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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_from_buffer().
*
* 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.
*/
/* Decode the tag for the next field in the stream. Gives the wire type and
* field tag. At end of the message, returns false and sets eof to true. */
bool pb_decode_tag(pb_istream_t *stream, pb_wire_type_t *wire_type, uint32_t *tag, bool *eof);
/* Skip the field payload data, given the wire type. */
bool pb_skip_field(pb_istream_t *stream, pb_wire_type_t wire_type);
/* Decode an integer in the varint format. This works for bool, enum, int32,
* int64, uint32 and uint64 field types. */
bool pb_decode_varint(pb_istream_t *stream, uint64_t *dest);
/* Decode an integer in the zig-zagged svarint format. This works for sint32
* and sint64. */
bool pb_decode_svarint(pb_istream_t *stream, int64_t *dest);
/* Decode a fixed32, sfixed32 or float value. You need to pass a pointer to
* a 4-byte wide C variable. */
bool pb_decode_fixed32(pb_istream_t *stream, void *dest);
/* Decode a fixed64, sfixed64 or double value. You need to pass a pointer to
* a 8-byte wide C variable. */
bool pb_decode_fixed64(pb_istream_t *stream, void *dest);
/* Make a limited-length substream for reading a PB_WT_STRING field. */
bool pb_make_string_substream(pb_istream_t *stream, pb_istream_t *substream);
void pb_close_string_substream(pb_istream_t *stream, pb_istream_t *substream);
/* --- Internal functions ---
* These functions are not terribly useful for the average library user, but
* are exported to make the unit testing and extending nanopb easier.
*/
#ifdef NANOPB_INTERNALS
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_fixed32(pb_istream_t *stream, const pb_field_t *field, void *dest);
bool pb_dec_fixed64(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);
bool pb_skip_varint(pb_istream_t *stream);
bool pb_skip_string(pb_istream_t *stream);
#endif
#endif
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