Mercurial > hg > nginx
view src/os/unix/ngx_linux_sendfile_chain.c @ 5915:ac3f78219f85
Moved the code for coalescing file buffers to a separate function.
author | Valentin Bartenev <vbart@nginx.com> |
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date | Wed, 13 Aug 2014 15:11:45 +0400 |
parents | 8e903522c17a |
children | e044893b4587 |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> /* * On Linux up to 2.4.21 sendfile() (syscall #187) works with 32-bit * offsets only, and the including <sys/sendfile.h> breaks the compiling, * if off_t is 64 bit wide. So we use own sendfile() definition, where offset * parameter is int32_t, and use sendfile() for the file parts below 2G only, * see src/os/unix/ngx_linux_config.h * * Linux 2.4.21 has the new sendfile64() syscall #239. * * On Linux up to 2.6.16 sendfile() does not allow to pass the count parameter * more than 2G-1 bytes even on 64-bit platforms: it returns EINVAL, * so we limit it to 2G-1 bytes. */ #define NGX_SENDFILE_MAXSIZE 2147483647L ngx_chain_t * ngx_linux_sendfile_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit) { int rc, tcp_nodelay; off_t send, prev_send, sent; size_t file_size; ngx_err_t err; ngx_buf_t *file; ngx_uint_t eintr; ngx_event_t *wev; ngx_chain_t *cl; ngx_iovec_t header; struct iovec headers[NGX_IOVS_PREALLOCATE]; #if (NGX_HAVE_SENDFILE64) off_t offset; #else int32_t offset; #endif wev = c->write; if (!wev->ready) { return in; } /* the maximum limit size is 2G-1 - the page size */ if (limit == 0 || limit > (off_t) (NGX_SENDFILE_MAXSIZE - ngx_pagesize)) { limit = NGX_SENDFILE_MAXSIZE - ngx_pagesize; } send = 0; header.iovs = headers; header.nalloc = NGX_IOVS_PREALLOCATE; for ( ;; ) { file = NULL; file_size = 0; eintr = 0; prev_send = send; /* create the iovec and coalesce the neighbouring bufs */ cl = ngx_output_chain_to_iovec(&header, in, limit - send, c->log); if (cl == NGX_CHAIN_ERROR) { return NGX_CHAIN_ERROR; } send += header.size; /* set TCP_CORK if there is a header before a file */ if (c->tcp_nopush == NGX_TCP_NOPUSH_UNSET && header.count != 0 && cl && cl->buf->in_file) { /* the TCP_CORK and TCP_NODELAY are mutually exclusive */ if (c->tcp_nodelay == NGX_TCP_NODELAY_SET) { tcp_nodelay = 0; if (setsockopt(c->fd, IPPROTO_TCP, TCP_NODELAY, (const void *) &tcp_nodelay, sizeof(int)) == -1) { err = ngx_socket_errno; /* * there is a tiny chance to be interrupted, however, * we continue a processing with the TCP_NODELAY * and without the TCP_CORK */ if (err != NGX_EINTR) { wev->error = 1; ngx_connection_error(c, err, "setsockopt(TCP_NODELAY) failed"); return NGX_CHAIN_ERROR; } } else { c->tcp_nodelay = NGX_TCP_NODELAY_UNSET; ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, 0, "no tcp_nodelay"); } } if (c->tcp_nodelay == NGX_TCP_NODELAY_UNSET) { if (ngx_tcp_nopush(c->fd) == NGX_ERROR) { err = ngx_socket_errno; /* * there is a tiny chance to be interrupted, however, * we continue a processing without the TCP_CORK */ if (err != NGX_EINTR) { wev->error = 1; ngx_connection_error(c, err, ngx_tcp_nopush_n " failed"); return NGX_CHAIN_ERROR; } } else { c->tcp_nopush = NGX_TCP_NOPUSH_SET; ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, 0, "tcp_nopush"); } } } /* get the file buf */ if (header.count == 0 && cl && cl->buf->in_file && send < limit) { file = cl->buf; /* coalesce the neighbouring file bufs */ file_size = (size_t) ngx_chain_coalesce_file(&cl, limit - send); send += file_size; } if (file) { #if 1 if (file_size == 0) { ngx_debug_point(); return NGX_CHAIN_ERROR; } #endif #if (NGX_HAVE_SENDFILE64) offset = file->file_pos; #else offset = (int32_t) file->file_pos; #endif ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0, "sendfile: @%O %uz", file->file_pos, file_size); rc = sendfile(c->fd, file->file->fd, &offset, file_size); 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, "sendfile() failed"); return NGX_CHAIN_ERROR; } ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, err, "sendfile() is not ready"); } sent = rc > 0 ? rc : 0; ngx_log_debug4(NGX_LOG_DEBUG_EVENT, c->log, 0, "sendfile: %d, @%O %O:%uz", rc, file->file_pos, sent, file_size); } else { rc = writev(c->fd, header.iovs, header.count); 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; ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, "writev: %O", sent); } c->sent += sent; in = ngx_chain_update_sent(in, sent); if (eintr) { send = prev_send; continue; } if (send - prev_send != sent) { wev->ready = 0; return in; } if (send >= limit || in == NULL) { return in; } } }