uloc_getCurrentLanguageID return the key itself is replacement is not found*/
                 if(replacement!=NULL && itemKey != replacement){
-                    item = ures_getStringByKeyWithFallback(&table, replacement, pLength, &errorCode);
+                    item = ures_getStringByKeyWithFallback(table.getAlias(), replacement, pLength, &errorCode);
                     if(U_SUCCESS(errorCode)){
                         *pErrorCode = errorCode;
                         break;
@@ -126,7 +121,7 @@ uloc_getTableStringWithFallback(const char *path, const char *locale,
             *pErrorCode = errorCode;
             errorCode = U_ZERO_ERROR;
 
-            fallbackLocale = ures_getStringByKeyWithFallback(&table, "Fallback", &len, &errorCode);
+            fallbackLocale = ures_getStringByKeyWithFallback(table.getAlias(), "Fallback", &len, &errorCode);
             if(U_FAILURE(errorCode)){
                *pErrorCode = errorCode;
                 break;

icu4c/source/common/uresbund.cpp

@@ -21,6 +21,7 @@
 ******************************************************************************
 */
 
+#include "unicode/ures.h"
 #include "unicode/ustring.h"
 #include "unicode/ucnv.h"
 #include "charstr.h"
@@ -512,6 +513,18 @@ U_CFUNC void ures_initStackObject(UResourceBundle* resB) {
   ures_setIsStackObject(resB, TRUE);
 }
 
+U_NAMESPACE_BEGIN
+
+StackUResourceBundle::StackUResourceBundle() {
+    ures_initStackObject(&bundle);
+}
+
+StackUResourceBundle::~StackUResourceBundle() {
+    ures_close(&bundle);
+}
+
+U_NAMESPACE_END
+
 static UBool  // returns U_SUCCESS(*status)
 loadParentsExceptRoot(UResourceDataEntry *&t1,
                       char name[], int32_t nameCapacity,

icu4c/source/common/uresimp.h

@@ -11,6 +11,7 @@
 #define URESIMP_H
 
 #include "unicode/ures.h"
+#include "unicode/utypes.h"
 
 #include "uresdata.h"
 
@@ -82,6 +83,57 @@ struct UResourceBundle {
 
 U_CAPI void U_EXPORT2 ures_initStackObject(UResourceBundle* resB);
 
+#ifdef __cplusplus
+
+U_NAMESPACE_BEGIN
+
+/**
+ * \class StackUResourceBundle
+ * "Smart pointer" like class, closes a UResourceBundle via ures_close().
+ *
+ * This code:
+ *
+ *   StackUResourceBundle bundle;
+ *   foo(bundle.getAlias());
+ *
+ * Is equivalent to this code:
+ *
+ *   UResourceBundle bundle;
+ *   ures_initStackObject(&bundle);
+ *   foo(&bundle);
+ *   ures_close(&bundle);
+ *
+ * @see LocalUResourceBundlePointer
+ * @internal
+ */
+class StackUResourceBundle {
+public:
+    StackUResourceBundle();
+    ~StackUResourceBundle();
+
+    UResourceBundle* getAlias() { return &bundle; }
+
+    StackUResourceBundle(const StackUResourceBundle&) = delete;
+    StackUResourceBundle& operator=(const StackUResourceBundle&) = delete;
+
+    StackUResourceBundle(StackUResourceBundle&&) = delete;
+    StackUResourceBundle& operator=(StackUResourceBundle&&) = delete;
+
+private:
+    UResourceBundle bundle;
+
+    // No heap allocation. Use only on the stack.
+    static void* U_EXPORT2 operator new(size_t);
+    static void* U_EXPORT2 operator new[](size_t);
+#if U_HAVE_PLACEMENT_NEW
+    static void* U_EXPORT2 operator new(size_t, void*);
+#endif
+};
+
+U_NAMESPACE_END
+
+#endif  /* __cplusplus */
+
 /**
  * Opens a resource bundle for the locale;
  * if there is not even a base language bundle, then loads the root bundle;