packet: Make pa_packet_new() create fixed-size packets

if length exceeds maximum appended size, create a packet of
type dynamic instead of type appended

this is a preparation to use a separate free-list for packets

document semantics of pa_packet_new_*() functions

Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net>
This commit is contained in:
Peter Meerwald 2014-10-23 13:48:21 +02:00 committed by Peter Meerwald
parent 5a2c41e5bf
commit c1a7f0e326
2 changed files with 18 additions and 3 deletions

View file

@ -29,11 +29,16 @@
#include "packet.h"
#define MAX_APPENDED_SIZE 128
typedef struct pa_packet {
PA_REFCNT_DECLARE;
enum { PA_PACKET_APPENDED, PA_PACKET_DYNAMIC } type;
size_t length;
uint8_t *data;
union {
uint8_t appended[MAX_APPENDED_SIZE];
} per_type;
} pa_packet;
pa_packet* pa_packet_new(size_t length) {
@ -41,11 +46,16 @@ pa_packet* pa_packet_new(size_t length) {
pa_assert(length > 0);
p = pa_xmalloc(PA_ALIGN(sizeof(pa_packet)) + length);
p = pa_xnew(pa_packet, 1);
PA_REFCNT_INIT(p);
p->length = length;
p->data = (uint8_t*) p + PA_ALIGN(sizeof(pa_packet));
p->type = PA_PACKET_APPENDED;
if (length > MAX_APPENDED_SIZE) {
p->data = pa_xmalloc(length);
p->type = PA_PACKET_DYNAMIC;
} else {
p->data = p->per_type.appended;
p->type = PA_PACKET_APPENDED;
}
return p;
}

View file

@ -25,7 +25,12 @@
typedef struct pa_packet pa_packet;
/* create empty packet (either of type appended or dynamic depending
* on length) */
pa_packet* pa_packet_new(size_t length);
/* data must have been malloc()ed; the packet takes ownership of the memory,
* i.e. memory is free()d with the packet */
pa_packet* pa_packet_new_dynamic(void* data, size_t length);
const void* pa_packet_data(pa_packet *p, size_t *l);