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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
|| 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;
}
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