Bundling of pure ruby json lib as "pson"

Bundeling and renaming the pure ruby json library to addresses a
number of cross version serliaization bugs (#2615, et al).

This patch adds a subset of the files from the json_pure gem to
lib/puppet/external/pson (renamed to avoid conflicts with rails) so
that we will always have a known-good erialization format available.

The pure ruby json gem as distibuted defers to the compiled version
if it is installed.  This is problematic in some circumstances so the
files that have been brought over have been modified to always and
only use the bundled version.

It's a large patch, so here's a breakdown of the change categories:

The majority of the lines are only marginally interesting:

* The json lib itself (in lib/puppet/external/pson) make up the bulk
  of the lines.
* Renaming of json to pson make up the second largest group.

Somewhat more interesting are the following, which can be located by
searching the diffs for the indicated strings:

* Adjusting tests to reflect the changes
* Changing the encoding/decoding behavior so that nested structures
  (e.g. resources) don't serialize as escaped strings.  This should
  make it much easier to process the results with external tools, if
  needed.  Search for "to_pson" and "to_pson_data_hash"
* Cleaning up the envelope/metadata
    * Now provides a document_type (as opposed to a ruby class name) by
      using a symple registration scheme instead of constant lookup
      (search for "document_type")
    * Added an api_version (search for "api_version")
    * Added a hash for document metadata (search for "metadata")
* Removing the yaml monkeypatch and instead disabling yaml serialization
  on ruby 1.8.1 in favor of pson (search for "yaml")
* Cleaning up the json/rails feature interaction (they're now totally
  independent) (search for "feature")

5 files changed, 1150 insertions, 0 deletions

diff --git a/lib/puppet/external/pson/common.rb b/lib/puppet/external/pson/common.rb
new file mode 100644
index 000000000..71b85ce54
--- /dev/null
+++ b/lib/puppet/external/pson/common.rb
@@ -0,0 +1,367 @@
+require 'puppet/external/pson/version'
+
+module PSON
+  class << self
+    # If _object_ is string-like parse the string and return the parsed result
+    # as a Ruby data structure. Otherwise generate a PSON text from the Ruby
+    # data structure object and return it.
+    #
+    # The _opts_ argument is passed through to generate/parse respectively, see
+    # generate and parse for their documentation.
+    def [](object, opts = {})
+      if object.respond_to? :to_str
+        PSON.parse(object.to_str, opts => {})
+      else
+        PSON.generate(object, opts => {})
+      end
+    end
+
+    # Returns the PSON parser class, that is used by PSON. This might be either
+    # PSON::Ext::Parser or PSON::Pure::Parser.
+    attr_reader :parser
+
+    # Set the PSON parser class _parser_ to be used by PSON.
+    def parser=(parser) # :nodoc:
+      @parser = parser
+      remove_const :Parser if const_defined? :Parser
+      const_set :Parser, parser
+    end
+
+    def registered_document_types
+        @registered_document_types ||= {}
+    end
+
+    # Register a class-constant for deserializaion.
+    def register_document_type(name,klass)
+        registered_document_types[name.to_s] = klass        
+    end
+
+    # Return the constant located at _path_. 
+    # Anything may be registered as a path by calling register_path, above.
+    # Otherwise, the format of _path_ has to be either ::A::B::C or A::B::C. 
+    # In either of these cases A has to be defined in Object (e.g. the path
+    # must be an absolute namespace path.  If the constant doesn't exist at
+    # the given path, an ArgumentError is raised.
+    def deep_const_get(path) # :nodoc:
+      path = path.to_s
+      registered_document_types[path] || path.split(/::/).inject(Object) do |p, c|
+        case
+        when c.empty?             then p
+        when p.const_defined?(c)  then p.const_get(c)
+        else                      raise ArgumentError, "can't find const #{path}"
+        end
+      end
+    end
+
+    # Set the module _generator_ to be used by PSON.
+    def generator=(generator) # :nodoc:
+      @generator = generator
+      generator_methods = generator::GeneratorMethods
+      for const in generator_methods.constants
+        klass = deep_const_get(const)
+        modul = generator_methods.const_get(const)
+        klass.class_eval do
+          instance_methods(false).each do |m|
+            m.to_s == 'to_pson' and remove_method m
+          end
+          include modul
+        end
+      end
+      self.state = generator::State
+      const_set :State, self.state
+    end
+
+    # Returns the PSON generator modul, that is used by PSON. This might be
+    # either PSON::Ext::Generator or PSON::Pure::Generator.
+    attr_reader :generator
+
+    # Returns the PSON generator state class, that is used by PSON. This might
+    # be either PSON::Ext::Generator::State or PSON::Pure::Generator::State.
+    attr_accessor :state
+
+    # This is create identifier, that is used to decide, if the _pson_create_
+    # hook of a class should be called. It defaults to 'document_type'.
+    attr_accessor :create_id
+  end
+  self.create_id = 'document_type'
+
+  NaN           = (-1.0) ** 0.5
+
+  Infinity      = 1.0/0
+
+  MinusInfinity = -Infinity
+
+  # The base exception for PSON errors.
+  class PSONError < StandardError; end
+
+  # This exception is raised, if a parser error occurs.
+  class ParserError < PSONError; end
+
+  # This exception is raised, if the nesting of parsed datastructures is too
+  # deep.
