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