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/*
* Copyright (C) Igor Sysoev
*/
#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_event.h>
#define NGX_IOVS 16
ngx_chain_t *
ngx_writev_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit)
{
u_char *prev;
ssize_t n, size, sent;
off_t send, prev_send;
ngx_uint_t eintr, complete;
ngx_err_t err;
ngx_array_t vec;
ngx_chain_t *cl;
ngx_event_t *wev;
struct iovec *iov, iovs[NGX_IOVS];
wev = c->write;
if (!wev->ready) {
return in;
}
#if (NGX_HAVE_KQUEUE)
if ((ngx_event_flags & NGX_USE_KQUEUE_EVENT) && wev->pending_eof) {
(void) ngx_connection_error(c, wev->kq_errno,
"kevent() reported about an closed connection");
wev->error = 1;
return NGX_CHAIN_ERROR;
}
#endif
/* the maximum limit size is the maximum size_t value - the page size */
if (limit == 0 || limit > NGX_MAX_SIZE_T_VALUE - ngx_pagesize) {
limit = NGX_MAX_SIZE_T_VALUE - ngx_pagesize;
}
send = 0;
complete = 0;
vec.elts = iovs;
vec.size = sizeof(struct iovec);
vec.nalloc = NGX_IOVS;
vec.pool = c->pool;
for ( ;; ) {
prev = NULL;
iov = NULL;
eintr = 0;
prev_send = send;
vec.nelts = 0;
/* create the iovec and coalesce the neighbouring bufs */
for (cl = in; cl && vec.nelts < IOV_MAX && send < limit; cl = cl->next)
{
if (ngx_buf_special(cl->buf)) {
continue;
}
#if 1
if (!ngx_buf_in_memory(cl->buf)) {
ngx_debug_point();
}
#endif
size = cl->buf->last - cl->buf->pos;
if (send + size > limit) {
size = limit - send;
}
if (prev == cl->buf->pos) {
iov->iov_len += size;
} else {
iov = ngx_array_push(&vec);
if (iov == NULL) {
return NGX_CHAIN_ERROR;
}
iov->iov_base = (void *) cl->buf->pos;
iov->iov_len = size;
}
prev = cl->buf->pos + size;
send += size;
}
n = writev(c->fd, vec.elts, vec.nelts);
if (n == -1) {
err = ngx_errno;
if (err == NGX_EAGAIN || err == NGX_EINTR) {
if (err == NGX_EINTR) {
eintr = 1;
}
ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, err,
"writev() not ready");
} else {
wev->error = 1;
(void) ngx_connection_error(c, err, "writev() failed");
return NGX_CHAIN_ERROR;
}
}
sent = n > 0 ? n : 0;
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, "writev: %z", sent);
if (send - prev_send == sent) {
complete = 1;
}
c->sent += sent;
for (cl = in; cl; cl = cl->next) {
if (ngx_buf_special(cl->buf)) {
continue;
}
if (sent == 0) {
break;
}
size = cl->buf->last - cl->buf->pos;
if (sent >= size) {
sent -= size;
cl->buf->pos = cl->buf->last;
continue;
}
cl->buf->pos += sent;
break;
}
if (eintr) {
continue;
}
if (!complete) {
wev->ready = 0;
return cl;
}
if (send >= limit || cl == NULL) {
return cl;
}
in = cl;
}
}
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