sds: add printf style function

Signed-off-by: Eduardo Silva <[email protected]>

include/cfl/cfl_sds.h

@@ -60,5 +60,6 @@ cfl_sds_t cfl_sds_cat(cfl_sds_t s, const char *str, int len);
 cfl_sds_t cfl_sds_create_size(size_t size);
 void cfl_sds_set_len(cfl_sds_t s, size_t len);
 void cfl_sds_cat_safe(cfl_sds_t *buf, const char *str, int len);
+cfl_sds_t cfl_sds_printf(cfl_sds_t *sds, const char *fmt, ...);
 
 #endif

src/cfl_sds.c

@@ -22,8 +22,10 @@
  * string storage
  */
 
+#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <stdarg.h>
 #include <inttypes.h>
 
 #include <cfl/cfl_sds.h>
@@ -181,3 +183,54 @@ void cfl_sds_cat_safe(cfl_sds_t *buf, const char *str, int len)
     *buf = tmp;
 }
 
+cfl_sds_t cfl_sds_printf(cfl_sds_t *sds, const char *fmt, ...)
+{
+    va_list ap;
+    int len = strlen(fmt)*2;
+    int size;
+    cfl_sds_t tmp = NULL;
+    cfl_sds_t s;
+    struct cfl_sds *head;
+
+    if (len < 64) len = 64;
+
+    s = *sds;
+    if (cfl_sds_avail(s)< len) {
+        tmp = cfl_sds_increase(s, len);
+        if (!tmp) {
+            return NULL;
+        }
+        *sds = s = tmp;
+    }
+
+    va_start(ap, fmt);
+    size = vsnprintf((char *) (s + cfl_sds_len(s)), cfl_sds_avail(s), fmt, ap);
+    if (size < 0) {
+        va_end(ap);
+        return NULL;
+    }
+    va_end(ap);
+
+    if (size > cfl_sds_avail(s)) {
+        tmp = cfl_sds_increase(s, size);
+        if (!tmp) {
+            return NULL;
+        }
+        *sds = s = tmp;
+
+        va_start(ap, fmt);
+        size = vsnprintf((char *) (s + cfl_sds_len(s)), cfl_sds_avail(s), fmt, ap);
+        if (size > cfl_sds_avail(s)) {
+            va_end(ap);
+            return NULL;
+        }
+        va_end(ap);
+    }
+
+    head = CFL_SDS_HEADER(s);
+    head->len += size;
+    s[head->len] = '\0';
+
+    return s;
+}
+

tests/CMakeLists.txt

@@ -2,6 +2,7 @@ include_directories(lib/acutest)
 
 set(UNIT_TESTS_FILES
   kv.c
+  sds.c
   hash.c
   list.c
   )

tests/sds.c

@@ -0,0 +1,59 @@
+/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+
+/*  CFL
+ *  ===
+ *  Copyright (C) 2022 The CFL Authors
+ *
+ *  Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+#include <cfl/cfl.h>
+#include "cfl_tests_internal.h"
+
+static void test_sds_usage()
+{
+    cfl_sds_t s;
+
+    s = cfl_sds_create("test");
+    TEST_CHECK(s != NULL);
+    TEST_CHECK(cfl_sds_len(s) == 4);
+    TEST_CHECK(cfl_sds_alloc(s) == 4);
+    TEST_CHECK(strcmp("test", s) == 0);
+
+    s = cfl_sds_cat(s, ",cat message", 12);
+    TEST_CHECK(strcmp("test,cat message", s) == 0);
+
+    cfl_sds_destroy(s);
+}
+
+static void test_sds_printf()
+{
+    int len;
+    cfl_sds_t s;
+    cfl_sds_t tmp;
+    char *str = "0123456789ABCDEFGHIJQLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvewxyz";
+
+    s = cfl_sds_create_size(10);
+    tmp = cfl_sds_printf(&s, "%s=%s", str, str);
+
+    len = (strlen(str) * 2) + 1;
+    TEST_CHECK(tmp == s);
+    TEST_CHECK(cfl_sds_len(s) == len);
+    cfl_sds_destroy(s);
+}
+
+TEST_LIST = {
+    { "sds_usage" , test_sds_usage},
+    { "sds_printf", test_sds_printf},
+    { 0 }
+};