1 files changed, 42 insertions, 0 deletions
diff --git a/pb_common.h b/pb_common.h
new file mode 100644
index 0000000..60b3d37
--- /dev/null
+++ b/pb_common.h
@@ -0,0 +1,42 @@
+/* pb_common.h: Common support functions for pb_encode.c and pb_decode.c.
+ * These functions are rarely needed by applications directly.
+ */
+
+#ifndef PB_COMMON_H_INCLUDED
+#define PB_COMMON_H_INCLUDED
+
+#include "pb.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Iterator for pb_field_t list */
+struct pb_field_iter_s {
+    const pb_field_t *start;       /* Start of the pb_field_t array */
+    const pb_field_t *pos;         /* Current position of the iterator */
+    unsigned required_field_index; /* Zero-based index that counts only the required fields */
+    void *dest_struct;             /* Pointer to start of the structure */
+    void *pData;                   /* Pointer to current field value */
+    void *pSize;                   /* Pointer to count/has field */
+};
+typedef struct pb_field_iter_s pb_field_iter_t;
+
+/* Initialize the field iterator structure to beginning.
+ * Returns false if the message type is empty. */
+bool pb_field_iter_begin(pb_field_iter_t *iter, const pb_field_t *fields, void *dest_struct);
+
+/* Advance the iterator to the next field.
+ * Returns false when the iterator wraps back to the first field. */
+bool pb_field_iter_next(pb_field_iter_t *iter);
+
+/* Advance the iterator until it points at a field with the given tag.
+ * Returns false if no such field exists. */
+bool pb_field_iter_find(pb_field_iter_t *iter, uint32_t tag);
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
+#endif
+