view src/http/modules/ngx_http_not_modified_filter_module.c @ 196:8759b346e431 NGINX_0_3_45

nginx 0.3.45 *) Feature: the "ssl_verify_client", "ssl_verify_depth", and "ssl_client_certificate" directives. *) Change: the $request_method variable now returns the main request method. *) Change: the ° symbol codes were changed in koi-win conversion table. *) Feature: the euro и N symbols were added to koi-win conversion table. *) Bugfix: if nginx distributed the requests among several backends and some backend failed, then requests intended for this backend was directed to one live backend only instead of being distributed among the rest.
author Igor Sysoev <http://sysoev.ru>
date Sat, 06 May 2006 00:00:00 +0400
parents 36af50a5582d
children 38e7b94d63ac
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/*
 * Copyright (C) Igor Sysoev
 */


#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_http.h>



static ngx_int_t ngx_http_not_modified_filter_init(ngx_cycle_t *cycle);


static ngx_http_module_t  ngx_http_not_modified_filter_module_ctx = {
    NULL,                                  /* preconfiguration */
    NULL,                                  /* postconfiguration */

    NULL,                                  /* create main configuration */
    NULL,                                  /* init main configuration */

    NULL,                                  /* create server configuration */
    NULL,                                  /* merge server configuration */

    NULL,                                  /* create location configuration */
    NULL                                   /* merge location configuration */
};


ngx_module_t  ngx_http_not_modified_filter_module = {
    NGX_MODULE_V1,
    &ngx_http_not_modified_filter_module_ctx, /* module context */
    NULL,                                  /* module directives */
    NGX_HTTP_MODULE,                       /* module type */
    NULL,                                  /* init master */
    ngx_http_not_modified_filter_init,     /* init module */
    NULL,                                  /* init process */
    NULL,                                  /* init thread */
    NULL,                                  /* exit thread */
    NULL,                                  /* exit process */
    NULL,                                  /* exit master */
    NGX_MODULE_V1_PADDING
};


static ngx_http_output_header_filter_pt  ngx_http_next_header_filter;


static ngx_int_t ngx_http_not_modified_header_filter(ngx_http_request_t *r)
{
    time_t  ims;

    if (r->headers_out.status != NGX_HTTP_OK
        || r != r->main
        || r->headers_in.if_modified_since == NULL
        || r->headers_out.last_modified_time == -1)
    {
        return ngx_http_next_header_filter(r);
    }

    ims = ngx_http_parse_time(r->headers_in.if_modified_since->value.data,
                              r->headers_in.if_modified_since->value.len);

    ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "http ims:%d lm:%d", ims, r->headers_out.last_modified_time);

    /*
     * I think that the equality of the dates is correcter
     */

    if (ims != NGX_ERROR && ims == r->headers_out.last_modified_time) {
        r->headers_out.status = NGX_HTTP_NOT_MODIFIED;
        r->headers_out.content_type.len = 0;
        ngx_http_clear_content_length(r);
        ngx_http_clear_accept_ranges(r);
    }

    return ngx_http_next_header_filter(r);
}


static ngx_int_t ngx_http_not_modified_filter_init(ngx_cycle_t *cycle)
{
    ngx_http_next_header_filter = ngx_http_top_header_filter;
    ngx_http_top_header_filter = ngx_http_not_modified_header_filter;

    return NGX_OK;
}