Module: Sundae

Defined in:
lib/sundae.rb

Overview

A collection of methods to mix the contents of several directories together using symbolic links.

Constant Summary collapse

LIBPATH =

:stopdoc:

::File.expand_path(::File.dirname(__FILE__)) + ::File::SEPARATOR
PATH = 
::File.dirname(LIBPATH) + ::File::SEPARATOR
VERSION =

:startdoc:

::File.read(PATH + 'version.txt').strip
DEFAULT_CONFIG_FILE = 
(Pathname.new(Dir.home) + '.sundae').expand_path

Class Method Summary collapse

Class Method Details

.all_mnts ⇒ Object

Return all mnts for every path as an array.



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# File 'lib/sundae.rb', line 150

def self.all_mnts 
  mnts = []

  @paths.each do |path| 
    next unless path.exist?
    mnts |= mnts_in_path(path).map { |mnt| path + mnt } # |= is the union operator
  end
  return mnts
end

.combine_directories(link_name, target_path1, target_path2) ⇒ Object

Create a directory and create links in it pointing to target_path1 and target_path2.



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# File 'lib/sundae.rb', line 360

def self.combine_directories(link_name, target_path1, target_path2) 
  raise unless File.symlink?(link_name)
  return if target_path1 == target_path2
  
  FileUtils.rm(link_name)
  FileUtils.mkdir_p(link_name)
  minimally_create_links(target_path1, link_name)
  minimally_create_links(target_path2, link_name)
end

.create_directory_link(target, link_name) ⇒ Object

Create a symbolic link to the directory at target from link_name, unless link_name already exists. In that case, create a directory and recursively run minimally_create_links.

Raises:

  • (ArgumentError) 


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# File 'lib/sundae.rb', line 335

def self.create_directory_link(target, link_name) 
  raise ArgumentError unless File.directory?(target)
  if (not File.exist?(link_name)) || 
      (File.symlink?(link_name) && (not File.exist?(File.readlink(link_name))))
    FileUtils.ln_sf(target, link_name)
  else
    case File.ftype(link_name)
    when 'file'
      raise "Could not link #{link_name} to #{target}: target exists."
    when 'directory'
      minimally_create_links(target, link_name)
    when 'link'
      case File.ftype(File.readlink(link_name))
      when 'file'
        raise "Could not link #{link_name} to #{target}: another link exists there."
      when 'directory'
        combine_directories(link_name, target, File.readlink(link_name))          
      end
    end
  end
end

.create_file_link(target, link_name) ⇒ Object

Create a symbolic link to target from link_name.

Raises:

  • (ArgumentError) 


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# File 'lib/sundae.rb', line 315

def self.create_file_link(target, link_name) 
  raise ArgumentError, "#{target} does not exist" unless File.file?(target)
  if File.exist?(link_name)
    raise ArgumentError, "#{link_name} cannot be overwritten for #{target}." unless File.symlink?(link_name)
    if (not File.exist?(File.readlink(link_name)))
      FileUtils.ln_sf(target, link_name)
    else
      unless (File.expand_path(File.readlink(link_name)) == File.expand_path(target))
        raise ArgumentError, "#{link_name} points to #{File.readlink(link_name)}, not #{target}" unless File.symlink?(link_name)
      end
    end
  else
    FileUtils.ln_s(target, link_name)
  end
end

.create_filesystem ⇒ Object

Call minimally_create_links for each mnt.



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# File 'lib/sundae.rb', line 252

def self.create_filesystem
  all_mnts.each do |mnt|
    install_location(mnt).expand_path.mkpath
    minimally_create_links(mnt, install_location(mnt))
  end
end

.create_link(target, link_name) ⇒ Object

Dispatch calls to create_directory_link and create_file_link.



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# File 'lib/sundae.rb', line 301

def self.create_link(target, link_name) 
  if File.directory?(target) 
    begin
      create_directory_link(target, link_name)
    rescue => message
      puts message
    end
  elsif File.file?(target) 
    create_file_link(target, link_name)
  end
end

.create_template_config_file(config_file) ⇒ Object

Create a template configuration file at config_file after asking the user.



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# File 'lib/sundae.rb', line 51

def self.create_template_config_file(config_file)
  config_file = Pathname.new(config_file).expand_path
  loop do
    print "#{config_file} does not exist.  Create template there? (y/n): "
    ans = gets.downcase.strip
    if ans == "y" || ans == "yes"
      File.open(config_file, "w") do |f|
        f.puts <<-EOM.gsub(/^ {14}/, '')
            # -*-Ruby-*- 

            # An array which lists the directories where mnts are stored.
            configatron.paths = ["~/mnt"]

            # These are the rules that are checked to see if a file in a mnt
            # should be ignored.
            #
            # For `ignore_rules', use either strings (can be globs)
            # or Ruby regexps.  You can mix both in the same array.
            # Globs are matched using the method File.fnmatch.
            configatron.ignore_rules = %w(.git, 
                                          .bzr,
                                          .svn,
                                          .DS_Store)
            EOM
      end
      puts 
      puts "Okay then."
      puts "#{config_file} template created, but it needs to be customized."
      exit
    elsif ans == "n" || ans == "no"
      exit
    end
  end
end

.find_source_directories(path) ⇒ Object

Return an array of mnts that are installing to path.



