view src/http/modules/ngx_http_not_modified_filter.c @ 34:aab2ea7c0458 NGINX_0_1_17

nginx 0.1.17 *) Change: the ngx_http_rewrite_module was rewritten from the scratch. Now it is possible to redirect, to return the error codes, to check the variables and referrers. The directives can be used inside locations. The redirect directive was canceled. *) Feature: the ngx_http_geo_module. *) Feature: the proxy_set_x_var and fastcgi_set_var directives. *) Bugfix: the location configuration with "=" modifier may be used in another location. *) Bugfix: the correct content type was set only for requests that use small caps letters in extension. *) Bugfix: if the proxy_pass or fastcgi_pass directives were set in the location, and access was denied, and the error was redirected to a static page, then the segmentation fault occurred. *) Bugfix: if in a proxied "Location" header was a relative URL, then a host name and a slash were added to them; bug appeared in 0.1.14. *) Bugfix: the system error message was not logged on Linux.
author Igor Sysoev <http://sysoev.ru>
date Thu, 03 Feb 2005 00:00:00 +0300
parents 46833bd150cb
children
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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,                                  /* pre conf */

    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,
    &ngx_http_not_modified_filter_module_ctx, /* module context */
    NULL,                                  /* module directives */
    NGX_HTTP_MODULE,                       /* module type */
    ngx_http_not_modified_filter_init,     /* init module */
    NULL                                   /* init process */
};


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->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->key.len = 0;
        r->headers_out.content_type = NULL;
        r->headers_out.content_length_n = -1;
        r->headers_out.content_length = NULL;
#if 0
        r->headers_out.accept_ranges->key.len = 0;
#endif
    }

    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;
}