Class: PureRubyStringIO

Inherits:
Object
  • Object
show all
Includes:
Enumerable
Defined in:
lib/bijou/prstringio.rb

Overview

This file is is not part of Bijou, but is included as a helper for Ruby installations without stringio.

Reference: rubyforge.org/projects/prstringio/

Original comment:

To load this in emergency situations when loading StringIO fails then use the following:

begin
    require 'stringio'
rescue LoadError
    require 'purerubystringio'      #or just put this entire file in your code at this point.
end

If you need stringio and you know for sure it isn’t going to be available then you can easily fake it without changing your existing code. Just add the following before the rest of your code starts. class StringIO < PureSybyStringIO end Any code that uses StringIO.new will now work. So will any subclass definitions. If you are only subclassing StringIO and you are willing to make small changes to you code you can change your class definitions to:

class MyClass < Object.const_defined?(:StringIO) ? StringIO : PureRubyStringIO
       ...
end

That will automatically select which ever is avaialable at the time. Savy coders, by now, will have begin to consider the delegator mixin. I’ll leave that exercise for you to finish. ;)

Constant Summary collapse

SEEK_CUR = 
IO::SEEK_CUR
SEEK_END = 
IO::SEEK_END
SEEK_SET = 
IO::SEEK_SET
@@relayMethods = 
[:<<, :all?, :any?, :binmode, :close, :close_read, :close_write, :closed?, :closed_read?,
:closed_write?, :collect, :detect, :each, :each_byte, :each_line, :each_with_index,
:entries, :eof, :eof?, :fcntl, :fileno, :find, :find_all, :flush, :fsync, :getc, :gets,
:grep, :include?, :inject, :isatty, :length, :lineno, :lineno=, :map, :max, :member?,
:min, :partition, :path, :pid, :pos, :pos=, :print, :printf, :putc, :puts, :read,
:readchar, :readline, :readlines, :reject, :rewind, :seek, :select, :size, :sort,
:sort_by, :string, :string=, :sync, :sync=, :sysread, :syswrite, :tell, :truncate, :tty?,
:ungetc, :write, :zip]

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(string = "", mode = "r+") ⇒ PureRubyStringIO

Returns a new instance of PureRubyStringIO.



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# File 'lib/bijou/prstringio.rb', line 142

def initialize(string="", mode="r+")
	@sio_string = string.to_s
	@sio_lineno = 0
	@mode = mode
	@relay = nil
	case mode.delete("b")
	when "r"
		@sio_closed_read = false
		@sio_closed_write = true
		@sio_pos = 0
	when "r+"
		@sio_closed_read = false
		@sio_closed_write = false
		@sio_pos = 0
	when "w"
		@sio_closed_read = true
		@sio_closed_write = false
		@sio_pos = 0
		@sio_string.replace("")
	when "w+"
		@sio_closed_read = false
		@sio_closed_write = false
		@sio_pos = 0
		@sio_string.replace("")
	when "a"
		@sio_closed_read = true
		@sio_closed_write = false
		@sio_pos = @sio_string.length
	when "a+"
		@sio_closed_read = false
		@sio_closed_write = false
		@sio_pos = @sio_string.length
	else
		raise ArgumentError, "illegal access mode #{mode}", caller
	end
end

Class Method Details

.open(string = "", mode = "r+") ⇒ Object 



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# File 'lib/bijou/prstringio.rb', line 43

def self.open(string="", mode="r+")
	if block_given? then
		sio = new(string, mode)
		rc = yield(sio)
		sio.close
		rc
	else
		new(string, mode)
	end
end

Instance Method Details

#<<(obj) ⇒ Object 



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# File 'lib/bijou/prstringio.rb', line 54

def <<(obj)
	requireWritable
	write obj
	self
end

#binmode ⇒ Object 



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# File 'lib/bijou/prstringio.rb', line 60

def binmode
	self
end

#close ⇒ Object 



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# File 'lib/bijou/prstringio.rb', line 64

def close
	requireOpen
	@sio_closed_read = true
	@sio_closed_write = true
	self
end

#close_read ⇒ Object

Raises:

  • (IOError) 


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# File 'lib/bijou/prstringio.rb', line 71

def close_read
	raise IOError, "closing non-duplex IO for reading", caller if closed_read?
	@sio_closed_read = true
	self
end

#close_write ⇒ Object

Raises:

  • (IOError) 


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# File 'lib/bijou/prstringio.rb', line 77

def close_write
	raise IOError, "closing non-duplex IO for writing", caller if closed_write?
	@sio_closed_read = true
	self
end

#closed? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/bijou/prstringio.rb', line 83

def closed?
	closed_read? && closed_write?
end

#closed_read? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/bijou/prstringio.rb', line 87

def closed_read?
	@sio_closed_read
end

#closed_write? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/bijou/prstringio.rb', line 91

def closed_write?
	@sio_closed_write
end

#each(sep_string = $/, &block) ⇒ Object Also known as: each_line 



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# File 'lib/bijou/prstringio.rb', line 95

def each(sep_string=$/, &block)
	requireReadable
	@sio_string.each(sep_string, &block)
	@sio_pos = @sio_string.length
end

#each_byte(&block) ⇒ Object 



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# File 'lib/bijou/prstringio.rb', line 101

def each_byte(&block)
	requireReadable
	@sio_string.each_byte(&block)
	@sio_pos = @sio_string.length
end

#eof ⇒ Object Also known as: eof? 



