diff options
Diffstat (limited to 'pb_decode.h')
| -rw-r--r-- | pb_decode.h | 36 |
1 files changed, 22 insertions, 14 deletions
diff --git a/pb_decode.h b/pb_decode.h index 448b55db..011efdd9 100644 --- a/pb_decode.h +++ b/pb_decode.h @@ -1,18 +1,32 @@ #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. - * If buf is NULL, read but don't store bytes. - * You can to provide a callback function for reading or use + * You can provide a callback function for reading or use * pb_istream_from_buffer. * - * You can use state to store your own data (e.g. buffer pointer), + * 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. - * However, substreams may change bytes_left so don't use that to - * compute any pointers. + * + * 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 { @@ -25,6 +39,7 @@ 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); @@ -49,15 +64,8 @@ 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, uint8_t *dest); -bool pb_dec_string(pb_istream_t *stream, const pb_field_t *field, uint8_t *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); -typedef bool (*pb_decoder_t)(pb_istream_t *stream, const pb_field_t *field, void *dest); - -/* --- Function pointers to field decoders --- - * Order in the array must match pb_action_t LTYPE numbering. - */ -const pb_decoder_t PB_DECODERS[PB_LTYPES_COUNT]; - #endif |