xref: /freebsd/contrib/libcbor/src/cbor/bytestrings.h (revision 5d3e7166f6a0187fa3f8831b16a06bd9955c21ff)
1 /*
2  * Copyright (c) 2014-2020 Pavel Kalvoda <me@pavelkalvoda.com>
3  *
4  * libcbor is free software; you can redistribute it and/or modify
5  * it under the terms of the MIT license. See LICENSE for details.
6  */
7 
8 #ifndef LIBCBOR_BYTESTRINGS_H
9 #define LIBCBOR_BYTESTRINGS_H
10 
11 #include "cbor/cbor_export.h"
12 #include "cbor/common.h"
13 
14 #ifdef __cplusplus
15 extern "C" {
16 #endif
17 
18 /*
19  * ============================================================================
20  * Byte string manipulation
21  * ============================================================================
22  */
23 
24 /** Returns the length of the binary data
25  *
26  * For definite byte strings only
27  *
28  * @param item a definite bytestring
29  * @return length of the binary data. Zero if no chunk has been attached yet
30  */
31 _CBOR_NODISCARD
32 CBOR_EXPORT size_t cbor_bytestring_length(const cbor_item_t *item);
33 
34 /** Is the byte string definite?
35  *
36  * @param item a byte string
37  * @return Is the byte string definite?
38  */
39 _CBOR_NODISCARD
40 CBOR_EXPORT bool cbor_bytestring_is_definite(const cbor_item_t *item);
41 
42 /** Is the byte string indefinite?
43  *
44  * @param item a byte string
45  * @return Is the byte string indefinite?
46  */
47 _CBOR_NODISCARD
48 CBOR_EXPORT bool cbor_bytestring_is_indefinite(const cbor_item_t *item);
49 
50 /** Get the handle to the binary data
51  *
52  * Definite items only. Modifying the data is allowed. In that case, the caller
53  * takes responsibility for the effect on items this item might be a part of
54  *
55  * @param item A definite byte string
56  * @return The address of the underlying binary data
57  * @return `NULL` if no data have been assigned
58  * yet.
59  */
60 _CBOR_NODISCARD
61 CBOR_EXPORT cbor_mutable_data cbor_bytestring_handle(const cbor_item_t *item);
62 
63 /** Set the handle to the binary data
64  *
65  * @param item A definite byte string
66  * @param data The memory block. The caller gives up the ownership of the block.
67  * libcbor will deallocate it when appropriate using the `free` implementation
68  * configured using #cbor_set_allocs
69  * @param length Length of the data block
70  */
71 CBOR_EXPORT void cbor_bytestring_set_handle(
72     cbor_item_t *item, cbor_mutable_data CBOR_RESTRICT_POINTER data,
73     size_t length);
74 
75 /** Get the handle to the array of chunks
76  *
77  * Manipulations with the memory block (e.g. sorting it) are allowed, but the
78  * validity and the number of chunks must be retained.
79  *
80  * @param item A indefinite byte string
81  * @return array of #cbor_bytestring_chunk_count definite bytestrings
82  */
83 _CBOR_NODISCARD
84 CBOR_EXPORT cbor_item_t **cbor_bytestring_chunks_handle(
85     const cbor_item_t *item);
86 
87 /** Get the number of chunks this string consist of
88  *
89  * @param item A indefinite bytestring
90  * @return The chunk count. 0 for freshly created items.
91  */
92 _CBOR_NODISCARD
93 CBOR_EXPORT size_t cbor_bytestring_chunk_count(const cbor_item_t *item);
94 
95 /** Appends a chunk to the bytestring
96  *
97  * Indefinite byte strings only.
98  *
99  * May realloc the chunk storage.
100  *
101  * @param item An indefinite byte string
102  * @param chunk A definite byte string. Its reference count will be be increased
103  * by one.
104  * @return true on success, false on realloc failure. In that case, the refcount
105  * of `chunk` is not increased and the `item` is left intact.
106  */
107 _CBOR_NODISCARD
108 CBOR_EXPORT bool cbor_bytestring_add_chunk(cbor_item_t *item,
109                                            cbor_item_t *chunk);
110 
111 /** Creates a new definite byte string
112  *
113  * The handle is initialized to `NULL` and length to 0
114  *
115  * @return Reference to the new bytestring item. The item's reference count is
116  * initialized to one.
117  * @return `NULL` if memory allocation fails
118  */
119 _CBOR_NODISCARD
120 CBOR_EXPORT cbor_item_t *cbor_new_definite_bytestring(void);
121 
122 /** Creates a new indefinite byte string
123  *
124  * The chunks array is initialized to `NULL` and chunk count to 0
125  *
126  * @return Reference to the new bytestring item. The item's reference count is
127  * initialized to one.
128  * @return `NULL` if memory allocation fails
129  */
130 _CBOR_NODISCARD
131 CBOR_EXPORT cbor_item_t *cbor_new_indefinite_bytestring(void);
132 
133 /** Creates a new byte string and initializes it
134  *
135  * The `handle` will be copied to a newly allocated block
136  *
137  * @param handle Block of binary data
138  * @param length Length of `data`
139  * @return Reference to the new bytestring item. The item's reference count is
140  * initialized to one.
141  * @return `NULL` if memory allocation fails
142  */
143 _CBOR_NODISCARD
144 CBOR_EXPORT cbor_item_t *cbor_build_bytestring(cbor_data handle, size_t length);
145 
146 #ifdef __cplusplus
147 }
148 #endif
149 
150 #endif  // LIBCBOR_BYTESTRINGS_H
151