brew/Library/Homebrew/download_strategy.rb

#  Copyright 2009 Max Howell and other contributors.
#
#  Redistribution and use in source and binary forms, with or without
#  modification, are permitted provided that the following conditions
#  are met:
#
#  1. Redistributions of source code must retain the above copyright
#     notice, this list of conditions and the following disclaimer.
#  2. Redistributions in binary form must reproduce the above copyright
#     notice, this list of conditions and the following disclaimer in the
#     documentation and/or other materials provided with the distribution.
#
#  THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
#  IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
#  OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
#  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
#  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
#  NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
#  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
#  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
#  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
#  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#
class AbstractDownloadStrategy
  def initialize url, name, version
    @url=url
    @unique_token="#{name}-#{version}" unless name.to_s.empty? or name == '__UNKNOWN__'
  end
end

class HttpDownloadStrategy <AbstractDownloadStrategy
  def fetch
    ohai "Downloading #{@url}"
    if @unique_token
      @dl=HOMEBREW_CACHE+(@unique_token+ext)
    else
      @dl=HOMEBREW_CACHE+File.basename(@url)
    end
    unless @dl.exist?
      curl @url, '-o', @dl
    else
      puts "File already downloaded and cached"
    end
    return @dl # thus performs checksum verification
  end
  def stage
    case `file -b #{@dl}`
      when /^Zip archive data/
        safe_system 'unzip', '-qq', @dl
        chdir
      when /^(gzip|bzip2) compressed data/
        # TODO do file -z now to see if it is in fact a tar
        safe_system 'tar', 'xf', @dl
        chdir
      else
        # we are assuming it is not an archive, use original filename
        # this behaviour is due to ScriptFileFormula expectations
        @dl.mv File.basename(@url)
    end
  end
private
  def chdir
    entries=Dir['*']
    case entries.length
      when 0 then raise "Empty archive"
      when 1 then Dir.chdir entries.first rescue nil
    end
  end
  def ext
    # GitHub uses odd URLs for zip files, so check for those
    rx=%r[http://(www\.)?github\.com/.*/(zip|tar)ball/]
    if rx.match @url
      if $2 == 'zip'
        '.zip'
      else
        '.tgz'
      end
    else
      Pathname.new(@url).extname
    end
  end
end

class SubversionDownloadStrategy <AbstractDownloadStrategy
  def fetch
    ohai "Checking out #{@url}"
    @co=HOMEBREW_CACHE+@unique_token
    unless @co.exist?
      safe_system 'svn', 'checkout', @url, @co
    else
      # TODO svn up?
      puts "Repository already checked out"
    end
  end
  def stage
    # Force the export, since the target directory will already exist
    safe_system 'svn', 'export', '--force', @co, Dir.pwd
  end
end

class GitDownloadStrategy <AbstractDownloadStrategy
  def fetch
    ohai "Cloning #{@url}"
    @clone=HOMEBREW_CACHE+@unique_token
    unless @clone.exist?
      safe_system 'git', 'clone', @url, @clone
    else
      # TODO git pull?
      puts "Repository already cloned"
    end
  end
  def stage
    dst=Dir.getwd
    Dir.chdir @clone do
      # http://stackoverflow.com/questions/160608/how-to-do-a-git-export-like-svn-export
      safe_system 'git', 'checkout-index', '-af', "--prefix=#{dst}/"
    end
  end
end