Mercurial > hg > nginx
view src/http/modules/ngx_http_not_modified_filter_module.c @ 5520:a336cbc3dd44
SPDY: send output queue after processing of read event.
During the processing of input some control frames can be added to the queue.
And if there were no writing streams at the moment, these control frames might
be left unsent for a long time (or even forever).
This long delay is especially critical for PING replies since a client can
consider connection as broken and then resend exactly the same request over
a new connection, which is not safe in case of non-idempotent HTTP methods.
author | Valentin Bartenev <vbart@nginx.com> |
---|---|
date | Wed, 15 Jan 2014 17:16:38 +0400 |
parents | 5b93a9ac60ed |
children | bb3d74fc4aea |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> static ngx_uint_t ngx_http_test_if_unmodified(ngx_http_request_t *r); static ngx_uint_t ngx_http_test_if_modified(ngx_http_request_t *r); static ngx_uint_t ngx_http_test_if_match(ngx_http_request_t *r, ngx_table_elt_t *header); static ngx_int_t ngx_http_not_modified_filter_init(ngx_conf_t *cf); static ngx_http_module_t ngx_http_not_modified_filter_module_ctx = { NULL, /* preconfiguration */ ngx_http_not_modified_filter_init, /* 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 */ NULL, /* 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) { if (r->headers_out.status != NGX_HTTP_OK || r != r->main || r->headers_out.last_modified_time == -1) { return ngx_http_next_header_filter(r); } if (r->headers_in.if_unmodified_since && !ngx_http_test_if_unmodified(r)) { return ngx_http_filter_finalize_request(r, NULL, NGX_HTTP_PRECONDITION_FAILED); } if (r->headers_in.if_match && !ngx_http_test_if_match(r, r->headers_in.if_match)) { return ngx_http_filter_finalize_request(r, NULL, NGX_HTTP_PRECONDITION_FAILED); } if (r->headers_in.if_modified_since || r->headers_in.if_none_match) { if (r->headers_in.if_modified_since && ngx_http_test_if_modified(r)) { return ngx_http_next_header_filter(r); } if (r->headers_in.if_none_match && !ngx_http_test_if_match(r, r->headers_in.if_none_match)) { return ngx_http_next_header_filter(r); } /* not modified */ r->headers_out.status = NGX_HTTP_NOT_MODIFIED; r->headers_out.status_line.len = 0; r->headers_out.content_type.len = 0; ngx_http_clear_content_length(r); ngx_http_clear_accept_ranges(r); if (r->headers_out.content_encoding) { r->headers_out.content_encoding->hash = 0; r->headers_out.content_encoding = NULL; } return ngx_http_next_header_filter(r); } return ngx_http_next_header_filter(r); } static ngx_uint_t ngx_http_test_if_unmodified(ngx_http_request_t *r) { time_t iums; iums = ngx_http_parse_time(r->headers_in.if_unmodified_since->value.data, r->headers_in.if_unmodified_since->value.len); ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "http iums:%d lm:%d", iums, r->headers_out.last_modified_time); if (iums >= r->headers_out.last_modified_time) { return 1; } return 0; } static ngx_uint_t ngx_http_test_if_modified(ngx_http_request_t *r) { time_t ims; ngx_http_core_loc_conf_t *clcf; clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module); if (clcf->if_modified_since == NGX_HTTP_IMS_OFF) { return 1; } 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); if (ims == r->headers_out.last_modified_time) { return 0; } if (clcf->if_modified_since == NGX_HTTP_IMS_EXACT || ims < r->headers_out.last_modified_time) { return 1; } return 0; } static ngx_uint_t ngx_http_test_if_match(ngx_http_request_t *r, ngx_table_elt_t *header) { u_char *start, *end, ch; ngx_str_t *etag, *list; list = &header->value; if (list->len == 1 && list->data[0] == '*') { return 1; } if (r->headers_out.etag == NULL) { return 0; } etag = &r->headers_out.etag->value; ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "http im:\"%V\" etag:%V", list, etag); start = list->data; end = list->data + list->len; while (start < end) { if (etag->len > (size_t) (end - start)) { return 0; } if (ngx_strncmp(start, etag->data, etag->len) != 0) { goto skip; } start += etag->len; while (start < end) { ch = *start; if (ch == ' ' || ch == '\t') { start++; continue; } break; } if (start == end || *start == ',') { return 1; } skip: while (start < end && *start != ',') { start++; } while (start < end) { ch = *start; if (ch == ' ' || ch == '\t' || ch == ',') { start++; continue; } break; } } return 0; } static ngx_int_t ngx_http_not_modified_filter_init(ngx_conf_t *cf) { ngx_http_next_header_filter = ngx_http_top_header_filter; ngx_http_top_header_filter = ngx_http_not_modified_header_filter; return NGX_OK; }