+  class NestingError < ParserError; end
+
+  # This exception is raised, if a generator or unparser error occurs.
+  class GeneratorError < PSONError; end
+  # For backwards compatibility
+  UnparserError = GeneratorError
+
+  # If a circular data structure is encountered while unparsing
+  # this exception is raised.
+  class CircularDatastructure < GeneratorError; end
+
+  # This exception is raised, if the required unicode support is missing on the
+  # system. Usually this means, that the iconv library is not installed.
+  class MissingUnicodeSupport < PSONError; end
+
+  module_function
+
+  # Parse the PSON string _source_ into a Ruby data structure and return it.
+  #
+  # _opts_ can have the following
+  # keys:
+  # * *max_nesting*: The maximum depth of nesting allowed in the parsed data
+  #   structures. Disable depth checking with :max_nesting => false, it defaults
+  #   to 19.
+  # * *allow_nan*: If set to true, allow NaN, Infinity and -Infinity in
+  #   defiance of RFC 4627 to be parsed by the Parser. This option defaults
+  #   to false.
+  # * *create_additions*: If set to false, the Parser doesn't create
+  #   additions even if a matchin class and create_id was found. This option
+  #   defaults to true.
+  def parse(source, opts = {})
+    PSON.parser.new(source, opts).parse
+  end
+
+  # Parse the PSON string _source_ into a Ruby data structure and return it.
+  # The bang version of the parse method, defaults to the more dangerous values
+  # for the _opts_ hash, so be sure only to parse trusted _source_ strings.
+  #
+  # _opts_ can have the following keys:
+  # * *max_nesting*: The maximum depth of nesting allowed in the parsed data
+  #   structures. Enable depth checking with :max_nesting => anInteger. The parse!
+  #   methods defaults to not doing max depth checking: This can be dangerous,
+  #   if someone wants to fill up your stack.
+  # * *allow_nan*: If set to true, allow NaN, Infinity, and -Infinity in
+  #   defiance of RFC 4627 to be parsed by the Parser. This option defaults
+  #   to true.
+  # * *create_additions*: If set to false, the Parser doesn't create
+  #   additions even if a matchin class and create_id was found. This option
+  #   defaults to true.
+  def parse!(source, opts = {})
+    opts = {
+      :max_nesting => false,
+      :allow_nan => true
+    }.update(opts)
+    PSON.parser.new(source, opts).parse
+  end
+
+  # Unparse the Ruby data structure _obj_ into a single line PSON string and
+  # return it. _state_ is
+  # * a PSON::State object,
+  # * or a Hash like object (responding to to_hash),
+  # * an object convertible into a hash by a to_h method,
+  # that is used as or to configure a State object.
+  #
+  # It defaults to a state object, that creates the shortest possible PSON text
+  # in one line, checks for circular data structures and doesn't allow NaN,
+  # Infinity, and -Infinity.
+  #
+  # A _state_ hash can have the following keys:
+  # * *indent*: a string used to indent levels (default: ''),
+  # * *space*: a string that is put after, a : or , delimiter (default: ''),
+  # * *space_before*: a string that is put before a : pair delimiter (default: ''),
+  # * *object_nl*: a string that is put at the end of a PSON object (default: ''), 
+  # * *array_nl*: a string that is put at the end of a PSON array (default: ''),
+  # * *check_circular*: true if checking for circular data structures
+  #   should be done (the default), false otherwise.
+  # * *allow_nan*: true if NaN, Infinity, and -Infinity should be
+  #   generated, otherwise an exception is thrown, if these values are
+  #   encountered. This options defaults to false.
+  # * *max_nesting*: The maximum depth of nesting allowed in the data
+  #   structures from which PSON is to be generated. Disable depth checking
+  #   with :max_nesting => false, it defaults to 19.
+  #
+  # See also the fast_generate for the fastest creation method with the least
+  # amount of sanity checks, and the pretty_generate method for some
+  # defaults for a pretty output.
+  def generate(obj, state = nil)
+    if state
+      state = State.from_state(state)
+    else
+      state = State.new
+    end
+    obj.to_pson(state)
+  end
+
+  # :stopdoc:
+  # I want to deprecate these later, so I'll first be silent about them, and
+  # later delete them.
+  alias unparse generate
+  module_function :unparse
+  # :startdoc:
+
+  # Unparse the Ruby data structure _obj_ into a single line PSON string and
+  # return it. This method disables the checks for circles in Ruby objects, and
+  # also generates NaN, Infinity, and, -Infinity float values.
+  #
+  # *WARNING*: Be careful not to pass any Ruby data structures with circles as
+  # _obj_ argument, because this will cause PSON to go into an infinite loop.
+  def fast_generate(obj)
+    obj.to_pson(nil)
+  end
+
+  # :stopdoc:
+  # I want to deprecate these later, so I'll first be silent about them, and later delete them.
+  alias fast_unparse fast_generate
+  module_function :fast_unparse
+  # :startdoc:
+
+  # Unparse the Ruby data structure _obj_ into a PSON string and return it. The
+  # returned string is a prettier form of the string returned by #unparse.
+  #
+  # The _opts_ argument can be used to configure the generator, see the
+  # generate method for a more detailed explanation.
