4 /* pb.h: Common parts for nanopb library.
5 * Most of these are quite low-level stuff. For the high-level interface,
6 * see pb_encode.h or pb_decode.h
14 /* This just reduces memory requirements, but is not required. */
15 #define pb_packed __attribute__((packed))
20 /* Handly macro for suppressing unreferenced-parameter compiler warnings. */
22 #define UNUSED(x) (void)(x)
25 /* List of possible field types. These are used in the autogenerated code.
26 * Least-significant 4 bits tell the scalar type
27 * Most-significant 4 bits specify repeated/required/packed etc.
29 * INT32 and UINT32 are treated the same, as are (U)INT64 and (S)FIXED*
30 * These types are simply casted to correct field type when they are
31 * assigned to the memory pointer.
32 * SINT* is different, though, because it is zig-zag coded.
36 /************************
37 * Field contents types *
38 ************************/
41 PB_LTYPE_VARINT = 0x00, /* int32, uint32, int64, uint64, bool, enum */
42 PB_LTYPE_SVARINT = 0x01, /* sint32, sint64 */
43 PB_LTYPE_FIXED32 = 0x02, /* fixed32, sfixed32, float */
44 PB_LTYPE_FIXED64 = 0x03, /* fixed64, sfixed64, double */
46 /* Marker for last packable field type. */
47 PB_LTYPE_LAST_PACKABLE = 0x03,
49 /* Byte array with pre-allocated buffer.
50 * data_size is the length of the allocated PB_BYTES_ARRAY structure. */
51 PB_LTYPE_BYTES = 0x04,
53 /* String with pre-allocated buffer.
54 * data_size is the maximum length. */
55 PB_LTYPE_STRING = 0x05,
58 * submsg_fields is pointer to field descriptions */
59 PB_LTYPE_SUBMESSAGE = 0x06,
61 /* Number of declared LTYPES */
68 /* Just the basic, write data at data_offset */
69 PB_HTYPE_REQUIRED = 0x00,
71 /* Write true at size_offset */
72 PB_HTYPE_OPTIONAL = 0x10,
74 /* Read to pre-allocated array
75 * Maximum number of entries is array_size,
76 * actual number is stored at size_offset */
77 PB_HTYPE_ARRAY = 0x20,
79 /* Works for all required/optional/repeated fields.
80 * data_offset points to pb_callback_t structure.
81 * LTYPE should be 0 (it is ignored, but sometimes
82 * used to speculatively index an array). */
83 PB_HTYPE_CALLBACK = 0x30
84 } pb_packed pb_type_t;
86 #define PB_HTYPE(x) ((x) & 0xF0)
87 #define PB_LTYPE(x) ((x) & 0x0F)
89 /* This structure is used in auto-generated constants
90 * to specify struct fields.
91 * You can change field sizes here if you need structures
92 * larger than 256 bytes or field tags larger than 256.
93 * The compiler should complain if your .proto has such
94 * structures ("initializer too large for type").
96 typedef struct _pb_field_t pb_field_t;
100 uint8_t data_offset; /* Offset of field data, relative to previous field. */
101 int8_t size_offset; /* Offset of array size or has-boolean, relative to data */
102 uint8_t data_size; /* Data size in bytes for a single item */
103 uint8_t array_size; /* Maximum number of entries in array */
105 /* Field definitions for submessage
106 * OR default value for all other non-array, non-callback types
107 * If null, then field will zeroed. */
111 /* This structure is used for 'bytes' arrays.
112 * It has the number of bytes in the beginning, and after that an array.
113 * Note that actual structs used will have a different length of bytes array.
120 /* This structure is used for giving the callback function.
121 * It is stored in the message structure and filled in by the method that
124 * The decoding callback will be given a limited-length stream
125 * If the wire type was string, the length is the length of the string.
126 * If the wire type was a varint/fixed32/fixed64, the length is the length
127 * of the actual value.
128 * The function may be called multiple times (especially for repeated types,
129 * but also otherwise if the message happens to contain the field multiple
132 * The encoding callback will receive the actual output stream.
133 * It should write all the data in one call, including the field tag and
134 * wire type. It can write multiple fields.
136 * The callback can be null if you want to skip a field.
138 typedef struct _pb_istream_t pb_istream_t;
139 typedef struct _pb_ostream_t pb_ostream_t;
140 typedef struct _pb_callback_t pb_callback_t;
141 struct _pb_callback_t {
143 bool (*decode)(pb_istream_t *stream, const pb_field_t *field, void *arg);
144 bool (*encode)(pb_ostream_t *stream, const pb_field_t *field, const void *arg);
147 /* Free arg for use by callback */
151 /* Wire types. Library user needs these only in encoder callbacks. */
159 /* These macros are used to declare pb_field_t's in the constant array. */
160 #define pb_membersize(st, m) (sizeof ((st*)0)->m)
161 #define pb_arraysize(st, m) (pb_membersize(st, m) / pb_membersize(st, m[0]))
162 #define pb_delta(st, m1, m2) ((int)offsetof(st, m1) - (int)offsetof(st, m2))
163 #define pb_delta_end(st, m1, m2) (offsetof(st, m1) - offsetof(st, m2) - pb_membersize(st, m2))
164 #define PB_LAST_FIELD {0,0,0,0}