1 /* pb_common.c: Common support functions for pb_encode.c and pb_decode.c.
2 *
3 * 2014 Petteri Aimonen <jpa@kapsi.fi>
4 */
5
6 #include "pb_common.h"
7
pb_field_iter_begin(pb_field_iter_t * iter,const pb_field_t * fields,void * dest_struct)8 bool pb_field_iter_begin(pb_field_iter_t *iter, const pb_field_t *fields, void *dest_struct)
9 {
10 iter->start = fields;
11 iter->pos = fields;
12 iter->required_field_index = 0;
13 iter->dest_struct = dest_struct;
14 iter->pData = (char*)dest_struct + iter->pos->data_offset;
15 iter->pSize = (char*)iter->pData + iter->pos->size_offset;
16
17 return (iter->pos->tag != 0);
18 }
19
pb_field_iter_next(pb_field_iter_t * iter)20 bool pb_field_iter_next(pb_field_iter_t *iter)
21 {
22 const pb_field_t *prev_field = iter->pos;
23
24 if (prev_field->tag == 0)
25 {
26 /* Handle empty message types, where the first field is already the terminator.
27 * In other cases, the iter->pos never points to the terminator. */
28 return false;
29 }
30
31 iter->pos++;
32
33 if (iter->pos->tag == 0)
34 {
35 /* Wrapped back to beginning, reinitialize */
36 (void)pb_field_iter_begin(iter, iter->start, iter->dest_struct);
37 return false;
38 }
39 else
40 {
41 /* Increment the pointers based on previous field size */
42 size_t prev_size = prev_field->data_size;
43
44 if (PB_HTYPE(prev_field->type) == PB_HTYPE_ONEOF &&
45 PB_HTYPE(iter->pos->type) == PB_HTYPE_ONEOF)
46 {
47 /* Don't advance pointers inside unions */
48 prev_size = 0;
49 iter->pData = (char*)iter->pData - prev_field->data_offset;
50 }
51 else if (PB_ATYPE(prev_field->type) == PB_ATYPE_STATIC &&
52 PB_HTYPE(prev_field->type) == PB_HTYPE_REPEATED)
53 {
54 /* In static arrays, the data_size tells the size of a single entry and
55 * array_size is the number of entries */
56 prev_size *= prev_field->array_size;
57 }
58 else if (PB_ATYPE(prev_field->type) == PB_ATYPE_POINTER)
59 {
60 /* Pointer fields always have a constant size in the main structure.
61 * The data_size only applies to the dynamically allocated area. */
62 prev_size = sizeof(void*);
63 }
64
65 if (PB_HTYPE(prev_field->type) == PB_HTYPE_REQUIRED)
66 {
67 /* Count the required fields, in order to check their presence in the
68 * decoder. */
69 iter->required_field_index++;
70 }
71
72 iter->pData = (char*)iter->pData + prev_size + iter->pos->data_offset;
73 iter->pSize = (char*)iter->pData + iter->pos->size_offset;
74 return true;
75 }
76 }
77
pb_field_iter_find(pb_field_iter_t * iter,uint32_t tag)78 bool pb_field_iter_find(pb_field_iter_t *iter, uint32_t tag)
79 {
80 const pb_field_t *start = iter->pos;
81
82 do {
83 if (iter->pos->tag == tag &&
84 PB_LTYPE(iter->pos->type) != PB_LTYPE_EXTENSION)
85 {
86 /* Found the wanted field */
87 return true;
88 }
89
90 (void)pb_field_iter_next(iter);
91 } while (iter->pos != start);
92
93 /* Searched all the way back to start, and found nothing. */
94 return false;
95 }
96
97
98