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Member "dateutils-0.4.6/src/alist.c" (19 Mar 2019, 4396 Bytes) of package /linux/privat/dateutils-0.4.6.tar.xz:


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    1 /*** alist.c -- bog standard associative lists
    2  *
    3  * Copyright (C) 2010-2019 Sebastian Freundt
    4  *
    5  * Author:  Sebastian Freundt <freundt@ga-group.nl>
    6  *
    7  * This file is part of dateutils.
    8  *
    9  * Redistribution and use in source and binary forms, with or without
   10  * modification, are permitted provided that the following conditions
   11  * are met:
   12  *
   13  * 1. Redistributions of source code must retain the above copyright
   14  *    notice, this list of conditions and the following disclaimer.
   15  *
   16  * 2. Redistributions in binary form must reproduce the above copyright
   17  *    notice, this list of conditions and the following disclaimer in the
   18  *    documentation and/or other materials provided with the distribution.
   19  *
   20  * 3. Neither the name of the author nor the names of any contributors
   21  *    may be used to endorse or promote products derived from this
   22  *    software without specific prior written permission.
   23  *
   24  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR "AS IS" AND ANY EXPRESS OR
   25  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
   26  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   27  * DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   29  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   30  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
   31  * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
   32  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
   33  * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
   34  * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   35  *
   36  ***/
   37 #if defined HAVE_CONFIG_H
   38 # include "config.h"
   39 #endif  /* HAVE_CONFIG_H */
   40 #include <stddef.h>
   41 #include <stdlib.h>
   42 #include <stdbool.h>
   43 #include <string.h>
   44 #include "alist.h"
   45 #include "nifty.h"
   46 
   47 /* our alist is a simple flat char array with pointers behind every key
   48  * aligned to void* boundaries. */
   49 
   50 static const void**
   51 __assoc(alist_t al, const char *key)
   52 {
   53     for (const char *ap = al->data, *const ep = ap + al->dend; ap < ep;) {
   54         const char *kp;
   55         const void **res = (const void**)al->data;
   56 
   57         /* unrolled strcmp */
   58         for (kp = key; *ap && *ap == *kp; ap++, kp++);
   59 
   60         /* fast forward to void** boundary */
   61         res += (ap - al->data) / sizeof(res) + 1U;
   62 
   63         if (*ap == *kp) {
   64             /* match! invariant: ap == kp == '\0' */
   65             return res;
   66         } else if (*ap) {
   67             /* fast forward in void** increments */
   68             for (; ((const char*)res)[-1]; res++);
   69         }
   70         /* skip over ptr, start again */
   71         ap = (const char*)++res;
   72     }
   73     return NULL;
   74 }
   75 
   76 static bool
   77 __fitsp(alist_t al, size_t keylen)
   78 {
   79     return al->dend + keylen + 2 * sizeof(void**) < al->allz;
   80 }
   81 
   82 static int
   83 __chk_resz(alist_t al, size_t keylen)
   84 {
   85     if (UNLIKELY(!__fitsp(al, keylen))) {
   86         size_t ol = al->allz;
   87         void *tmp;
   88 
   89         al->allz = (al->allz * 2U) ?: 64U;
   90         if (UNLIKELY((tmp = realloc(al->data, al->allz)) == NULL)) {
   91             free_alist(al);
   92             return -1;
   93         }
   94         al->data = tmp;
   95         memset(al->data + ol, 0, al->allz - ol);
   96     }
   97     return 0;
   98 }
   99 
  100 
  101 /* public api */
  102 void
  103 free_alist(alist_t al)
  104 {
  105     if (LIKELY(al->data != NULL)) {
  106         free(al->data);
  107         memset(al, 0, sizeof(*al));
  108     }
  109     return;
  110 }
  111 
  112 const void*
  113 alist_assoc(alist_t al, const char *key)
  114 {
  115     const void **res;
  116 
  117     if (UNLIKELY(al->data == NULL)) {
  118         goto nada;
  119     } else if ((res = __assoc(al, key)) == NULL) {
  120         goto nada;
  121     }
  122     return *res;
  123 nada:
  124     return NULL;
  125 }
  126 
  127 void
  128 alist_put(alist_t al, const char *key, const void *val)
  129 {
  130     size_t klen = strlen(key);
  131 
  132     __chk_resz(al, klen);
  133     memcpy(al->data + al->dend, key, klen);
  134     /* round up to void** boundary */
  135     with (const void **data = (const void**)al->data) {
  136         data += (al->dend + klen) / sizeof(data) + 1U;
  137         *data++ = val;
  138         al->dend = (const char*)data - al->data;
  139     }
  140     return;
  141 }
  142 
  143 void
  144 alist_set(alist_t al, const char *key, const void *val)
  145 {
  146     const void **ass;
  147 
  148     if ((ass = __assoc(al, key)) != NULL) {
  149         *ass = val;
  150         return;
  151     }
  152     alist_put(al, key, val);
  153     return;
  154 }
  155 
  156 acons_t
  157 alist_next(alist_t al)
  158 {
  159     acons_t res;
  160 
  161     if (UNLIKELY((const char*)al->iter >= al->data + al->dend)) {
  162         al->iter = NULL;
  163         res = (acons_t){NULL, NULL};
  164     } else {
  165         const char *p = al->iter ?: al->data;
  166         size_t klen = strlen(p);
  167 
  168         with (const void *const *d = (const void*)p) {
  169             d += klen / sizeof(d) + 1U;
  170             res.key = p;
  171             res.val = *d++;
  172             al->iter = d;
  173         }
  174     }
  175     return res;
  176 }
  177 
  178 /* alist.c ends here */