cache.rb in radiospiel-app-0.2.9

- old
+ new

@@ -5,10 +5,43 @@
 # stored away in a redis store.
 #
 # Entries are packed via Marshal.
 module App
   module Cache
+    class SqliteStore < MicroSql::KeyValueTable
+      def self.db_path
+        @db_path ||= begin
+          path = "#{Dir.home}/cache/#{File.basename(App.root)}/#{App.root.uid64}.sqlite3"
+          FileUtils.mkdir_p File.dirname(path)
+          path
+        end
+      end
+
+      def initialize
+        @db = MicroSql.create(SqliteStore.db_path)
+        super @db, "cache"
+      end
+
+      def get(key)
+        encoded = self[key]
+        Base64.decode64(encoded) if encoded
+      end 
+      
+      def set(key, value)
+        update key, Base64.encode64(value)
+      end
+      
+      def expire(key, max_age)
+        ttl = max_age + Time.now.to_i if max_age
+        @db.ask("UPDATE cache SET ttl=? WHERE uid=?", ttl, key)
+      end
+      
+      def flushdb
+        @db.exec "DELETE FROM cache"
+      end
+    end
+    
     DEFAULT_MAX_AGE = 4 * 3600     # 4 hours.
 
     attr :store, true
     extend self
     
@@ -29,21 +62,25 @@
         }
       end
     end
 
     def self.setup
-      if !(cache_url = App.config[:cache])
-        App.logger.warn "No :cache configuration"
-      elsif !(self.store = connect_to_redis(cache_url))
-        App.logger.warn "Using cache at #{cache_url}"
+      cache_url = App.config[:cache] || begin
+        App.logger.warn "No :cache configuration, fallback to #{SqliteStore.db_path}"
+        SqliteStore.db_path
       end
-    end
-    
-    def self.connect_to_redis(url)
-      require "redis"
-      Redis.connect(:url => url)
+      
+      uri = URI.parse(cache_url)
+
+      self.store = case uri.scheme
+      when "redis"
+        require "redis"
+        Redis.connect(:url => cache_url)
+      when nil
+        SqliteStore.new
+      end
     rescue LoadError
-      App.logger.warn "Cannot load 'redis' gem (connecting to #{url})"
+      App.logger.warn "LoadError: #{$!}"
       nil
     end
   end
 
   def cached(key, max_age = Cache::DEFAULT_MAX_AGE, &block)