On Sun, 2012-07-22 at 12:16 +0200, ifarkas(a)redhat.com wrote:
From: Imre Farkas <ifarkas(a)redhat.com>
---
src/lib/provider_selection.rb | 4 +
src/lib/provider_selection/base.rb | 92 ++++++++++++++++++++++
src/lib/provider_selection/chainable_strategy.rb | 16 ++++
src/lib/provider_selection/match.rb | 15 ++++
src/lib/provider_selection/priority_group.rb | 57 ++++++++++++++
src/lib/provider_selection/rank.rb | 19 +++++
src/lib/provider_selection/strategy.rb | 25 ++++++
7 files changed, 228 insertions(+)
create mode 100644 src/lib/provider_selection.rb
create mode 100644 src/lib/provider_selection/base.rb
create mode 100644 src/lib/provider_selection/chainable_strategy.rb
create mode 100644 src/lib/provider_selection/match.rb
create mode 100644 src/lib/provider_selection/priority_group.rb
create mode 100644 src/lib/provider_selection/rank.rb
create mode 100644 src/lib/provider_selection/strategy.rb
diff --git a/src/lib/provider_selection.rb b/src/lib/provider_selection.rb
new file mode 100644
index 0000000..eff3c25
--- /dev/null
+++ b/src/lib/provider_selection.rb
@@ -0,0 +1,4 @@
+# Require files in lib dir
+['match', 'priority_group', 'rank', 'strategy',
'base'].each do |file_name|
+ require File.join(File.dirname(__FILE__), 'provider_selection', file_name)
+end
diff --git a/src/lib/provider_selection/base.rb b/src/lib/provider_selection/base.rb
new file mode 100644
index 0000000..d2525fb
--- /dev/null
+++ b/src/lib/provider_selection/base.rb
@@ -0,0 +1,92 @@
+module ProviderSelection
+
+ class Base
+
+ @strategies = []
+ @view_paths = []
+
+ class << self
+ attr_reader :strategies
+ attr_reader :view_paths
+
+ def register_strategy(name, lib_path, options = {})
+ require lib_path
^ this can be potentially security hole, where the loaded lib can get
access to the whole environment. For now, put here TODO with notice of security issue
+ new_klass =
"provider_selection/strategies/#{name.to_s}".classify.constantize
+ @strategies << Strategy.new(name, new_klass)
+ end
+
+ def find_strategy_by_name(name)
+ @strategies.detect{ |strategy| strategy.name == name }
+ end
+
+ def add_view_path(view_path)
+ @view_paths << view_path
+ end
+ end
+
+ attr_reader :instances
+
+ def initialize(instances)
+ @instances = instances
+ @strategy_chain = self
+ end
+
+ def calculate
+ rank = Rank.new(@instances)
+
+ provider_accounts = find_common_provider_accounts.map do |provider_account|
+ provider_account if provider_account.quota.can_start?(@instances)
+ end.uniq.compact
+
+ default_priority_group = PriorityGroup.new
+ rank.priority_groups << default_priority_group
+
+ provider_accounts.uniq.each do |provider_account|
+ default_priority_group.matches << Match.new(provider_account)
+ end
+
+ rank
+ end
+
+ def next_match
+ rank = @strategy_chain.calculate
+
+ rank.ordered_priority_groups.each do |priority_group|
+ random_match = priority_group.get_random_match
+ return random_match if random_match.present?
+ end
+
+ nil
+ end
+
+ def chain_strategy(name, options = {})
+ @strategy_chain =
"provider_selection/strategies/#{name.to_s}".classify.constantize.new(@strategy_chain,
options)
+ end
+
+ private
+
+ def find_common_provider_accounts
+ instance_matches_grouped_by_instances = @instances.map do |instance|
+ matches, errors = instance.matches
+ matches
+ end
+
+ result = []
+ if instance_matches_grouped_by_instances.any?
