engine/stringbucket.c

   1 /*
   2     stringbucket.c - MaLa stringbucket handling
   3
   4   Copyright (C) 2004, 2005, Christian Thaeter <chth@gmx.net>
   5
   6   This program is free software; you can redistribute it and/or modify
   7   it under the terms of the GNU General Public License version 2 as
   8   published by the Free Software Foundation.
   9
  10   This program is distributed in the hope that it will be useful,
  11   but WITHOUT ANY WARRANTY; without even the implied warranty of
  12   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13   GNU General Public License for more details.
  14
  15   You should have received a copy of the GNU General Public License
  16   along with this program; if not, contact me.
  17
  18 */
  19 \f
  20 #define _GNU_SOURCE
  21
  22 #include <stdlib.h>
  23 #include <search.h>
  24 #include "stringbucket.h"
  25 #include "strings.h"
  26
  27
  28 void mala_stringbucket_init (MalaStringBucket bucket,
  29                              mala_string_cmp_fn cmpfn,
  30                              void (*freefn)(void*))
  31 {
  32   bucket->bucket = NULL;
  33   bucket->cmpfn = cmpfn;
  34   bucket->freefn = freefn;
  35   bucket->gc_trace = MALA_NOTRACE;
  36 }
  37
  38 void
  39 mala_stringbucket_erase (MalaStringBucket bucket)
  40 {
  41   tdestroy (bucket->bucket, (void(*)(void*)) mala_string_free_forced);
  42   bucket->bucket = NULL;
  43 }
  44
  45
  46 int
  47 mala_stringbucket_exists_cstr (MalaStringBucket bucket, const char * cstr)
  48 {
  49   mala_string tmp = MALA_STRING_AUTO (cstr);
  50   return !!tfind (&tmp, &bucket->bucket, bucket->cmpfn);
  51 }
  52
  53 /*
  54  * remove string from bucket
  55  */
  56 MalaString
  57 mala_stringbucket_string_remove (MalaString_ref self)
  58 {
  59   MALA_ASSERT(self);
  60
  61   if (!(*self)->bucket)
  62     return *self;
  63
  64   /* self is the last reference in the bucket */
  65   if ((*self)->refcnt <= 8)
  66     {
  67       if ((*self)->user && (*self)->bucket->freefn)
  68         (*self)->bucket->freefn ((*self)->user);
  69       (*self)->user = NULL;
  70
  71       tdelete (*self, &(*self)->bucket->bucket, (*self)->bucket->cmpfn);
  72       (*self)->bucket = NULL;
  73
  74       /* buckets counted as reference too */
  75       (*self)->refcnt -= 4;
  76
  77       return *self;
  78     }
  79   else
  80     {
  81       /* make a new string */
  82       (*self)->refcnt -= 4;
  83       return *self = mala_string_new ((*self)->str, NULL);
  84     }
  85 }
  86
  87
  88 MalaString
  89 mala_stringbucket_insert (MalaStringBucket bucket, MalaString_ref s)
  90 {
  91   MalaString_ref loc;
  92
  93   /* no bucket */
  94   if (!bucket)
  95     return *s;
  96
  97   /* already in this bucket */
  98   if (bucket && (*s)->bucket == bucket)
  99     return *s;
 100
 101   /* in another bucket, remove it */
 102   if ((*s)->bucket)
 103     {
 104       mala_stringbucket_string_remove (s);
 105     }
 106
 107   /*create in bucket*/
 108   mala_string tmp = MALA_STRING_AUTO ((*s)->str);
 109
 110   /*create in bucket*/
 111   loc = (MalaString_ref) tsearch (&tmp, &bucket->bucket, bucket->cmpfn);
 112   if (!loc)
 113     return NULL;
 114
 115   if (*loc == &tmp)
 116     {
 117       /*not in bucket*/
 118       (*s)->bucket = bucket;
 119       *loc = *s;
 120     }
 121   else
 122     {
 123       /*string already in bucket*/
 124       mala_string_free (*s);
 125       *s = *loc;
 126     }
 127   (*s)->refcnt += 4;
 128   return *s;
 129 }
 130
 131
 132
 133 /*
 134 // Local Variables:
 135 // mode: C
 136 // c-file-style: "gnu"
 137 // End:
 138 // arch-tag: 84fbd8ab-4e90-4d04-ab70-d9b955dde41c
 139 // end_of_file
 140 */