[registry] refactoring into a abstract and factory

* a new abstract class AbstractAccessor is the new base
  for all concrete database implementations.
* a factory now, dynamically discovers those implementations
  in the registry/ directory and will create the configured
  type for the plugins.
* again: this makes db keys case-sensitive (aka 'the correct
  way of doing things' -.-)
* re-added tokyocabinet

1 files changed, 10 insertions, 234 deletions

diff --git a/lib/rbot/registry/dbm.rb b/lib/rbot/registry/dbm.rb
index a0676539..a13cb8ce 100644
--- a/lib/rbot/registry/dbm.rb
+++ b/lib/rbot/registry/dbm.rb
@@ -1,14 +1,14 @@
 #-- vim:sw=2:et
 #++
 #
-# The DBM class of the ruby std-lib provides wrappers for Unix-style
-# dbm or Database Manager libraries. The exact library used depends
+# :title: DBM registry implementation
+#
+# DBM is the ruby standard library wrapper module for Unix-style
+# dbm libraries. The specific library used depends
 # on how ruby was compiled. Its any of the following: ndbm, bdb,
 # gdbm or qdbm.
-# DBM API Documentation:
 # http://ruby-doc.org/stdlib-2.1.0/libdoc/dbm/rdoc/DBM.html
 #
-# :title: DB interface
 
 require 'dbm'
 
@@ -16,74 +16,10 @@ module Irc
 class Bot
 class Registry
 
-  # This class provides persistent storage for plugins via a hash interface.
-  # The default mode is an object store, so you can store ruby objects and
-  # reference them with hash keys. This is because the default store/restore
-  # methods of the plugins' RegistryAccessor are calls to Marshal.dump and
-  # Marshal.restore,
-  # for example:
-  #   blah = Hash.new
-  #   blah[:foo] = "fum"
-  #   @registry[:blah] = blah
-  # then, even after the bot is shut down and disconnected, on the next run you
-  # can access the blah object as it was, with:
-  #   blah = @registry[:blah]
-  # The registry can of course be used to store simple strings, fixnums, etc as
-  # well, and should be useful to store or cache plugin data or dynamic plugin
-  # configuration.
-  #
-  # WARNING:
-  # in object store mode, don't make the mistake of treating it like a live
-  # object, e.g. (using the example above)
-  #   @registry[:blah][:foo] = "flump"
-  # will NOT modify the object in the registry - remember that Registry#[]
-  # returns a Marshal.restore'd object, the object you just modified in place
-  # will disappear. You would need to:
-  #   blah = @registry[:blah]
-  #   blah[:foo] = "flump"
-  #   @registry[:blah] = blah
-  #
-  # If you don't need to store objects, and strictly want a persistant hash of
-  # strings, you can override the store/restore methods to suit your needs, for
-  # example (in your plugin):
-  #   def initialize
-  #     class << @registry
-  #       def store(val)
-  #         val
-  #       end
-  #       def restore(val)
-  #         val
-  #       end
-  #     end
-  #   end
-  # Your plugins section of the registry is private, it has its own namespace
-  # (derived from the plugin's class name, so change it and lose your data).
-  # Calls to registry.each etc, will only iterate over your namespace.
-  class Accessor
-
-    attr_accessor :recovery
-
-    # plugins don't call this - a Registry::Accessor is created for them and
-    # is accessible via @registry.
-    def initialize(bot, name)
-      @bot = bot
-      @name = name.downcase
-      @filename = @bot.path 'registry_dbm', @name
-      dirs = File.dirname(@filename).split("/")
-      dirs.length.times { |i|
-        dir = dirs[0,i+1].join("/")+"/"
-        unless File.exist?(dir)
-          debug "creating subregistry directory #{dir}"
-          Dir.mkdir(dir)
-        end
-      }
-      @registry = nil
-      @default = nil
-      @recovery = nil
-      # debug "initializing registry accessor with name #{@name}"
-    end
+  class DBMAccessor < AbstractAccessor
 
     def registry
+      super
       @registry ||= DBM.open(@filename, 0666, DBM::WRCREAT)
     end
 
