1 /*
2 * Copyright © 2009 Red Hat, Inc.
3 *
4 * This is part of HarfBuzz, a text shaping library.
5 *
6 * Permission is hereby granted, without written agreement and without
7 * license or royalty fees, to use, copy, modify, and distribute this
8 * software and its documentation for any purpose, provided that the
9 * above copyright notice and the following two paragraphs appear in
10 * all copies of this software.
11 *
12 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
13 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
14 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
15 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
16 * DAMAGE.
17 *
18 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
19 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
20 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
21 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
22 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
23 *
24 * Red Hat Author(s): Behdad Esfahbod
25 */
26
27 #if !defined(HB_H_IN) && !defined(HB_NO_SINGLE_HEADER_ERROR)
28 #error "Include <hb.h> instead."
29 #endif
30
31 #ifndef HB_BLOB_H
32 #define HB_BLOB_H
33
34 #include "hb-common.h"
35
36 HB_BEGIN_DECLS
37
38
39 /**
40 * hb_memory_mode_t:
41 * @HB_MEMORY_MODE_DUPLICATE: HarfBuzz immediately makes a copy of the data.
42 * @HB_MEMORY_MODE_READONLY: HarfBuzz client will never modify the data,
43 * and HarfBuzz will never modify the data.
44 * @HB_MEMORY_MODE_WRITABLE: HarfBuzz client made a copy of the data solely
45 * for HarfBuzz, so HarfBuzz may modify the data.
46 * @HB_MEMORY_MODE_READONLY_MAY_MAKE_WRITABLE: See above
47 *
48 * Data type holding the memory modes available to
49 * client programs.
50 *
51 * Regarding these various memory-modes:
52 *
53 * - In no case shall the HarfBuzz client modify memory
54 * that is passed to HarfBuzz in a blob. If there is
55 * any such possibility, @HB_MEMORY_MODE_DUPLICATE should be used
56 * such that HarfBuzz makes a copy immediately,
57 *
58 * - Use @HB_MEMORY_MODE_READONLY otherwise, unless you really really
59 * really know what you are doing,
60 *
61 * - @HB_MEMORY_MODE_WRITABLE is appropriate if you really made a
62 * copy of data solely for the purpose of passing to
63 * HarfBuzz and doing that just once (no reuse!),
64 *
65 * - If the font is mmap()ed, it's okay to use
66 * @HB_MEMORY_MODE_READONLY_MAY_MAKE_WRITABLE, however, using that mode
67 * correctly is very tricky. Use @HB_MEMORY_MODE_READONLY instead.
68 **/
69 typedef enum {
70 HB_MEMORY_MODE_DUPLICATE,
71 HB_MEMORY_MODE_READONLY,
72 HB_MEMORY_MODE_WRITABLE,
73 HB_MEMORY_MODE_READONLY_MAY_MAKE_WRITABLE
74 } hb_memory_mode_t;
75
76 /**
77 * hb_blob_t:
78 *
79 * Data type for blobs. A blob wraps a chunk of binary
80 * data and facilitates its lifecycle management between
81 * a client program and HarfBuzz.
82 *
83 **/
84 typedef struct hb_blob_t hb_blob_t;
85
86 HB_EXTERN hb_blob_t *
87 hb_blob_create (const char *data,
88 unsigned int length,
89 hb_memory_mode_t mode,
90 void *user_data,
91 hb_destroy_func_t destroy);
92
93 HB_EXTERN hb_blob_t *
94 hb_blob_create_or_fail (const char *data,
95 unsigned int length,
96 hb_memory_mode_t mode,
97 void *user_data,
98 hb_destroy_func_t destroy);
99
100 HB_EXTERN hb_blob_t *
101 hb_blob_create_from_file (const char *file_name);
102
103 HB_EXTERN hb_blob_t *
104 hb_blob_create_from_file_or_fail (const char *file_name);
105
106 /* Always creates with MEMORY_MODE_READONLY.
107 * Even if the parent blob is writable, we don't
108 * want the user of the sub-blob to be able to
109 * modify the parent data as that data may be
110 * shared among multiple sub-blobs.
111 */
112 HB_EXTERN hb_blob_t *
113 hb_blob_create_sub_blob (hb_blob_t *parent,
114 unsigned int offset,
115 unsigned int length);
116
117 HB_EXTERN hb_blob_t *
118 hb_blob_copy_writable_or_fail (hb_blob_t *blob);
119
120 HB_EXTERN hb_blob_t *
121 hb_blob_get_empty (void);
122
123 HB_EXTERN hb_blob_t *
124 hb_blob_reference (hb_blob_t *blob);
125
126 HB_EXTERN void
127 hb_blob_destroy (hb_blob_t *blob);
128
129 HB_EXTERN hb_bool_t
130 hb_blob_set_user_data (hb_blob_t *blob,
131 hb_user_data_key_t *key,
132 void * data,
133 hb_destroy_func_t destroy,
134 hb_bool_t replace);
135
136
137 HB_EXTERN void *
138 hb_blob_get_user_data (const hb_blob_t *blob,
139 hb_user_data_key_t *key);
140
141
142 HB_EXTERN void
143 hb_blob_make_immutable (hb_blob_t *blob);
144
145 HB_EXTERN hb_bool_t
146 hb_blob_is_immutable (hb_blob_t *blob);
147
148
149 HB_EXTERN unsigned int
150 hb_blob_get_length (hb_blob_t *blob);
151
152 HB_EXTERN const char *
153 hb_blob_get_data (hb_blob_t *blob, unsigned int *length);
154
155 HB_EXTERN char *
156 hb_blob_get_data_writable (hb_blob_t *blob, unsigned int *length);
157
158 HB_END_DECLS
159
160 #endif /* HB_BLOB_H */