/*
ringbuffy.c
Copyright (C) Marcus Metzler for convergence integrated media.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#define __NO_VERSION__
#include "margi.h"
#include "ringbuffy.h"
int ring_init (ringbuffy *rbuf, long size)
{
rbuf->size = 0;
rbuf->read_pos = 0;
rbuf->write_pos = 0;
if (size > 0){
if( !(rbuf->buffy = (char *) vmalloc(sizeof(char)*size)) ){
MDEBUG(0,
"Not enough memory for ringbuffy\n");
return -1;
}
} else {
MDEBUG(0, "Wrong size for ringbuffy\n");
return -1;
}
rbuf->size = size;
return 0;
}
void ring_destroy(ringbuffy *rbuf)
{
if (rbuf->size){
vfree(rbuf->buffy);
rbuf->buffy = NULL;
}
rbuf->size = 0;
rbuf->read_pos = 0;
rbuf->write_pos = 0;
}
int ring_write(ringbuffy *rbuf, const char *data, int count)
{
long diff, free, pos, rest;
if (count <=0 || !rbuf->buffy) return 0;
pos = rbuf->write_pos;
rest = rbuf->size - pos;
diff = rbuf->read_pos - pos;
free = (diff > 0) ? diff-4 : rbuf->size+diff-4;
if ( free <= 0 ) return 0;
if ( free < count ) count = free;
if (count >= rest){
if(copy_from_user (rbuf->buffy+pos, data, rest))
return -EFAULT;
if (count - rest)
if(copy_from_user(rbuf->buffy, data+rest,
count - rest))
return -EFAULT;
rbuf->write_pos = count - rest;
} else {
copy_from_user (rbuf->buffy+pos, data, count);
rbuf->write_pos += count;
}
return count;
}
int ring_read(ringbuffy *rbuf, char *data, int count)
{
long diff, free, pos, rest;
if (count <=0 || !rbuf->buffy) return 0;
pos = rbuf->read_pos;
rest = rbuf->size - pos;
diff = rbuf->write_pos - pos;
free = (diff >= 0) ? diff : rbuf->size+diff;
if ( free <= 0 ) return 0;
if ( free < count ) count = free;
if ( count >= rest ){
memcpy(data,rbuf->buffy+pos,rest);
if ( count - rest)
memcpy(data+rest,rbuf->buffy,count-rest);
rbuf->read_pos = count - rest;
} else {
memcpy(data,rbuf->buffy+pos,count);
rbuf->read_pos += count;
}
return count;
}
int ring_read_direct(ringbuffy *rbuf, int addr, int count)
{
long diff, free, pos, rest;
if (count <=0 || !rbuf->buffy) return 0;
pos = rbuf->read_pos;
rest = rbuf->size - pos;
diff = rbuf->write_pos - pos;
free = (diff >= 0) ? diff : rbuf->size+diff;
if ( free <= 0 ) return 0;
if ( free < count ) count = free;
if ( count >= rest ){
outsl_ns(addr,rbuf->buffy+pos,rest/4);
if ( count - rest)
outsl_ns(addr,rbuf->buffy,(count-rest)/4);
rbuf->read_pos = count - rest;
} else {
outsl_ns(addr,rbuf->buffy+pos,count/4);
rbuf->read_pos += count;
}
return count;
}
long ring_read_rest(ringbuffy *rbuf){
long diff, free, pos;
if (!rbuf->buffy) return 0;
pos = rbuf->read_pos;
diff = rbuf->write_pos - pos;
free = (diff >= 0) ? diff : rbuf->size+diff;
return free;
}
long ring_write_rest(ringbuffy *rbuf){
long diff, free, pos;
if (!rbuf->buffy) return 0;
pos = rbuf->write_pos;
diff = rbuf->read_pos - pos;
free = (diff > 0) ? diff-4 : rbuf->size+diff-4;
return free;
}
void ring_flush(ringbuffy *rbuf){
rbuf->read_pos = 0;
rbuf->write_pos = 0;
}
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