Mercurial > hg > nginx
view src/os/unix/ngx_darwin_sendfile_chain.c @ 4596:089cc5154c1e
IOV_MAX handling microoptimization.
We now stop on IOV_MAX iovec entries only if we are going to add new one,
i.e. next buffer can't be coalesced into last iovec.
This also fixes incorrect checks for trailer creation on FreeBSD and
Mac OS X, header.nelts was checked instead of trailer.nelts.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Tue, 17 Apr 2012 09:13:15 +0000 |
parents | 778ef9c3fd2d |
children | ad137a80919f |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> /* * It seems that Darwin 9.4 (Mac OS X 1.5) sendfile() has the same * old bug as early FreeBSD sendfile() syscall: * http://www.freebsd.org/cgi/query-pr.cgi?pr=33771 * * Besides sendfile() has another bug: if one calls sendfile() * with both a header and a trailer, then sendfile() ignores a file part * at all and sends only the header and the trailer together. * For this reason we send a trailer only if there is no a header. * * Although sendfile() allows to pass a header or a trailer, * it may send the header or the trailer and a part of the file * in different packets. And FreeBSD workaround (TCP_NOPUSH option) * does not help. */ #if (IOV_MAX > 64) #define NGX_HEADERS 64 #define NGX_TRAILERS 64 #else #define NGX_HEADERS IOV_MAX #define NGX_TRAILERS IOV_MAX #endif ngx_chain_t * ngx_darwin_sendfile_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit) { int rc; u_char *prev; off_t size, send, prev_send, aligned, sent, fprev; off_t header_size, file_size; ngx_uint_t eintr, complete; ngx_err_t err; ngx_buf_t *file; ngx_array_t header, trailer; ngx_event_t *wev; ngx_chain_t *cl; struct sf_hdtr hdtr; struct iovec *iov, headers[NGX_HEADERS], trailers[NGX_TRAILERS]; 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; header.elts = headers; header.size = sizeof(struct iovec); header.nalloc = NGX_HEADERS; header.pool = c->pool; trailer.elts = trailers; trailer.size = sizeof(struct iovec); trailer.nalloc = NGX_TRAILERS; trailer.pool = c->pool; for ( ;; ) { file = NULL; file_size = 0; header_size = 0; eintr = 0; complete = 0; prev_send = send; header.nelts = 0; trailer.nelts = 0; /* create the header iovec and coalesce the neighbouring bufs */ prev = NULL; iov = NULL; for (cl = in; cl && send < limit; cl = cl->next) { if (ngx_buf_special(cl->buf)) { continue; } if (!ngx_buf_in_memory_only(cl->buf)) { break; } size = cl->buf->last - cl->buf->pos; if (send + size > limit) { size = limit - send; } if (prev == cl->buf->pos) { iov->iov_len += (size_t) size; } else { if (header.nelts >= IOV_MAX) { break; } iov = ngx_array_push(&header); if (iov == NULL) { return NGX_CHAIN_ERROR; } iov->iov_base = (void *) cl->buf->pos; iov->iov_len = (size_t) size; } prev = cl->buf->pos + (size_t) size; header_size += size; send += size; } if (cl && cl->buf->in_file && send < limit) { file = cl->buf; /* coalesce the neighbouring file bufs */ do { size = cl->buf->file_last - cl->buf->file_pos; if (send + size > limit) { size = limit - send; aligned = (cl->buf->file_pos + size + ngx_pagesize - 1) & ~((off_t) ngx_pagesize - 1); if (aligned <= cl->buf->file_last) { size = aligned - cl->buf->file_pos; } } file_size += size; send += size; fprev = cl->buf->file_pos + size; cl = cl->next; } while (cl && cl->buf->in_file && send < limit && file->file->fd == cl->buf->file->fd && fprev == cl->buf->file_pos); } if (file && header.nelts == 0) { /* create the trailer iovec and coalesce the neighbouring bufs */ prev = NULL; iov = NULL; while (cl && send < limit) { if (ngx_buf_special(cl->buf)) { cl = cl->next; continue; } if (!ngx_buf_in_memory_only(cl->buf)) { break; } size = cl->buf->last - cl->buf->pos; if (send + size > limit) { size = limit - send; } if (prev == cl->buf->pos) { iov->iov_len += (size_t) size; } else { if (trailer.nelts >= IOV_MAX) { break; } iov = ngx_array_push(&trailer); if (iov == NULL) { return NGX_CHAIN_ERROR; } iov->iov_base = (void *) cl->buf->pos; iov->iov_len = (size_t) size; } prev = cl->buf->pos + (size_t) size; send += size; cl = cl->next; } } if (file) { /* * sendfile() returns EINVAL if sf_hdtr's count is 0, * but corresponding pointer is not NULL */ hdtr.headers = header.nelts ? (struct iovec *) header.elts: NULL; hdtr.hdr_cnt = header.nelts; hdtr.trailers = trailer.nelts ? (struct iovec *) trailer.elts: NULL; hdtr.trl_cnt = trailer.nelts; sent = header_size + file_size; ngx_log_debug3(NGX_LOG_DEBUG_EVENT, c->log, 0, "sendfile: @%O %O h:%O", file->file_pos, sent, header_size); rc = sendfile(file->file->fd, c->fd, file->file_pos, &sent, &hdtr, 0); if (rc == -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, "sendfile() failed"); return NGX_CHAIN_ERROR; } ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, err, "sendfile() sent only %O bytes", sent); } if (rc == 0 && sent == 0) { /* * if rc and sent equal to zero, then someone * has truncated the file, so the offset became beyond * the end of the file */ ngx_log_error(NGX_LOG_ALERT, c->log, 0, "sendfile() reported that \"%s\" was truncated", file->file->name.data); return NGX_CHAIN_ERROR; } ngx_log_debug4(NGX_LOG_DEBUG_EVENT, c->log, 0, "sendfile: %d, @%O %O:%O", rc, file->file_pos, sent, file_size + header_size); } else { rc = writev(c->fd, header.elts, header.nelts); ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0, "writev: %d of %uz", rc, send); if (rc == -1) { err = ngx_errno; switch (err) { case NGX_EAGAIN: break; case NGX_EINTR: eintr = 1; break; default: wev->error = 1; 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 = rc > 0 ? rc : 0; } 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 = ngx_buf_size(cl->buf); if (sent >= size) { sent -= size; if (ngx_buf_in_memory(cl->buf)) { cl->buf->pos = cl->buf->last; } if (cl->buf->in_file) { cl->buf->file_pos = cl->buf->file_last; } continue; } if (ngx_buf_in_memory(cl->buf)) { cl->buf->pos += (size_t) sent; } if (cl->buf->in_file) { cl->buf->file_pos += sent; } break; } if (eintr) { continue; } if (!complete) { wev->ready = 0; return cl; } if (send >= limit || cl == NULL) { return cl; } in = cl; } }