+  def pretty_generate(obj, opts = nil)
+    state = PSON.state.new(
+      :indent     => '  ',
+      :space      => ' ',
+      :object_nl  => "\n",
+      :array_nl   => "\n",
+      :check_circular => true
+    )
+    if opts
+      if opts.respond_to? :to_hash
+        opts = opts.to_hash
+      elsif opts.respond_to? :to_h
+        opts = opts.to_h
+      else
+        raise TypeError, "can't convert #{opts.class} into Hash"
+      end
+      state.configure(opts)
+    end
+    obj.to_pson(state)
+  end
+
+  # :stopdoc:
+  # I want to deprecate these later, so I'll first be silent about them, and later delete them.
+  alias pretty_unparse pretty_generate
+  module_function :pretty_unparse
+  # :startdoc:
+
+  # Load a ruby data structure from a PSON _source_ and return it. A source can
+  # either be a string-like object, an IO like object, or an object responding
+  # to the read method. If _proc_ was given, it will be called with any nested
+  # Ruby object as an argument recursively in depth first order.
+  #
+  # This method is part of the implementation of the load/dump interface of
+  # Marshal and YAML.
+  def load(source, proc = nil)
+    if source.respond_to? :to_str
+      source = source.to_str
+    elsif source.respond_to? :to_io
+      source = source.to_io.read
+    else
+      source = source.read
+    end
+    result = parse(source, :max_nesting => false, :allow_nan => true)
+    recurse_proc(result, &proc) if proc
+    result
+  end
+
+  def recurse_proc(result, &proc)
+    case result
+    when Array
+      result.each { |x| recurse_proc x, &proc }
+      proc.call result
+    when Hash
+      result.each { |x, y| recurse_proc x, &proc; recurse_proc y, &proc }
+      proc.call result
+    else
+      proc.call result
+    end
+  end
+  private :recurse_proc
+  module_function :recurse_proc
+
+  alias restore load
+  module_function :restore
+
+  # Dumps _obj_ as a PSON string, i.e. calls generate on the object and returns
+  # the result.
+  #
+  # If anIO (an IO like object or an object that responds to the write method)
+  # was given, the resulting PSON is written to it.
+  #
+  # If the number of nested arrays or objects exceeds _limit_ an ArgumentError
+  # exception is raised. This argument is similar (but not exactly the
+  # same!) to the _limit_ argument in Marshal.dump.
+  #
+  # This method is part of the implementation of the load/dump interface of
+  # Marshal and YAML.
+  def dump(obj, anIO = nil, limit = nil)
+    if anIO and limit.nil?
+      anIO = anIO.to_io if anIO.respond_to?(:to_io)
+      unless anIO.respond_to?(:write)
+        limit = anIO
+        anIO = nil
+      end
+    end
+    limit ||= 0
+    result = generate(obj, :allow_nan => true, :max_nesting => limit)
+    if anIO
+      anIO.write result
+      anIO
+    else
+      result
+    end
+  rescue PSON::NestingError
+    raise ArgumentError, "exceed depth limit"
+  end
+end
+
+module ::Kernel
+  private
+
+  # Outputs _objs_ to STDOUT as PSON strings in the shortest form, that is in
+  # one line.
+  def j(*objs)
+    objs.each do |obj|
+      puts PSON::generate(obj, :allow_nan => true, :max_nesting => false)
+    end
+    nil
+  end
+
+  # Ouputs _objs_ to STDOUT as PSON strings in a pretty format, with
+  # indentation and over many lines.
+  def jj(*objs)
+    objs.each do |obj|
+      puts PSON::pretty_generate(obj, :allow_nan => true, :max_nesting => false)
+    end
+    nil
+  end
+
+  # If _object_ is string-like parse the string and return the parsed result as
+  # a Ruby data structure. Otherwise generate a PSON text from the Ruby data
+  # structure object and return it.
+  #
+  # The _opts_ argument is passed through to generate/parse respectively, see
+  # generate and parse for their documentation.
+  def PSON(object, opts = {})
+    if object.respond_to? :to_str
+      PSON.parse(object.to_str, opts)
+    else
+      PSON.generate(object, opts)
+    end
+  end
+end
+
+class ::Class
+  # Returns true, if this class can be used to create an instance
+  # from a serialised PSON string. The class has to implement a class
+  # method _pson_create_ that expects a hash as first parameter, which includes
+  # the required data.
+  def pson_creatable?
+    respond_to?(:pson_create)
+  end
+end
diff --git a/lib/puppet/external/pson/pure.rb b/lib/puppet/external/pson/pure.rb
new file mode 100644
index 000000000..43f39b2a6
--- /dev/null
+++ b/lib/puppet/external/pson/pure.rb
@@ -0,0 +1,77 @@
+require 'puppet/external/pson/common'
+require 'puppet/external/pson/pure/parser'
+require 'puppet/external/pson/pure/generator'
+
+module PSON
+  begin
+    require 'iconv'
+    # An iconv instance to convert from UTF8 to UTF16 Big Endian.
+    UTF16toUTF8 = Iconv.new('utf-8', 'utf-16be') # :nodoc:
+    # An iconv instance to convert from UTF16 Big Endian to UTF8.
+    UTF8toUTF16 = Iconv.new('utf-16be', 'utf-8') # :nodoc:
+    UTF8toUTF16.iconv('no bom')
+  rescue LoadError
+    raise MissingUnicodeSupport,
+      "iconv couldn't be loaded, which is required for UTF-8/UTF-16 conversions"
+  rescue Errno::EINVAL, Iconv::InvalidEncoding
+    # Iconv doesn't support big endian utf-16. Let's try to hack this manually
+    # into the converters.
