engine/stringbucket.h

   1 /*
   2     stringbucket.h - MaLa stringbuckets
   3
   4   Copyright (C) 2004, 2005, 2006, 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 #ifndef MALA_STRINGBUCKET_H
  21 #define MALA_STRINGBUCKET_H
  22
  23 #include "acogc.h"
  24 #include "mala_types.h"
  25 #include "strings.h"
  26 \f
  27 typedef int (*mala_string_cmp_fn) (const void*, const void*);
  28
  29 #define MALA_STRING_FWD (mala_string_cmp_fn) mala_string_compare
  30 #define MALA_STRING_REV (mala_string_cmp_fn) mala_string_compare_rev
  31
  32 /*
  33   strings are looked up in a weak-splay tree, that is a splay tree
  34   which contains weak-pointers to the strings,
  35   when a splay tree node to a expired string is encountered it will be instantly removed
  36
  37   Note that the acogc allows caching and reinstantiating of swept strings
  38 */
  39 struct mala_stringbucketnode_struct
  40 {
  41   acogc_weakref weak_string;
  42   MalaStringBucketNode left;
  43   MalaStringBucketNode right;
  44   MalaStringBucketNode parent;  //makes splaying more efficent/easier
  45 };
  46
  47
  48 struct mala_stringbucket_struct
  49 {
  50   MalaStringBucketNode tree;
  51   AcogcRoot gcroot;
  52   AcogcFactory gcfactory_strings;
  53   AcogcFactory gcfactory_splaynodes;
  54   mala_string_cmp_fn cmpfn;
  55 };
  56 \f
  57
  58 /*
  59  *      StringBucket
  60  */
  61
  62 typedef
  63 enum
  64   {
  65     MALA_STRINGBUCKET_FIND,             // try to find string
  66     MALA_STRINGBUCKET_SEARCH,           // search string, create it if not already existing
  67     MALA_STRINGBUCKET_ATTACH,           // attach string which must be allocated by the caller,
  68                                         // freed by stringbucket when already in the tree or at garbage collection
  69     MALA_STRINGBUCKET_REFERENCE         // reference string, will not be freed, reference will not be used if string already exists
  70   } mala_stringbucket_mode;
  71
  72
  73 #ifdef EBUG_ACOGC
  74 void
  75 mala_stringbucketnode_dump (const char* name, MalaStringBucketNode_ref n, unsigned depth);
  76 #else
  77 #define mala_stringbucketnode_dump(s,n,d)
  78 #endif
  79
  80 void
  81 mala_stringbucketnode_simpleremove (MalaStringBucketNode_ref n, MalaStringBucket bucket);
  82
  83 acogc_mark_result
  84 mala_stringbucketnode_acogc_mark (void * p);
  85
  86 void
  87 mala_stringbucketnode_acogc_initize (void * p);
  88
  89 void
  90 mala_stringbucketnode_acogc_finalize (void * p);
  91
  92 acogc_mark_result
  93 mala_stringbucket_acogc_mark (void * bucket);
  94
  95 void
  96 mala_stringbucket_acogc_initize (void * p);
  97
  98 MalaStringBucketNode
  99 mala_stringbucket_node_find (MalaStringBucket bucket,
 100                              const char * what,
 101                              mala_stringbucket_mode mode);
 102
 103 void
 104 mala_stringbucketnode_splay (MalaStringBucketNode n, MalaStringBucket bucket);
 105
 106 MalaStringBucket
 107 mala_stringbucket_new (mala_string_cmp_fn cmpfn,
 108                        AcogcFactory bucketfactory,
 109                        AcogcFactory gcfactory_strings,
 110                        AcogcFactory gcfactory_splaynodes);
 111
 112 void
 113 mala_stringbucket_init (MalaStringBucket bucket,
 114                         mala_string_cmp_fn cmpfn,
 115                         AcogcRoot gcroot,
 116                         AcogcFactory gcfactory_strings,
 117                         AcogcFactory gcfactory_splaynodes);
 118
 119 static inline MalaString
 120 mala_stringbucket_find (MalaStringBucket bucket, const char * what)
 121 {
 122   MalaStringBucketNode ret = mala_stringbucket_node_find (bucket, what, MALA_STRINGBUCKET_FIND);
 123   return (MalaString) ret ? acogc_weakref_reinstget (&ret->weak_string) : NULL;
 124 }
 125
 126 static inline MalaString
 127 mala_stringbucket_search (MalaStringBucket bucket, const char * what)
 128 {
 129   return (MalaString) acogc_weakref_reinstget
 130     (&mala_stringbucket_node_find (bucket, what, MALA_STRINGBUCKET_SEARCH)->weak_string);
 131 }
 132
 133 static inline MalaString
 134 mala_stringbucket_attach (MalaStringBucket bucket, const char * what)
 135 {
 136   return (MalaString) acogc_weakref_reinstget
 137     (&mala_stringbucket_node_find (bucket, what, MALA_STRINGBUCKET_ATTACH)->weak_string);
 138 }
 139
 140 static inline MalaString
 141 mala_stringbucket_reference (MalaStringBucket bucket, const char * what)
 142 {
 143   return (MalaString) acogc_weakref_reinstget
 144     (&mala_stringbucket_node_find (bucket, what, MALA_STRINGBUCKET_REFERENCE)->weak_string);
 145 }
 146
 147 #endif /* MALA_STRINGBUCKET_H */
 148
 149 /*
 150 // Local Variables:
 151 // mode: C
 152 // c-file-style: "gnu"
 153 // End:
 154 // arch-tag: 09e98f6d-4992-4014-a18f-a5e532bdeb27
 155 // end_of_file
 156 */
 157