Changeset 1484

Timestamp:

Dec 4, 2011, 7:25:08 PM (7 years ago)

Author:

mnot@…

Message:

Refine age calculation for 1.1 proxy chains (#212).

Location:

draft-ietf-httpbis/latest

Files:

• p6-cache.html (modified) (2 diffs)
• p6-cache.xml (modified) (2 diffs)

draft-ietf-httpbis/latest/p6-cache.html

@@ -978 +978 @@
   corrected_age_value = age_value + response_delay;  
 </pre> <div id="rfc.figure.u.6"></div> 
-      <p>These are combined as</p>  <pre class="text">  corrected_initial_age = max(apparent_age, corrected_age_value);
-</pre><p id="rfc.section.2.3.2.p.11">The current_age of a stored response can then be calculated by adding the amount of time (in seconds) since the stored response
+      <p>These <em class="bcp14">SHOULD</em> be combined as
+      </p>  <pre class="text">  corrected_initial_age = max(apparent_age, corrected_age_value);
+</pre><p id="rfc.section.2.3.2.p.11">unless the cache is confident in the value of the Age header (e.g., because there are no HTTP/1.0 hops in the Via header),
+         in which case the corrected_age_value <em class="bcp14">MAY</em> be used as the corrected_initial_age.
+      </p>
+      <p id="rfc.section.2.3.2.p.12">The current_age of a stored response can then be calculated by adding the amount of time (in seconds) since the stored response
          was last validated by the origin server to the corrected_initial_age.
       </p>
       <div id="rfc.figure.u.7"></div><pre class="text">  resident_time = now - response_time;
   current_age = corrected_initial_age + resident_time;
-</pre><p id="rfc.section.2.3.2.p.13">Additionally, to avoid common problems in date parsing:</p>
-      <p id="rfc.section.2.3.2.p.14"> </p>
+</pre><p id="rfc.section.2.3.2.p.14">Additionally, to avoid common problems in date parsing:</p>
+      <p id="rfc.section.2.3.2.p.15"> </p>
       <ul>
          <li>HTTP/1.1 clients and caches <em class="bcp14">SHOULD</em> assume that an RFC-850 date which appears to be more than 50 years in the future is in fact in the past (this helps solve
@@ -2099 +2103 @@
          <li> &lt;<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/293">http://tools.ietf.org/wg/httpbis/trac/ticket/293</a>&gt;: "Interaction of request and response Cache-Control"
          </li>
+         <li> &lt;<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/212">http://tools.ietf.org/wg/httpbis/trac/ticket/212</a>&gt;: "Refining age for 1.1 proxy chains"
+         </li>
       </ul>
       <h1 id="rfc.index"><a href="#rfc.index">Index</a></h1>

draft-ietf-httpbis/latest/p6-cache.xml

@@ -880 +880 @@
 </figure>
 <figure>
-<preamble>These are combined as</preamble>
+<preamble>These &SHOULD; be combined as</preamble>
 <artwork type="code">
   corrected_initial_age = max(apparent_age, corrected_age_value);
 </artwork></figure>
+<t>
+   unless the cache is confident in the value of the Age header (e.g., because
+   there are no HTTP/1.0 hops in the Via header), in which case the
+   corrected_age_value &MAY; be used as the corrected_initial_age.</t>
 <t>
    The current_age of a stored response can then be calculated by adding the
@@ -2938 +2942 @@
       "Interaction of request and response Cache-Control"
     </t>
+    <t>
+      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/212"/>:
+      "Refining age for 1.1 proxy chains"
+    </t>
   </list>
 </t>