98 lines
3.0 KiB
C
98 lines
3.0 KiB
C
/* pb_common.c: Common support functions for pb_encode.c and pb_decode.c.
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*
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* 2014 Petteri Aimonen <jpa@kapsi.fi>
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*/
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#include "pb_common.h"
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bool pb_field_iter_begin(pb_field_iter_t *iter, const pb_field_t *fields, void *dest_struct)
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{
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iter->start = fields;
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iter->pos = fields;
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iter->required_field_index = 0;
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iter->dest_struct = dest_struct;
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iter->pData = (char*)dest_struct + iter->pos->data_offset;
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iter->pSize = (char*)iter->pData + iter->pos->size_offset;
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return (iter->pos->tag != 0);
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}
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bool pb_field_iter_next(pb_field_iter_t *iter)
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{
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const pb_field_t *prev_field = iter->pos;
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if (prev_field->tag == 0)
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{
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/* Handle empty message types, where the first field is already the terminator.
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* In other cases, the iter->pos never points to the terminator. */
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return false;
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}
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iter->pos++;
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if (iter->pos->tag == 0)
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{
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/* Wrapped back to beginning, reinitialize */
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(void)pb_field_iter_begin(iter, iter->start, iter->dest_struct);
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return false;
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}
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else
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{
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/* Increment the pointers based on previous field size */
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size_t prev_size = prev_field->data_size;
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if (PB_HTYPE(prev_field->type) == PB_HTYPE_ONEOF &&
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PB_HTYPE(iter->pos->type) == PB_HTYPE_ONEOF)
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{
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/* Don't advance pointers inside unions */
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prev_size = 0;
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iter->pData = (char*)iter->pData - prev_field->data_offset;
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}
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else if (PB_ATYPE(prev_field->type) == PB_ATYPE_STATIC &&
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PB_HTYPE(prev_field->type) == PB_HTYPE_REPEATED)
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{
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/* In static arrays, the data_size tells the size of a single entry and
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* array_size is the number of entries */
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prev_size *= prev_field->array_size;
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}
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else if (PB_ATYPE(prev_field->type) == PB_ATYPE_POINTER)
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{
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/* Pointer fields always have a constant size in the main structure.
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* The data_size only applies to the dynamically allocated area. */
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prev_size = sizeof(void*);
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}
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if (PB_HTYPE(prev_field->type) == PB_HTYPE_REQUIRED)
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{
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/* Count the required fields, in order to check their presence in the
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* decoder. */
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iter->required_field_index++;
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}
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iter->pData = (char*)iter->pData + prev_size + iter->pos->data_offset;
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iter->pSize = (char*)iter->pData + iter->pos->size_offset;
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return true;
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}
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}
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bool pb_field_iter_find(pb_field_iter_t *iter, uint32_t tag)
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{
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const pb_field_t *start = iter->pos;
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do {
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if (iter->pos->tag == tag &&
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PB_LTYPE(iter->pos->type) != PB_LTYPE_EXTENSION)
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{
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/* Found the wanted field */
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return true;
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}
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(void)pb_field_iter_next(iter);
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} while (iter->pos != start);
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/* Searched all the way back to start, and found nothing. */
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return false;
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}
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