wxbuff.c

wimax BS simulation code,implemented under linux.

/*
 * This piece of code is totally free. If any pitfalls found, 
 * please feel free to contact me at [e-mail]
 * THANKS A LOT!
 */

#include <stdlib.h>
#include <string.h>

#include "que.h"
#include "wxbuff.h"


#define NR_WXBUFF_MAX		32
#define NR_DATABUFF_MAX		16


pool_t g_wxbuffpool;
pool_t g_databuffpool;


int32_t wxbuff_pool_init()
{
	int32_t i;
	wxbuff_t *wxb;
	databuff_t *db;

	
	pool_init(&g_wxbuffpool);
	pool_init(&g_databuffpool);

	for ( i = 0; i < NR_WXBUFF_MAX; i++ ) {
		if ( (wxb = (wxbuff_t *)malloc(sizeof(wxbuff_t))) == NULL )
			return -1;

		memset(wxb, 0, sizeof(wxbuff_t));
		list_add_tail(&wxb->junior, &g_wxbuffpool.link);
		g_wxbuffpool.count++;
	}

	for ( i = 0; i < NR_DATABUFF_MAX; i++ ) {
		if ( (db = (databuff_t *)malloc(sizeof(databuff_t))) == NULL )
			return -1;

		atomic_set(&db->ref, 0);
		list_add_tail(&db->link, &g_databuffpool.link);
		g_databuffpool.count++;
	}

	return 0;
}


wxbuff_t * get_wxbuff(wxbuff_t *refwxb)
{
	wxbuff_t *wxb;
	databuff_t *db;
	

	pthread_mutex_lock(&g_wxbuffpool.mutex);

	if ( g_wxbuffpool.count == 0 ) {
		pthread_mutex_unlock(&g_wxbuffpool.mutex);
		return NULL;
	}
	else {
		wxb = list_entry(g_wxbuffpool.link.next, wxbuff_t, junior);
		list_del(g_wxbuffpool.link.next);
		g_wxbuffpool.count--;
		pthread_mutex_unlock(&g_wxbuffpool.mutex);

		memset(wxb, 0, sizeof(wxbuff_t));
		INIT_LIST_HEAD(&wxb->senior);
		INIT_LIST_HEAD(&wxb->junior);
	}

	if ( refwxb == NULL ) {
		pthread_mutex_lock(&g_databuffpool.mutex);

		if ( g_databuffpool.count == 0 ) {
			pthread_mutex_unlock(&g_databuffpool.mutex);
			put_wxbuff(wxb);

			wxb = NULL;
		}
		else {
			db = list_entry(g_databuffpool.link.next, databuff_t, link);
			list_del(g_databuffpool.link.next);
			g_databuffpool.count--;

			atomic_set(&db->ref,1);
			wxb->data = &db->data[0];
			wxb->beg = wxb->end = wxb->data;
			wxb->tail = &db->data[2048];
		}
		
		pthread_mutex_unlock(&g_databuffpool.mutex);
	}
	else {
		wxb->data = refwxb->data;
		wxb->tail = refwxb->tail;
		wxb->beg = wxb->end = wxb->data;

		db = wxbuff_databuff(refwxb);
		atomic_inc(&db->ref);
	}
	
	return wxb;
}


int32_t put_wxbuff(wxbuff_t *wxb)
{
	databuff_t *db;


	if ( wxb->data != NULL && wxb->tail != NULL ) {
		db = wxbuff_databuff(wxb);
		
		if ( atomic_dec_and_test(&db->ref) ) {
			pthread_mutex_lock(&g_databuffpool.mutex);
			list_add_tail(&db->link, &g_databuffpool.link);
			g_databuffpool.count++;
			pthread_mutex_unlock(&g_databuffpool.mutex);
		}
	}

	pthread_mutex_lock(&g_wxbuffpool.mutex);
	list_add_tail(&wxb->junior, &g_wxbuffpool.link);
	g_wxbuffpool.count++;
	pthread_mutex_unlock(&g_wxbuffpool.mutex);

	return 0;
}


void init_wxbuff(wxbuff_t *wxb)
{
	databuff_t *db = wxbuff_databuff(wxb);


	atomic_set(&db->ref, 0);
	wxb->tolen = wxb->len = 0;
	wxb->cid = 0;
	wxb->beg = wxb->end = wxb->data;
	wxbuff_reserve(wxb, 64);

	return;
}


uint8_t * copy_and_free_wxbuff(wxbuff_t *wxb, uint32_t *len)
{
	uint8_t *buffer;
	struct list_head hdr, *pos, *tmp;
	wxbuff_t *_wxb;
	uint32_t off = 0;


	if ( (buffer = (uint8_t *)malloc(wxb->tolen)) == NULL )
		return NULL;

	*len = wxb->tolen;
	list_add_tail(&hdr, &wxb->junior);

	list_for_each_safe(pos, tmp, &hdr) {
		_wxb = list_entry(pos, wxbuff_t, junior);

		memcpy(buffer+off, _wxb->beg, _wxb->len);
		off += _wxb->len;
		
		put_wxbuff(_wxb);
	}

	return buffer;
}


void wxbuff_reserve(wxbuff_t *wxb, uint32_t size)
{
	wxb->beg += size;
	wxb->end += size;

	return;
}


int32_t wxbuff_push(wxbuff_t *wxb, uint8_t *in, uint32_t len)
{
	if ( wxb->end+len > wxb->tail )
		return -1;

	memcpy(wxb->end, in, len);
	wxb->end += len;
	wxb->len += len;
	
	return 0;
}