Class: Walrus::Runner

Inherits:
Object
  • Object
show all
Defined in:
lib/walrus/runner.rb

Defined Under Namespace

Classes: ArgumentError, Error

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Runner

Returns a new instance of Runner.

Raises:



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# File 'lib/walrus/runner.rb', line 39

def initialize
  @options = OpenStruct.new
  @options.output_dir         = nil
  @options.input_extension    = 'tmpl'
  @options.output_extension   = ''
  @options.recurse            = true
  @options.backup             = true
  @options.force              = false
  @options.debug              = false
  @options.halt               = false
  @options.dry                = false
  @options.verbose            = false

  @command  = nil # "compile", "fill" (saves to disk), "run" (prints to standard out)
  @inputs   = []  # list of input files and/or directories
  parser    = OptionParser.new do |o|
    o.banner  = "Usage: #{o.program_name} command input-file(s)-or-directory/ies [options]"
    o.separator ''
    o.separator "          ___"
    o.separator "       .-9 9 `\\           #{o.program_name} version #{Walrus::VERSION}"
    o.separator "     =(:(::)=  ;          Command-line front-end for the Walrus templating system"
    o.separator "       ||||     \\         #{Walrus::COPYRIGHT}"
    o.separator "       ||||      `-."
    o.separator "      ,\\|\\|         `,"
    o.separator "     /                \\"
    o.separator "    ;                  `'---.,"
    o.separator "    |                         `\\"
    o.separator "    ;                     /     |"
    o.separator "    \\                    |      /"
    o.separator "     )           \\  __,.--\\    /"
    o.separator "  .-' \\,..._\\     \\`   .-'  .-'"
    o.separator " `-=``       `:    |  /-/-/`"
    o.separator "               `.__/           jgs"
    o.separator ''
    o.separator 'Commands: compile -- compile templates to Ruby code'
    o.separator '          fill    -- runs compiled templates, writing output to disk'
    o.separator '          run     -- runs compiled templates, printing output to standard output'
    o.separator ''

    o.on('-o', '--output-dir DIR', 'Output directory (when filling)', 'defaults to same directory as input file') do |opt|
      @options.output_dir = Pathname.new(opt)
    end

    o.on('-i', '--input-extension EXT', 'Extension for input file(s)', 'default: tmpl') do |opt|
      @options.input_extension = opt
    end

    o.on('-e', '--output-extension EXT', 'Extension for output file(s) (when filling)', 'default: none') do |opt|
      @options.output_extension = opt
    end

    o.on('-R', 'Search subdirectories recursively for input files', 'default: on') do |opt|
      @options.recurse = opts
    end

    o.on('-b', '--[no-]backup', 'Make backups before overwriting', 'default: on') do |opt|
      @options.backup = opt
    end

    o.on('-f', '--force', 'Force a recompile (when filling)', 'default: off (files only recompiled if source newer than output)') do |opt|
      @options.force = opt
    end

    o.on('--halt', 'Halts on encountering an error (even a non-fatal error)', 'default: off') do |opt|
      @options.halt = opt
    end

    o.on('-t', '--test', 'Performs a "dry" (test) run', 'default: off') do |opt|
      @options.dry = opt
    end

    o.on('-d', '--debug', 'Print debugging information to standard error', 'default: off') do |opt|
      @options.debug = opt
    end

    o.on('-v', '--verbose', 'Run verbosely', 'default: off') do |opt|
      @options.verbose = opt
    end

    o.separator ''

    o.on_tail('-h', '--help', 'Show this message') do
      $stderr.puts o
      exit
    end

    o.on_tail('--version', 'Show version') do
      $stderr.puts 'Walrus ' + Walrus::VERSION
      exit
    end
  end

  begin
    parser.parse!
  rescue OptionParser::InvalidOption => e
    raise ArgumentError.new(e)
  end

  parser.order! do |item|
    if @command.nil?
      @command = item               # get command first ("compile", "fill" or "run")
    else
      @inputs << Pathname.new(item) # all others (and there must be at least one) are file or directory names
    end
  end

  raise ArgumentError.new('no command specified') if @command.nil?
  raise ArgumentError.new('no inputs specified') unless @inputs.length > 0
end

Instance Method Details

#adjusted_output_path(path) ⇒ Object 



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# File 'lib/walrus/runner.rb', line 297

def adjusted_output_path(path)
  if @options.output_dir
    if path.absolute?
      path = @options.output_dir + path.to_s.sub(/\A\//, '')
    else
      path = @options.output_dir + path
    end
  else
    path
  end
end

#compile(input, force = true) ⇒ Object 



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# File 'lib/walrus/runner.rb', line 220

def compile(input, force = true)
  template_source_path  = template_source_path_for_input(input)
  compiled_path         = compiled_source_path_for_input(input)
  if force or @options.force or not compiled_path.exist? or compiled_path_older_than_source_path(compiled_path, template_source_path)
    begin
      template = Template.new(template_source_path)
    rescue Exception => e
      handle_error("failed to read input template '#{template_source_path}' (#{e.to_s})")
      return
    end

    begin
      compiled = template.compile
    rescue Walrat::ParseError => e
      handle_error("failed to compile input template '#{template_source_path}' (#{e.to_s})")
      return
    end

    write_string_to_path(compiled, compiled_path, true)
  end
end

#compile_if_needed(input) ⇒ Object 



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# File 'lib/walrus/runner.rb', line 206

def compile_if_needed(input)
  compile(input, false)
end

#compiled_path_older_than_source_path(compiled_path, source_path) ⇒ Object 



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# File 'lib/walrus/runner.rb', line 210

def compiled_path_older_than_source_path(compiled_path, source_path)
  begin
    compiled  = File.mtime(compiled_path)
    source    = File.mtime(source_path)
  rescue SystemCallError # perhaps one of them doesn't exist
    return true
  end
  compiled < source
end

