Implemented caching of PROPSTATS and PROPFIND using MemCacheStore (memcached).

Gemfile

@@ -27,6 +27,7 @@ gem 'zip-zip'
 gem 'simple_enum'
 gem 'uuidtools'
 gem 'dav4rack'
+gem 'dalli'
 
 group :xapian do
   gem 'xapian-full-alaveteli', :require => false

app/models/dmsf_file.rb

@@ -478,4 +478,33 @@ class DmsfFile < ActiveRecord::Base
     nil
   end
 
+  def save(*args)
+    RedmineDmsf::Webdav::Cache.invalidate_item(propfind_cache_key)
+    super(*args)
+  end
+  
+  def save!(*args)
+    RedmineDmsf::Webdav::Cache.invalidate_item(propfind_cache_key)
+    super(*args)
+  end
+  
+  def destroy
+    RedmineDmsf::Webdav::Cache.invalidate_item(propfind_cache_key)
+    super
+  end
+
+  def destroy!
+    RedmineDmsf::Webdav::Cache.invalidate_item(propfind_cache_key)
+    super
+  end
+  
+  def propfind_cache_key
+    if dmsf_folder_id.nil?
+      # File is in project root
+      return "PROPFIND/#{project_id}"
+    else
+      return "PROPFIND/#{project_id}/#{dmsf_folder_id}"
+    end
+  end
+
 end

app/models/dmsf_file_revision.rb

@@ -109,6 +109,7 @@ class DmsfFileRevision < ActiveRecord::Base
       dependencies = DmsfFileRevision.where(:disk_filename => self.disk_filename).all.count
       File.delete(self.disk_file) if dependencies <= 1 && File.exist?(self.disk_file)
     end
+    RedmineDmsf::Webdav::Cache.invalidate_item(propfind_cache_key)
     super
   end
 
@@ -290,5 +291,19 @@ class DmsfFileRevision < ActiveRecord::Base
     end
     ActionView::Base.full_sanitizer.sanitize(text)
   end
+  
+  def save(*args)
+    RedmineDmsf::Webdav::Cache.invalidate_item(propfind_cache_key)
+    super(*args)
+  end
 
-end
+  def save!(*args)
+    RedmineDmsf::Webdav::Cache.invalidate_item(propfind_cache_key)
+    super(*args)
+  end
+  
+  def propfind_cache_key
+    dmsf_file.propfind_cache_key
+  end
+
+end

app/models/dmsf_folder.rb

@@ -295,7 +295,7 @@ class DmsfFolder < ActiveRecord::Base
     file_links.visible.count +
     url_links.visible.count
   end
-
+  
   def self.is_column_on?(column)
     columns = Setting.plugin_redmine_dmsf['dmsf_columns']
     columns = DmsfFolder::DEFAULT_COLUMNS unless columns
@@ -395,6 +395,35 @@ class DmsfFolder < ActiveRecord::Base
     nil
   end
 
+  def save(*args)
+    RedmineDmsf::Webdav::Cache.invalidate_item(propfind_cache_key)    
+    super(*args)
+  end
+  
+  def save!(*args)
+    RedmineDmsf::Webdav::Cache.invalidate_item(propfind_cache_key)    
+    super(*args)
+  end
+
+  def destroy
+    RedmineDmsf::Webdav::Cache.invalidate_item(propfind_cache_key)    
+    super
+  end
+
+  def destroy!
+    RedmineDmsf::Webdav::Cache.invalidate_item(propfind_cache_key)    
+    super
+  end
+  
+  def propfind_cache_key
+    if dmsf_folder_id.nil?
+      # Folder is in project root
+      return "PROPFIND/#{project_id}"
+    else
+      return "PROPFIND/#{project_id}/#{dmsf_folder_id}"
+    end
+  end
+
   private
 
   def self.directory_subtree(tree, folder, level, current_folder)
@@ -406,4 +435,4 @@ class DmsfFolder < ActiveRecord::Base
     end
   end
 
-end
+end

app/views/settings/_dmsf_settings.html.erb

@@ -176,6 +176,13 @@
       <%= l(:note_webdav_strategy).html_safe %> <%= l(:label_default) %>: <%= l(:select_option_webdav_readonly) %>    
     </em>
   </p>
+  <p>
+    <%= content_tag(:label, l(:label_memcached_servers)) %>
+    <%= text_field_tag 'settings[dmsf_memcached_servers]', @settings['dmsf_memcached_servers'], :size => 50 %>
+	<em class="info">
+	  <%= l(:text_memcached_servers) %>
+	</em>
+  </p>  
 <% end %>
 
