xref: /freebsd/contrib/libcbor/src/cbor/bytestrings.h (revision 4731124cace5e7a0224e29784617d2856e5c59ab)
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[borrow] a definite bytestring
29  * @return length of the binary data. Zero if no chunk has been attached yet
30  */
31 CBOR_EXPORT size_t cbor_bytestring_length(const cbor_item_t *item);
32 
33 /** Is the byte string definite?
34  *
35  * @param item[borrow] a byte string
36  * @return Is the byte string definite?
37  */
38 CBOR_EXPORT bool cbor_bytestring_is_definite(const cbor_item_t *item);
39 
40 /** Is the byte string indefinite?
41  *
42  * @param item[borrow] a byte string
43  * @return Is the byte string indefinite?
44  */
45 CBOR_EXPORT bool cbor_bytestring_is_indefinite(const cbor_item_t *item);
46 
47 /** Get the handle to the binary data
48  *
49  * Definite items only. Modifying the data is allowed. In that case, the caller
50  * takes responsibility for the effect on items this item might be a part of
51  *
52  * @param item[borrow] A definite byte string
53  * @return The address of the binary data. `NULL` if no data have been assigned
54  * yet.
55  */
56 CBOR_EXPORT cbor_mutable_data cbor_bytestring_handle(const cbor_item_t *item);
57 
58 /** Set the handle to the binary data
59  *
60  * @param item[borrow] A definite byte string
61  * @param data The memory block. The caller gives up the ownership of the block.
62  * libcbor will deallocate it when appropriate using its free function
63  * @param length Length of the data block
64  */
65 CBOR_EXPORT void cbor_bytestring_set_handle(
66     cbor_item_t *item, cbor_mutable_data CBOR_RESTRICT_POINTER data,
67     size_t length);
68 
69 /** Get the handle to the array of chunks
70  *
71  * Manipulations with the memory block (e.g. sorting it) are allowed, but the
72  * validity and the number of chunks must be retained.
73  *
74  * @param item[borrow] A indefinite byte string
75  * @return array of #cbor_bytestring_chunk_count definite bytestrings
76  */
77 CBOR_EXPORT cbor_item_t **cbor_bytestring_chunks_handle(
78     const cbor_item_t *item);
79 
80 /** Get the number of chunks this string consist of
81  *
82  * @param item[borrow] A indefinite bytestring
83  * @return The chunk count. 0 for freshly created items.
84  */
85 CBOR_EXPORT size_t cbor_bytestring_chunk_count(const cbor_item_t *item);
86 
87 /** Appends a chunk to the bytestring
88  *
89  * Indefinite byte strings only.
90  *
91  * May realloc the chunk storage.
92  *
93  * @param item[borrow] An indefinite byte string
94  * @param item[incref] A definite byte string
95  * @return true on success, false on realloc failure. In that case, the refcount
96  * of `chunk` is not increased and the `item` is left intact.
97  */
98 CBOR_EXPORT bool cbor_bytestring_add_chunk(cbor_item_t *item,
99                                            cbor_item_t *chunk);
100 
101 /** Creates a new definite byte string
102  *
103  * The handle is initialized to `NULL` and length to 0
104  *
105  * @return **new** definite bytestring. `NULL` on malloc failure.
106  */
107 CBOR_EXPORT cbor_item_t *cbor_new_definite_bytestring();
108 
109 /** Creates a new indefinite byte string
110  *
111  * The chunks array is initialized to `NULL` and chunkcount to 0
112  *
113  * @return **new** indefinite bytestring. `NULL` on malloc failure.
114  */
115 CBOR_EXPORT cbor_item_t *cbor_new_indefinite_bytestring();
116 
117 /** Creates a new byte string and initializes it
118  *
119  * The `handle` will be copied to a newly allocated block
120  *
121  * @param handle Block of binary data
122  * @param length Length of `data`
123  * @return A **new** byte string with content `handle`. `NULL` on malloc
124  * failure.
125  */
126 CBOR_EXPORT cbor_item_t *cbor_build_bytestring(cbor_data handle, size_t length);
127 
128 #ifdef __cplusplus
129 }
130 #endif
131 
132 #endif  // LIBCBOR_BYTESTRINGS_H
133