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-rw-r--r--libs/nanopb/pb_common.c97
1 files changed, 97 insertions, 0 deletions
diff --git a/libs/nanopb/pb_common.c b/libs/nanopb/pb_common.c
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+/* 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_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;
+}
+
+