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# File 'lib/sundae.rb', line 383

def self.find_source_directories(path)
  sources = Array.new
  all_mnts.each do |mnt|
    install_location = File.expand_path(install_location(mnt))
    if path.include?(install_location)
      relative_path =  path.sub(Regexp.new(install_location), "")
      sources << mnt if File.exist?(File.join(mnt, relative_path))
    end
  end
  return sources
end

.find_static_file(directory) ⇒ Object

Search through directory and return the first static file found, nil otherwise.



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# File 'lib/sundae.rb', line 203

def self.find_static_file(directory)
  directory = Pathname.new(directory).expand_path

  directory.find do |path|
    return path if path.exist? && path.ftype == 'file' 
  end
  return nil
end

.generated_directories ⇒ Object

Return all subdirectories of the mnts returned by all_mnts. These are the ‘mirror’ directories that are generated by sundae.



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# File 'lib/sundae.rb', line 180

def self.generated_directories 
  generated_files.select {|f| f.directory?} 
end

.generated_files ⇒ Object

Return all subdirectories and files in the mnts returned by all_mnts. These are the ‘mirror’ files and directories that are generated by sundae.



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# File 'lib/sundae.rb', line 164

def self.generated_files
  dirs = Array.new

  all_mnts.each do |mnt|
    mnt_dirs = mnt.children(false).delete_if { |e| ignore_file?(e) }
    mnt_dirs.each do |dir|
      dirs << (install_location(mnt) + dir)
    end
  end

  return dirs.sort.uniq#.select { |d| d.directory? }
end

.ignore_file?(file) ⇒ Boolean

Use the array of Regexp to see if a certain file should be ignored (i.e., no link will be made pointing to it).

Returns:

  • (Boolean) 


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# File 'lib/sundae.rb', line 89

def self.ignore_file?(file) # :doc:
  file = Pathname.new(file)
  basename = file.basename.to_s
  return true if basename =~ /^\.\.?$/
  return true if basename == ".sundae_path"
  @ignore_rules.each do |r| 
    if r.kind_of? Regexp
      return true if basename =~ r 
    else
      return true if file.fnmatch(r)
    end
  end
  return false
end

.install_location(mnt) ⇒ Object

Read the .sundae_path file in the root of a mnt to see where in the file system links should be created for this mnt.



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# File 'lib/sundae.rb', line 107

def self.install_location(mnt) 
  mnt = Pathname.new(mnt).expand_path
  mnt_config = mnt + '.sundae_path'
  if mnt_config.exist?
    return Pathname.new(mnt_config.readlines[0].strip).expand_path
  end

  base = mnt.basename.to_s
  match = (/dot[-_](.*)/).match(base)
  if match
    return Pathname.new(Dir.home) + ('.' + match[1])
  end

  return Pathname.new(Dir.home)
end

.install_locations ⇒ Object

Return an array of all paths in the file system where links will be created.



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# File 'lib/sundae.rb', line 126

def self.install_locations 
  all_mnts.map { |m| install_location(m) }.sort.uniq
end

.load_config_file(config_file = DEFAULT_CONFIG_FILE) ⇒ Object

Read configuration from .sundae.



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# File 'lib/sundae.rb', line 31

def self.load_config_file(config_file = DEFAULT_CONFIG_FILE)
  config_file ||= DEFAULT_CONFIG_FILE # if nil is passed
  config_file = Pathname.new(config_file).expand_path
  config_file += '.sundae' if config_file.directory?

  create_template_config_file(config_file) unless config_file.file?

  load(config_file)
  configatron.paths.map! { |p| Pathname.new(p).expand_path }

  # An array which lists the directories where mnts are stored.
  @paths = configatron.paths
  # These are the rules that are checked to see if a file in a mnt
  # should be ignored.
  @ignore_rules = configatron.ignore_rules
end

.minimally_create_links(target, link_path) ⇒ Object

For each directory and file in target, create a link at link_name. If there is currently no file at link_path, create a symbolic link there. If there is currently a symbolic link, combine the contents at the link location and target in a new directory and proceed recursively.



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# File 'lib/sundae.rb', line 265

def self.minimally_create_links(target, link_path) 
  target = File.expand_path(target)
  link_path = File.expand_path(link_path)

  unless File.exist?(target)
    raise "attempt to create links from missing directory: " + target
  end

  Find.find(target) do |path|
    next if path == target
    Find.prune if ignore_file?(File.basename(path))

    rel_path = path.gsub(target, '')
    link_name = File.join(link_path, rel_path)
    create_link(path, link_name)

    Find.prune if File.directory?(path) 
  end
end

.mnts_in_path(path) ⇒ Object

Given path, return all mnts (i.e., directories two levels down) as an array.



