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/*
* Copyright (C) Igor Sysoev
* Copyright (C) Nginx, Inc.
*/
#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_event.h>
ssize_t
ngx_readv_chain(ngx_connection_t *c, ngx_chain_t *chain, off_t limit)
{
u_char *prev;
ssize_t n, size;
ngx_err_t err;
ngx_array_t vec;
ngx_event_t *rev;
struct iovec *iov, iovs[NGX_IOVS_PREALLOCATE];
rev = c->read;
#if (NGX_HAVE_KQUEUE)
if (ngx_event_flags & NGX_USE_KQUEUE_EVENT) {
ngx_log_debug3(NGX_LOG_DEBUG_EVENT, c->log, 0,
"readv: eof:%d, avail:%d, err:%d",
rev->pending_eof, rev->available, rev->kq_errno);
if (rev->available == 0) {
if (rev->pending_eof) {
rev->ready = 0;
rev->eof = 1;
ngx_log_error(NGX_LOG_INFO, c->log, rev->kq_errno,
"kevent() reported about an closed connection");
if (rev->kq_errno) {
rev->error = 1;
ngx_set_socket_errno(rev->kq_errno);
return NGX_ERROR;
}
return 0;
} else {
return NGX_AGAIN;
}
}
}
#endif
#if (NGX_HAVE_EPOLLRDHUP)
if (ngx_event_flags & NGX_USE_EPOLL_EVENT) {
ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0,
"readv: eof:%d, avail:%d",
rev->pending_eof, rev->available);
if (!rev->available && !rev->pending_eof) {
return NGX_AGAIN;
}
}
#endif
prev = NULL;
iov = NULL;
size = 0;
vec.elts = iovs;
vec.nelts = 0;
vec.size = sizeof(struct iovec);
vec.nalloc = NGX_IOVS_PREALLOCATE;
vec.pool = c->pool;
/* coalesce the neighbouring bufs */
while (chain) {
n = chain->buf->end - chain->buf->last;
if (limit) {
if (size >= limit) {
break;
}
if (size + n > limit) {
n = (ssize_t) (limit - size);
}
}
if (prev == chain->buf->last) {
iov->iov_len += n;
} else {
if (vec.nelts >= IOV_MAX) {
break;
}
iov = ngx_array_push(&vec);
if (iov == NULL) {
return NGX_ERROR;
}
iov->iov_base = (void *) chain->buf->last;
iov->iov_len = n;
}
size += n;
prev = chain->buf->end;
chain = chain->next;
}
ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0,
"readv: %ui, last:%uz", vec.nelts, iov->iov_len);
do {
n = readv(c->fd, (struct iovec *) vec.elts, vec.nelts);
if (n == 0) {
rev->ready = 0;
rev->eof = 1;
#if (NGX_HAVE_KQUEUE)
/*
* on FreeBSD readv() may return 0 on closed socket
* even if kqueue reported about available data
*/
if (ngx_event_flags & NGX_USE_KQUEUE_EVENT) {
rev->available = 0;
}
#endif
return 0;
}
if (n > 0) {
#if (NGX_HAVE_KQUEUE)
if (ngx_event_flags & NGX_USE_KQUEUE_EVENT) {
rev->available -= n;
/*
* rev->available may be negative here because some additional
* bytes may be received between kevent() and readv()
*/
if (rev->available <= 0) {
if (!rev->pending_eof) {
rev->ready = 0;
}
rev->available = 0;
}
return n;
}
#endif
#if (NGX_HAVE_EPOLLRDHUP)
if ((ngx_event_flags & NGX_USE_EPOLL_EVENT)
&& ngx_use_epoll_rdhup)
{
if (n < size) {
if (!rev->pending_eof) {
rev->ready = 0;
}
rev->available = 0;
}
return n;
}
#endif
if (n < size && !(ngx_event_flags & NGX_USE_GREEDY_EVENT)) {
rev->ready = 0;
}
return n;
}
err = ngx_socket_errno;
if (err == NGX_EAGAIN || err == NGX_EINTR) {
ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, err,
"readv() not ready");
n = NGX_AGAIN;
} else {
n = ngx_connection_error(c, err, "readv() failed");
break;
}
} while (err == NGX_EINTR);
rev->ready = 0;
if (n == NGX_ERROR) {
c->read->error = 1;
}
return n;
}
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