#include "tunala.h"

#ifndef NO_BUFFER

void buffer_init(buffer_t *buf)
{
	buf->used = 0;
}

void buffer_close(buffer_t *buf)
{
	/* Our data is static - nothing needs "release", just reset */
	buffer_init(buf);
}

/* Code these simple ones in compact form */
unsigned int buffer_used(buffer_t *buf) {
	return buf->used; }
unsigned int buffer_unused(buffer_t *buf) {
	return (MAX_DATA_SIZE - buf->used); }
int buffer_full(buffer_t *buf) {
	return (buf->used == MAX_DATA_SIZE ? 1 : 0); }
int buffer_notfull(buffer_t *buf) {
	return (buf->used < MAX_DATA_SIZE ? 1 : 0); }
int buffer_empty(buffer_t *buf) {
	return (buf->used == 0 ? 1 : 0); }
int buffer_notempty(buffer_t *buf) {
	return (buf->used > 0 ? 1 : 0); }

unsigned int buffer_adddata(buffer_t *buf, const unsigned char *ptr,
		unsigned int size)
{
	unsigned int added = MAX_DATA_SIZE - buf->used;
	if(added > size)
		added = size;
	if(added == 0)
		return 0;
	memcpy(buf->data + buf->used, ptr, added);
	buf->used += added;
	return added;
}

unsigned int buffer_takedata(buffer_t *buf, unsigned char *ptr,
		unsigned int size)
{
	unsigned int taken = buf->used;
	if(taken > size)
		taken = size;
	if(taken == 0)
		return 0;
	if(ptr)
		memcpy(ptr, buf->data, taken);
	buf->used -= taken;
	/* Do we have to scroll? */
	if(buf->used > 0)
		memmove(buf->data, buf->data + taken, buf->used);
	return taken;
}

unsigned int buffer_tobuffer(buffer_t *to, buffer_t *from, int cap)
{
	unsigned int moved, tomove = from->used;
	if((int)tomove > cap)
		tomove = cap;
	if(tomove == 0)
		return 0;
	moved = buffer_adddata(to, from->data, tomove);
	if(moved == 0)
		return 0;
	buffer_takedata(from, NULL, moved);
	return moved;
}

#ifndef NO_IP

int buffer_from_fd(buffer_t *buf, int fd)
{
	unsigned int toread = buffer_unused(buf);
	if(toread == 0)
		/* Shouldn't be called in this case! */
		abort();
	toread = read(fd, buf->data + buf->used, toread);
	if(toread > 0)
		buf->used += toread;
	return toread;
}

int buffer_to_fd(buffer_t *buf, int fd)
{
	unsigned int towrite = buffer_used(buf);
	if(towrite == 0)
		/* Shouldn't be called in this case! */
		abort();
	towrite = write(fd, buf->data, towrite);
	if(towrite > 0)
		buffer_takedata(buf, NULL, towrite);
	return towrite;
}

#endif /* !defined(NO_IP) */

#ifndef NO_OPENSSL

void buffer_from_SSL(buffer_t *buf, SSL *ssl)
{
	int ret;
	if(!ssl || buffer_full(buf))
		return;
	ret = SSL_read(ssl, buf->data + buf->used, buffer_unused(buf));
	if(ret > 0)
		buf->used += ret;
}

void buffer_to_SSL(buffer_t *buf, SSL *ssl)
{
	int ret;
	if(!ssl || buffer_empty(buf))
		return;
	ret = SSL_write(ssl, buf->data, buf->used);
	if(ret > 0)
		buffer_takedata(buf, NULL, ret);
}

void buffer_from_BIO(buffer_t *buf, BIO *bio)
{
	int ret;
	if(!bio || buffer_full(buf))
		return;
	ret = BIO_read(bio, buf->data + buf->used, buffer_unused(buf));
	if(ret > 0)
		buf->used += ret;
}

void buffer_to_BIO(buffer_t *buf, BIO *bio)
{
	int ret;
	if(!bio || buffer_empty(buf))
		return;
	ret = BIO_write(bio, buf->data, buf->used);
	if(ret > 0)
		buffer_takedata(buf, NULL, ret);
}

#endif /* !defined(NO_OPENSSL) */

#endif /* !defined(NO_BUFFER) */