Module: PHP

Defined in:
lib/smklib/php_serialize.rb

Overview

PHP serialize() and unserialize() workalikes

First Released: 2003-06-02 (1.0.0)
Prev Release: 2003-06-16 (1.0.1), by Thomas Hurst <[email protected]>
This Release: 2004-09-17 (1.0.2), by Thomas Hurst <[email protected]>
              Switch all {}'s to explicit Hash.new's.

These two methods should, for the most part, be functionally identical
to the respective PHP functions;
 http://www.php.net/serialize, http://www.php.net/unserialize

string = PHP.serialize(mixed var[, bool assoc])
 Returns a string representing the argument in a form PHP.unserialize
 and PHP's unserialize() should both be able to load.

 Array, Hash, Fixnum, Float, True/FalseClass, NilClass, String and Struct
 are supported; as are objects which support the to_assoc method, which
 returns an array of the form [['attr_name', 'value']..].  Anything else
 will raise a TypeError.

 If 'assoc' is specified, Array's who's first element is a two value
 array will be assumed to be an associative array, and will be serialized
 as a PHP associative array rather than a multidimensional array.

mixed = PHP.unserialize(string serialized, [hash classmap, [bool assoc]])
 Returns an object containing the reconstituted data from serialized.

 If a PHP array (associative; like an ordered hash) is encountered, it
 scans the keys; if they're all incrementing integers counting from 0,
 it's unserialized as an Array, otherwise it's unserialized as a Hash.
 Note: this will lose ordering.  To avoid this, specify assoc=true,
 and it will be unserialized as an associative array: [[key,value],...]

 If a serialized object is encountered, the hash 'classmap' is searched for
 the class name (as a symbol).  Since PHP classnames are not case-preserving,
 this *must* be a .capitalize()d representation.  The value is expected
 to be the class itself; i.e. something you could call .new on.

 If it's not found in 'classmap', the current constant namespace is searched,
 and failing that, a new Struct(classname) is generated, with the arguments
 for .new specified in the same order PHP provided; since PHP uses hashes
 to represent attributes, this should be the same order they're specified
 in PHP, but this is untested.

 each serialized attribute is sent to the new object using the respective
 {attribute}=() method; you'll get a NameError if the method doesn't exist.

 Array, Hash, Fixnum, Float, True/FalseClass, NilClass and String should
 be returned identically (i.e. foo == PHP.unserialize(PHP.serialize(foo))
 for these types); Struct should be too, provided it's in the namespace
 Module.const_get within unserialize() can see, or you gave it the same
 name in the Struct.new(<structname>), otherwise you should provide it in
 classmap.

Note: StringIO is required for unserialize(); it’s loaded as needed

Class Method Summary collapse

Class Method Details

.do_unserialize(string, classmap, assoc) ⇒ Object 



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# File 'lib/smklib/php_serialize.rb', line 163

def PHP.do_unserialize(string, classmap, assoc)
	val = nil
	# determine a type
	type = string.read(2)[0,1]
	case type
		when 'a' # associative array, a:length:{[index][value]...}
			count = string.read_until('{').to_i
			val = vals = Array.new
			count.times do |i|
				vals << [do_unserialize(string, classmap, assoc), do_unserialize(string, classmap, assoc)]
			end
			string.read(1) # skip the ending }

			unless assoc
				# now, we have an associative array, let's clean it up a bit...
				# arrays have all numeric indexes, in order; otherwise we assume a hash
				array = true
				i = 0
				vals.each do |key,value|
					if key != i # wrong index -> assume hash
						array = false
						break
					end
					i += 1
				end

				if array
					vals.collect! do |key,value|
						value
					end
				else
					val = Hash.new
					vals.each do |key,value|
						val[key] = value
					end
				end
			end

		when 'O' # object, O:length:"class":length:{[attribute][value]...}
			# class name (lowercase in PHP, grr)
			len = string.read_until(':').to_i + 3 # quotes, seperator
			klass = string.read(len)[1...-2].capitalize.intern # read it, kill useless quotes

