Introduce g_string_overwrite(_len)? for overwriting parts of strings (#368686, Samuel Cormier-Iijima)

svn path=/trunk/; revision=5563

ChangeLog

@@ -1,3 +1,9 @@
+2007-06-15  Mathias Hasselmann  <mathias.hasselmann@gmx.de>
+
+	* build, tests/string-test.c, glib/glib.symbols, 
+	glib/gstring.c, glib/gstring.h: Introduce g_string_overwrite(_len)?
+	for overwriting parts of strings (#368686, Samuel Cormier-Iijima)
+
 2007-06-14  Cody Russell  <bratsche@gnome.org>
 
 	* gobject/gtype.c (g_type_class_add_private): Check for 0-sized

glib/glib.symbols

@@ -1143,6 +1143,8 @@ g_string_insert_len
 g_string_insert_unichar
 g_string_new
 g_string_new_len
+g_string_overwrite
+g_string_overwrite_len
 g_string_prepend
 g_string_prepend_c
 g_string_prepend_len

glib/gstring.c

@@ -1022,6 +1022,76 @@ g_string_insert_unichar (GString *string,
   return string;
 }
 
+/**
+ * g_string_overwrite:
+ * @string: a #GString
+ * @pos: the position at which to start overwriting
+ * @val: the string that will overwrite the @string starting at @pos
+ * 
+ * Overwrites part of a string, lengthening it if necessary.
+ * 
+ * Return value: @string
+ *
+ * Since: 2.14
+ **/
+GString *
+g_string_overwrite (GString     *string,
+		    gsize        pos,
+		    const gchar *val)
+{
+  g_return_val_if_fail (val != NULL, string);
+  return g_string_overwrite_len (string, pos, val, strlen (val));
+}
+
+/**
+ * g_string_overwrite_len:
+ * @string: a #GString
+ * @pos: the position at which to start overwriting
+ * @val: the string that will overwrite the @string starting at @pos
+ * @len: the number of bytes to write from @val
+ * 
+ * Overwrites part of a string, lengthening it if necessary. This function
+ * will work with embedded NULLs.
+ * 
+ * Return value: @string
+ *
+ * Since: 2.14
+ **/
+GString *
+g_string_overwrite_len (GString       *string,
+			gsize          pos,
+			const gchar   *val,
+			gssize         len)
+{
+  gsize end;
+
+  g_return_val_if_fail (string != NULL, NULL);
+
+  if (!len)
+    return string;
+
+  g_return_val_if_fail (val != NULL, string);
+  g_return_val_if_fail (pos <= string->len, string);
+
+  if (len < 0)
+    len = strlen (val);
+
+  end = pos + len;
+
+  if (end > string->len)
+    g_string_maybe_expand (string, end - string->len);
+
+  memcpy (string->str + pos, val, len);
+
+  if (end > string->len)
+    {
+      string->str[end] = '\0';
+      string->len = end;
+    }
+
+  return string;
+}
+
 /**
  * g_string_erase:
  * @string: a #GString

glib/gstring.h

@@ -105,6 +105,13 @@ GString*     g_string_insert_c          (GString	 *string,
 GString*     g_string_insert_unichar    (GString	 *string,
 					 gssize		  pos,    
 					 gunichar	  wc);
+GString*     g_string_overwrite         (GString	 *string,
+					 gsize		  pos,    
+					 const gchar	 *val);
+GString*     g_string_overwrite_len     (GString	 *string,
+					 gsize		  pos,    
+					 const gchar	 *val,
+					 gssize           len);
 GString*     g_string_erase	        (GString	 *string,
 					 gssize		  pos,
 					 gssize		  len);

tests/string-test.c

@@ -258,6 +258,26 @@ main (int   argc,
   g_string_free (string1, TRUE);
   g_string_free (string2, TRUE);
 
+  /* overwriting functions */
+  string1 = g_string_new ("testing");
+
+  g_string_overwrite (string1, 4, " and expand");
+  g_assert (15 == string1->len);
+  g_assert ('\0' == string1->str[15]);
+  g_assert (g_str_equal ("test and expand", string1->str));
+
+  g_string_overwrite (string1, 5, "NOT-");
+  g_assert (15 == string1->len);
+  g_assert ('\0' == string1->str[15]);
+  g_assert (g_str_equal ("test NOT-expand", string1->str));
+
+  g_string_overwrite_len (string1, 9, "blablabla", 6);
+  g_assert (15 == string1->len);
+  g_assert ('\0' == string1->str[15]);
+  g_assert (g_str_equal ("test NOT-blabla", string1->str));
+
+  g_string_free (string1, TRUE);
+
   /* Check handling of embedded ASCII 0 (NUL) characters in GString. */
   string1 = g_string_new ("fiddle");
   string2 = g_string_new ("fiddle");