Better resize rotine, linear instead of double.

Increment in steps linearly instead of doubling them, otherwise it
will get to maximum limit of 4096 too soon.

Also replace the loop with simple math.



SVN revision: 46585

legacy/eina/src/lib/eina_strbuf.c

@@ -717,50 +717,34 @@ _eina_strbuf_grow(Eina_Strbuf *buf, size_t size)
 static inline Eina_Bool
 _eina_strbuf_resize(Eina_Strbuf *buf, size_t size)
 {
+   size_t new_size, new_step, delta;
    char *buffer;
-   size_t new_size;
-   size_t new_step;
 
    size += 1; // Add extra space for '\0'
 
-   new_size = buf->size;
-   new_step = buf->step;
-
-   /*
-    * first we have to determine the new buffer size
-    */
    if (size == buf->size)
      /* nothing to do */
      return EINA_TRUE;
    else if (size > buf->size)
-     {
-	/* enlarge the buffer */
-	while (size > new_size)
-	  {
-	     new_size += new_step;
-	     if (new_step < EINA_STRBUF_MAX_STEP)
-	       new_step *= 2;
-	     if (new_step > EINA_STRBUF_MAX_STEP)
-	       new_step = EINA_STRBUF_MAX_STEP;
-	  }
-     }
+     delta = size - buf->size;
+   else
+     delta = buf->size - size;
+
+   /* check if should keep the same step (just used while growing) */
+   if ((delta <= buf->step) && (size > buf->size))
+     new_step = buf->step;
    else
      {
-	/* shrink the buffer */
-	if (new_step > EINA_STRBUF_INIT_STEP)
-	  new_step /= 2;
-	while (new_size - new_step > size)
-	  {
-	     new_size -= new_step;
-	     if (new_step > EINA_STRBUF_INIT_STEP)
-	       new_step /= 2;
-	     if (new_step < EINA_STRBUF_INIT_STEP)
-	       new_step = EINA_STRBUF_INIT_STEP;
-	  }
+	new_step = (((delta / EINA_STRBUF_INIT_STEP) + 1)
+		    * EINA_STRBUF_INIT_STEP);
+
+	if (new_step > EINA_STRBUF_MAX_STEP)
+	  new_step = EINA_STRBUF_MAX_STEP;
      }
 
+   new_size = (((size / new_step) + 1) * new_step);
+
    /* reallocate the buffer to the new size */
-   eina_error_set(0);
    buffer = realloc(buf->buf, new_size);
    if (EINA_UNLIKELY(!buffer))
      {
@@ -771,6 +755,7 @@ _eina_strbuf_resize(Eina_Strbuf *buf, size_t size)
    buf->buf = buffer;
    buf->size = new_size;
    buf->step = new_step;
+   eina_error_set(0);
    return EINA_TRUE;
 }
 

legacy/eina/src/tests/eina_test_strbuf.c

@@ -252,6 +252,74 @@ START_TEST(strbuf_replace)
 }
 END_TEST
 
+START_TEST(strbuf_realloc)
+{
+   Eina_Strbuf *buf;
+   char pattern[1024 * 16];
+   unsigned int i;
+   size_t sz;
+
+   for (i = 0; i < sizeof(pattern) - 1; i++)
+     pattern[i] = 'a' + (i % 26);
+   pattern[i] = '\0';
+
+   eina_init();
+
+   buf = eina_strbuf_new();
+   fail_if(!buf);
+
+   sz = 0;
+
+   eina_strbuf_append_length(buf, pattern, 1);
+   fail_if(eina_strbuf_length_get(buf) != sz + 1);
+   fail_if(memcmp(eina_strbuf_string_get(buf) + sz, pattern, 1));
+   sz += 1;
+
+   eina_strbuf_append_length(buf, pattern, 32);
+   fail_if(eina_strbuf_length_get(buf) != sz + 32);
+   fail_if(memcmp(eina_strbuf_string_get(buf) + sz, pattern, 32));
+   sz += 32;
+
+   eina_strbuf_append_length(buf, pattern, 64);
+   fail_if(eina_strbuf_length_get(buf) != sz + 64);
+   fail_if(memcmp(eina_strbuf_string_get(buf) + sz, pattern, 64));
+   sz += 64;
+
+   eina_strbuf_append_length(buf, pattern, 128);
+   fail_if(eina_strbuf_length_get(buf) != sz + 128);
+   fail_if(memcmp(eina_strbuf_string_get(buf) + sz, pattern, 128));
+   sz += 128;
+
+   eina_strbuf_append_length(buf, pattern, 4096);
+   fail_if(eina_strbuf_length_get(buf) != sz + 4096);
+   fail_if(memcmp(eina_strbuf_string_get(buf) + sz, pattern, 4096));
+   sz += 4096;
+
+   eina_strbuf_append_length(buf, pattern, sizeof(pattern) - 1);
+   fail_if(eina_strbuf_length_get(buf) != sz + sizeof(pattern) - 1);
+   fail_if(memcmp(eina_strbuf_string_get(buf) + sz, pattern, sizeof(pattern) - 1));
+   sz += sizeof(pattern) - 1;
+
+
+   eina_strbuf_remove(buf, 1024, 1024 + 1234);
+   fail_if(eina_strbuf_length_get(buf) != sz - 1234);
+   sz -= 1234;
+
+   eina_strbuf_remove(buf, 0, 0 + 8192);
+   fail_if(eina_strbuf_length_get(buf) != sz - 8192);
+   sz -= 8192;
+
+   eina_strbuf_remove(buf, 0, 0 + 32);
+   fail_if(eina_strbuf_length_get(buf) != sz - 32);
+   sz -= 32;
+
+
+   eina_strbuf_free(buf);
+
+   eina_shutdown();
+}
+END_TEST
+
 START_TEST(strbuf_append_realloc)
 {
    Eina_Strbuf *buf;
@@ -330,6 +398,7 @@ eina_test_strbuf(TCase *tc)
    tcase_add_test(tc, strbuf_append);
    tcase_add_test(tc, strbuf_insert);
    tcase_add_test(tc, strbuf_replace);
+   tcase_add_test(tc, strbuf_realloc);
    tcase_add_test(tc, strbuf_append_realloc);
    tcase_add_test(tc, strbuf_prepend_realloc);
 }