 <hr/>

config/locales/en.yml

@@ -338,4 +338,8 @@ en:
 
   label_webdav: WebDAV
   label_full_text: Full-text search
-  link_extension: Ext
+  link_extension: Ext
+
+  label_memcached_servers: "memcached server address"
+  text_memcached_servers: "Address to memcached server. Only a single server is supported, if empty then caching is disabled. After changing this the server must be restarted!"
+

init.rb

@@ -47,7 +47,8 @@ Redmine::Plugin.register :redmine_dmsf do
               'dmsf_webdav' => '1',
               'dmsf_display_notified_recipients' => 0,
               'dmsf_global_title_format' => '',
-              'dmsf_columns' => %w(title size modified version workflow author)
+              'dmsf_columns' => %w(title size modified version workflow author),
+              'dmsf_memcached_servers' => ''
             }
   
   menu :project_menu, :dmsf, { :controller => 'dmsf', :action => 'show' }, :caption => :menu_dmsf, :before => :documents, :param => :id

lib/redmine_dmsf.rb

@@ -35,6 +35,7 @@ require 'redmine_dmsf/patches/user_patch'
 # Load up classes that make up our WebDAV solution ontop of DAV4Rack
 require 'redmine_dmsf/webdav/base_resource'
 require 'redmine_dmsf/webdav/controller'
+require 'redmine_dmsf/webdav/cache'
 require 'redmine_dmsf/webdav/dmsf_resource'
 require 'redmine_dmsf/webdav/download'
 require 'redmine_dmsf/webdav/index_resource'
@@ -57,3 +58,7 @@ require 'redmine_dmsf/hooks/views/my_account_view_hooks'
 
 # Macros
 require 'redmine_dmsf/macros'
+
+# Add the plugin view folder into ActionMailer's paths to search
+ActionMailer::Base.append_view_path(File.expand_path(
+    File.dirname(__FILE__) + '/../app/views'))

lib/redmine_dmsf/webdav/cache.rb

@@ -0,0 +1,83 @@
+# encoding: utf-8
+#
+# Redmine plugin for Document Management System "Features"
+#
+# Copyright (C) 2012   Daniel Munn <dan.munn@munnster.co.uk>
+# Copyright (C) 2011-16 Karel Picman <karel.picman@kontron.com>
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+
+module RedmineDmsf
+  module Webdav
+    class Cache
+      def self.read(name, options = nil)
+        init unless defined?(@@WebDAVCache)
+        @@WebDAVCache.read(name, options)
+      end
+      
+      def self.write(name, value, options = nil)
+        init unless defined?(@@WebDAVCache)
+        @@WebDAVCache.write(name, value, options)
+      end
+      
+      def self.delete(name, options = nil)
+        init unless defined?(@@WebDAVCache)
+        @@WebDAVCache.delete(name, options)
+      end
+      
+      def self.exist?(name, options = nil)
+        init unless defined?(@@WebDAVCache)
+        @@WebDAVCache.exist?(name, options)
+      end
+      
+      def self.invalidate_item(key)
+        init unless defined?(@@WebDAVCache)
+        # Write an .invalid entry to notify anyone that is currently creating a response
+        # that that response is invalid and should not be cached
+        @@WebDAVCache.write("#{key}.invalid", expires_in: 60.seconds)
+        # Delete any existing entry in the cache
+        @@WebDAVCache.delete(key)
+      end
+      
+      def self.cache
+        @@WebDAVCache
+      end
+      
+      def self.init_testcache
+        puts "Webdav::Cache: Enable MemoryStore cache."
+        @@WebDAVCache = ActiveSupport::Cache::MemoryStore.new(options={:namespace => "RedmineDmsfWebDAV"})
+      end
+      
+      def self.init_nullcache
+        puts "Webdav::Cache: Disable cache."
+        @@WebDAVCache = ActiveSupport::Cache::NullStore.new
+      end
+      
+      private
+      
+      def self.init
+        if Setting.plugin_redmine_dmsf['dmsf_memcached_servers'].nil? || Setting.plugin_redmine_dmsf['dmsf_memcached_servers'].empty?
+          # Disable caching by using a null cache
+          Rails.logger.info "Webdav::Cache: Cache disabled!"
+          @@WebDAVCache = ActiveSupport::Cache::NullStore.new
+        else
+          # Create cache using the provided server address
+          Rails.logger.info "Webdav::Cache: Cache enabled, using memcached server '#{Setting.plugin_redmine_dmsf['dmsf_memcached_servers']}'"
+          @@WebDAVCache = ActiveSupport::Cache::MemCacheStore.new(Setting.plugin_redmine_dmsf['dmsf_memcached_servers'], options={:namespace => "RedmineDmsfWebDAV"})
+        end
+      end
+    end
+  end
+end

