Create unique cache dir to prevent race conditions. Issue #344.

lib/common/cache_file_store.rb

@@ -18,8 +18,8 @@ class CacheFileStore
   # YAML is Human Readable, contrary to Marshal which store in a binary format
   # Marshal does not need any "require"
   def initialize(storage_path, serializer = Marshal)
-    @storage_path = File.expand_path(storage_path)
-    @serializer = serializer
+    @storage_path = File.expand_path(storage_path + '/' + storage_dir)
+    @serializer   = serializer
 
     # File.directory? for ruby <= 1.9 otherwise,
     # it makes more sense to do Dir.exist? :/
@@ -58,4 +58,11 @@ class CacheFileStore
     File::join(@storage_path, key)
   end
 
+  def storage_dir
+    time   = Time.now
+    random = (0...8).map { (65 + rand(26)).chr }.join
+
+    Digest::MD5.hexdigest("#{time}#{random}")
+  end
+
 end

spec/lib/common/cache_file_store_spec.rb

@@ -17,13 +17,13 @@ describe CacheFileStore do
 
   describe '#storage_path' do
     it 'returns the storage path given in the #new' do
-      @cache.storage_path.should == cache_dir
+      @cache.storage_path.should match(/#{cache_dir}/)
     end
   end
 
   describe '#serializer' do
     it 'should return the default serializer : Marshal' do
-      @cache.serializer.should == Marshal
+      @cache.serializer.should     == Marshal
       @cache.serializer.should_not == YAML
     end
   end
@@ -32,12 +32,12 @@ describe CacheFileStore do
     it "should remove all files from the cache dir (#{@cache_dir}" do
       # let's create some files into the directory first
       (0..5).each do |i|
-        File.new(cache_dir + "/file_#{i}.txt", File::CREAT)
+        File.new(@cache.storage_path + "/file_#{i}.txt", File::CREAT)
       end
 
-      count_files_in_dir(cache_dir, 'file_*.txt').should == 6
+      count_files_in_dir(@cache.storage_path, 'file_*.txt').should == 6
       @cache.clean
-      count_files_in_dir(cache_dir).should == 0
+      count_files_in_dir(@cache.storage_path).should == 0
     end
   end
 
@@ -70,4 +70,16 @@ describe CacheFileStore do
 
     ## TODO write / read for an object
   end
+
+  describe '#storage_dir' do
+    it 'should create a unique storage dir' do
+      storage_dirs = []
+
+      (1..5).each do |i|
+        storage_dirs << CacheFileStore.new(cache_dir).storage_path
+      end
+
+      storage_dirs.uniq.size.should == 5
+    end
+  end
 end