Class: CGI::Session::FileStore

Inherits:
Object
  • Object
show all
Defined in:
lib/cgi/session.rb

Overview

File-based session storage class.

Implements session storage as a flat file of 'key=value' values. This storage type only works directly with String values; the user is responsible for converting other types to Strings when storing and from Strings when retrieving.

Instance Method Summary collapse

Constructor Details

#initialize(session, option = {}) ⇒ FileStore

Create a new FileStore instance.

This constructor is used internally by CGI::Session. The user does not generally need to call it directly.

session is the session for which this instance is being created. The session id must only contain alphanumeric characters; automatically generated session ids observe this requirement.

option is a hash of options for the initialiser. The following options are recognised:

tmpdir

the directory to use for storing the FileStore file. Defaults to Dir::tmpdir (generally "/tmp" on Unix systems).

prefix

the prefix to add to the session id when generating the filename for this session's FileStore file. Defaults to the empty string.

suffix

the prefix to add to the session id when generating the filename for this session's FileStore file. Defaults to the empty string.

This session's FileStore file will be created if it does not exist, or opened if it does.



371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
 
# File 'lib/cgi/session.rb', line 371

def initialize(session, option={})
	dir = option['tmpdir'] || Dir::tmpdir
	prefix = option['prefix'] || ''
	suffix = option['suffix'] || ''
	id = session.session_id
  require 'digest/md5'
  md5 = Digest::MD5.hexdigest(id)[0,16]
	@path = dir+"/"+prefix+md5+suffix
	if File::exist? @path
	  @hash = nil
	else
    unless session.new_session
      raise CGI::Session::NoSession, "uninitialized session"
    end
	  @hash = {}
	end
end

Instance Method Details

#close ⇒ Object

Update and close the session's FileStore file.



431
432
433
 
# File 'lib/cgi/session.rb', line 431

def close
	update
end

#delete ⇒ Object

Close and delete the session's FileStore file.



436
437
438
439
440
441
 
# File 'lib/cgi/session.rb', line 436

def delete
  File::unlink @path+".lock" rescue nil
  File::unlink @path+".new" rescue nil
  File::unlink @path
rescue Errno::ENOENT
end

#restore ⇒ Object

Restore session state from the session's FileStore file.

Returns the session state as a hash.



392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
 
# File 'lib/cgi/session.rb', line 392

def restore
	unless @hash
	  @hash = {}
    begin
      lockf = File.open(@path+".lock", "r")
      lockf.flock File::LOCK_SH
	    f = File.open(@path, 'r')
	    for line in f
 line.chomp!
 k, v = line.split('=',2)
 @hash[CGI::unescape(k)] = CGI::unescape(v)
	    end
    ensure
	    f.close unless f.nil?
      lockf.close if lockf
    end
	end
	@hash
end

#update ⇒ Object

Save session state to the session's FileStore file.



413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
 
# File 'lib/cgi/session.rb', line 413

def update
	return unless @hash
  begin
    lockf = File.open(@path+".lock", File::CREAT|File::RDWR, 0600)
	  lockf.flock File::LOCK_EX
    f = File.open(@path+".new", File::CREAT|File::TRUNC|File::WRONLY, 0600)
for k,v in @hash
	    f.printf "%s=%s\n", CGI::escape(k), CGI::escape(String(v))
	  end
    f.close
    File.rename @path+".new", @path
  ensure
    f.close if f and !f.closed?
    lockf.close if lockf
  end
end