Merge branch 'gstring-optimizations' into 'main'

Some GString optimizations

See merge request GNOME/glib!3199

glib/gmarkup.c

@@ -195,13 +195,6 @@ free_list_node (GMarkupParseContext *context, GSList *node)
   context->spare_list_nodes = g_slist_concat (node, context->spare_list_nodes);
 }
 
-static inline void
-string_blank (GString *string)
-{
-  string->str[0] = '\0';
-  string->len = 0;
-}
-
 /**
  * g_markup_parse_context_new:
  * @parser: a #GMarkupParser
@@ -856,7 +849,7 @@ release_chunk (GMarkupParseContext *context, GString *str)
       g_string_free (str, TRUE);
       return;
     }
-  string_blank (str);
+  g_string_truncate (str, 0);
   node = get_list_node (context, str);
   context->spare_chunks = g_slist_concat (node, context->spare_chunks);
 }
@@ -881,7 +874,7 @@ add_to_partial (GMarkupParseContext *context,
     }
 
   if (text_start != text_end)
-    g_string_insert_len (context->partial_chunk, -1,
+    g_string_append_len (context->partial_chunk,
                          text_start, text_end - text_start);
 }
 
@@ -889,7 +882,7 @@ static inline void
 truncate_partial (GMarkupParseContext *context)
 {
   if (context->partial_chunk != NULL)
-    string_blank (context->partial_chunk);
+    g_string_truncate (context->partial_chunk, 0);
 }
 
 static inline const gchar*

glib/gstring.c

@@ -75,22 +75,29 @@
  */
 
 static void
-g_string_maybe_expand (GString *string,
+g_string_expand (GString *string,
-                       gsize    len)
+                 gsize    len)
 {
   /* Detect potential overflow */
   if G_UNLIKELY ((G_MAXSIZE - string->len - 1) < len)
     g_error ("adding %" G_GSIZE_FORMAT " to string would overflow", len);
 
-  if (string->len + len >= string->allocated_len)
+  string->allocated_len = g_nearest_pow (string->len + len + 1);
-    {
+  /* If the new size is bigger than G_MAXSIZE / 2, only allocate enough
-      string->allocated_len = g_nearest_pow (string->len + len + 1);
+   * memory for this string and don't over-allocate.
-      /* If the new size is bigger than G_MAXSIZE / 2, only allocate enough
+   */
-       * memory for this string and don't over-allocate. */
+  if (string->allocated_len == 0)
-      if (string->allocated_len == 0)
+    string->allocated_len = string->len + len + 1;
-        string->allocated_len = string->len + len + 1;
+
-      string->str = g_realloc (string->str, string->allocated_len);
+  string->str = g_realloc (string->str, string->allocated_len);
-    }
+}
+
+static inline void
+g_string_maybe_expand (GString *string,
+                       gsize    len)
+{
+  if (G_UNLIKELY (string->len + len >= string->allocated_len))
+    g_string_expand (string, len);
 }
 
 /**
@@ -113,7 +120,7 @@ g_string_sized_new (gsize dfl_size)
   string->len   = 0;
   string->str   = NULL;
 
-  g_string_maybe_expand (string, MAX (dfl_size, 64));
+  g_string_expand (string, MAX (dfl_size, 64));
   string->str[0] = 0;
 
   return string;
@@ -351,8 +358,8 @@ g_string_assign (GString     *string,
  * Returns: (transfer none): @string
  */
 GString *
-g_string_truncate (GString *string,
+(g_string_truncate) (GString *string,
-                   gsize    len)
+                     gsize    len)
 {
   g_return_val_if_fail (string != NULL, NULL);
 
@@ -532,8 +539,8 @@ g_string_append_uri_escaped (GString     *string,
  * Returns: (transfer none): @string
  */
 GString *
-g_string_append (GString     *string,
+(g_string_append) (GString     *string,
-                 const gchar *val)
+                   const gchar *val)
 {
   return g_string_insert_len (string, -1, val, -1);
 }
@@ -557,9 +564,9 @@ g_string_append (GString     *string,
  * Returns: (transfer none): @string
  */
 GString *
-g_string_append_len (GString     *string,
+(g_string_append_len) (GString     *string,
-                     const gchar *val,
+                       const gchar *val,
-                     gssize       len)
+                       gssize       len)
 {
   return g_string_insert_len (string, -1, val, len);
 }
@@ -574,10 +581,9 @@ g_string_append_len (GString     *string,
  *
  * Returns: (transfer none): @string
  */
-#undef g_string_append_c
 GString *
-g_string_append_c (GString *string,
+(g_string_append_c) (GString *string,
-                   gchar    c)
+                     gchar    c)
 {
   g_return_val_if_fail (string != NULL, NULL);
 

glib/gstring.h

@@ -35,6 +35,7 @@
 #include <glib/gunicode.h>
 #include <glib/gbytes.h>
 #include <glib/gutils.h>  /* for G_CAN_INLINE */
+#include <string.h>
 