@@ -94,174 +30,14 @@ class Registry
       registry
     end
 
-    def close
-      return if !@registry
-      registry.close
-      @registry = nil
-    end
-
-    # convert value to string form for storing in the registry
-    # defaults to Marshal.dump(val) but you can override this in your module's
-    # registry object to use any method you like.
-    # For example, if you always just handle strings use:
-    #   def store(val)
-    #     val
-    #   end
-    def store(val)
-      Marshal.dump(val)
-    end
-
-    # restores object from string form, restore(store(val)) must return val.
-    # If you override store, you should override restore to reverse the
-    # action.
-    # For example, if you always just handle strings use:
-    #   def restore(val)
-    #     val
-    #   end
-    def restore(val)
-      begin
-        Marshal.restore(val)
-      rescue Exception => e
-        error _("failed to restore marshal data for #{val.inspect}, attempting recovery or fallback to default")
-        debug e
-        if defined? @recovery and @recovery
-          begin
-            return @recovery.call(val)
-          rescue Exception => ee
-            error _("marshal recovery failed, trying default")
-            debug ee
-          end
-        end
-        return default
-      end
-    end
-
-    # lookup a key in the registry
-    def [](key)
-      if registry.has_key?(key.to_s)
-        return restore(registry[key.to_s])
-      else
-        return default
-      end
-    end
-
-    # set a key in the registry
-    def []=(key,value)
-      registry[key.to_s] = store(value)
-    end
-
-    # set the default value for registry lookups, if the key sought is not
-    # found, the default will be returned. The default default (har) is nil.
-    def set_default (default)
-      @default = default
-    end
-
-    def default
-      @default && (@default.dup rescue @default)
-    end
-
-    # like Hash#each
-    def each(&block)
-      registry.each_key do |key|
-        block.call(key, self[key])
-      end
-    end
-
-    alias each_pair each
-
-    # like Hash#each_key
-    def each_key(&block)
-      registry.each_key do |key|
-        block.call(key)
-      end
-    end
-
-    # like Hash#each_value
-    def each_value(&block)
-      registry.each_key do |key|
-        block.call(self[key])
-      end
-    end
-
-    # just like Hash#has_key?
-    def has_key?(key)
-      return registry.has_key?(key.to_s)
-    end
-
-    alias include? has_key?
-    alias member? has_key?
-    alias key? has_key?
-
-    # just like Hash#has_both?
-    def has_both?(key, value)
-      registry.has_key?(key.to_s) and registry.has_value?(store(value))
-    end
-
-    # just like Hash#has_value?
-    def has_value?(value)
-      return registry.has_value?(store(value))
-    end
-
-    # just like Hash#index?
-    def index(value)
-      self.each do |k,v|
-        return k if v == value
-      end
-      return nil
-    end
-
-    # delete a key from the registry
-    def delete(key)
-      return registry.delete(key.to_s)
+    def dbexists?
+      not Dir.glob(@filename + '.*').empty?
     end
 
-    # returns a list of your keys
-    def keys
-      return registry.keys
+    def optimize
+      # unsupported!
     end
 
-    # Return an array of all associations [key, value] in your namespace
-    def to_a
-      ret = Array.new
-      registry.each {|key, value|
-        ret << [key, restore(value)]
-      }
-      return ret
-    end
-
-    # Return an hash of all associations {key => value} in your namespace
-    def to_hash
-      ret = Hash.new
-      registry.each {|key, value|
-        ret[key] = restore(value)
-      }
-      return ret
-    end
-
-    # empties the registry (restricted to your namespace)
-    def clear
-      registry.clear
-    end
-    alias truncate clear
-
-    # returns an array of the values in your namespace of the registry
-    def values
-      ret = Array.new
-      self.each {|k,v|
-        ret << restore(v)
-      }
-      return ret
-    end
-
-    def sub_registry(prefix)
-      return Accessor.new(@bot, @name + "/" + prefix.to_s)
-    end
-
-    # returns the number of keys in your registry namespace
-    def length
-      registry.length
-    end
-    alias size length
   end
 
 end # Registry