+    begin
+      old_verbose, $VERBSOSE = $VERBOSE, nil
+      # An iconv instance to convert from UTF8 to UTF16 Big Endian.
+      UTF16toUTF8 = Iconv.new('utf-8', 'utf-16') # :nodoc:
+      # An iconv instance to convert from UTF16 Big Endian to UTF8.
+      UTF8toUTF16 = Iconv.new('utf-16', 'utf-8') # :nodoc:
+      UTF8toUTF16.iconv('no bom')
+      if UTF8toUTF16.iconv("\xe2\x82\xac") == "\xac\x20"
+        swapper = Class.new do
+          def initialize(iconv) # :nodoc:
+            @iconv = iconv
+          end
+
+          def iconv(string) # :nodoc:
+            result = @iconv.iconv(string)
+            PSON.swap!(result)
+          end
+        end
+        UTF8toUTF16 = swapper.new(UTF8toUTF16) # :nodoc:
+      end
+      if UTF16toUTF8.iconv("\xac\x20") == "\xe2\x82\xac"
+        swapper = Class.new do
+          def initialize(iconv) # :nodoc:
+            @iconv = iconv
+          end
+
+          def iconv(string) # :nodoc:
+            string = PSON.swap!(string.dup)
+            @iconv.iconv(string)
+          end
+        end
+        UTF16toUTF8 = swapper.new(UTF16toUTF8) # :nodoc:
+      end
+    rescue Errno::EINVAL, Iconv::InvalidEncoding
+      raise MissingUnicodeSupport, "iconv doesn't seem to support UTF-8/UTF-16 conversions"
+    ensure
+      $VERBOSE = old_verbose
+    end
+  end
+
+  # Swap consecutive bytes of _string_ in place.
+  def self.swap!(string) # :nodoc:
+    0.upto(string.size / 2) do |i|
+      break unless string[2 * i + 1]
+      string[2 * i], string[2 * i + 1] = string[2 * i + 1], string[2 * i]
+    end
+    string
+  end
+
+  # This module holds all the modules/classes that implement PSON's
+  # functionality in pure ruby.
+  module Pure
+    $DEBUG and warn "Using pure library for PSON."
+    PSON.parser = Parser
+    PSON.generator = Generator
+  end
+
+  PSON_LOADED = true
+end
diff --git a/lib/puppet/external/pson/pure/generator.rb b/lib/puppet/external/pson/pure/generator.rb
new file mode 100644
index 000000000..b2a7ddeb5
--- /dev/null
+++ b/lib/puppet/external/pson/pure/generator.rb
@@ -0,0 +1,429 @@
+module PSON
+  MAP = {
+    "\x0" => '\u0000',
+    "\x1" => '\u0001',
+    "\x2" => '\u0002',
+    "\x3" => '\u0003',
+    "\x4" => '\u0004',
+    "\x5" => '\u0005',
+    "\x6" => '\u0006',
+    "\x7" => '\u0007',
+    "\b"  =>  '\b',
+    "\t"  =>  '\t',
+    "\n"  =>  '\n',
+    "\xb" => '\u000b',
+    "\f"  =>  '\f',
+    "\r"  =>  '\r',
+    "\xe" => '\u000e',
+    "\xf" => '\u000f',
+    "\x10" => '\u0010',
+    "\x11" => '\u0011',
+    "\x12" => '\u0012',
+    "\x13" => '\u0013',
+    "\x14" => '\u0014',
+    "\x15" => '\u0015',
+    "\x16" => '\u0016',
+    "\x17" => '\u0017',
+    "\x18" => '\u0018',
+    "\x19" => '\u0019',
+    "\x1a" => '\u001a',
+    "\x1b" => '\u001b',
+    "\x1c" => '\u001c',
+    "\x1d" => '\u001d',
+    "\x1e" => '\u001e',
+    "\x1f" => '\u001f',
+    '"'   =>  '\"',
+    '\\'  =>  '\\\\',
+  } # :nodoc:
+
+  # Convert a UTF8 encoded Ruby string _string_ to a PSON string, encoded with
+  # UTF16 big endian characters as \u????, and return it.
