#-- 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'
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
- def flush
- return if !@registry
- # ruby dbm has no flush, so we close/reopen :(
- close
- 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
+ def dbexists?
+ not Dir.glob(@filename + '.*').empty?
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)
- end
-
- # returns a list of your keys
- def keys
- return registry.keys
- 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
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