			# read the attributes
			attrs = []
			len = string.read_until('{').to_i

			len.times do
				attr = (do_unserialize(string, classmap, assoc))
				attrs << [attr.intern, (attr << '=').intern, do_unserialize(string, classmap, assoc)]
			end
			string.read(1)

			val = nil
			# See if we need to map to a particular object
			if classmap.has_key?(klass)
				val = classmap[klass].new
			elsif Struct.const_defined?(klass) # Nope; see if there's a Struct
				classmap[klass] = val = Struct.const_get(klass)
				val = val.new
			else # Nope; see if there's a Constant
				begin
					classmap[klass] = val = Module.const_get(klass)

					val = val.new
				rescue NameError # Nope; make a new Struct
					classmap[klass] = val = Struct.new(klass.to_s, *attrs.collect { |v| v[0].to_s })
				end
			end

			attrs.each do |attr,attrassign,v|
				val.__send__(attrassign, v)
			end

		when 's' # string, s:length:"data";
			len = string.read_until(':').to_i + 3 # quotes, separator
			val = string.read(len)[1...-2] # read it, kill useless quotes

		when 'i' # integer, i:123
			val = string.read_until(';').to_i

		when 'd' # double (float), d:1.23
			val = string.read_until(';').to_f

		when 'N' # NULL, N;
			val = nil

		when 'b' # bool, b:0 or 1
			val = (string.read(2)[0] == ?1 ? true : false)

		else
			raise TypeError, "Unable to unserialize type '#{type}'"
	end

	val
end

.serialize(var, assoc = false) ⇒ Object

{{{



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# File 'lib/smklib/php_serialize.rb', line 83

def PHP.serialize(var, assoc = false) # {{{
	s = ''
	case var
		when Array
			s << "a:#{var.size}:{"
			if assoc and var.first.is_a?(Array) and var.first.size == 2
				var.each { |k,v|
					s << PHP.serialize(k) << PHP.serialize(v)
				}
			else
				var.each_with_index { |v,i|
					s << "i:#{i};#{PHP.serialize(v)}"
				}
			end

			s << '}'

		when Hash
			s << "a:#{var.size}:{"
			var.each do |k,v|
				s << "#{PHP.serialize(k)}#{PHP.serialize(v)}"
			end
			s << '}'

		when Struct
			# encode as Object with same name
			s << "O:#{var.class.to_s.length}:\"#{var.class.to_s.downcase}\":#{var.members.length}:{"
			var.members.each do |member|
				s << "#{PHP.serialize(member)}#{PHP.serialize(var[member])}"
			end
			s << '}'

		when String
			s << "s:#{var.length}:\"#{var}\";"

		when Fixnum # PHP doesn't have bignums
			s << "i:#{var};"

		when Float
			s << "d:#{var};"

		when NilClass
			s << 'N;'

		when FalseClass, TrueClass
			s << "b:#{var ? 1 :0};"

		else
			if var.respond_to?(:to_assoc)
				v = var.to_assoc
				# encode as Object with same name
				s << "O:#{var.class.to_s.length}:\"#{var.class.to_s.downcase}\":#{v.length}:{"
				v.each do |k,v|
					s << "#{PHP.serialize(k.to_s)}#{PHP.serialize(v)}"
				end
				s << '}'
			else
				raise TypeError, "Unable to serialize type #{var.class}"
			end
	end

	s
end

.unserialize(string, classmap = nil, assoc = false) ⇒ Object

}}}



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# File 'lib/smklib/php_serialize.rb', line 147

def PHP.unserialize(string, classmap = nil, assoc = false) # {{{
	require 'stringio'
	string = StringIO.new(string)
	def string.read_until(char)
		val = ''
		while (c = self.read(1)) != char
			val << c
		end
		val
	end

	classmap ||= Hash.new

	do_unserialize(string, classmap, assoc)
end