Files
nanopb/pb_encode.h
Petteri Aimonen a8d0172507 Encoder
git-svn-id: https://svn.kapsi.fi/jpa/nanopb@951 e3a754e5-d11d-0410-8d38-ebb782a927b9
2011-08-04 16:49:32 +00:00

69 lines
2.7 KiB
C

#ifndef _PB_ENCODE_H_
#define _PB_ENCODE_H_
/* pb_encode.h: Functions to encode protocol buffers. Depends on pb_encode.c.
* The main function is pb_encode. You also need an output stream, structures
* and their field descriptions (just like with pb_decode).
*/
#include <stdbool.h>
#include "pb.h"
/* Lightweight output stream.
* You can provide callback for writing or use pb_ostream_from_buffer.
*
* Alternatively, callback can be NULL in which case the stream will just
* count the number of bytes that would have been written. In this case
* max_size is not checked.
*
* Rules for callback:
* 1) Return false on IO errors. This will cause decoding to abort.
*
* 2) You can use state to store your own data (e.g. buffer pointer).
*
* 3) pb_write will update bytes_written before your callback runs.
*
* 4) Your callback will be always used with the same pb_ostream_t.
* There are no substreams when encoding.
*/
struct _pb_ostream_t
{
bool (*callback)(pb_ostream_t *stream, const uint8_t *buf, size_t count);
void *state; /* Free field for use by callback implementation */
size_t max_size; /* Limit number of output bytes written (or use SIZE_MAX). */
size_t bytes_written;
};
pb_ostream_t pb_ostream_from_buffer(uint8_t *buf, size_t bufsize);
bool pb_write(pb_ostream_t *stream, const uint8_t *buf, size_t count);
/* Encode struct to given output stream.
* Returns true on success, false on any failure.
* The actual struct pointed to by src_struct must match the description in fields.
* All required fields in the struct are assumed to have been filled in.
*/
bool pb_encode(pb_ostream_t *stream, const pb_field_t fields[], const void *src_struct);
/* --- Helper functions ---
* You may want to use these from your caller or callbacks.
*/
bool pb_encode_varint(pb_ostream_t *stream, uint64_t value);
bool pb_encode_tag(pb_ostream_t *stream, pb_wire_type_t wiretype, int field_number);
bool pb_encode_tag_for_field(pb_ostream_t *stream, const pb_field_t *field);
bool pb_encode_string(pb_ostream_t *stream, uint8_t *buffer, size_t size);
/* --- Field encoders ---
* Each encoder writes the content for the field.
* The tag/wire type has been written already.
*/
bool pb_enc_varint(pb_ostream_t *stream, const pb_field_t *field, const void *src);
bool pb_enc_svarint(pb_ostream_t *stream, const pb_field_t *field, const void *src);
bool pb_enc_fixed(pb_ostream_t *stream, const pb_field_t *field, const void *src);
bool pb_enc_bytes(pb_ostream_t *stream, const pb_field_t *field, const void *src);
bool pb_enc_string(pb_ostream_t *stream, const pb_field_t *field, const void *src);
bool pb_enc_submessage(pb_ostream_t *stream, const pb_field_t *field, const void *src);
#endif