class PEROBS::DataBase
Base class for all storage back-ends.
Public Class Methods
new(options)
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Create a new DataBase
object. This method must be overwritten by the deriving classes and then called via their constructor.
# File lib/perobs/DataBase.rb, line 45 def initialize(options) @serializer = options[:serializer] || :json @progressmeter = options[:progressmeter] || ProgressMeter.new @config = {} end
Public Instance Methods
check_option(name)
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Check a config option and adjust it if needed. @param name [String] Name of the config option.
# File lib/perobs/DataBase.rb, line 101 def check_option(name) value = instance_variable_get('@' + name) if @config.include?(name) # The database already existed and has a setting for this config # option. If it does not match the instance variable, adjust the # instance variable accordingly. unless @config[name] == value instance_variable_set('@' + name, @config[name]) end else # There is no such config option yet. Create it with the value of the # corresponding instance variable. @config[name] = value end end
close()
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A dummy close method. Deriving classes must overload them to insert their open/close semantics.
# File lib/perobs/DataBase.rb, line 58 def close end
deserialize(raw)
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De-serialize the given String into a Ruby object. @param raw [String] @return [Hash] Deserialized version
# File lib/perobs/DataBase.rb, line 83 def deserialize(raw) begin case @serializer when :marshal Marshal.load(raw) when :json JSON.parse(raw, :create_additions => true) when :yaml YAML.load(raw) end rescue => e PEROBS.log.fatal "Cannot de-serialize object with #{@serializer} " + "parser: " + e.message end end
open()
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A dummy open method. Deriving classes must overload them to insert their open/close semantics.
# File lib/perobs/DataBase.rb, line 53 def open end
serialize(obj)
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Serialize the given object using the object serializer. @param obj [ObjectBase] Object
to serialize @return [String] Serialized version
# File lib/perobs/DataBase.rb, line 64 def serialize(obj) begin case @serializer when :marshal Marshal.dump(obj) when :json obj.to_json when :yaml YAML.dump(obj) end rescue => e PEROBS.log.fatal "Cannot serialize object as #{@serializer}: " + e.message end end
Private Instance Methods
ensure_dir_exists(dir)
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Ensure that we have a directory to store the DB items.
# File lib/perobs/DataBase.rb, line 121 def ensure_dir_exists(dir) unless Dir.exist?(dir) begin Dir.mkdir(dir) rescue IOError => e PEROBS.log.fatal "Cannote create DB directory '#{dir}': #{e.message}" end end end