lazy load latest package definitions with yumhelper 2.2

merge commit to 0.24x, original commit:

I could observe that yumhelper.py can run quite some time
and use quite a lot of memory (up to 100MB!) if you're
using many repositories. As the yumhelper is only needed
if you use latest as a ensure-keyword it makes no sense
for people like me letting puppet fetch these details
always, if you're never going to use latest.  => lazy loading.

After discussion on the list, this is the new version for
lazy loading yum latest package versions. It is implemented
mainly in the way that Luke proposed. However it stores
the latest informations in the variable latest_info so
the latest method didn't get too hackish and could nearly be
left like it was before.

1 files changed, 24 insertions, 17 deletions

diff --git a/lib/puppet/provider/package/yum.rb b/lib/puppet/provider/package/yum.rb
index 7998b92c0..56fad1af9 100755
--- a/lib/puppet/provider/package/yum.rb
+++ b/lib/puppet/provider/package/yum.rb
@@ -7,9 +7,7 @@ Puppet::Type.type(:package).provide :yum, :parent => :rpm, :source => :rpm do
     
     YUMHELPER = File::join(File::dirname(__FILE__), "yumhelper.py")
 
-    class << self
-        attr_reader :updates
-    end
+    attr_accessor :latest_info
 
     if command('rpm')
         confine :true => begin
@@ -24,22 +22,32 @@ Puppet::Type.type(:package).provide :yum, :parent => :rpm, :source => :rpm do
     defaultfor :operatingsystem => [:fedora, :centos, :redhat]
 
     def self.prefetch(packages)
-        @updates = {}
         if Process.euid != 0
             raise Puppet::Error, "The yum provider can only be used as root"
         end
         super
-        python(YUMHELPER).each_line do |l|
-            l.chomp!
-            next if l.empty?
-            if l[0,4] == "_pkg"
-                hash = nevra_to_hash(l[5..-1])
-                [hash[:name], "#{hash[:name]}.#{hash[:arch]}"].each do |n|
-                    @updates[n] ||= []
-                    @updates[n] << hash
-                end
-            end
-        end
+        return unless packages.detect { |name, package| package.should(:ensure) == :latest }
+
+         # collect our 'latest' info
+         updates = {}
+         python(YUMHELPER).each_line do |l|
+             l.chomp!
+             next if l.empty?
+             if l[0,4] == "_pkg"
+                 hash = nevra_to_hash(l[5..-1])
+                 [hash[:name], "#{hash[:name]}.#{hash[:arch]}"].each  do |n|
+                     updates[n] ||= []
+                     updates[n] << hash
+                 end
+             end
+         end
+
+         # Add our 'latest' info to the providers.
+         packages.each do |name, package|
+             if info = updates[package[:name]]
+                 package.provider.latest_info = info[0]
+             end
+         end
     end
 
     def install
@@ -73,11 +81,10 @@ Puppet::Type.type(:package).provide :yum, :parent => :rpm, :source => :rpm do
 
     # What's the latest package version available?
     def latest
-        upd = self.class.updates[@resource[:name]]
+        upd = latest_info
         unless upd.nil?
             # FIXME: there could be more than one update for a package
             # because of multiarch
-            upd = upd[0]
             return "#{upd[:version]}-#{upd[:release]}"
         else
             # Yum didn't find updates, pretend the current