Author: mdounin
Date: 2012-07-07 21:20:27 +0000 (Sat, 07 Jul 2012)
New Revision: 4745
URL: http://trac.nginx.org/nginx/changeset/4745/nginx

Log:
Entity tags: basic support in not modified filter.

This includes handling of ETag headers (if present in a response) with
basic support for If-Match, If-None-Match conditionals in not modified
filter.

Note that the "r->headers_out.last_modified_time == -1" check in the not
modified filter is left as is intentionally. It's to prevent handling
of If-* headers in case of proxy without cache (much like currently
done with If-Modified-Since).


Modified:
trunk/src/http/modules/ngx_http_not_modified_filter_module.c
trunk/src/http/ngx_http_request.c
trunk/src/http/ngx_http_request.h

Modified: trunk/src/http/modules/ngx_http_not_modified_filter_module.c
===================================================================
--- trunk/src/http/modules/ngx_http_not_modified_filter_module.c 2012-07-07 21:18:30 UTC (rev 4744)
+++ trunk/src/http/modules/ngx_http_not_modified_filter_module.c 2012-07-07 21:20:27 UTC (rev 4745)
@@ -12,6 +12,8 @@

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);


@@ -66,9 +68,27 @@
NGX_HTTP_PRECONDITION_FAILED);
}

- if (r->headers_in.if_modified_since
- && !ngx_http_test_if_modified(r))
+ 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;
@@ -140,6 +160,76 @@
}


+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)
{

Modified: trunk/src/http/ngx_http_request.c
===================================================================
--- trunk/src/http/ngx_http_request.c 2012-07-07 21:18:30 UTC (rev 4744)
+++ trunk/src/http/ngx_http_request.c 2012-07-07 21:20:27 UTC (rev 4745)
@@ -93,6 +93,14 @@
offsetof(ngx_http_headers_in_t, if_unmodified_since),
ngx_http_process_unique_header_line },

+ { ngx_string("If-Match"),
+ offsetof(ngx_http_headers_in_t, if_match),
+ ngx_http_process_unique_header_line },
+
+ { ngx_string("If-None-Match"),
+ offsetof(ngx_http_headers_in_t, if_none_match),
+ ngx_http_process_unique_header_line },
+
{ ngx_string("User-Agent"), offsetof(ngx_http_headers_in_t, user_agent),
ngx_http_process_user_agent },


Modified: trunk/src/http/ngx_http_request.h
===================================================================
--- trunk/src/http/ngx_http_request.h 2012-07-07 21:18:30 UTC (rev 4744)
+++ trunk/src/http/ngx_http_request.h 2012-07-07 21:20:27 UTC (rev 4745)
@@ -172,6 +172,8 @@
ngx_table_elt_t *connection;
ngx_table_elt_t *if_modified_since;
ngx_table_elt_t *if_unmodified_since;
+ ngx_table_elt_t *if_match;
+ ngx_table_elt_t *if_none_match;
ngx_table_elt_t *user_agent;
ngx_table_elt_t *referer;
ngx_table_elt_t *content_length;

_______________________________________________
nginx-devel mailing list
nginx-devel@nginx.org
http://mailman.nginx.org/mailman/listinfo/nginx-devel