Add uc_dstr_copy

include/ucore/dstr.h

@@ -40,6 +40,15 @@ void uc_dstr_init(struct DStr *str);
  */
 void uc_dstr_destroy(struct DStr *str);
 
+/** Copy a DStr
+ *
+ * @param dest destination string to copy to, must not contain an existing string
+ * @param src DStr to copy
+ *
+ * @return 0 if success, != 0 if allocation fails
+ */
+int uc_dstr_copy(struct DStr *dest, const struct DStr *src);
+
 /**
  * @return the available/unused tail bytes in the string.
  */

src/dstr.c

@@ -17,6 +17,27 @@ void uc_dstr_destroy(struct DStr *str)
     free(str->str);
 }
 
+int uc_dstr_copy(struct DStr *dest, const struct DStr *src)
+{
+    char *s;
+
+    uc_dstr_init(dest);
+    if (src->allocated == 0) {
+        return 0;
+    }
+
+    s = uc_dstr_put(dest, src->len);
+    if (s == NULL) {
+        return -1;
+    }
+
+    //+1 to copy a potential nul terminator, uc_dstr_put 
+    //guarantees we have room for it.
+    memcpy(s, src->str, UC_MIN(src->len + 1, src->allocated));
+
+    return 0;
+}
+
 size_t uc_dstr_available(const struct DStr *str)
 {
     return str->allocated - str->len;

test/test_dstr.c

@@ -140,6 +140,33 @@ START_TEST (test_dstr_sprintf)
 
 END_TEST
 
+START_TEST (test_dstr_copy)
+    struct DStr str;
+    struct DStr copy;
+    size_t rc; 
+
+    uc_dstr_init(&str);
+    rc = uc_dstr_put_str(&str, "123");
+    ck_assert_int_eq(rc, 0);
+    
+    rc = uc_dstr_copy(&copy, &str);
+    ck_assert_int_eq(rc, 0);
+    ck_assert_str_eq(uc_dstr_str(&copy), uc_dstr_str(&str));
+    
+    uc_dstr_destroy(&str);
+    uc_dstr_destroy(&copy);
+    uc_dstr_init(&str);
+    uc_dstr_init(&copy);
+
+    rc = uc_dstr_copy(&copy, &str);
+    ck_assert_int_eq(rc, 0);
+    ck_assert_str_eq(uc_dstr_str(&copy), "");
+
+    uc_dstr_destroy(&str);
+    uc_dstr_destroy(&copy);
+
+END_TEST
+
 Suite *dstr_suite(void)
 {
     Suite *s = suite_create("dstr");
@@ -150,6 +177,7 @@ Suite *dstr_suite(void)
     tcase_add_test(tc, test_dstr_replace);
     tcase_add_test(tc, test_dstr_filter);
     tcase_add_test(tc, test_dstr_sprintf);
+    tcase_add_test(tc, test_dstr_copy);
 
     suite_add_tcase(s, tc);