application_cache.rb

# Encoding: utf-8
# Cloud Foundry Java Buildpack
# Copyright 2013 the original author or authors.
#
# 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 'time'
require 'java_buildpack/util'
require 'java_buildpack/util/download_cache'
require 'java_buildpack/util/format_duration'

module JavaBuildpack::Util

  # An extension of {DownloadCache} that is configured to use the application cache.  The application
  # cache location is defined by the second argument (<tt>ARGV[1]</tt>) to the +compile+ script.
  #
  # <b>WARNING: This cache should only by used by code run by the +compile+ script</b>
  class ApplicationCache < DownloadCache

    # Downloads an item with the given name and version from the given URI, then yields the resultant
    # file to the given block. The application cache location is defined by
    # the second argument (<tt>ARGV[1]</tt>) to the +compile+ script.
    #
    # @param [String] name
    # @param [JavaBuildpack::Util::TokenizedVersion] version
    # @param [String] uri
    # @raise if the second argument (<tt>ARGV[1]</tt>) to the +compile+ script is +nil+
    def self.download(name, version, uri)
      download_start_time = Time.now
      print "-----> Downloading #{name} #{version} from #{uri} "

      new.get(uri) do |file| # TODO: Use global cache #50175265
        puts "(#{(Time.now - download_start_time).duration})"
        yield file
      end
    end

    # Downloads a given JAR and copies it to a given destination. The application cache location is defined by
    # the second argument (<tt>ARGV[1]</tt>) to the +compile+ script.
    #
    # @param [JavaBuildpack::Util::TokenizedVersion] version the version of the item
    # @param [String] uri the URI of the item
    # @param [String] description a description of the item
    # @param [String] jar_name the filename of the item
    # @param [String] target_directory the path of the directory into which to download the item
    # @raise if the second argument (<tt>ARGV[1]</tt>) to the +compile+ script is +nil+
    def self.download_jar(version, uri, description, jar_name, target_directory)
      download(description, version, uri) do |file|
        system "cp #{file.path} #{File.join(target_directory, jar_name)}"
      end
    end

    private_class_method :new

    def initialize
      application_cache_directory = ARGV[1]
      raise 'Application cache directory is undefined' if application_cache_directory.nil?
      super(application_cache_directory)
    end

  end

end