# 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 374
    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 434
    def close
      update
    end

delete() click to toggle source

Close and delete the session's FileStore file.

    # File lib/cgi/session.rb, line 439
    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 395
    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 416
    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
        lockf.close if lockf
      end
    end