rt-thread-official/components/external/nanopb/pb_common.c

91 lines
2.7 KiB
C

/* pb_common.c: Common support functions for pb_encode.c and pb_decode.c.
*
* 2014 Petteri Aimonen <jpa@kapsi.fi>
*/
#include "pb_common.h"
bool pb_field_iter_begin(pb_field_iter_t *iter, const pb_field_t *fields, void *dest_struct)
{
iter->start = fields;
iter->pos = fields;
iter->required_field_index = 0;
iter->dest_struct = dest_struct;
iter->pData = (char*)dest_struct + iter->pos->data_offset;
iter->pSize = (char*)iter->pData + iter->pos->size_offset;
return (iter->pos->tag != 0);
}
bool pb_field_iter_next(pb_field_iter_t *iter)
{
const pb_field_t *prev_field = iter->pos;
if (prev_field->tag == 0)
{
/* Handle empty message types, where the first field is already the terminator.
* In other cases, the iter->pos never points to the terminator. */
return false;
}
iter->pos++;
if (iter->pos->tag == 0)
{
/* Wrapped back to beginning, reinitialize */
(void)pb_field_iter_begin(iter, iter->start, iter->dest_struct);
return false;
}
else
{
/* Increment the pointers based on previous field size */
size_t prev_size = prev_field->data_size;
if (PB_ATYPE(prev_field->type) == PB_ATYPE_STATIC &&
PB_HTYPE(prev_field->type) == PB_HTYPE_REPEATED)
{
/* In static arrays, the data_size tells the size of a single entry and
* array_size is the number of entries */
prev_size *= prev_field->array_size;
}
else if (PB_ATYPE(prev_field->type) == PB_ATYPE_POINTER)
{
/* Pointer fields always have a constant size in the main structure.
* The data_size only applies to the dynamically allocated area. */
prev_size = sizeof(void*);
}
if (PB_HTYPE(prev_field->type) == PB_HTYPE_REQUIRED)
{
/* Count the required fields, in order to check their presence in the
* decoder. */
iter->required_field_index++;
}
iter->pData = (char*)iter->pData + prev_size + iter->pos->data_offset;
iter->pSize = (char*)iter->pData + iter->pos->size_offset;
return true;
}
}
bool pb_field_iter_find(pb_field_iter_t *iter, uint32_t tag)
{
const pb_field_t *start = iter->pos;
do {
if (iter->pos->tag == tag &&
PB_LTYPE(iter->pos->type) != PB_LTYPE_EXTENSION)
{
/* Found the wanted field */
return true;
}
(void)pb_field_iter_next(iter);
} while (iter->pos != start);
/* Searched all the way back to start, and found nothing. */
return false;
}