/* 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; if (!dest_struct) { iter->pData = NULL; iter->pSize = NULL; } else { 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_HTYPE(prev_field->type) == PB_HTYPE_ONEOF && PB_HTYPE(iter->pos->type) == PB_HTYPE_ONEOF && iter->pos->data_offset == PB_SIZE_MAX) { /* Don't advance pointers inside unions */ return true; } else 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; }