+ result +=
instance_matches_grouped_by_instances.first.map(&:provider_account)
+ end
+
+ instance_matches_grouped_by_instances.each_with_index do |instance_matches,
index|
+ if index == 0
+ result += instance_matches.map(&:provider_account)
+ else
+ result &= instance_matches.map(&:provider_account)
+ end
+ end
+
+ result
+ end
+
+ end
+
+end
diff --git a/src/lib/provider_selection/chainable_strategy.rb
b/src/lib/provider_selection/chainable_strategy.rb
new file mode 100644
index 0000000..12377de
--- /dev/null
+++ b/src/lib/provider_selection/chainable_strategy.rb
@@ -0,0 +1,16 @@
+module ProviderSelection
+
+ module ChainableStrategy
+
+ def initialize(strategies, options)
+ @strategies = strategies
+ @options = options
+ end
+
+ def method_missing(method, *args)
+ args.empty? ? @strategies.send(method) : @strategies.send(method, args)
+ end
+
+ end
+
+end
diff --git a/src/lib/provider_selection/match.rb b/src/lib/provider_selection/match.rb
new file mode 100644
index 0000000..5b4c5ed
--- /dev/null
+++ b/src/lib/provider_selection/match.rb
@@ -0,0 +1,15 @@
+module ProviderSelection
+
+ class Match
+
+ attr_accessor :score
+ attr_accessor :provider_account
+
+ def initialize(provider_account, score = nil)
+ @provider_account = provider_account
+ @score = score
+ end
+
+ end
+
+end
\ No newline at end of file
diff --git a/src/lib/provider_selection/priority_group.rb
b/src/lib/provider_selection/priority_group.rb
new file mode 100644
index 0000000..c884ca2
--- /dev/null
+++ b/src/lib/provider_selection/priority_group.rb
@@ -0,0 +1,57 @@
+module ProviderSelection
+
+ class PriorityGroup
+
+ attr_accessor :matches
+ attr_accessor :score
+
+ def initialize(score = nil)
+ @matches = []
+ @score = score
+ end
+
+ def self.create_from_active_record(obj, allowed_provider_accounts)
+ return nil if allowed_provider_accounts.nil? || allowed_provider_accounts.empty?
+
+ priority_group = PriorityGroup.new(obj.score)
+
+ possible_provider_accounts = []
+ obj.provider_priority_group_elements.each do |element|
+ if element.value.is_a?(Provider)
+ possible_provider_accounts += element.value.provider_accounts
+ elsif element.value.is_a?(ProviderAccount)
+ possible_provider_accounts << element.value
+ end
+ end
+
+ possible_provider_accounts &= allowed_provider_accounts
+
+ return nil if possible_provider_accounts.empty?
+
+ possible_provider_accounts.each do |provider_account|
+ priority_group.matches << Match.new(provider_account)
+ end
+
+ priority_group
+ end
+
+ # TODO: extend the implementation to be able to work with negative scores
+ def get_random_match
+ # In order to work with 0 scores adding the size of the @matches array
+ match_sum_score = @matches.sum{ |match| match.score.to_i } + @matches.length
+ random_value = rand(match_sum_score)
+
+ sum = 0
+ matches.each_with_index do |match, index|
+ sum += match.score.to_i
+ if random_value < sum + index + 1
+ return match
+ end
+ end
+
+ nil
+ end
+
+ end
+
+end
diff --git a/src/lib/provider_selection/rank.rb b/src/lib/provider_selection/rank.rb
new file mode 100644
index 0000000..643dd71
--- /dev/null
+++ b/src/lib/provider_selection/rank.rb
@@ -0,0 +1,19 @@
+module ProviderSelection
+
+ class Rank
+
+ attr_accessor :priority_groups
+ attr_reader :instances
+
+ def initialize(instances)
+ @priority_groups = []
+ @instances = instances
+ end
+
+ def ordered_priority_groups
+ @priority_groups.sort_by{ |priority_group| priority_group.score.to_i }.reverse
+ end
+
+ end
+
+end
\ No newline at end of file
diff --git a/src/lib/provider_selection/strategy.rb
b/src/lib/provider_selection/strategy.rb
new file mode 100644
index 0000000..4e0fa6a
--- /dev/null
+++ b/src/lib/provider_selection/strategy.rb
@@ -0,0 +1,25 @@
+module ProviderSelection
+
+ class Strategy
+
+ attr_reader :name
+ attr_reader :klass
+ attr_reader :include_in_listings
+
+ def initialize(name, klass)
+ @name = name
+ @klass = klass
+ @include_in_listing = if klass.respond_to?('include_in_listings?')
+ klass.include_in_listings?
+ else
+ true
+ end
+ end
+
+ def translated_name
+ I18n.t("strategies.#{(a)name}.name")
+ end
+
+ end
+
+end
\ No newline at end of file
Please consider using 'require' in a method. Also I'm
not sure, but I think that RH Copyright's text should be applied on
those lib files.
--
Jozef Zigmund