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#ifndef _PB_DECODE_H_
#define _PB_DECODE_H_
/* pb_decode.h: Functions to decode protocol buffers. Depends on pb_decode.c.
* The main function is pb_decode. You will also need to create an input
* stream, which is easiest to do with pb_istream_t.
*
* You also need structures and their corresponding pb_field_t descriptions.
* These are usually generated from .proto-files with a script.
*/
#include <stdbool.h>
#include "pb.h"
/* Lightweight input stream.
* You can provide a callback function for reading or use
* pb_istream_from_buffer.
*
* Rules for callback:
* 1) Return false on IO errors. This will cause decoding to abort.
*
* 2) If buf is NULL, read but don't store bytes ("skip input").
*
* 3) You can use state to store your own data (e.g. buffer pointer),
* and rely on pb_read to verify that no-body reads past bytes_left.
*
* 4) Your callback may be used with substreams, in which case bytes_left
* is different than from the main stream. Don't use bytes_left to compute
* any pointers.
*/
struct _pb_istream_t
{
bool (*callback)(pb_istream_t *stream, uint8_t *buf, size_t count);
void *state; /* Free field for use by callback implementation */
size_t bytes_left;
};
pb_istream_t pb_istream_from_buffer(uint8_t *buf, size_t bufsize);
bool pb_read(pb_istream_t *stream, uint8_t *buf, size_t count);
/* Decode from stream to destination struct.
* Returns true on success, false on any failure.
* The actual struct pointed to by dest must match the description in fields.
*/
bool pb_decode(pb_istream_t *stream, const pb_field_t fields[], void *dest_struct);
/* --- Helper functions ---
* You may want to use these from your caller or callbacks.
*/
bool pb_decode_varint(pb_istream_t *stream, uint64_t *dest);
bool pb_skip_varint(pb_istream_t *stream);
bool pb_skip_string(pb_istream_t *stream);
/* --- Field decoders ---
* Each decoder takes stream and field description, and a pointer to the field
* in the destination struct (dest = struct_addr + field->data_offset).
* For arrays, these functions are called repeatedly.
*/
bool pb_dec_varint(pb_istream_t *stream, const pb_field_t *field, void *dest);
bool pb_dec_svarint(pb_istream_t *stream, const pb_field_t *field, void *dest);
bool pb_dec_fixed(pb_istream_t *stream, const pb_field_t *field, void *dest);
bool pb_dec_bytes(pb_istream_t *stream, const pb_field_t *field, void *dest);
bool pb_dec_string(pb_istream_t *stream, const pb_field_t *field, void *dest);
bool pb_dec_submessage(pb_istream_t *stream, const pb_field_t *field, void *dest);
#endif
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