lib/redmine_dmsf/webdav/controller.rb

@@ -107,18 +107,44 @@ module RedmineDmsf
               raise BadRequest
             end
           end
-          multistatus do |xml|
-            find_resources.each do |resource|
-              xml.response do
-                unless(resource.propstat_relative_path)
-                  xml.href "#{scheme}://#{host}:#{port}#{url_format(resource)}"                  
-                else
-                  xml.href url_format(resource)
-                end
-                propstats(xml, get_properties(resource, properties.empty? ? resource.properties : properties))
+          
+          if depth != 0
+            # Only use cache for requests with a depth>0, depth=0 responses are already fast.
+            pinfo = resource.path.split('/').drop(1)
+            if (pinfo.length == 0) # If this is the base_path, we're at root
+              # Don't know when projects are added/removed from the visibility list for this user,
+              # so don't cache root.
+            elsif (pinfo.length == 1) #This is first level, and as such, project path
+              propfind_key = "PROPFIND/#{resource.resource.project_id}"
+            else # We made it all the way to DMSF Data
+              if resource.collection?
+                # Only store collections in the cache since responses to files are simple and fast already.
+                propfind_key = "PROPFIND/#{resource.resource.project_id}/#{resource.resource.folder.id}"
               end
             end
-          end          
+          end
+          
+          if propfind_key.nil?
+            # This PROPFIND is never cached so always create a new response
+            create_propfind_response(properties)
+          else
+            response.body = RedmineDmsf::Webdav::Cache.read(propfind_key)
+            if !response.body.nil?
+              # Found cached PROPFIND, fill in Content-Type and Content-Length
+              response["Content-Type"] = 'text/xml; charset="utf-8"'
+              response["Content-Length"] = response.body.size.to_s
+            else
+              # No cached PROPFIND found
+              # Remove .invalid entry for this propfind since we are now creating a new valid propfind
+              RedmineDmsf::Webdav::Cache.delete("#{propfind_key}.invalid")
+              create_propfind_response(properties)
+
+              # Cache response.body, but only if no .invalid entry was stored while creating the propfind
+              RedmineDmsf::Webdav::Cache.write(propfind_key, response.body) unless RedmineDmsf::Webdav::Cache.exist?("#{propfind_key}.invalid")
+            end
+          end
+          # Return HTTP code.
+          MultiStatus
         end
       end
     
@@ -179,6 +205,57 @@ module RedmineDmsf
         Addressable::URI.unescape str
       end
       
+      private
+      
+      def create_propfind_response(properties)
+        # Generate response, is stored in response.body
+        render_xml(:multistatus) do |xml|
+          find_resources.each do |resource|
+            if resource.collection?
+              # Index, Project or Folder
+              # path is unique enough for the key and is available for all three, and the path doesn't change 
+              # for this path as long as it stays. On its path. The path does not stray from its path without 
+              # changing its path.
+              propstats_key = "PROPSTATS/#{resource.path}"
+            else
+              # File
+              # Use file.id & file.last_revision.id as key
+              # When revision changes then the key will change and the old cached item will eventually be evicted
+              propstats_key = "PROPSTATS/#{resource.resource.file.id}-#{resource.resource.file.last_revision.id}"
+            end
+
+            xml_str = RedmineDmsf::Webdav::Cache.read(propstats_key)
+            if xml_str.nil?
+              # Create the complete PROPSTATS response
+              propstats_builder = Nokogiri::XML::Builder.new do |propstats_xml|
+                propstats_xml.send('propstat', {'xmlns:D' => 'DAV:'}.merge(resource.root_xml_attributes)) do
+                  propstats_xml.parent.namespace = propstats_xml.parent.namespace_definitions.first
+                  xml2 = propstats_xml['D']
+                  
+                  xml2.response do
+                    unless(resource.propstat_relative_path)
+                      xml2.href "#{scheme}://#{host}:#{port}#{url_format(resource)}"                  
+                    else
+                      xml2.href url_format(resource)
+                    end
+                    propstats(xml2, get_properties(resource, properties.empty? ? resource.properties : properties))
+                  end
+                end
+              end
+
+              # Just want to add the <:D:response> so extract it.
+              # Q: Is there a better/faster way to do this?
+              xml_str = Nokogiri::XML.parse(propstats_builder.to_xml).xpath('//D:response').first.to_xml
+              
+              # Add PROPSTATS to cache
+              # Caching the PROPSTATS response as xml text string.
+              RedmineDmsf::Webdav::Cache.write(propstats_key, xml_str)
+            end
+            xml << xml_str
+          end
+        end
+      end
+      
     end
   end
 end

lib/redmine_dmsf/webdav/dmsf_resource.rb

@@ -79,6 +79,10 @@ module RedmineDmsf
       def really_exist?
         return project && project.module_enabled?('dmsf') && (folder || file)        
       end
+      
+      def project_id
+        project.id unless project.nil?
+      end
 
       # Is this entity a folder?
       def collection?

lib/redmine_dmsf/webdav/project_resource.rb

@@ -78,6 +78,10 @@ module RedmineDmsf
       def long_name
         project.name unless project.nil?
       end
+      
+      def project_id
+        project.id unless project.nil?
+      end
 
       def content_type
         'inode/directory'

lib/redmine_dmsf/webdav/resource_proxy.rb

@@ -84,6 +84,10 @@ module RedmineDmsf
       def really_exist?
         @resource_c.really_exist?
       end
+      
+      def project_id
+        @resource_c.project_id
+      end
 
       def creation_date
         @resource_c.creation_date