libevent: event2/tag.h File Reference

libevent 2.1.13 Event notification library

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tag.h File Reference

Helper functions for reading and writing tagged data onto buffers. More...

`#include <event2/visibility.h>`
`#include <event2/event-config.h>`
`#include <event2/util.h>`

Go to the source code of this file.

## Functions
EVENT2_EXPORT_SYMBOL int | evtag_consume (struct evbuffer *evbuf)
EVENT2_EXPORT_SYMBOL void | evtag_encode_int (struct evbuffer *evbuf, ev_uint32_t number)
| Encode an integer and store it in an evbuffer.
EVENT2_EXPORT_SYMBOL void | evtag_encode_int64 (struct evbuffer *evbuf, ev_uint64_t number)
EVENT2_EXPORT_SYMBOL void | evtag_init (void)
EVENT2_EXPORT_SYMBOL void | evtag_marshal (struct evbuffer *evbuf, ev_uint32_t tag, const void *data, ev_uint32_t len)
EVENT2_EXPORT_SYMBOL void | evtag_marshal_buffer (struct evbuffer *evbuf, ev_uint32_t tag, struct evbuffer *data)
EVENT2_EXPORT_SYMBOL void | evtag_marshal_int (struct evbuffer *evbuf, ev_uint32_t tag, ev_uint32_t integer)
EVENT2_EXPORT_SYMBOL void | evtag_marshal_int64 (struct evbuffer *evbuf, ev_uint32_t tag, ev_uint64_t integer)
EVENT2_EXPORT_SYMBOL void | evtag_marshal_string (struct evbuffer *buf, ev_uint32_t tag, const char *string)
EVENT2_EXPORT_SYMBOL void | evtag_marshal_timeval (struct evbuffer *evbuf, ev_uint32_t tag, struct timeval *tv)
EVENT2_EXPORT_SYMBOL int | evtag_payload_length (struct evbuffer *evbuf, ev_uint32_t *plength)
EVENT2_EXPORT_SYMBOL int | evtag_peek (struct evbuffer *evbuf, ev_uint32_t *ptag)
EVENT2_EXPORT_SYMBOL int | evtag_peek_length (struct evbuffer *evbuf, ev_uint32_t *plength)
EVENT2_EXPORT_SYMBOL int | evtag_unmarshal (struct evbuffer *src, ev_uint32_t *ptag, struct evbuffer *dst)
EVENT2_EXPORT_SYMBOL int | evtag_unmarshal_fixed (struct evbuffer *src, ev_uint32_t need_tag, void *data, size_t len)
EVENT2_EXPORT_SYMBOL int | evtag_unmarshal_header (struct evbuffer *evbuf, ev_uint32_t *ptag)
| Unmarshals the header and returns the length of the payload.
EVENT2_EXPORT_SYMBOL int | evtag_unmarshal_int (struct evbuffer *evbuf, ev_uint32_t need_tag, ev_uint32_t *pinteger)
EVENT2_EXPORT_SYMBOL int | evtag_unmarshal_int64 (struct evbuffer *evbuf, ev_uint32_t need_tag, ev_uint64_t *pinteger)
EVENT2_EXPORT_SYMBOL int | evtag_unmarshal_string (struct evbuffer *evbuf, ev_uint32_t need_tag, char **pstring)
EVENT2_EXPORT_SYMBOL int | evtag_unmarshal_timeval (struct evbuffer *evbuf, ev_uint32_t need_tag, struct timeval *ptv)

## Detailed Description

Helper functions for reading and writing tagged data onto buffers.

## Function Documentation

## ◆ evtag_encode_int()

EVENT2_EXPORT_SYMBOL void evtag_encode_int | ( | struct evbuffer * | evbuf,
|  | ev_uint32_t | number )

Encode an integer and store it in an evbuffer.

We encode integers by nybbles; the first nibble contains the number of significant nibbles - 1; this allows us to encode up to 64-bit integers. This function is byte-order independent.

Parameters

  evbuf | evbuffer to store the encoded number
  number | a 32-bit integer

## ◆ evtag_unmarshal_header()

EVENT2_EXPORT_SYMBOL int evtag_unmarshal_header | ( | struct evbuffer * | evbuf,
|  | ev_uint32_t * | ptag )

Unmarshals the header and returns the length of the payload.

Returns an error if the payload length is above INT_MAX.

Parameters

  evbuf | the buffer from which to unmarshal data
  ptag | a pointer in which the tag id is being stored

Returns
  -1 on failure or the number of bytes in the remaining payload.