Mercurial > hg > nginx-ranges
view src/os/unix/ngx_writev_chain.c @ 391:1d9bef53cd8e
Range filter: late_ranges functionality.
Add one more filtering point after postpone filter. This allows to serve
range capable replies with subrequests. It's not as efficient as range
filtering for static data (i.e. doesn't save us from reading data from
disk if some filter needs them in memory), but it may save some network
bandwidth for us and for our users.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Mon, 21 Jul 2008 05:33:01 +0400 |
parents | f7cd062ee035 |
children | d41628eb4d0a |
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/* * Copyright (C) Igor Sysoev */ #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; 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 = (ssize_t) (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; } }