+  if String.method_defined?(:force_encoding)
+    def utf8_to_pson(string) # :nodoc:
+      string = string.dup
+      string << '' # XXX workaround: avoid buffer sharing
+      string.force_encoding(Encoding::ASCII_8BIT)
+      string.gsub!(/["\\\x0-\x1f]/) { MAP[$&] }
+      string.gsub!(/(
+                      (?:
+                        [\xc2-\xdf][\x80-\xbf]    |
+                        [\xe0-\xef][\x80-\xbf]{2} |
+                        [\xf0-\xf4][\x80-\xbf]{3}
+                      )+ |
+                      [\x80-\xc1\xf5-\xff]       # invalid
+                    )/nx) { |c|
+                      c.size == 1 and raise GeneratorError, "invalid utf8 byte: '#{c}'"
+                      s = PSON::UTF8toUTF16.iconv(c).unpack('H*')[0]
+                      s.gsub!(/.{4}/n, '\\\\u\&')
+                    }
+      string.force_encoding(Encoding::UTF_8)
+      string
+    rescue Iconv::Failure => e
+      raise GeneratorError, "Caught #{e.class}: #{e}"
+    end
+  else
+    def utf8_to_pson(string) # :nodoc:
+      string = string.gsub(/["\\\x0-\x1f]/) { MAP[$&] }
+      string.gsub!(/(
+                      (?:
+                        [\xc2-\xdf][\x80-\xbf]    |
+                        [\xe0-\xef][\x80-\xbf]{2} |
+                        [\xf0-\xf4][\x80-\xbf]{3}
+                      )+ |
+                      [\x80-\xc1\xf5-\xff]       # invalid
+                    )/nx) { |c|
+        c.size == 1 and raise GeneratorError, "invalid utf8 byte: '#{c}'"
+        s = PSON::UTF8toUTF16.iconv(c).unpack('H*')[0]
+        s.gsub!(/.{4}/n, '\\\\u\&')
+      }
+      string
+    rescue Iconv::Failure => e
+      raise GeneratorError, "Caught #{e.class}: #{e}"
+    end
+  end
+  module_function :utf8_to_pson
+
+  module Pure
+    module Generator
+      # This class is used to create State instances, that are use to hold data
+      # while generating a PSON text from a a Ruby data structure.
+      class State
+        # Creates a State object from _opts_, which ought to be Hash to create
+        # a new State instance configured by _opts_, something else to create
+        # an unconfigured instance. If _opts_ is a State object, it is just
+        # returned.
+        def self.from_state(opts)
+          case opts
+          when self
+            opts
+          when Hash
+            new(opts)
+          else
+            new
+          end
+        end
+
+        # Instantiates a new State object, configured by _opts_.
+        #
+        # _opts_ can have the following keys:
+        #
+        # * *indent*: a string used to indent levels (default: ''),
+        # * *space*: a string that is put after, a : or , delimiter (default: ''),
+        # * *space_before*: a string that is put before a : pair delimiter (default: ''),
+        # * *object_nl*: a string that is put at the end of a PSON object (default: ''), 
+        # * *array_nl*: a string that is put at the end of a PSON array (default: ''),
+        # * *check_circular*: true if checking for circular data structures
+        #   should be done (the default), false otherwise.
+        # * *check_circular*: true if checking for circular data structures
+        #   should be done, false (the default) otherwise.
+        # * *allow_nan*: true if NaN, Infinity, and -Infinity should be
+        #   generated, otherwise an exception is thrown, if these values are
+        #   encountered. This options defaults to false.
+        def initialize(opts = {})
+          @seen = {}
+          @indent         = ''
+          @space          = ''
+          @space_before   = ''
+          @object_nl      = ''
+          @array_nl       = ''
+          @check_circular = true
+          @allow_nan      = false
+          configure opts
+        end
+
+        # This string is used to indent levels in the PSON text.
+        attr_accessor :indent
+
+        # This string is used to insert a space between the tokens in a PSON
+        # string.
+        attr_accessor :space
+
+        # This string is used to insert a space before the ':' in PSON objects.
+        attr_accessor :space_before
+
+        # This string is put at the end of a line that holds a PSON object (or
+        # Hash).
+        attr_accessor :object_nl
+
+        # This string is put at the end of a line that holds a PSON array.
+        attr_accessor :array_nl
+
+        # This integer returns the maximum level of data structure nesting in
+        # the generated PSON, max_nesting = 0 if no maximum is checked.
+        attr_accessor :max_nesting
+
+        def check_max_nesting(depth) # :nodoc:
+          return if @max_nesting.zero?
+          current_nesting = depth + 1
+          current_nesting > @max_nesting and
+            raise NestingError, "nesting of #{current_nesting} is too deep"
+        end
+
+        # Returns true, if circular data structures should be checked,
+        # otherwise returns false.
+        def check_circular?
+          @check_circular
+        end
+
+        # Returns true if NaN, Infinity, and -Infinity should be considered as
+        # valid PSON and output.
+        def allow_nan?
+          @allow_nan
+        end
+
+        # Returns _true_, if _object_ was already seen during this generating
+        # run. 
+        def seen?(object)
+          @seen.key?(object.__id__)
+        end
+
+        # Remember _object_, to find out if it was already encountered (if a
+        # cyclic data structure is if a cyclic data structure is rendered). 
+        def remember(object)
+          @seen[object.__id__] = true
+        end
+
+        # Forget _object_ for this generating run.
+        def forget(object)
+          @seen.delete object.__id__
+        end
+
+        # Configure this State instance with the Hash _opts_, and return
+        # itself.
+        def configure(opts)
+          @indent         = opts[:indent] if opts.key?(:indent)
+          @space          = opts[:space] if opts.key?(:space)
+          @space_before   = opts[:space_before] if opts.key?(:space_before)
+          @object_nl      = opts[:object_nl] if opts.key?(:object_nl)
+          @array_nl       = opts[:array_nl] if opts.key?(:array_nl)
+          @check_circular = !!opts[:check_circular] if opts.key?(:check_circular)
+          @allow_nan      = !!opts[:allow_nan] if opts.key?(:allow_nan)
+          if !opts.key?(:max_nesting) # defaults to 19
+            @max_nesting = 19
+          elsif opts[:max_nesting]
+            @max_nesting = opts[:max_nesting]
+          else
+            @max_nesting = 0
+          end
+          self
+        end
+
+        # Returns the configuration instance variables as a hash, that can be
+        # passed to the configure method.