 G_BEGIN_DECLS
 
@@ -162,13 +163,15 @@ GString*     g_string_append_uri_escaped (GString         *string,
                                           const gchar     *reserved_chars_allowed,
                                           gboolean         allow_utf8);
 
-/* -- optimize g_strig_append_c --- */
+#ifndef __GTK_DOC_IGNORE__
+
 #ifdef G_CAN_INLINE
+G_ALWAYS_INLINE
 static inline GString*
 g_string_append_c_inline (GString *gstring,
                           gchar    c)
 {
-  if (gstring->len + 1 < gstring->allocated_len)
+  if (G_LIKELY (gstring->len + 1 < gstring->allocated_len))
     {
       gstring->str[gstring->len++] = c;
       gstring->str[gstring->len] = 0;
@@ -178,8 +181,53 @@ g_string_append_c_inline (GString *gstring,
   return gstring;
 }
 #define g_string_append_c(gstr,c)       g_string_append_c_inline (gstr, c)
+
+G_ALWAYS_INLINE
+static inline GString *
+g_string_append_len_inline (GString    *gstring,
+                            const char *val,
+                            gssize      len)
+{
+  if (len < 0)
+    len = strlen (val);
+
+  if (G_LIKELY (gstring->len + len < gstring->allocated_len))
+    {
+      char *end = gstring->str + gstring->len;
+      if (G_LIKELY (val + len <= end || val > end + len))
+        memcpy (end, val, len);
+      else
+        memmove (end, val, len);
+      gstring->len += len;
+      gstring->str[gstring->len] = 0;
+      return gstring;
+    }
+  else
+    return g_string_insert_len (gstring, -1, val, len);
+}
+#define g_string_append_len(gstr,val,len) g_string_append_len_inline (gstr, val, len)
+
+G_ALWAYS_INLINE
+static inline GString *
+g_string_truncate_inline (GString *gstring,
+                          gsize    len)
+{
+  gstring->len = MIN (len, gstring->len);
+  gstring->str[gstring->len] = '\0';
+  return gstring;
+}
+
+#define g_string_truncate(gstr,len) g_string_truncate_inline (gstr, len)
+
+#if G_GNUC_CHECK_VERSION (2, 0)
+
+#define g_string_append(gstr,val) g_string_append_len (gstr, val, __builtin_constant_p (val) ? (gssize) strlen (val) : (gssize) -1)
+
+#endif
+
 #endif /* G_CAN_INLINE */
 
+#endif /* __GTK_DOC_IGNORE__ */
 
 GLIB_DEPRECATED
 GString *g_string_down (GString *string);

glib/tests/string.c

@@ -193,8 +193,11 @@ test_string_append_c (void)
     else
       (g_string_append_c) (string, 'a'+(i%26));
 
-  g_assert((strlen("hi pete!") + 10000) == string->len);
+  g_assert_true ((strlen("hi pete!") + 10000) == string->len);
-  g_assert((strlen("hi pete!") + 10000) == strlen(string->str));
+  g_assert_true ((strlen("hi pete!") + 10000) == strlen(string->str));
+
+  for (i = 0; i < 10000; i++)
+    g_assert_true (string->str[strlen ("Hi pete!") + i] == 'a' + (i%26));
 
   g_string_free (string, TRUE);
 }
@@ -203,17 +206,35 @@ static void
 test_string_append (void)
 {
   GString *string;
+  char *tmp;
+  int i;
+
+  tmp = g_strdup ("more");
 
   /* append */
   string = g_string_new ("firsthalf");
-  g_string_append (string, "lasthalf");
+  g_string_append (string, "last");
+  (g_string_append) (string, "half");
+
   g_assert_cmpstr (string->str, ==, "firsthalflasthalf");
+
+  i = 0;
+  g_string_append (string, &tmp[i++]);
+  (g_string_append) (string, &tmp[i++]);
+  g_assert_true (i == 2);
+
+  g_assert_cmpstr (string->str, ==, "firsthalflasthalfmoreore");
+
   g_string_free (string, TRUE);
 
   /* append_len */
   string = g_string_new ("firsthalf");
-  g_string_append_len (string, "lasthalfjunkjunk", strlen ("lasthalf"));
+  g_string_append_len (string, "lasthalfjunkjunk", strlen ("last"));
-  g_assert_cmpstr (string->str, ==, "firsthalflasthalf");
+  (g_string_append_len) (string, "halfjunkjunk", strlen ("half"));
+  g_string_append_len (string, "more", -1);
+  (g_string_append_len) (string, "ore", -1);
+
+  g_assert_cmpstr (string->str, ==, "firsthalflasthalfmoreore");
   g_string_free (string, TRUE);
 }
 
@@ -415,7 +436,7 @@ test_string_truncate (void)
   g_assert (string->len == strlen("testing"));
   g_assert_cmpstr (string->str, ==, "testing");
 
-  g_string_truncate (string, 4);
+  (g_string_truncate) (string, 4);
   g_assert (string->len == 4);
   g_assert_cmpstr (string->str, ==, "test");