From 0f24543b256e418365f1c56147ced7094723ba8a Mon Sep 17 00:00:00 2001
From: Rich Bowen <rbowen@apache.org>
Date: Tue, 14 Apr 2015 17:18:59 +0000
Subject: [PATCH] Add "pre-compressed content" reccipe, as per
 https://bz.apache.org/bugzilla/show_bug.cgi?id=51336

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1673473 13f79535-47bb-0310-9956-ffa450edef68
---
 docs/manual/mod/mod_deflate.html.en | 43 +++++++++++++++++++++++++++++
 docs/manual/mod/mod_deflate.xml     | 42 ++++++++++++++++++++++++++++
 2 files changed, 85 insertions(+)

diff --git a/docs/manual/mod/mod_deflate.html.en b/docs/manual/mod/mod_deflate.html.en
index 8b7ca19e3ab..63ce2db542f 100644
--- a/docs/manual/mod/mod_deflate.html.en
+++ b/docs/manual/mod/mod_deflate.html.en
@@ -57,6 +57,8 @@ client</td></tr>
 <li><img alt="" src="../images/down.gif" /> <a href="#recommended">Sample Configurations</a></li>
 <li><img alt="" src="../images/down.gif" /> <a href="#enable">Enabling Compression</a></li>
 <li><img alt="" src="../images/down.gif" /> <a href="#proxies">Dealing with proxy servers</a></li>
+<li><img alt="" src="../images/down.gif" /> <a href="#precompressed">Serving pre-compressed
+content</a></li>
 </ul><h3>See also</h3>
 <ul class="seealso">
 <li><a href="../filter.html">Filters</a></li>
@@ -185,6 +187,47 @@ SetEnvIfNoCase Request_URI \.(?:gif|jpe?g|png)$ no-gzip</pre>
 
     <div class="example"><h3>Example</h3><pre class="prettyprint lang-config">Header set Vary *</pre>
 </div>
+</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
+<div class="section">
+<h2><a name="precompressed" id="precompressed">Serving pre-compressed
+content</a></h2>
+
+    <p>Since <code class="module"><a href="../mod/mod_deflate.html">mod_deflate</a></code> re-compresses content each 
+    time a request is made, some performance benefit can be derived by
+    pre-compressing the content and telling mod_deflate to serve them
+    without re-compressing them. This may be accomplished using a
+    configuration like the following:</p>
+
+    <pre class="prettyprint lang-config">&lt;IfModule mod_headers.c&gt;
+    # Serve gzip compressed CSS files if they exist 
+    # and the client accepts gzip.
+    RewriteCond %{HTTP:Accept-encoding} gzip
+    RewriteCond %{REQUEST_FILENAME}\.gz -s
+    RewriteRule ^(.*)\.css $1\.css\.gz [QSA]
+
+    # Serve gzip compressed JS files if they exist 
+    # and the client accepts gzip.
+    RewriteCond %{HTTP:Accept-encoding} gzip
+    RewriteCond %{REQUEST_FILENAME}\.gz -s
+    RewriteRule ^(.*)\.js $1\.js\.gz [QSA]
+
+
+    # Serve correct content types, and prevent mod_deflate double gzip.
+    RewriteRule \.css\.gz$ - [T=text/css,E=no-gzip:1]
+    RewriteRule \.js\.gz$ - [T=text/javascript,E=no-gzip:1]
+
+
+    &lt;FilesMatch "(\.js\.gz|\.css\.gz)$"&gt;
+      # Serve correct encoding type.
+      Header append Content-Encoding gzip
+
+      # Force proxies to cache gzipped &amp; 
+      # non-gzipped css/js files separately.
+      Header append Vary Accept-Encoding
+    &lt;/FilesMatch&gt;
+&lt;/IfModule&gt;</pre>
+
+
 </div>
 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
 <div class="directive-section"><h2><a name="DeflateBufferSize" id="DeflateBufferSize">DeflateBufferSize</a> <a name="deflatebuffersize" id="deflatebuffersize">Directive</a></h2>
diff --git a/docs/manual/mod/mod_deflate.xml b/docs/manual/mod/mod_deflate.xml
index c654db83889..083ed62e08c 100644
--- a/docs/manual/mod/mod_deflate.xml
+++ b/docs/manual/mod/mod_deflate.xml
@@ -178,6 +178,48 @@ SetEnvIfNoCase Request_URI \.(?:gif|jpe?g|png)$ no-gzip
     </example>
 </section>
 
+<section id="precompressed"><title>Serving pre-compressed
+content</title>
+
+    <p>Since <module>mod_deflate</module> re-compresses content each 
+    time a request is made, some performance benefit can be derived by
+    pre-compressing the content and telling mod_deflate to serve them
+    without re-compressing them. This may be accomplished using a
+    configuration like the following:</p>
+
+    <highlight language="config">
+&lt;IfModule mod_headers.c&gt;
+    # Serve gzip compressed CSS files if they exist 
+    # and the client accepts gzip.
+    RewriteCond %{HTTP:Accept-encoding} gzip
+    RewriteCond %{REQUEST_FILENAME}\.gz -s
+    RewriteRule ^(.*)\.css $1\.css\.gz [QSA]
+
+    # Serve gzip compressed JS files if they exist 
+    # and the client accepts gzip.
+    RewriteCond %{HTTP:Accept-encoding} gzip
+    RewriteCond %{REQUEST_FILENAME}\.gz -s
+    RewriteRule ^(.*)\.js $1\.js\.gz [QSA]
+
+
+    # Serve correct content types, and prevent mod_deflate double gzip.
+    RewriteRule \.css\.gz$ - [T=text/css,E=no-gzip:1]
+    RewriteRule \.js\.gz$ - [T=text/javascript,E=no-gzip:1]
+
+
+    &lt;FilesMatch "(\.js\.gz|\.css\.gz)$"&gt;
+      # Serve correct encoding type.
+      Header append Content-Encoding gzip
+
+      # Force proxies to cache gzipped &amp; 
+      # non-gzipped css/js files separately.
+      Header append Vary Accept-Encoding
+    &lt;/FilesMatch&gt;
+&lt;/IfModule&gt;
+    </highlight>
+
+</section>
+
 <directivesynopsis>
 <name>DeflateFilterNote</name>
 <description>Places the compression ratio in a note for logging</description>
-- 
2.47.2