DOC: compression: add some details and clean up the formatting

commit 82fe75c1 provided useful details in its log message. We should report
part of them in the documentation to know which algorithms are available.

This patch also makes some formatting cleanups (including a line outside the
compression scope, which exceeded 80 chars).

diff --git a/doc/configuration.txt b/doc/configuration.txt
index 0b310ee301699a438c803df03b82c26c52b0e0fa..dfb37ae4aeaf1fbd24b80174662862492a2c749a 100644 (file)
--- a/doc/configuration.txt
+++ b/doc/configuration.txt
@@ -1815,16 +1815,34 @@ clitimeout <timeout> (deprecated)
   See also : "timeout client", "timeout http-request", "timeout server", and
              "srvtimeout".
 
-compression algo [ gzip ] ...
-compression type ...
+compression algo <algorithm> ...
+compression type <mime type> ...
 compression offload
   Enable HTTP compression.
   May be used in sections :   defaults | frontend | listen | backend
                                  yes   |    yes   |   yes  |   yes
   Arguments :
-    algo  is followed by the list of supported compression algorithms.
-    type  is followed by the list of MIME types that will be compressed.
-    offload makes haproxy work as a compression offloader only (see notes).
+    algo     is followed by the list of supported compression algorithms.
+    type     is followed by the list of MIME types that will be compressed.
+    offload  makes haproxy work as a compression offloader only (see notes).
+
+  The currently supported algorithms are :
+    identity  this is mostly for debugging, and it was useful for developping
+              the compression feature. Identity does not apply any change on
+              data.
+
+    gzip      applies gzip compression. This setting is only available when
+              support for zlib was built in.
+
+    deflate   same as gzip, but with deflate algorithm and zlib format.
+              Note that this algorithm has ambiguous support on many browsers
+              and no support at all from recent ones. It is strongly
+              recommended not to use it for anything else than experimentation.
+              This setting is only available when support for zlib was built
+              in.
+
+  Compression will be activated depending of the Accept-Encoding request
+  header. With identity, it does not take care of that header.
 
   The "offload" setting makes haproxy remove the Accept-Encoding header to
   prevent backend servers from compressing responses. It is strongly
@@ -9359,8 +9377,8 @@ The list of currently supported pattern fetch functions is the following :
                haproxy -vv). See also the "npn" bind keyword.
 
   ssl_fc_protocol
-               Returns the name of the used protocol when the incoming connection
-               was made over an SSL/TLS transport layer.
+               Returns the name of the used protocol when the incoming
+               connection was made over an SSL/TLS transport layer.
 
   ssl_fc_session_id
                Returns the SSL ID of the front connection when the incoming