+        def to_h
+          result = {}
+          for iv in %w[indent space space_before object_nl array_nl check_circular allow_nan max_nesting]
+            result[iv.intern] = instance_variable_get("@#{iv}")
+          end
+          result
+        end
+      end
+
+      module GeneratorMethods
+        module Object
+          # Converts this object to a string (calling #to_s), converts
+          # it to a PSON string, and returns the result. This is a fallback, if no
+          # special method #to_pson was defined for some object.
+          def to_pson(*) to_s.to_pson end
+        end
+
+        module Hash
+          # Returns a PSON string containing a PSON object, that is unparsed from
+          # this Hash instance.
+          # _state_ is a PSON::State object, that can also be used to configure the
+          # produced PSON string output further.
+          # _depth_ is used to find out nesting depth, to indent accordingly.
+          def to_pson(state = nil, depth = 0, *)
+            if state
+              state = PSON.state.from_state(state)
+              state.check_max_nesting(depth)
+              pson_check_circular(state) { pson_transform(state, depth) }
+            else
+              pson_transform(state, depth)
+            end
+          end
+
+          private
+
+          def pson_check_circular(state)
+            if state and state.check_circular?
+              state.seen?(self) and raise PSON::CircularDatastructure,
+                  "circular data structures not supported!"
+              state.remember self
+            end
+            yield
+          ensure
+            state and state.forget self
+          end
+
+          def pson_shift(state, depth)
+            state and not state.object_nl.empty? or return ''
+            state.indent * depth
+          end
+
+          def pson_transform(state, depth)
+            delim = ','
+            if state
+              delim << state.object_nl
+              result = '{'
+              result << state.object_nl
+              result << map { |key,value|
+                s = pson_shift(state, depth + 1)
+                s << key.to_s.to_pson(state, depth + 1)
+                s << state.space_before
+                s << ':'
+                s << state.space
+                s << value.to_pson(state, depth + 1)
+              }.join(delim)
+              result << state.object_nl
+              result << pson_shift(state, depth)
+              result << '}'
+            else
+              result = '{'
+              result << map { |key,value|
+                key.to_s.to_pson << ':' << value.to_pson
+              }.join(delim)
+              result << '}'
+            end
+            result
+          end
+        end
+
+        module Array
+          # Returns a PSON string containing a PSON array, that is unparsed from
+          # this Array instance.
+          # _state_ is a PSON::State object, that can also be used to configure the
+          # produced PSON string output further.
+          # _depth_ is used to find out nesting depth, to indent accordingly.
+          def to_pson(state = nil, depth = 0, *)
+            if state
+              state = PSON.state.from_state(state)
+              state.check_max_nesting(depth)
+              pson_check_circular(state) { pson_transform(state, depth) }
+            else
+              pson_transform(state, depth)
+            end
+          end
+
+          private
+
+          def pson_check_circular(state)
+            if state and state.check_circular?
+              state.seen?(self) and raise PSON::CircularDatastructure,
+                "circular data structures not supported!"
+              state.remember self
+            end
+            yield
+          ensure
+            state and state.forget self
+          end
+
+          def pson_shift(state, depth)
+            state and not state.array_nl.empty? or return ''
+            state.indent * depth
+          end
+
+          def pson_transform(state, depth)
+            delim = ','
+            if state
+              delim << state.array_nl
+              result = '['
+              result << state.array_nl
+              result << map { |value|
+                pson_shift(state, depth + 1) << value.to_pson(state, depth + 1)
+              }.join(delim)
+              result << state.array_nl
+              result << pson_shift(state, depth) 
+              result << ']'
+            else
+              '[' << map { |value| value.to_pson }.join(delim) << ']'
+            end
+          end
+        end
+
+        module Integer
+          # Returns a PSON string representation for this Integer number.
+          def to_pson(*) to_s end
+        end
+
+        module Float
+          # Returns a PSON string representation for this Float number.
+          def to_pson(state = nil, *)
+            case
+            when infinite?
+              if !state || state.allow_nan?
+                to_s
+              else
+                raise GeneratorError, "#{self} not allowed in PSON"
+              end
+            when nan?
+              if !state || state.allow_nan?
+                to_s
+              else
+                raise GeneratorError, "#{self} not allowed in PSON"
+              end
+            else
+              to_s
+            end
+          end
+        end
+
+        module String
+          # This string should be encoded with UTF-8 A call to this method
+          # returns a PSON string encoded with UTF16 big endian characters as
+          # \u????.
+          def to_pson(*)
+            '"' << PSON.utf8_to_pson(self) << '"'
+          end
+
+          # Module that holds the extinding methods if, the String module is
+          # included.
+          module Extend
+            # Raw Strings are PSON Objects (the raw bytes are stored in an array for the
+            # key "raw"). The Ruby String can be created by this module method.
+            def pson_create(o)
+              o['raw'].pack('C*')
+            end
+          end
+
+          # Extends _modul_ with the String::Extend module.
+          def self.included(modul)
+            modul.extend Extend
+          end
+
+          # This method creates a raw object hash, that can be nested into
+          # other data structures and will be unparsed as a raw string. This
+          # method should be used, if you want to convert raw strings to PSON
+          # instead of UTF-8 strings, e. g. binary data.
