Mercurial > hg > nginx-quic
view src/os/unix/ngx_writev_chain.c @ 4749:613750237b36
Entity tags: the "etag" directive.
It allows to disable generation of nginx's own entity tags, while
still handling ETags in cache properly. This may be useful e.g.
if one want to serve static files from servers with different ETag
generation algorithms.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Mon, 09 Jul 2012 14:53:42 +0000 |
parents | 089cc5154c1e |
children | f9c83484d9ce |
line wrap: on
line source
/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> #if (IOV_MAX > 64) #define NGX_IOVS 64 #else #define NGX_IOVS IOV_MAX #endif 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 > (off_t) (NGX_MAX_SIZE_T_VALUE - ngx_pagesize)) { limit = NGX_MAX_SIZE_T_VALUE - ngx_pagesize; } send = 0; vec.elts = iovs; vec.size = sizeof(struct iovec); vec.nalloc = NGX_IOVS; vec.pool = c->pool; for ( ;; ) { prev = NULL; iov = NULL; eintr = 0; complete = 0; prev_send = send; vec.nelts = 0; /* create the iovec and coalesce the neighbouring bufs */ for (cl = in; cl && 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 = (ssize_t) (limit - send); } if (prev == cl->buf->pos) { iov->iov_len += size; } else { if (vec.nelts >= IOV_MAX) { break; } 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; switch (err) { case NGX_EAGAIN: break; case NGX_EINTR: eintr = 1; break; default: wev->error = 1; (void) ngx_connection_error(c, err, "writev() failed"); return NGX_CHAIN_ERROR; } ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, err, "writev() not ready"); } 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; } }