#compiled_source_path_for_input(input) ⇒ Object 



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# File 'lib/walrus/runner.rb', line 319

def compiled_source_path_for_input(input)
  # remove input extension if present
  if input.extname == ".#{@options.input_extension}" and @options.input_extension.length > 0
    dir, base = input.split
    input = dir + base.basename(base.extname)
  end

  # add rb as an extension
  dir, base = input.split
  dir + "#{base.to_s}.rb"
end

#expand(inputs) ⇒ Object

Expects an array of Pathname objects. Directory inputs are themselves recursively expanded if the “recurse” option is set to true; otherwise only their top-level entries are expanded. Returns an expanded array of Pathname objects.



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# File 'lib/walrus/runner.rb', line 186

def expand(inputs)
  expanded = []
  inputs.each do |input|
    if input.directory?
      input.entries.each do |entry|
        if entry.directory?
          if @options.recurse
            expanded.concat expand(entry.entries)
          end
        else # not a directory
          expanded << entry
        end
      end
    else # not a directory
      expanded << input
    end
  end
  expanded
end

#filled_output_path_for_input(input) ⇒ Object 



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# File 'lib/walrus/runner.rb', line 331

def filled_output_path_for_input(input)
  # remove input extension if present
  if input.extname == ".#{@options.input_extension}" and @options.input_extension.length > 0
    dir, base = input.split
    input = dir + base.basename(base.extname)
  end

  # add output extension if appropriate
  if @options.output_extension.length > 0
    dir, base = input.split
    adjusted_output_path(dir + "#{base.to_s}.#{@options.output_extension}")
  else
    adjusted_output_path(input)
  end
end

#get_output(input) ⇒ Object 



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# File 'lib/walrus/runner.rb', line 242

def get_output(input)
  if @options.dry
    "(no output: dry run)\n"
  else
    # use Wopen3 (backticks choke if there is a space in the path, open3 throws away the exit status)
    output = ''
    Wopen3.popen3([compiled_source_path_for_input(input).realpath, '']) do |stdin, stdout, stderr|
      threads = []
      threads << Thread.new(stdout) do |out|
        out.each { |line| output << line }
      end
      threads << Thread.new(stderr) do |err|
        err.each { |line| STDERR.puts line }
      end
      threads.each { |thread| thread.join }
    end
    status = $?.exitstatus
    raise SystemCallError.new("non-zero exit status (#{status})") if status != 0
    output
  end
end

#run ⇒ Object 



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# File 'lib/walrus/runner.rb', line 149

def run
  log "Beginning processing: #{Time.new.to_s}."

  # TODO: flush memoizing cache after each file

  expand(@inputs).each do |input|
    case @command
    when 'compile'
      log "Compiling '#{input}'."
      compile(input)
    when 'fill'
      log "Filling '#{input}'."
      compile_if_needed(input)
      begin
        write_string_to_path(get_output(input), filled_output_path_for_input(input))
      rescue Exception => e
        handle_error(e)
      end
    when 'run'
      log "Running '#{input}'."
      compile_if_needed(input)
      begin
        printf('%s', get_output(input))
        $stdout.flush
      rescue Exception => e
        handle_error(e)
      end
    else
      raise ArgumentError.new("unrecognized command '#{@command}'")
    end
  end
  log "Processing complete: #{Time.new.to_s}."
end

#template_source_path_for_input(input) ⇒ Object

If “input” already has the right extension it is returned unchanged. If the “input extension” is zero-length then “input” is returned unchanged. Otherwise the “input extension” is added to “input” and returned.



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# File 'lib/walrus/runner.rb', line 312

def template_source_path_for_input(input)
  return input if input.extname == ".#{@options.input_extension}" # input already has the right extension
  return input if @options.input_extension.length == 0            # zero-length extension, nothing to add
  dir, base = input.split
  dir + "#{base.to_s}.#{@options.input_extension}"                # otherwise, add extension and return
end

#write_string_to_path(string, path, executable = false) ⇒ Object 



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# File 'lib/walrus/runner.rb', line 264

def write_string_to_path(string, path, executable = false)
  if @options.dry
    log "Would write '#{path}' (dry run)."
  else
    unless path.dirname.exist?
      begin
        log "Creating directory '#{path.dirname}'."
        FileUtils.mkdir_p path.dirname
      rescue SystemCallError => e
        handle_error(e)
        return
      end
    end

    log "Writing '#{path}'."
    begin
      File.open(path, "a+") do |f|
        if not File.zero? path and @options.backup
          log "Making backup of existing file at '#{path}'."
          dir, base = path.split
          FileUtils.cp path, dir + "#{base.to_s}.bak"
        end
        f.flock File::LOCK_EX
        f.truncate 0
        f.write string
        f.chmod 0744 if executable
      end
    rescue SystemCallError => e
      handle_error(e)
    end
  end
end