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 /* Compile-time assertion, used for checking compatible compilation options. */
27 #define STATIC_ASSERT(COND,MSG) typedef char static_assertion_##MSG[(COND)?1:-1];
30 /* Number of required fields to keep track of
31 * (change here or on compiler command line). */
32 #ifndef PB_MAX_REQUIRED_FIELDS
33 #define PB_MAX_REQUIRED_FIELDS 64
36 #if PB_MAX_REQUIRED_FIELDS < 64
37 #error You should not lower PB_MAX_REQUIRED_FIELDS from the default value (64).
40 /* List of possible field types. These are used in the autogenerated code.
41 * Least-significant 4 bits tell the scalar type
42 * Most-significant 4 bits specify repeated/required/packed etc.
44 * INT32 and UINT32 are treated the same, as are (U)INT64 and (S)FIXED*
45 * These types are simply casted to correct field type when they are
46 * assigned to the memory pointer.
47 * SINT* is different, though, because it is zig-zag coded.
51 /************************
52 * Field contents types *
53 ************************/
56 PB_LTYPE_VARINT = 0x00, /* int32, uint32, int64, uint64, bool, enum */
57 PB_LTYPE_SVARINT = 0x01, /* sint32, sint64 */
58 PB_LTYPE_FIXED32 = 0x02, /* fixed32, sfixed32, float */
59 PB_LTYPE_FIXED64 = 0x03, /* fixed64, sfixed64, double */
61 /* Marker for last packable field type. */
62 PB_LTYPE_LAST_PACKABLE = 0x03,
64 /* Byte array with pre-allocated buffer.
65 * data_size is the length of the allocated PB_BYTES_ARRAY structure. */
66 PB_LTYPE_BYTES = 0x04,
68 /* String with pre-allocated buffer.
69 * data_size is the maximum length. */
70 PB_LTYPE_STRING = 0x05,
73 * submsg_fields is pointer to field descriptions */
74 PB_LTYPE_SUBMESSAGE = 0x06,
76 /* Number of declared LTYPES */
83 /* Just the basic, write data at data_offset */
84 PB_HTYPE_REQUIRED = 0x00,
86 /* Write true at size_offset */
87 PB_HTYPE_OPTIONAL = 0x10,
89 /* Read to pre-allocated array
90 * Maximum number of entries is array_size,
91 * actual number is stored at size_offset */
92 PB_HTYPE_ARRAY = 0x20,
94 /* Works for all required/optional/repeated fields.
95 * data_offset points to pb_callback_t structure.
96 * LTYPE should be 0 (it is ignored, but sometimes
97 * used to speculatively index an array). */
98 PB_HTYPE_CALLBACK = 0x30
99 } pb_packed pb_type_t;
101 #define PB_HTYPE(x) ((x) & 0xF0)
102 #define PB_LTYPE(x) ((x) & 0x0F)
104 /* This structure is used in auto-generated constants
105 * to specify struct fields.
106 * You can change field sizes if you need structures
107 * larger than 256 bytes or field tags larger than 256.
108 * The compiler should complain if your .proto has such
109 * structures. Fix that by defining PB_FIELD_16BIT or
112 typedef struct _pb_field_t pb_field_t;
115 #if !defined(PB_FIELD_16BIT) && !defined(PB_FIELD_32BIT)
118 uint8_t data_offset; /* Offset of field data, relative to previous field. */
119 int8_t size_offset; /* Offset of array size or has-boolean, relative to data */
120 uint8_t data_size; /* Data size in bytes for a single item */
121 uint8_t array_size; /* Maximum number of entries in array */
122 #elif defined(PB_FIELD_16BIT) && !defined(PB_FIELD_32BIT)
138 /* Field definitions for submessage
139 * OR default value for all other non-array, non-callback types
140 * If null, then field will zeroed. */
144 /* This structure is used for 'bytes' arrays.
145 * It has the number of bytes in the beginning, and after that an array.
146 * Note that actual structs used will have a different length of bytes array.
153 /* This structure is used for giving the callback function.
154 * It is stored in the message structure and filled in by the method that
157 * The decoding callback will be given a limited-length stream
158 * If the wire type was string, the length is the length of the string.
159 * If the wire type was a varint/fixed32/fixed64, the length is the length
160 * of the actual value.
161 * The function may be called multiple times (especially for repeated types,
162 * but also otherwise if the message happens to contain the field multiple
165 * The encoding callback will receive the actual output stream.
166 * It should write all the data in one call, including the field tag and
167 * wire type. It can write multiple fields.
169 * The callback can be null if you want to skip a field.
171 typedef struct _pb_istream_t pb_istream_t;
172 typedef struct _pb_ostream_t pb_ostream_t;
173 typedef struct _pb_callback_t pb_callback_t;
174 struct _pb_callback_t {
176 bool (*decode)(pb_istream_t *stream, const pb_field_t *field, void *arg);
177 bool (*encode)(pb_ostream_t *stream, const pb_field_t *field, const void *arg);
180 /* Free arg for use by callback */
184 /* Wire types. Library user needs these only in encoder callbacks. */
192 /* These macros are used to declare pb_field_t's in the constant array. */
193 #define pb_membersize(st, m) (sizeof ((st*)0)->m)
194 #define pb_arraysize(st, m) (pb_membersize(st, m) / pb_membersize(st, m[0]))
195 #define pb_delta(st, m1, m2) ((int)offsetof(st, m1) - (int)offsetof(st, m2))
196 #define pb_delta_end(st, m1, m2) (offsetof(st, m1) - offsetof(st, m2) - pb_membersize(st, m2))
197 #define PB_LAST_FIELD {0,(pb_type_t) 0,0,0,0,0,0}
199 /* These macros are used for giving out error messages.
200 * They are mostly a debugging aid; the main error information
201 * is the true/false return value from functions.
202 * Some code space can be saved by disabling the error
203 * messages if not used.
206 #define PB_RETURN_ERROR(stream,msg) return false
207 #define PB_GET_ERROR(stream) "(errmsg disabled)"
209 #define PB_RETURN_ERROR(stream,msg) \
211 if ((stream)->errmsg == NULL) \
212 (stream)->errmsg = (msg); \
215 #define PB_GET_ERROR(stream) ((stream)->errmsg ? (stream)->errmsg : "(none)")