int nghttp2_bufs_add(nghttp2_bufs *bufs, const void *data, size_t len)
{
int rv;
size_t nwrite;
nghttp2_buf *buf;
const uint8_t *p;
if(bufs_avail(bufs) < (ssize_t)len) {
return NGHTTP2_ERR_BUFFER_ERROR;
}
p = (const uint8_t *)data;
while(len) {
buf = &bufs->cur->buf;
nwrite = nghttp2_min((size_t)nghttp2_buf_avail(buf), len);
if(nwrite == 0) {
rv = bufs_alloc_chain(bufs);
if(rv != 0) {
return rv;
}
continue;
}
buf->last = nghttp2_cpymem(buf->last, p, nwrite);
p += len;
len -= nwrite;
}
return 0;
}
/*
* local_window_size
* ^ *
* | * recv_window_size
* | * * ^
* | * * |
* 0+++++++++
* | * * \
* | * * | This rage is hidden in flow control. But it must be
* v * * / kept in order to restore it when window size is enlarged.
* recv_reduction
* (+ for negative direction)
*
* recv_window_size could be negative if we decrease
* local_window_size more than recv_window_size:
*
* local_window_size
* ^ *
* | *
* | *
* 0++++++++
* | * ^ recv_window_size (negative)
* | * |
* v * *
* recv_reduction
*/
int nghttp2_adjust_local_window_size(int32_t *local_window_size_ptr,
int32_t *recv_window_size_ptr,
int32_t *recv_reduction_ptr,
int32_t *delta_ptr) {
if (*delta_ptr > 0) {
int32_t recv_reduction_delta;
int32_t delta;
int32_t new_recv_window_size =
nghttp2_max(0, *recv_window_size_ptr) - *delta_ptr;
if (new_recv_window_size >= 0) {
*recv_window_size_ptr = new_recv_window_size;
return 0;
}
delta = -new_recv_window_size;
/* The delta size is strictly more than received bytes. Increase
local_window_size by that difference |delta|. */
if (*local_window_size_ptr > NGHTTP2_MAX_WINDOW_SIZE - delta) {
return NGHTTP2_ERR_FLOW_CONTROL;
}
*local_window_size_ptr += delta;
/* If there is recv_reduction due to earlier window_size
reduction, we have to adjust it too. */
recv_reduction_delta = nghttp2_min(*recv_reduction_ptr, delta);
*recv_reduction_ptr -= recv_reduction_delta;
if (*recv_window_size_ptr < 0) {
*recv_window_size_ptr += recv_reduction_delta;
} else {
/* If *recv_window_size_ptr > 0, then those bytes are going to
be returned to the remote peer (by WINDOW_UPDATE with the
adjusted *delta_ptr), so it is effectively 0 now. We set to
*recv_reduction_delta, because caller does not take into
account it in *delta_ptr. */
*recv_window_size_ptr = recv_reduction_delta;
}
/* recv_reduction_delta must be paied from *delta_ptr, since it
was added in window size reduction (see below). */
*delta_ptr -= recv_reduction_delta;
return 0;
}
if (*local_window_size_ptr + *delta_ptr < 0 ||
*recv_window_size_ptr < INT32_MIN - *delta_ptr ||
*recv_reduction_ptr > INT32_MAX + *delta_ptr) {
return NGHTTP2_ERR_FLOW_CONTROL;
}
/* Decreasing local window size. Note that we achieve this without
noticing to the remote peer. To do this, we cut
recv_window_size by -delta. This means that we don't send
WINDOW_UPDATE for -delta bytes. */
*local_window_size_ptr += *delta_ptr;
*recv_window_size_ptr += *delta_ptr;
*recv_reduction_ptr -= *delta_ptr;
*delta_ptr = 0;
return 0;
}
int nghttp2_bufs_add(nghttp2_bufs *bufs, const void *data, size_t len) {
int rv;
size_t nwrite;
nghttp2_buf *buf;
const uint8_t *p;
// h1994st:
if (!bufs->random_enabled && bufs_avail(bufs) < len) {
return NGHTTP2_ERR_BUFFER_ERROR;
}
p = data;
while (len) {
buf = &bufs->cur->buf;
nwrite = nghttp2_min(nghttp2_buf_avail(buf), len);
if (nwrite == 0) {
rv = bufs_alloc_chain(bufs);
if (rv != 0) {
return rv;
}
continue;
}
buf->last = nghttp2_cpymem(buf->last, p, nwrite);
p += nwrite;
len -= nwrite;
}
return 0;
}
int nghttp2_increase_local_window_size(int32_t *local_window_size_ptr,
int32_t *recv_window_size_ptr,
int32_t *recv_reduction_ptr,
int32_t *delta_ptr) {
int32_t recv_reduction_delta;
int32_t delta;
delta = *delta_ptr;
assert(delta >= 0);
/* The delta size is strictly more than received bytes. Increase
local_window_size by that difference |delta|. */
if (*local_window_size_ptr > NGHTTP2_MAX_WINDOW_SIZE - delta) {
return NGHTTP2_ERR_FLOW_CONTROL;
}
*local_window_size_ptr += delta;
/* If there is recv_reduction due to earlier window_size
reduction, we have to adjust it too. */
recv_reduction_delta = nghttp2_min(*recv_reduction_ptr, delta);
*recv_reduction_ptr -= recv_reduction_delta;
*recv_window_size_ptr += recv_reduction_delta;
/* recv_reduction_delta must be paid from *delta_ptr, since it was
added in window size reduction (see below). */
*delta_ptr -= recv_reduction_delta;
return 0;
}
static ssize_t data_feed_recv_callback(nghttp2_session *session, uint8_t *data,
size_t len, int flags, void *user_data) {
data_feed *df = ((my_user_data *)user_data)->df;
size_t avail = (size_t)(df->datalimit - df->datamark);
size_t wlen = nghttp2_min(avail, len);
(void)session;
(void)flags;
memcpy(data, df->datamark, wlen);
df->datamark += wlen;
return (ssize_t)wlen;
}
int nghttp2_buffer_reserve(nghttp2_buffer *buffer, size_t len)
{
if(len > buffer->max_capacity) {
return NGHTTP2_ERR_BUFFER_ERROR;
}
if(buffer->capacity < len) {
uint8_t *new_buf;
size_t new_cap = buffer->capacity == 0 ? 8 : buffer->capacity * 3 / 2;
new_cap = nghttp2_min(buffer->max_capacity, nghttp2_max(new_cap, len));
new_buf = realloc(buffer->buf, new_cap);
if(new_buf == NULL) {
return NGHTTP2_ERR_NOMEM;
}
buffer->buf = new_buf;
buffer->capacity = new_cap;
}
return 0;
}
