Mercurial > hg > nginx-ranges
view src/os/unix/ngx_aio_write_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 | 86dad910eeb6 |
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/* * Copyright (C) Igor Sysoev */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> #include <ngx_aio.h> ngx_chain_t * ngx_aio_write_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit) { u_char *buf, *prev; off_t send, sent; size_t len; ssize_t n, size; ngx_chain_t *cl; /* 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; sent = 0; cl = in; while (cl) { if (cl->buf->pos == cl->buf->last) { cl = cl->next; continue; } /* we can post the single aio operation only */ if (!c->write->ready) { return cl; } buf = cl->buf->pos; prev = buf; len = 0; /* coalesce the neighbouring bufs */ while (cl && prev == cl->buf->pos && send < limit) { if (ngx_buf_special(cl->buf)) { continue; } size = cl->buf->last - cl->buf->pos; if (send + size > limit) { size = limit - send; } len += size; prev = cl->buf->pos + size; send += size; cl = cl->next; } n = ngx_aio_write(c, buf, len); ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, "aio_write: %z", n); if (n == NGX_ERROR) { return NGX_CHAIN_ERROR; } if (n > 0) { sent += n; c->sent += n; } ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, "aio_write sent: %O", c->sent); for (cl = in; cl; cl = cl->next) { if (sent >= cl->buf->last - cl->buf->pos) { sent -= cl->buf->last - cl->buf->pos; cl->buf->pos = cl->buf->last; continue; } cl->buf->pos += sent; break; } } return cl; }