+          def to_pson_raw_object
+            {
+              PSON.create_id  => self.class.name,
+              'raw'           => self.unpack('C*'),
+            }
+          end
+
+          # This method creates a PSON text from the result of
+          # a call to to_pson_raw_object of this String.
+          def to_pson_raw(*args)
+            to_pson_raw_object.to_pson(*args)
+          end
+        end
+
+        module TrueClass
+          # Returns a PSON string for true: 'true'.
+          def to_pson(*) 'true' end
+        end
+
+        module FalseClass
+          # Returns a PSON string for false: 'false'.
+          def to_pson(*) 'false' end
+        end
+
+        module NilClass
+          # Returns a PSON string for nil: 'null'.
+          def to_pson(*) 'null' end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/puppet/external/pson/pure/parser.rb b/lib/puppet/external/pson/pure/parser.rb
new file mode 100644
index 000000000..16643ac02
--- /dev/null
+++ b/lib/puppet/external/pson/pure/parser.rb
@@ -0,0 +1,269 @@
+require 'strscan'
+
+module PSON
+  module Pure
+    # This class implements the PSON parser that is used to parse a PSON string
+    # into a Ruby data structure.
+    class Parser < StringScanner
+      STRING                = /" ((?:[^\x0-\x1f"\\] |
+                                   # escaped special characters:
+                                  \\["\\\/bfnrt] |
+                                  \\u[0-9a-fA-F]{4} |
+                                   # match all but escaped special characters:
+                                  \\[\x20-\x21\x23-\x2e\x30-\x5b\x5d-\x61\x63-\x65\x67-\x6d\x6f-\x71\x73\x75-\xff])*)
+                              "/nx
+      INTEGER               = /(-?0|-?[1-9]\d*)/
+      FLOAT                 = /(-?
+                                (?:0|[1-9]\d*)
+                                (?:
+                                  \.\d+(?i:e[+-]?\d+) |
+                                  \.\d+ |
+                                  (?i:e[+-]?\d+)
+                                )
+                                )/x
+      NAN                   = /NaN/
+      INFINITY              = /Infinity/
+      MINUS_INFINITY        = /-Infinity/
+      OBJECT_OPEN           = /\{/
+      OBJECT_CLOSE          = /\}/
+      ARRAY_OPEN            = /\[/
+      ARRAY_CLOSE           = /\]/
+      PAIR_DELIMITER        = /:/
+      COLLECTION_DELIMITER  = /,/
+      TRUE                  = /true/
+      FALSE                 = /false/
+      NULL                  = /null/
+      IGNORE                = %r(
+        (?:
+         //[^\n\r]*[\n\r]| # line comments
+         /\*               # c-style comments
+         (?:
+          [^*/]|        # normal chars
+          /[^*]|        # slashes that do not start a nested comment
+          \*[^/]|       # asterisks that do not end this comment
+          /(?=\*/)      # single slash before this comment's end 
+         )*
+           \*/               # the End of this comment
+           |[ \t\r\n]+       # whitespaces: space, horicontal tab, lf, cr
+        )+
+      )mx
+
+      UNPARSED = Object.new
+
+      # Creates a new PSON::Pure::Parser instance for the string _source_.
+      #
+      # It will be configured by the _opts_ hash. _opts_ can have the following
+      # keys:
+      # * *max_nesting*: The maximum depth of nesting allowed in the parsed data
+      #   structures. Disable depth checking with :max_nesting => false|nil|0,
+      #   it defaults to 19.
+      # * *allow_nan*: If set to true, allow NaN, Infinity and -Infinity in
+      #   defiance of RFC 4627 to be parsed by the Parser. This option defaults
+      #   to false.
+      # * *create_additions*: If set to false, the Parser doesn't create
+      #   additions even if a matchin class and create_id was found. This option
+      #   defaults to true.
+      # * *object_class*: Defaults to Hash
+      # * *array_class*: Defaults to Array
+      def initialize(source, opts = {})
+        super
+        if !opts.key?(:max_nesting) # defaults to 19
+          @max_nesting = 19
+        elsif opts[:max_nesting]
+          @max_nesting = opts[:max_nesting]
+        else
+          @max_nesting = 0
+        end
+        @allow_nan = !!opts[:allow_nan]
+        ca = true
+        ca = opts[:create_additions] if opts.key?(:create_additions)
+        @create_id = ca ? PSON.create_id : nil
+        @object_class = opts[:object_class] || Hash
+        @array_class = opts[:array_class] || Array
+      end
+
+      alias source string
+
+      # Parses the current PSON string _source_ and returns the complete data
+      # structure as a result.
+      def parse
+        reset
+        obj = nil
+        until eos?
+          case
+          when scan(OBJECT_OPEN)
+            obj and raise ParserError, "source '#{peek(20)}' not in PSON!"
+            @current_nesting = 1
+            obj = parse_object
+          when scan(ARRAY_OPEN)
+            obj and raise ParserError, "source '#{peek(20)}' not in PSON!"
+            @current_nesting = 1
+            obj = parse_array
+          when skip(IGNORE)
+            ;
+          else
+            raise ParserError, "source '#{peek(20)}' not in PSON!"
+          end
+        end
+        obj or raise ParserError, "source did not contain any PSON!"
+        obj
+      end
+
+      private
+
+      # Unescape characters in strings.
