view src/http/modules/ngx_http_not_modified_filter_module.c @ 543:511a89da35ad release-0.2.0

nginx-0.2.0-RELEASE import *) The pid-file names used during online upgrade was changed and now is not required a manual rename operation. The old master process adds the ".oldbin" suffix to its pid-file and executes a new binary file. The new master process creates usual pid-file without the ".newbin" suffix. If the master process exits, then old master process renames back its pid-file with the ".oldbin" suffix to the pid-file without suffix. *) Change: the "worker_connections" directive, new name of the "connections" directive; now the directive specifies maximum number of connections, but not maximum socket descriptor number. *) Feature: SSL supports the session cache inside one worker process. *) Feature: the "satisfy_any" directive. *) Change: the ngx_http_access_module and ngx_http_auth_basic_module do not run for subrequests. *) Feature: the "worker_rlimit_nofile" and "worker_rlimit_sigpending" directives. *) Bugfix: if all backend using in load-balancing failed after one error, then nginx did not try do connect to them during 60 seconds. *) Bugfix: in IMAP/POP3 command argument parsing. Thanks to Rob Mueller. *) Bugfix: errors while using SSL in IMAP/POP3 proxy. *) Bugfix: errors while using SSI and gzipping. *) Bugfix: the "Expires" and "Cache-Control" header lines were omitted from the 304 responses. Thanks to Alexandr Kukushkin.
author Igor Sysoev <igor@sysoev.ru>
date Fri, 23 Sep 2005 11:02:22 +0000
parents b09ee85d0ac8
children 45033d85b30e
line wrap: on
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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->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;
        r->headers_out.content_length_n = -1;
        r->headers_out.content_length = NULL;
#if 0
        r->headers_out.accept_ranges->hash = 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;
}