view netinstall/hash.cc @ 5253:b6a398dbb403

Fewer algorithmic complexity surprises, nicer errors, mapcarX(), maplist() src/ChangeLog addition: 2010-09-01 Aidan Kehoe <kehoea@parhasard.net> * fns.c (list_merge, list_array_merge_into_list) (list_array_merge_into_array): Avoid algorithmic complexity surprises when checking for circularity in these functions. (Freduce): Fix some formatting, in passing. (mapcarX): Drop the SOME_OR_EVERY argument to this function; instead, take CALLER, a symbol reflecting the Lisp-visible function that called mapcarX(). Use CALLER with mapping_interaction_error() when sequences are modified illegally. Don't cons with #'some, #'every, not even a little. (Fmapconcat, FmapcarX, Fmapvector, Fmapcan, Fmapc, Fmap) (Fmap_into, Fsome, Fevery): Call mapcarX() with its new arguments. (Fmapcan): Don't unnecessarily complicate the nconc call. (maplist): Take CALLER, a symbol reflecting the Lisp-visible function that called maplist(), rather than having separate arguments to indicate mapl vs. mapcon. Avoid algorithmic complexity surprises when checking for circularity. In #'mapcon, check a given stretch of result for well-formedness once, which was not previously the case, despite what the comments said. (Fmaplist, Fmapl, Fmapcon): Call maplist() with its new arguments.
author Aidan Kehoe <kehoea@parhasard.net>
date Wed, 01 Sep 2010 12:51:32 +0100
parents 3078fd1074e8
children
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/*
 * Copyright (c) 2000, Red Hat, Inc.
 *
 *     This program is free software; you can redistribute it and/or modify
 *     it under the terms of the GNU General Public License as published by
 *     the Free Software Foundation; either version 2 of the License, or
 *     (at your option) any later version.
 *
 *     A copy of the GNU General Public License can be found at
 *     http://www.gnu.org/
 *
 * Written by DJ Delorie <dj@cygnus.com>
 *
 */

/* Simple hash class for install.cc */

#include "win32.h"
#include <stdlib.h>
#include <string.h>

#include "hash.h"

class hash_internals {
public:
  char **keys;
  int numkeys;
  int maxkeys;
  int prev_index;
};

hash::hash ()
{
  h = new hash_internals;
  h->numkeys = 0;
  h->maxkeys = 10;
  h->keys = (char **) malloc (h->maxkeys * sizeof (char *));
  h->prev_index = 0;
}

hash::~hash ()
{
  free (h->keys);
  free (h);
}


void
hash::add (char *string)
{
  int i;
  for (i=0; i<h->numkeys; i++)
    if (strcmp (h->keys[i], string) == 0)
      return;
  if (h->numkeys >= h->maxkeys)
    {
      h->maxkeys += 10;
      h->keys = (char **) realloc (h->keys, h->maxkeys * sizeof (char *));
    }

  h->keys[h->numkeys] = _strdup (string);
  h->numkeys ++;
}


int
hash::has (char *string)
{
  int i;
  for (i=0; i<h->numkeys; i++)
    if (strcmp (h->keys[i], string) == 0)
      return 1;
  return 0;
}

char *
hash::enumerate (char *prev)
{
  if (prev == 0)
    h->prev_index = -1;
  h->prev_index ++;
  if (h->prev_index >= h->numkeys)
    return 0;
  return h->keys[h->prev_index];
}

static int CDECL
rev_len (const void *va, const void *vb)
{
  char *a = *(char **)va;
  char *b = *(char **)vb;
  return strcmp (b, a);
}

void
hash::reverse_sort ()
{
  qsort (h->keys, h->numkeys, sizeof (h->keys[0]), rev_len);
}