Class CGI::Session::FileStore
In: lib/cgi/session.rb
Parent: Object

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.

Methods

close   delete   new   restore   update  

Public Class methods

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 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.

[Source]

# File lib/cgi/session.rb, line 375
      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

Public Instance methods

Update and close the session‘s FileStore file.

[Source]

# File lib/cgi/session.rb, line 435
      def close
        update
      end

Close and delete the session‘s FileStore file.

[Source]

# File lib/cgi/session.rb, line 440
      def delete
        File::unlink @path+".lock" rescue nil
        File::unlink @path+".new" rescue nil
        File::unlink @path
      rescue Errno::ENOENT
      end

Restore session state from the session‘s FileStore file.

Returns the session state as a hash.

[Source]

# File lib/cgi/session.rb, line 396
      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

Save session state to the session‘s FileStore file.

[Source]

# File lib/cgi/session.rb, line 417
      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

[Validate]