class CGI::Session::FileStore

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.

Public Class Methods

new(session, option={}) click to toggle source

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 initializer. 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 "cgi_sid_".
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.

# File lib/cgi/session.rb, line 372
def initialize(session, option={})
 dir = option['tmpdir'] || Dir::tmpdir
 prefix = option['prefix'] || 'cgi_sid_'
 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

Public Instance Methods

close() click to toggle source

Update and close the session's FileStore file.

# File lib/cgi/session.rb, line 432
def close
 update
end

delete() click to toggle source

Close and delete the session's FileStore file.

# File lib/cgi/session.rb, line 437
def delete
 File::unlink @path+".lock" rescue nil
 File::unlink @path+".new" rescue nil
 File::unlink @path rescue nil
end

restore() click to toggle source

Restore session state from the session's FileStore file.

Returns the session state as a hash.

# File lib/cgi/session.rb, line 393
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)] = Marshal.restore(CGI::unescape(v))
 end
 ensure
 f.close unless f.nil?
 lockf.close if lockf
 end
 end
 @hash
end

update() click to toggle source

Save session state to the session's FileStore file.

# File lib/cgi/session.rb, line 414
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(Marshal.dump(v)))
 end
 f.close
 File.rename @path+".new", @path
 ensure
 f.close if f and !f.closed?
 lockf.close if lockf
 end
end