hb-object-private.hh revision 852e08ec8fbfbce1d50e571d0bb0b52ef4d4cc58 
1/*
2 * Copyright © 2007  Chris Wilson
3 * Copyright © 2009,2010  Red Hat, Inc.
4 * Copyright © 2011  Google, Inc.
5 *
6 *  This is part of HarfBuzz, a text shaping library.
7 *
8 * Permission is hereby granted, without written agreement and without
9 * license or royalty fees, to use, copy, modify, and distribute this
10 * software and its documentation for any purpose, provided that the
11 * above copyright notice and the following two paragraphs appear in
12 * all copies of this software.
13 *
14 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
15 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
16 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
17 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
18 * DAMAGE.
19 *
20 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
21 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
22 * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
23 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
24 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
25 *
26 * Contributor(s):
27 *	Chris Wilson <chris@chris-wilson.co.uk>
28 * Red Hat Author(s): Behdad Esfahbod
29 * Google Author(s): Behdad Esfahbod
30 */
31
32#ifndef HB_OBJECT_PRIVATE_HH
33#define HB_OBJECT_PRIVATE_HH
34
35#include "hb-private.hh"
36
37HB_BEGIN_DECLS
38
39
40/* Debug */
41
42#ifndef HB_DEBUG_OBJECT
43#define HB_DEBUG_OBJECT (HB_DEBUG+0)
44#endif
45
46
47/* reference_count */
48
49typedef struct {
50  hb_atomic_int_t ref_count;
51
52#define HB_REFERENCE_COUNT_INVALID_VALUE ((hb_atomic_int_t) -1)
53#define HB_REFERENCE_COUNT_INVALID {HB_REFERENCE_COUNT_INVALID_VALUE}
54
55  inline void init (int v) { ref_count = v; /* non-atomic is fine */ }
56  inline int inc (void) { return hb_atomic_int_fetch_and_add (ref_count,  1); }
57  inline int dec (void) { return hb_atomic_int_fetch_and_add (ref_count, -1); }
58  inline void set (int v) { hb_atomic_int_set (ref_count, v); }
59
60  inline int get (void) const { return hb_atomic_int_get (ref_count); }
61  inline bool is_invalid (void) const { return get () == HB_REFERENCE_COUNT_INVALID_VALUE; }
62
63} hb_reference_count_t;
64
65
66/* user_data */
67
68/* XXX make this thread-safe, somehow! */
69
70typedef struct {
71  void *data;
72  hb_destroy_func_t destroy;
73
74  void finish (void) { if (destroy) destroy (data); }
75} hb_user_data_t;
76
77struct hb_user_data_array_t {
78
79  hb_map_t<hb_user_data_key_t *, hb_user_data_t> map;
80
81  inline bool set (hb_user_data_key_t *key,
82		   void *              data,
83		   hb_destroy_func_t   destroy)
84  {
85    if (!data && !destroy) {
86      map.unset (key);
87      return true;
88    }
89    hb_user_data_t user_data = {data, destroy};
90    return map.set (key, user_data);
91  }
92
93  inline void *get (hb_user_data_key_t *key) {
94    return map.get (key);
95  }
96
97  void finish (void) { map.finish (); }
98};
99
100
101/* object_header */
102
103typedef struct _hb_object_header_t hb_object_header_t;
104
105struct _hb_object_header_t {
106  hb_reference_count_t ref_count;
107  hb_user_data_array_t user_data;
108
109#define HB_OBJECT_HEADER_STATIC {HB_REFERENCE_COUNT_INVALID}
110
111  static inline void *create (unsigned int size) {
112    hb_object_header_t *obj = (hb_object_header_t *) calloc (1, size);
113
114    if (likely (obj))
115      obj->init ();
116
117    return obj;
118  }
119
120  inline void init (void) {
121    ref_count.init (1);
122  }
123
124  inline bool is_inert (void) const {
125    return unlikely (ref_count.is_invalid ());
126  }
127
128  inline void reference (void) {
129    if (unlikely (!this || this->is_inert ()))
130      return;
131    ref_count.inc ();
132  }
133
134  inline bool destroy (void) {
135    if (unlikely (!this || this->is_inert ()))
136      return false;
137    if (ref_count.dec () != 1)
138      return false;
139
140    user_data.finish ();
141
142    return true;
143  }
144
145  inline bool set_user_data (hb_user_data_key_t *key,
146			     void *              data,
147			     hb_destroy_func_t   destroy) {
148    if (unlikely (!this || this->is_inert ()))
149      return false;
150
151    return user_data.set (key, data, destroy);
152  }
153
154  inline void *get_user_data (hb_user_data_key_t *key) {
155    return user_data.get (key);
156  }
157
158  inline void trace (const char *function) const {
159    (void) (HB_DEBUG_OBJECT &&
160	    fprintf (stderr, "OBJECT(%p) refcount=%d %s\n",
161		     this,
162		     this ? ref_count.get () : 0,
163		     function));
164  }
165
166};
167
168
169HB_END_DECLS
170
171
172/* object */
173
174template <typename Type>
175static inline void hb_object_trace (const Type *obj, const char *function)
176{
177  obj->header.trace (function);
178}
179template <typename Type>
180static inline Type *hb_object_create ()
181{
182  Type *obj = (Type *) hb_object_header_t::create (sizeof (Type));
183  hb_object_trace (obj, HB_FUNC);
184  return obj;
185}
186template <typename Type>
187static inline bool hb_object_is_inert (const Type *obj)
188{
189  return unlikely (obj->header.is_inert());
190}
191template <typename Type>
192static inline Type *hb_object_reference (Type *obj)
193{
194  hb_object_trace (obj, HB_FUNC);
195  obj->header.reference ();
196  return obj;
197}
198template <typename Type>
199static inline bool hb_object_destroy (Type *obj)
200{
201  hb_object_trace (obj, HB_FUNC);
202  return obj->header.destroy ();
203}
204template <typename Type>
205static inline bool hb_object_set_user_data (Type               *obj,
206					    hb_user_data_key_t *key,
207					    void *              data,
208					    hb_destroy_func_t   destroy)
209{
210  return obj->header.set_user_data (key, data, destroy);
211}
212
213template <typename Type>
214static inline void *hb_object_get_user_data (Type               *obj,
215					     hb_user_data_key_t *key)
216{
217  return obj->header.get_user_data (key);
218}
219
220
221HB_BEGIN_DECLS
222
223
224HB_END_DECLS
225
226#endif /* HB_OBJECT_PRIVATE_HH */
227