Packet (C-API)

This page describes the C implementation of Packets

group PACKET

Functions

A0_STATIC_INLINE void a0_packet_callback_call (a0_packet_callback_t callback, a0_packet_t pkt)

a0_err_t a0_packet_init(a0_packet_t*)

Initializes a packet. This includes setting the id.

a0_err_t a0_packet_stats(a0_packet_t, a0_packet_stats_t*)

Compute packet statistics.

a0_err_t a0_packet_header_iterator_init(a0_packet_header_iterator_t*, a0_packet_t*)

Initializes an iterator over all headers.

a0_err_t a0_packet_header_iterator_next(a0_packet_header_iterator_t*, a0_packet_header_t *out)

Emit the next header.

a0_err_t a0_packet_header_iterator_next_match(a0_packet_header_iterator_t*, const char *key, a0_packet_header_t *out)

Emit the next header with the given key.

a0_err_t a0_packet_serialize(a0_packet_t, a0_alloc_t, a0_flat_packet_t *out)

Serializes the packet to the allocated location.

Note: the header order will NOT be retained.

a0_err_t a0_packet_deserialize(a0_flat_packet_t, a0_alloc_t, a0_packet_t *out_pkt, a0_buf_t *out_buf)

Deserializes the flat packet into a normal packet.

a0_err_t a0_packet_deep_copy(a0_packet_t, a0_alloc_t, a0_packet_t *out_pkt, a0_buf_t *out_buf)

Deep copies the packet contents.

a0_err_t a0_flat_packet_stats(a0_flat_packet_t, a0_packet_stats_t*)

Compute packet statistics, for serialized packets.

a0_err_t a0_flat_packet_id(a0_flat_packet_t, a0_uuid_t**)

Retrieve the uuid within the flat packet.

Note: the result points into the flat packet. It is not copied out.

a0_err_t a0_flat_packet_payload(a0_flat_packet_t, a0_buf_t*)

Retrieve the payload within the flat packet.

Note: the result points into the flat packet. It is not copied out.

a0_err_t a0_flat_packet_header(a0_flat_packet_t, size_t idx, a0_packet_header_t*)

Retrieve the i-th header within the flat packet.

Note: the result points into the flat packet. It is not copied out.

a0_err_t a0_flat_packet_header_iterator_init(a0_flat_packet_header_iterator_t*, a0_flat_packet_t*)

Initializes an iterator over all headers.

a0_err_t a0_flat_packet_header_iterator_next(a0_flat_packet_header_iterator_t*, a0_packet_header_t *out)

Emit the next header.

a0_err_t a0_flat_packet_header_iterator_next_match(a0_flat_packet_header_iterator_t*, const char *key, a0_packet_header_t *out)

Emit the next header with the given key.

Variables

const char *A0_DEP

Packet header key used to annotate a dependence on another packet.

The value should be a packet id.

struct a0_packet_header_t

#include <packet.h>

A single packet header.

struct a0_packet_headers_block_s

#include <packet.h>

A headers block contains a list of headers, along with an optional pointer to the next block.

https://en.wikipedia.org/wiki/Unrolled_linked_list

This is meant to make it easier for abstractions to add additional headers without allocating heap space.

void foo(a0_packet_headers_block_t* caller_headers) {
  a0_packet_headers_block_t all_headers;
  all_headers.headers = additional_headers;
  all_headers.size = num_additional_headers;
  all_headers.next_block = caller_headers;
  bar(&all_headers);
}

struct a0_packet_t

#include <packet.h>

A Packet is a unit of information used by protocols to transmit user data. There is a primary user payload, as well as key-value annotations, and a unique identifier.

struct a0_flat_packet_t

#include <packet.h>

A Flat Packet is a serialized Packet.

struct a0_packet_callback_t

#include <packet.h>

struct a0_packet_id_callback_t

#include <packet.h>

struct a0_packet_stats_t

#include <packet.h>

Various computed stats of a given packet.

struct a0_packet_header_iterator_t

#include <packet.h>

struct a0_flat_packet_header_iterator_t

#include <packet.h>