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# File 'lib/sundae.rb', line 133

def self.mnts_in_path(path) 
  Pathname.new(path).expand_path
  mnts = []
  collections = path.children(false).delete_if {|c| c.to_s =~ /^\./}

  collections.each do |c|
    collection_mnts = (path + c).children(false).delete_if {|kid| kid.to_s =~ /^\./}
    collection_mnts.map! { |mnt| (c + mnt) }

    mnts |= collection_mnts # |= is the union
  end

  return mnts.sort.uniq
end

.move_to_mnt(path, mnt) ⇒ Object

Move the file at path (or its target in the case of a link) to mnt preserving relative path.



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# File 'lib/sundae.rb', line 398

def self.move_to_mnt(path, mnt)
  if File.symlink?(path)
    to_move = File.readlink(path)
    current = Sundae.find_source_directories(path)[0]
    relative_path = to_move.sub(Regexp.new(current), "")
    FileUtils.mv(to_move, mnt + relative_path) unless current == mnt
    FileUtils.ln_sf(mnt + relative_path, path)
  else
    location = Sundae.install_location(mnt)
    relative_path = path.sub(Regexp.new(location), "")
    FileUtils.mv(path, mnt + relative_path) unless path == mnt + relative_path
    FileUtils.ln_s(mnt + relative_path, path)
  end
end

.move_to_relative_path(link, relative_path) ⇒ Object

Move the target at link according to relative_path.

Raises:

  • (ArgumentError) 


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# File 'lib/sundae.rb', line 415

def self.move_to_relative_path(link, relative_path)
  raise ArgumentError, "#{link} is not a link." unless File.symlink?(link)

  target = File.readlink(link)

  pwd = FileUtils.pwd
  mnt = Sundae.find_source_directories(link)[0]
  mnt_pwd = File.join(mnt, pwd.sub(Regexp.new(install_location(mnt)), ""))

  if File.directory?(relative_path)
    new_target_path = File.join(mnt_pwd, relative_path, File.basename(link))
    new_link_path   = File.join(pwd,     relative_path, File.basename(link))
  else
    new_target_path = File.join(mnt_pwd, relative_path)
    new_link_path   = File.join(pwd,     relative_path)   
  end

  target          = File.expand_path(target)
  new_target_path = File.expand_path(new_target_path)
  new_link_path   = File.expand_path(new_link_path)

  raise ArgumentError, "#{link} and #{new_target_path} are the same file" if target == new_target_path
  FileUtils.mkdir_p(File.dirname(new_target_path))
  FileUtils.mv(target, new_target_path)
  FileUtils.rm(link)
  FileUtils.ln_s(new_target_path, new_link_path)
end

.remove_dead_links ⇒ Object

Check for symlinks in the base directories that are missing their targets.



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# File 'lib/sundae.rb', line 187

def self.remove_dead_links
  install_locations.each do |location|
    next unless location.exist?
    files = location.entries.map { |f| location + f }
    files.each do |file|
      next unless file.symlink?
      next if file.readlink.exist?
      next unless root_path(file.readlink)
      file.delete 
    end
  end
end

.remove_filesystem ⇒ Object 



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# File 'lib/sundae.rb', line 376

def self.remove_filesystem
  remove_dead_links
  remove_generated_files
end

.remove_generated_directories ⇒ Object

Delete each generated directory if there aren’t any real files in them.



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# File 'lib/sundae.rb', line 215

def self.remove_generated_directories
  generated_directories.each do |dir| 
    # don't get rid of the linked config file
    next if dir.basename.to_s == '.sundae' 
    remove_generated_stuff dir

    # if sf = find_static_file(dir)
    #   puts "found static file: #{sf}"
    # else
    #   dir.rmtree
    # end
  end
end

.remove_generated_files ⇒ Object 



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# File 'lib/sundae.rb', line 229

def self.remove_generated_files
  generated_files.each do |fod| 
    # don't get rid of the linked config file
    next if fod.basename.to_s == '.sundae' 
    remove_generated_stuff fod
  end
end

.remove_generated_stuff(fod) ⇒ Object 



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# File 'lib/sundae.rb', line 237

def self.remove_generated_stuff(fod)
  return unless fod.exist?
  if fod.ftype == 'directory'
    fod.each_child do |c|
      remove_generated_stuff c
    end
    fod.rmdir if fod.children.empty?
  else
    return unless fod.symlink?
    fod.delete if root_path(fod.readlink) # try to only delete sundae links
  end
end

.root_path(path) ⇒ Object

Starting at dir, walk up the directory hierarchy and return the directory that is contained in _@paths_.



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# File 'lib/sundae.rb', line 288

def self.root_path(path)
  path = Pathname.new(path).expand_path
  last = path
  path.ascend do |v|
    return last if @paths.include? v
    last = v
  end

  return nil
end

.update_filesystem ⇒ Object 



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# File 'lib/sundae.rb', line 370

def self.update_filesystem
  remove_dead_links
  remove_generated_files
  create_filesystem
end