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, specs
    @url=url
    case specs when Hash
      @spec = specs.keys.first # only use first spec
      @ref = specs.values.first
    end
    @unique_token="#{name}-#{version}" unless name.to_s.empty? or name == '__UNKNOWN__'
  end
end

class CurlDownloadStrategy <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?
      begin
        curl @url, '-o', @dl
      rescue Exception
        ignore_interrupts { @dl.unlink if @dl.exist? }
        raise
      end
    else
      puts "File already downloaded and cached to #{HOMEBREW_CACHE}"
    end
    return @dl # thus performs checksum verification
  end

  def stage
    # magic numbers stolen from /usr/share/file/magic/
    File.open(@dl) do |f|
      # get the first four bytes
      case f.read(4)
      when /^PK\003\004/ # .zip archive
        safe_system '/usr/bin/unzip', '-qq', @dl
        chdir
      when /^\037\213/, /^BZh/ # gzip/bz2 compressed
        # TODO check if it's really a tar archive
        safe_system '/usr/bin/tar', 'xf', @dl
        chdir
      else
        # we are assuming it is not an archive, use original filename
        # this behaviour is due to ScriptFileFormula expectations
        # So I guess we should cp, but we mv, for this historic reason
        # HOWEVER if this breaks some expectation you had we *will* change the
        # behaviour, just open an issue at github
        FileUtils.mv @dl, File.basename(@url)
      end
    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

# Use this strategy to download but not unzip a file.
# Useful for installing jars.
class NoUnzipCurlDownloadStrategy <CurlDownloadStrategy
  def stage
    FileUtils.mv @dl, File.basename(@url)
  end
end

class SubversionDownloadStrategy <AbstractDownloadStrategy
  def fetch
    ohai "Checking out #{@url}"
    @co=HOMEBREW_CACHE+@unique_token
    unless @co.exist?
      args = [svn, 'checkout', @url, @co]
      args << '-q' unless ARGV.verbose?
      safe_system *args
    else
      # TODO svn up?
      puts "Repository already checked out"
    end
  end

  def stage
    # Force the export, since the target directory will already exist
    args = [svn, 'export', '--force', @co, Dir.pwd]
    args << '-r' << @ref if @spec == :revision and @ref
    args << '-q' unless ARGV.verbose?
    safe_system *args
  end

  # Override this method in a DownloadStrategy to force the use of a non-
  # sysetm svn binary. mplayer.rb uses this to require a svn that
  # understands externals.
  def svn
    '/usr/bin/svn'
  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 to #{@clone}"
    end
  end

  def stage
    dst = Dir.getwd
    Dir.chdir @clone do
      if @spec and @ref
        ohai "Checking out #{@spec} #{@ref}"
        case @spec
        when :branch
          nostdout { safe_system 'git', 'checkout', "origin/#{@ref}" }
        when :tag
          nostdout { safe_system 'git', 'checkout', @ref }
        end
      end
      # 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

class CVSDownloadStrategy <AbstractDownloadStrategy
  def fetch
    ohai "Checking out #{@url}"
    @co=HOMEBREW_CACHE+@unique_token

    # URL of cvs cvs://:pserver:anoncvs@www.gccxml.org:/cvsroot/GCC_XML:gccxml
    # will become:
    # cvs -d :pserver:anoncvs@www.gccxml.org:/cvsroot/GCC_XML login
    # cvs -d :pserver:anoncvs@www.gccxml.org:/cvsroot/GCC_XML co gccxml
    mod, url = split_url(@url)

    unless @co.exist?
      Dir.chdir HOMEBREW_CACHE do
        safe_system '/usr/bin/cvs', '-d', url, 'login'
        safe_system '/usr/bin/cvs', '-d', url, 'checkout', '-d', @unique_token, mod
      end
    else
      # TODO cvs up?
      puts "Repository already checked out"
    end
  end

  def stage
    FileUtils.cp_r(Dir[HOMEBREW_CACHE+@unique_token+"*"], Dir.pwd)

    require 'find'
    Find.find(Dir.pwd) do |path|
      if FileTest.directory?(path) && File.basename(path) == "CVS"
        Find.prune
        FileUtil.rm_r path, :force => true
      end
    end
  end

private
  def split_url(in_url)
    parts=in_url.sub(%r[^cvs://], '').split(/:/)
    mod=parts.pop
    url=parts.join(':')
    [ mod, url ]
  end
end

class MercurialDownloadStrategy <AbstractDownloadStrategy
  def fetch
    raise "You must install mercurial, there are two options:\n\n"+
          "    brew install pip && pip install mercurial\n"+
          "    easy_install mercurial\n\n"+
          "Homebrew recommends pip over the OS X provided easy_install." \
          unless system "/usr/bin/which hg"

    ohai "Cloning #{@url}"
    @clone=HOMEBREW_CACHE+@unique_token

    url=@url.sub(%r[^hg://], '')

    unless @clone.exist?
      checkout_args = []
      if (@spec == :revision) and @ref
        checkout_args << '-r' << @ref
      end
      checkout_args << url << @clone
      safe_system 'hg', 'clone', *checkout_args
    else
      # TODO hg pull?
      puts "Repository already cloned"
    end
  end

  def stage
    dst=Dir.getwd
    Dir.chdir @clone do
      if @spec and @ref
        ohai "Checking out #{@spec} #{@ref}"
        Dir.chdir @clone do
          safe_system 'hg', 'archive', '-y', '-r', @ref, '-t', 'files', dst
        end
      else
        safe_system 'hg', 'archive', '-y', '-t', 'files', dst
      end
    end
  end
end