class Riak::MapReduce::Phase
Represents an individual phase in a map-reduce pipeline. Generally you’ll want to call methods of MapReduce
instead of using this directly.
Attributes
@return [Array] any extra static arguments to pass to the phase
@return [Boolean] whether results of this phase will be returned
@return [String] the language of the phase’s function - “javascript” or “erlang”. Meaningless for :link type phases.
@return [Symbol] the type of phase - :map, :reduce, or :link
Public Class Methods
Creates a phase in the map-reduce pipeline @param [Hash] options options for the phase @option options [Symbol] :type one of :map, :reduce, :link @option options [String] :language (“javascript”) “erlang” or “javascript” @option options [String, Array
, Hash] :function In the case of Javascript, a literal function in a string, or a hash with :bucket and :key. In the case of Erlang, an Array
of [module, function]. For a :link phase, a hash including any of :bucket, :tag or a WalkSpec
. @option options [Boolean] :keep (false) whether to return the results of this phase @option options [Array] :arg (nil) any extra static arguments to pass to the phase
# File lib/riak/map_reduce/phase.rb, line 34 def initialize(options = {}) self.type = options[:type] self.language = options[:language] || "javascript" self.function = options[:function] self.keep = options[:keep] || false self.arg = options[:arg] end
Public Instance Methods
Converts the phase to its JSON-compatible representation for job invocation. @return [Hash] a Hash-equivalent of the phase
# File lib/riak/map_reduce/phase.rb, line 73 def as_json(options = nil) obj = case type when :map, :reduce defaults = {"language" => language, "keep" => keep} case function when Hash defaults.merge(function) when String if function =~ /\s*function\s*\(/ || function =~ /\s*fun\s*\(.*\)\s*->/ defaults.merge("source" => function) else defaults.merge("name" => function) end when Array defaults.merge("module" => function[0], "function" => function[1]) end when :link spec = WalkSpec.normalize(function).first {"bucket" => spec.bucket, "tag" => spec.tag, "keep" => spec.keep || keep} end obj["arg"] = arg if arg { type => obj } end
# File lib/riak/map_reduce/phase.rb, line 47 def function=(value) case value when Array raise ArgumentError, t("module_function_pair_required") unless value.size == 2 @language = "erlang" when Hash raise ArgumentError, t("stored_function_invalid") unless type == :link || value.has_key?(:bucket) && value.has_key?(:key) @language = "javascript" when String @language = (value =~ /\s*fun\s*\(.*\)\s*->/) ? "erlang" : "javascript" when WalkSpec raise ArgumentError, t("walk_spec_invalid_unless_link") unless type == :link else raise ArgumentError, t("invalid_function_value", :value => value.inspect) end @function = value end
# File lib/riak/map_reduce/phase.rb, line 42 def type=(value) raise ArgumentError, t("invalid_phase_type") unless value.to_s =~ /^(map|reduce|link)$/i @type = value.to_s.downcase.to_sym end