Caching whether named autoloaded files are missing

This is the big win, because it causes us to just
skip the whole loading infrastructure, including
skipping looking through the modulepath.

Signed-off-by: Luke Kanies <luke@madstop.com>

4 files changed, 49 insertions, 3 deletions

diff --git a/lib/puppet/util/autoload.rb b/lib/puppet/util/autoload.rb
index db06ea934..fb15adf92 100644
--- a/lib/puppet/util/autoload.rb
+++ b/lib/puppet/util/autoload.rb
@@ -73,6 +73,8 @@ class Puppet::Util::Autoload
     # Load a single plugin by name.  We use 'load' here so we can reload a
     # given plugin.
     def load(name)
+        return false if named_file_missing?(name)
+
         path = name.to_s + ".rb"
 
         searchpath.each do |dir|
@@ -92,10 +94,10 @@ class Puppet::Util::Autoload
                         puts detail.backtrace
                     end
                 end
-                return false
+                return named_file_is_missing(name)
             end
         end
-        return false
+        return named_file_is_missing(name)
     end
 
     # Mark the named object as loaded.  Note that this supports unqualified
diff --git a/lib/puppet/util/autoload/file_cache.rb b/lib/puppet/util/autoload/file_cache.rb
index 6de525a8d..12400f620 100644
--- a/lib/puppet/util/autoload/file_cache.rb
+++ b/lib/puppet/util/autoload/file_cache.rb
@@ -79,6 +79,20 @@ module Puppet::Util::Autoload::FileCache
         missing_files[path] = Time.now
     end
 
+    def named_file_missing?(name)
+        @named_files ||= {}
+        if time = @named_files[name] and ! data_expired?(time)
+            return true
+        end
+        false
+    end
+
+    def named_file_is_missing(name)
+        @named_files ||= {}
+        @named_files[name] = Time.now
+        false
+    end
+
     private
 
     def cached_data?(path, type = nil)
diff --git a/spec/unit/util/autoload.rb b/spec/unit/util/autoload.rb
index 3bd5b50ad..d05bc15f0 100755
--- a/spec/unit/util/autoload.rb
+++ b/spec/unit/util/autoload.rb
@@ -71,11 +71,17 @@ describe Puppet::Util::Autoload do
         end
 
         it "should skip files that it knows are missing" do
-            @autoload.expects(:missing_file?).returns true
+            @autoload.expects(:named_file_missing?).with("foo").returns true
             @autoload.expects(:eachdir).never
 
             @autoload.load("foo")
         end
+
+        it "should register that files are missing if they cannot be found" do
+            @autoload.load("foo")
+
+            @autoload.should be_named_file_missing("foo")
+        end
     end
 
     describe "when loading all files" do
diff --git a/spec/unit/util/autoload/file_cache.rb b/spec/unit/util/autoload/file_cache.rb
index ad4e75f74..333ddb545 100755
--- a/spec/unit/util/autoload/file_cache.rb
+++ b/spec/unit/util/autoload/file_cache.rb
@@ -126,4 +126,28 @@ describe Puppet::Util::Autoload::FileCache do
             other.should be_directory_exist("/my/file")
         end
     end
+
+    describe "when checking whether a named file exists" do
+        it "should have a method for testing whether a named file is missing" do
+            @cacher.should respond_to(:named_file_missing?)
+        end
+
+        it "should have a method for registering that a named file is missing" do
+            @cacher.should respond_to(:named_file_is_missing)
+        end
+
+        it "should cache that a file is missing for 15 seconds" do
+            now = Time.now
+
+            later = now + 16
+
+            Time.expects(:now).times(2).returns(now).then.returns(later)
+            @cacher.named_file_is_missing("foo")
+            @cacher.should_not be_named_file_missing("foo")
+        end
+
+        it "should return false when registering a file as missing" do
+            @cacher.named_file_is_missing("foo").should be_false
+        end
+    end
 end