+      UNESCAPE_MAP = Hash.new { |h, k| h[k] = k.chr }
+      UNESCAPE_MAP.update({
+        ?"  => '"',
+        ?\\ => '\\',
+        ?/  => '/',
+        ?b  => "\b",
+        ?f  => "\f",
+        ?n  => "\n",
+        ?r  => "\r",
+        ?t  => "\t",
+        ?u  => nil, 
+      })
+
+      def parse_string
+        if scan(STRING)
+          return '' if self[1].empty?
+          string = self[1].gsub(%r((?:\\[\\bfnrt"/]|(?:\\u(?:[A-Fa-f\d]{4}))+|\\[\x20-\xff]))n) do |c|
+            if u = UNESCAPE_MAP[$&[1]]
+              u
+            else # \uXXXX
+              bytes = ''
+              i = 0
+              while c[6 * i] == ?\\ && c[6 * i + 1] == ?u
+                bytes << c[6 * i + 2, 2].to_i(16) << c[6 * i + 4, 2].to_i(16)
+                i += 1
+              end
+              PSON::UTF16toUTF8.iconv(bytes)
+            end
+          end
+          if string.respond_to?(:force_encoding)
+            string.force_encoding(Encoding::UTF_8)
+          end
+          string
+        else
+          UNPARSED
+        end
+      rescue Iconv::Failure => e
+        raise GeneratorError, "Caught #{e.class}: #{e}"
+      end
+
+      def parse_value
+        case
+        when scan(FLOAT)
+          Float(self[1])
+        when scan(INTEGER)
+          Integer(self[1])
+        when scan(TRUE)
+          true
+        when scan(FALSE)
+          false
+        when scan(NULL)
+          nil
+        when (string = parse_string) != UNPARSED
+          string
+        when scan(ARRAY_OPEN)
+          @current_nesting += 1
+          ary = parse_array
+          @current_nesting -= 1
+          ary
+        when scan(OBJECT_OPEN)
+          @current_nesting += 1
+          obj = parse_object
+          @current_nesting -= 1
+          obj
+        when @allow_nan && scan(NAN)
+          NaN
+        when @allow_nan && scan(INFINITY)
+          Infinity
+        when @allow_nan && scan(MINUS_INFINITY)
+          MinusInfinity
+        else
+          UNPARSED
+        end
+      end
+
+      def parse_array
+        raise NestingError, "nesting of #@current_nesting is too deep" if
+          @max_nesting.nonzero? && @current_nesting > @max_nesting
+        result = @array_class.new
+        delim = false
+        until eos?
+          case
+          when (value = parse_value) != UNPARSED
+            delim = false
+            result << value
+            skip(IGNORE)
+            if scan(COLLECTION_DELIMITER)
+              delim = true
+            elsif match?(ARRAY_CLOSE)
+              ;
+            else
+              raise ParserError, "expected ',' or ']' in array at '#{peek(20)}'!"
+            end
+          when scan(ARRAY_CLOSE)
+            if delim
+              raise ParserError, "expected next element in array at '#{peek(20)}'!"
+            end
+            break
+          when skip(IGNORE)
+            ;
+          else
+            raise ParserError, "unexpected token in array at '#{peek(20)}'!"
+          end
+        end
+        result
+      end
+
+      def parse_object
+        raise NestingError, "nesting of #@current_nesting is too deep" if
+          @max_nesting.nonzero? && @current_nesting > @max_nesting
+        result = @object_class.new
+        delim = false
+        until eos?
+          case
+          when (string = parse_string) != UNPARSED
+            skip(IGNORE)
+            unless scan(PAIR_DELIMITER)
+              raise ParserError, "expected ':' in object at '#{peek(20)}'!"
+            end
+            skip(IGNORE)
+            unless (value = parse_value).equal? UNPARSED
+              result[string] = value
+              delim = false
+              skip(IGNORE)
+              if scan(COLLECTION_DELIMITER)
+                delim = true
+              elsif match?(OBJECT_CLOSE)
+                ;
+              else
+                raise ParserError, "expected ',' or '}' in object at '#{peek(20)}'!"
+              end
+            else
+              raise ParserError, "expected value in object at '#{peek(20)}'!"
+            end
+          when scan(OBJECT_CLOSE)
+            if delim
+              raise ParserError, "expected next name, value pair in object at '#{peek(20)}'!"
+            end
+            if @create_id and klassname = result[@create_id]
+              klass = PSON.deep_const_get klassname
+              break unless klass and klass.pson_creatable?
+              result = klass.pson_create(result)
+            end
+            break
+          when skip(IGNORE)
+            ;
+          else
+            raise ParserError, "unexpected token in object at '#{peek(20)}'!"
+          end
+        end
+        result
+      end
+    end
+  end
+end
diff --git a/lib/puppet/external/pson/version.rb b/lib/puppet/external/pson/version.rb
new file mode 100644
index 000000000..a5a8e4702
--- /dev/null
+++ b/lib/puppet/external/pson/version.rb
@@ -0,0 +1,8 @@
+module PSON
+  # PSON version
+  VERSION         = '1.1.9'
+  VERSION_ARRAY   = VERSION.split(/\./).map { |x| x.to_i } # :nodoc:
+  VERSION_MAJOR   = VERSION_ARRAY[0] # :nodoc:
+  VERSION_MINOR   = VERSION_ARRAY[1] # :nodoc:
+  VERSION_BUILD   = VERSION_ARRAY[2] # :nodoc:
+end