1 files changed, 190 insertions, 0 deletions
diff --git a/lib/chef/checksum_cache.rb b/lib/chef/checksum_cache.rb
new file mode 100644
index 0000000000..6db7115a56
--- /dev/null
+++ b/lib/chef/checksum_cache.rb
@@ -0,0 +1,190 @@
+#
+# Author:: Adam Jacob (<adam@opscode.com>)
+# Author:: Daniel DeLeo (<dan@kallistec.com>)
+# Copyright:: Copyright (c) 2009 Opscode, Inc.
+# Copyright:: Copyright (c) 2009 Daniel DeLeo
+# License:: Apache License, Version 2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+require 'set'
+require 'fileutils'
+require 'chef/log'
+require 'chef/config'
+require 'chef/client'
+require 'chef/mixin/convert_to_class_name'
+require 'singleton'
+require 'moneta'
+
+class Chef
+  class ChecksumCache
+    include Chef::Mixin::ConvertToClassName
+    include ::Singleton
+
+    attr_reader :moneta
+
+    def initialize(*args)
+      self.reset!(*args)
+    end
+
+    def reset!(backend=nil, options=nil)
+      backend ||= Chef::Config[:cache_type]
+      options ||= Chef::Config[:cache_options]
+
+      begin
+        require "moneta/#{convert_to_snake_case(backend, 'Moneta')}"
+        require 'chef/monkey_patches/moneta'
+      rescue LoadError => e
+        Chef::Log.fatal("Could not load Moneta back end #{backend.inspect}")
+        raise e
+      end
+
+      @moneta = Moneta.const_get(backend).new(options)
+    end
+
+    def self.reset_cache_validity
+      @valid_cached_checksums = nil
+    end
+
+    Chef::Client.when_run_starts do |run_status|
+      reset_cache_validity
+    end
+
+    def self.valid_cached_checksums
+      @valid_cached_checksums ||= Set.new
+    end
+
+    def self.validate_checksum(checksum_key)
+      valid_cached_checksums << checksum_key
+    end
+
+    def self.all_cached_checksums
+      all_checksums_with_filenames = {}
+
+      Dir[File.join(Chef::Config[:cache_options][:path], '*')].each do |cksum_file|
+        all_checksums_with_filenames[File.basename(cksum_file)] = cksum_file
+      end
+      all_checksums_with_filenames
+    end
+
+    def self.cleanup_checksum_cache
+      Chef::Log.debug("Cleaning the checksum cache")
+      if (Chef::Config[:cache_type].to_s == "BasicFile")
+        all_cached_checksums.each do |cache_key, cksum_cache_file|
+          unless valid_cached_checksums.include?(cache_key)
+            remove_unused_checksum(cksum_cache_file)
+          end
+        end
+      end
+    end
+
+    Chef::Client.when_run_completes_successfully do |run_status|
+      cleanup_checksum_cache
+    end
+
+    def self.remove_unused_checksum(checksum_file)
+      Chef::Log.debug("Removing unused checksum cache file #{checksum_file}")
+      FileUtils.rm(checksum_file)
+    end
+
+    def self.checksum_for_file(*args)
+      instance.checksum_for_file(*args)
+    end
+
+    def validate_checksum(*args)
+      self.class.validate_checksum(*args)
+    end
+
+    def checksum_for_file(file, key=nil)
+      key ||= generate_key(file)
+      fstat = File.stat(file)
+      lookup_checksum(key, fstat) || generate_checksum(key, file, fstat)
+    end
+
+    def lookup_checksum(key, fstat)
+      cached = fetch(key)
+      if cached && file_unchanged?(cached, fstat)
+        validate_checksum(key)
+        cached["checksum"]
+      else
+        nil
+      end
+    end
+
+    def generate_checksum(key, file, fstat)
+      checksum = checksum_file(file, Digest::SHA256.new)
+      moneta.store(key, {"mtime" => fstat.mtime.to_f, "checksum" => checksum})
+      validate_checksum(key)
+      checksum
+    end
+
+    def generate_key(file, group="chef")
+      "#{group}-file-#{file.gsub(/(#{File::SEPARATOR}|\.)/, '-')}"
+    end
+
+    def self.generate_md5_checksum_for_file(*args)
+      instance.generate_md5_checksum_for_file(*args)
+    end
+
+    def generate_md5_checksum_for_file(file)
+      checksum_file(file, Digest::MD5.new)
+    end
+
+    def generate_md5_checksum(io)
+      checksum_io(io, Digest::MD5.new)
+    end
+
+    private
+
+    def fetch(key)
+      @moneta.fetch(key)
+    rescue ArgumentError => e
+      Log.warn "Error loading cached checksum for key #{key.inspect}"
+      Log.warn(e)
+      repair_checksum_cache
+      nil
+    end
+
+    def repair_checksum_cache
+      Chef::Log.info("Removing invalid checksum cache files")
+      Dir["#{Chef::Config[:cache_options][:path]}/*"].each do |file_path|
+        File.unlink(file_path) unless File.size?(file_path)
+      end
+    end
+
+    def file_unchanged?(cached, fstat)
+      cached["mtime"].to_f == fstat.mtime.to_f
+    end
+
+    def checksum_file(file, digest)
+      File.open(file, 'rb') { |f| checksum_io(f, digest) }
+    end
+
+    def checksum_io(io, digest)
+      while chunk = io.read(1024 * 8)
+        digest.update(chunk)
+      end
+      digest.hexdigest
+    end
+
+  end
+end
+
+module Moneta
+  module Defaults
+    def default
+      nil
+    end
+  end
+end