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# File 'lib/bijou/prstringio.rb', line 107

def eof
	requireReadable { @sio_pos >= @sio_string.length }
end

#fcntl(integer_cmd, arg) ⇒ Object

Raises:

  • (NotImplementedError) 


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# File 'lib/bijou/prstringio.rb', line 111

def fcntl(integer_cmd, arg)
	raise NotImplementedError, "The fcntl() function is unimplemented on this machine", caller
end

#fileno ⇒ Object 



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# File 'lib/bijou/prstringio.rb', line 115

def fileno
	nil
end

#flush ⇒ Object 



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# File 'lib/bijou/prstringio.rb', line 119

def flush
	self
end

#fsync ⇒ Object 



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# File 'lib/bijou/prstringio.rb', line 123

def fsync
	0
end

#getc ⇒ Object 



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# File 'lib/bijou/prstringio.rb', line 127

def getc
	requireReadable
	char = @sio_string[@sio_pos]
	@sio_pos +=  1 unless char.nil?
	char
end

#gets(sep_string = $/) ⇒ Object 



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# File 'lib/bijou/prstringio.rb', line 134

def gets(sep_string=$/)
	requireReadable
	@sio_lineno += 1
	pstart = @sio_pos
	@sio_pos = @sio_string.index(sep_string, @sio_pos) || [@sio_string.length, @sio_pos].max
	@sio_string[pstart..@sio_pos]
end

#isatty ⇒ Object Also known as: tty? 



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# File 'lib/bijou/prstringio.rb', line 179

def isatty
	flase
end

#length ⇒ Object Also known as: size 



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# File 'lib/bijou/prstringio.rb', line 183

def length
	@sio_string.length
end

#lineno ⇒ Object 



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# File 'lib/bijou/prstringio.rb', line 187

def lineno
	@sio_lineno
end

#lineno=(integer) ⇒ Object 



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# File 'lib/bijou/prstringio.rb', line 191

def lineno=(integer)
	@sio_lineno = integer
end

#path ⇒ Object 



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# File 'lib/bijou/prstringio.rb', line 195

def path
	nil
end

#pid ⇒ Object 



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# File 'lib/bijou/prstringio.rb', line 199

def pid
	nil
end

#pos ⇒ Object Also known as: tell 



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# File 'lib/bijou/prstringio.rb', line 203

def pos
	@sio_pos
end

#pos=(integer) ⇒ Object

Raises:

  • (Errno::EINVAL) 


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# File 'lib/bijou/prstringio.rb', line 207

def pos=(integer)
	raise Errno::EINVAL, "Invalid argument", caller if integer < 0
	@sio_pos = integer
end

#print(*args) ⇒ Object 



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# File 'lib/bijou/prstringio.rb', line 212

def print(*args)
	requireWritable
	args.unshift($_) if args.empty
	args.each { |obj| write(obj) }
	write($\) unless $\.nil?
	nil
end

#printf(format_string, *args) ⇒ Object 



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# File 'lib/bijou/prstringio.rb', line 220

def printf(format_string, *args)
	requireWritable
	write format(format_string, *args)
	nil
end

#putc(obj) ⇒ Object 



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# File 'lib/bijou/prstringio.rb', line 226

def putc(obj)
	requireWritable
	write(obj.is_a?(Numeric) ? sprintf("%c", obj) : obj.to_s[0..0])
	obj
end

#puts(*args) ⇒ Object 



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# File 'lib/bijou/prstringio.rb', line 232

def puts(*args)
	requireWritable
	args.unshift("") if args.empty?
	args.each { |obj|
		write obj
		write $/
	}
	nil
end

#read(length = nil, buffer = nil) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/bijou/prstringio.rb', line 242

def read(length=nil, buffer=nil)
	requireReadable
	len = length || [@sio_string.length - @sio_pos, 0].max
	raise ArgumentError, "negative length #{len} given", caller if len < 0
	buffer ||= ""
	pstart = @sio_pos
	@sio_pos += len
	buffer.replace(@sio_string[pstart..@sio_pos])
	buffer.empty? && !length.nil? ? nil : buffer
end

#readchar ⇒ Object

Raises:

