str-utils.h

Go to the documentation of this file.

/*
 * Copyright (c) 2002-2012 Balabit
 * Copyright (c) 1998-2012 Balázs Scheidler
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * As an additional exemption you are allowed to compile & link against the
 * OpenSSL libraries as published by the OpenSSL project. See the file
 * COPYING for details.
 *
 */
 
#ifndef STR_UTILS_H_INCLUDED
#define STR_UTILS_H_INCLUDED 1
 
#include "syslog-ng.h"
#include <string.h>
 
/* functions that should be implemented by GLib but they aren't */
GString *g_string_assign_len(GString *s, const gchar *val, gint len);
gchar *g_string_steal(GString *s);
 
static inline GString *
g_string_append_unichar_optimized(GString *string, gunichar wc)
{
  if (wc < 0x80)
    g_string_append_c(string, (gchar) wc);
  else
    g_string_append_unichar(string, wc);
 
  return string;
}
 
/*
 * DO NOT USE THIS MACRO UNLESS STRICTLY NECESSARY FOR PERFORMANCE REASONS.
 *
 * This macro tries hard to zero-terminate the string without moving it to a
 * new buffer.
 *
 * It is expected to be used at sites where the length is known and where
 * the input string is expected to be properly NUL terminated but not always.
 *
 * The macro checks if the string is indeed NUL terminated and if it is it
 * just assigns the original pointer to dest.  If it's not, it allocates a
 * new string via g_alloca() so it is automatically freed when the current
 * scope exits.
 *
 * This does not work as an inline function as we use g_alloca() and that
 * would be freed when the inline function exits (e.g.  when it is in fact
 * not inlined).
 */
#define APPEND_ZERO(dest, value, value_len) \
  do { \
    gchar *__buf; \
    if (G_UNLIKELY(value[value_len] != 0)) \
      { \
        /* value is NOT zero terminated */ \
        \
        __buf = g_alloca(value_len + 1); \
        memcpy(__buf, value, value_len); \
        __buf[value_len] = 0; \
      } \
    else \
      { \
        /* value is zero terminated */ \
        __buf = (gchar *) value; \
      } \
    dest = __buf; \
  } while (0)
 
gchar *__normalize_key(const gchar *buffer);
gchar *normalize_flag(const gchar *buffer);
 
 
/* This version of strchr() is optimized for cases where the string we are
 * looking up characters in is often zero or one character in length.  In
 * those cases we can avoid the strchr() call, which can make a tight loop
 * doing a lot of strchr() calls a lot faster, especially as this function
 * is inlined.
 *
 * Naming: I originally wanted to use the original function as a prefix
 * (strchr), however that would potentially pollute the namespace of the
 * library that we are optimizing.  So I've added an underscore prefix in
 * order not to clash, with that it is still obvious that it intends to
 * behave the same as strchr().
 *
 * NOTE: don't use this unless strchr() really shows up in your profile.
 */
static inline const char *
_strchr_optimized_for_single_char_haystack(const char *str, int c)
{
  if (str[0] == c)
    return str;
  else if (str[0] == '\0')
    return NULL;
  if (str[1] == '\0')
    {
      if (c != '\0')
        return NULL;
      else
        return &str[1];
    }
  return strchr(str + 1, c);
}
 
/*
 * strsplit() splits the `str` into `maxtokens` pieces.
 * This version skips multiple `delims`.
 *
 */
static inline
gchar **strsplit(const gchar *str, char delim, gint maxtokens)
{
  if (!str || delim == '\0')
    return NULL;
 
  const gchar *delim_pos = NULL;
  const gchar *remainder = str;
  GPtrArray *array = g_ptr_array_new();
 
  if (maxtokens < 1)
    maxtokens = G_MAXINT;
 
  for (delim_pos = strchr(remainder, delim); delim_pos && maxtokens; maxtokens--)
    {
      const gchar *d = delim_pos;
      while (d && *d++ == delim);
      if (!d)
        break;
      --d;
      gint len = delim_pos - remainder;
 
      if (len > 0)
        g_ptr_array_add(array, g_strndup(remainder, len));
      remainder = d;
      delim_pos = strchr(remainder, delim);
    }
 
  if (remainder)
    g_ptr_array_add(array, g_strdup(remainder));
  g_ptr_array_add(array, NULL);
 
  return (gchar **) g_ptr_array_free(array, FALSE);
}
 
#endif