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#ifndef HB_H_IN
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
36HB_BEGIN_DECLS
37
38
39/**
40 * hb_memory_mode_t:
41 * @HB_MEMORY_MODE_DUPLICATE
42 * @HB_MEMORY_MODE_READONLY
43 * @HB_MEMORY_MODE_WRITABLE
44 * @HB_MEMORY_MODE_READONLY_MAY_MAKE_WRITABLE
45 *
46 * Data type holding the memory modes available to
47 * client programs.
48 *
49 * Regarding these various memory-modes:
50 *
51 * - In no case shall the HarfBuzz client modify memory
52 * that is passed to HarfBuzz in a blob. If there is
53 * any such possibility, @HB_MEMORY_MODE_DUPLICATE should be used
54 * such that HarfBuzz makes a copy immediately,
55 *
56 * - Use @HB_MEMORY_MODE_READONLY otherwise, unless you really really
57 * really know what you are doing,
58 *
59 * - @HB_MEMORY_MODE_WRITABLE is appropriate if you really made a
60 * copy of data solely for the purpose of passing to
61 * HarfBuzz and doing that just once (no reuse!),
62 *
63 * - If the font is mmap()ed, it's okay to use
64 * @HB_MEMORY_READONLY_MAY_MAKE_WRITABLE, however, using that mode
65 * correctly is very tricky. Use @HB_MEMORY_MODE_READONLY instead.
66 **/
67typedef enum {
68 HB_MEMORY_MODE_DUPLICATE,
69 HB_MEMORY_MODE_READONLY,
70 HB_MEMORY_MODE_WRITABLE,
71 HB_MEMORY_MODE_READONLY_MAY_MAKE_WRITABLE
72} hb_memory_mode_t;
73
74/**
75 * hb_blob_t:
76 *
77 * Data type for blobs. A blob wraps a chunk of binary
78 * data and facilitates its lifecycle management between
79 * a client program and HarfBuzz.
80 *
81 **/
82typedef struct hb_blob_t hb_blob_t;
83
84HB_EXTERN hb_blob_t *
85hb_blob_create (const char *data,
86 unsigned int length,
87 hb_memory_mode_t mode,
88 void *user_data,
89 hb_destroy_func_t destroy);
90
91HB_EXTERN hb_blob_t *
92hb_blob_create_from_file (const char *file_name);
93
94/* Always creates with MEMORY_MODE_READONLY.
95 * Even if the parent blob is writable, we don't
96 * want the user of the sub-blob to be able to
97 * modify the parent data as that data may be
98 * shared among multiple sub-blobs.
99 */
100HB_EXTERN hb_blob_t *
101hb_blob_create_sub_blob (hb_blob_t *parent,
102 unsigned int offset,
103 unsigned int length);
104
105HB_EXTERN hb_blob_t *
106hb_blob_copy_writable_or_fail (hb_blob_t *blob);
107
108HB_EXTERN hb_blob_t *
109hb_blob_get_empty (void);
110
111HB_EXTERN hb_blob_t *
112hb_blob_reference (hb_blob_t *blob);
113
114HB_EXTERN void
115hb_blob_destroy (hb_blob_t *blob);
116
117HB_EXTERN hb_bool_t
118hb_blob_set_user_data (hb_blob_t *blob,
119 hb_user_data_key_t *key,
120 void * data,
121 hb_destroy_func_t destroy,
122 hb_bool_t replace);
123
124
125HB_EXTERN void *
126hb_blob_get_user_data (hb_blob_t *blob,
127 hb_user_data_key_t *key);
128
129
130HB_EXTERN void
131hb_blob_make_immutable (hb_blob_t *blob);
132
133HB_EXTERN hb_bool_t
134hb_blob_is_immutable (hb_blob_t *blob);
135
136
137HB_EXTERN unsigned int
138hb_blob_get_length (hb_blob_t *blob);
139
140HB_EXTERN const char *
141hb_blob_get_data (hb_blob_t *blob, unsigned int *length);
142
143HB_EXTERN char *
144hb_blob_get_data_writable (hb_blob_t *blob, unsigned int *length);
145
146HB_END_DECLS
147
148#endif /* HB_BLOB_H */
149

source code of include/harfbuzz/hb-blob.h