  • (EOFError) 


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# File 'lib/bijou/prstringio.rb', line 253

def readchar
	requireReadable
	raise EOFError, "End of file reached", caller if eof?
	getc
end

#readline ⇒ Object

Raises:

  • (EOFError) 


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# File 'lib/bijou/prstringio.rb', line 259

def readline
	requireReadable
	raise EOFError, "End of file reached", caller if eof?
	gets
end

#readlines(sep_string = $/) ⇒ Object

Raises:

  • (EOFError) 


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# File 'lib/bijou/prstringio.rb', line 265

def readlines(sep_string=$/)
	requireReadable
	raise EOFError, "End of file reached", caller if eof?
	rc = []
	until eof
		rc << gets(sep_string)
	end
	rc
end

#reopen(string, mode = nil) ⇒ Object 



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# File 'lib/bijou/prstringio.rb', line 275

def reopen(string, mode=nil)
	if string.is_a?(self.class) then
		raise ArgumentError, "wrong number of arguments (2 for 1)", caller if !mode.nil?
		@relay = string
		instance_eval(%Q{
			class << self
				@@relayMethods.each { |name|
					define_method(name, ObjectSpace._id2ref(#{@relay.object_id}).method(("original_" + name.to_s).to_sym).to_proc)
				}
			end
		})
	else
		raise ArgumentError, "wrong number of arguments (1 for 2)", caller if mode.nil?
		class << self
			@@relayMethods.each { |name|
				alias_method(name, "original_#{name}".to_sym)
				public name
			}
			@relay = nil
		end unless @relay.nil?
		@sio_string = string.to_s
		@mode = mode
	end
end

#rewind ⇒ Object 



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# File 'lib/bijou/prstringio.rb', line 300

def rewind
	@sio_pos = 0
	@sio_lineno = 0
end

#seek(amount, whence = SEEK_SET) ⇒ Object 



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# File 'lib/bijou/prstringio.rb', line 305

def seek(amount, whence=SEEK_SET)
	if whence == SEEK_CUR then
		offset += @sio_pos
	elsif whence == SEEK_END then
		offset += size
	end
	@sio_pos = offset
end

#string ⇒ Object 



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# File 'lib/bijou/prstringio.rb', line 314

def string
	@sio_string
end

#string=(newstring) ⇒ Object 



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# File 'lib/bijou/prstringio.rb', line 318

def string=(newstring)
	@sio_string = newstring
end

#sync ⇒ Object 



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# File 'lib/bijou/prstringio.rb', line 322

def sync
	true
end

#sync=(boolean) ⇒ Object 



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# File 'lib/bijou/prstringio.rb', line 326

def sync=(boolean)
	boolean
end

#sysread(length = nil, buffer = nil) ⇒ Object

Raises:

  • (EOFError) 


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# File 'lib/bijou/prstringio.rb', line 330

def sysread(length=nil, buffer=nil)
	requireReadable
	raise EOFError, "End of file reached", caller if eof?
	read(length, buffer)
end

#syswrite(string) ⇒ Object Also known as: write 



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# File 'lib/bijou/prstringio.rb', line 336

def syswrite(string)
	requireWritable
	addition = "\000" * (@sio_string.length - @sio_pos) + string.to_s
	@sio_string[@sio_pos..(addition.length - 1)] = addition
	@sio_pos +=  addition.size
	addition.size
end

#truncate(integer) ⇒ Object

In ruby 1.8.4 truncate differs from the docs in two ways. First, if an integer greater that the length is given then the string is expanded to the new integer length. As this expansion seems to contain junk characters instead of nulls I suspect this may be a flaw in the C code which could cause a core dump if abused/used. Second, the documentation states that truncate returns 0. It returns the integer instead. This implementation follows the documentation in the first instance as I suspect this will be fixed in the C code. In the second instance, it follows the actions of the C code instead of the docs. This was decided as it causes no immedeate harm and this ruby implentation is to be as compatable as possible with the C version. Should the C version change to match the docs the ruby version will be simple to update as well.

Raises:

  • (Errno::EINVAL) 


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# File 'lib/bijou/prstringio.rb', line 354

def truncate(integer)
	requireWritable
	raise Errno::EINVAL, "Invalid argument - negative length", caller if integer < 0
	@sio_string[[integer, @sio_string.length].max..-1] = ""
	integer
end

#ungetc(integer) ⇒ Object 



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# File 'lib/bijou/prstringio.rb', line 361

def ungetc(integer)
	requireWritable
	if @sio_pos > 0 then
		@sio_pos -= 1
# BUGBUG: This wreaks havok with the existing string.
#			putc(integer)
#			@sio_pos -= 1
# We use this as a simple workaround since we're not modifying the stream.
           @sio_string[@sio_pos] = integer
	end
end