/* Tries to copy block <blk> at once into the channel's buffer after length
* controls. The chn->o and to_forward pointers are updated. If the channel
* input is closed, -2 is returned. If the block is too large for this buffer,
* -3 is returned. If there is not enough room left in the buffer, -1 is
* returned. Otherwise the number of bytes copied is returned (0 being a valid
* number). Channel flag READ_PARTIAL is updated if some data can be
* transferred.
*/
int ci_putblk(struct channel *chn, const char *blk, int len)
{
int max;
if (unlikely(channel_input_closed(chn)))
return -2;
if (len < 0)
return -3;
max = channel_recv_limit(chn);
if (unlikely(len > max - c_data(chn))) {
/* we can't write this chunk right now because the buffer is
* almost full or because the block is too large. Return the
* available space or -2 if impossible.
*/
if (len > max)
return -3;
return -1;
}
if (unlikely(len == 0))
return 0;
/* OK so the data fits in the buffer in one or two blocks */
max = b_contig_space(&chn->buf);
memcpy(ci_tail(chn), blk, MIN(len, max));
if (len > max)
memcpy(c_orig(chn), blk + max, len - max);
b_add(&chn->buf, len);
channel_add_input(chn, len);
return len;
}
/* Tries to copy block <blk> at once into the channel's buffer after length
* controls. The chn->o and to_forward pointers are updated. If the channel
* input is closed, -2 is returned. If the block is too large for this buffer,
* -3 is returned. If there is not enough room left in the buffer, -1 is
* returned. Otherwise the number of bytes copied is returned (0 being a valid
* number). Channel flag READ_PARTIAL is updated if some data can be
* transferred.
*/
int ci_putblk(struct channel *chn, const char *blk, int len)
{
int max;
if (unlikely(channel_input_closed(chn)))
return -2;
if (len < 0)
return -3;
max = channel_recv_limit(chn);
if (unlikely(len > max - c_data(chn))) {
/* we can't write this chunk right now because the buffer is
* almost full or because the block is too large. Return the
* available space or -2 if impossible.
*/
if (len > max)
return -3;
return -1;
}
if (unlikely(len == 0))
return 0;
/* OK so the data fits in the buffer in one or two blocks */
max = b_contig_space(&chn->buf);
memcpy(ci_tail(chn), blk, MIN(len, max));
if (len > max)
memcpy(c_orig(chn), blk + max, len - max);
b_add(&chn->buf, len);
chn->total += len;
if (chn->to_forward) {
unsigned long fwd = len;
if (chn->to_forward != CHN_INFINITE_FORWARD) {
if (fwd > chn->to_forward)
fwd = chn->to_forward;
chn->to_forward -= fwd;
}
c_adv(chn, fwd);
}
/* notify that some data was read from the SI into the buffer */
chn->flags |= CF_READ_PARTIAL;
return len;
}
/* Gets one full block of data at once from a channel's input buffer.
* This function can return the data slitted in one or two blocks.
* Return values :
* >0 : number of blocks returned (1 or 2). blk1 is always filled before blk2.
* =0 : not enough data available.
* <0 : no more bytes readable because input is shut.
*/
int ci_getblk_nc(const struct channel *chn,
char **blk1, size_t *len1,
char **blk2, size_t *len2)
{
if (unlikely(ci_data(chn) == 0)) {
if (chn->flags & CF_SHUTR)
return -1;
return 0;
}
if (unlikely(ci_head(chn) + ci_data(chn) > c_wrap(chn))) {
*blk1 = ci_head(chn);
*len1 = c_wrap(chn) - ci_head(chn);
*blk2 = c_orig(chn);
*len2 = ci_data(chn) - *len1;
return 2;
}
*blk1 = ci_head(chn);
*len1 = ci_data(chn);
return 1;
}
