Mercurial > hg > nginx-ranges
view src/os/unix/ngx_aio_read_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 | df17fbafec8f |
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> ssize_t ngx_aio_read_chain(ngx_connection_t *c, ngx_chain_t *cl) { int n; u_char *buf, *prev; size_t size; ssize_t total; if (c->read->pending_eof) { c->read->ready = 0; return 0; } total = 0; while (cl) { /* we can post the single aio operation only */ if (!c->read->ready) { return total ? total : NGX_AGAIN; } buf = cl->buf->last; prev = cl->buf->last; size = 0; /* coalesce the neighbouring bufs */ while (cl && prev == cl->buf->last) { size += cl->buf->end - cl->buf->last; prev = cl->buf->end; cl = cl->next; } n = ngx_aio_read(c, buf, size); ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, "aio_read: %d", n); if (n == NGX_AGAIN) { return total ? total : NGX_AGAIN; } if (n == NGX_ERROR) { return NGX_ERROR; } if (n == 0) { c->read->pending_eof = 1; if (total) { c->read->eof = 0; c->read->ready = 1; } return total; } if (n > 0) { total += n; } ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, "aio_read total: %d", total); } return total ? total : NGX_AGAIN; }