lib/sitediff/cache.rb in sitediff-1.0.0 vs lib/sitediff/cache.rb in sitediff-1.1.1

@@ -4,10 +4,12 @@
 require 'fileutils'
 
 class SiteDiff
   # SiteDiff Cache Handler.
   class Cache
+    TIMESTAMP_FILE = 'timestamp'
+
     attr_accessor :read_tags, :write_tags
 
     ##
     # Creates a Cache object.
     def initialize(opts = {})
@@ -15,10 +17,11 @@
 
       # Read and Write tags are sets that can contain :before and :after.
       # They indicate whether we should use the cache for reading or writing.
       @read_tags = Set.new
       @write_tags = Set.new
+      @timestamp_flag = { before: false, after: false }
 
       # The directory used by the cache for storage.
       @dir = opts[:directory] || '.'
     end
 
@@ -50,10 +53,11 @@
     ##
     # Set data to cache.
     def set(tag, path, result)
       return unless @write_tags.include? tag
 
+      save_timestamp(tag)
       filename = File.join(
         @dir,
         'snapshot',
         tag.to_s,
         *path.split(File::SEPARATOR)
@@ -99,8 +103,22 @@
     def get_dir(directory)
       # Create the dir. Must go before cache initialization!
       @dir = Pathname.new(directory || '.')
       @dir.mkpath unless @dir.directory?
       @dir.to_s
+    end
+
+    private
+
+    def save_timestamp(tag)
+      # run once
+      return if @timestamp_flag[tag]
+
+      @timestamp_flag[tag] = true
+      cache_dir = File.join(@dir, 'snapshot', tag.to_s)
+      if File.exist? cache_dir
+        file = File.join(cache_dir, TIMESTAMP_FILE)
+        FileUtils.touch(file)
+      end
     end
   end
 end