Class: KeyDB::DB

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

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(filename) ⇒ DB

Returns a new instance of DB.



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# File 'lib/keydb.rb', line 8

def initialize filename
  # Makes sure the filename ends in .db
  @filename = filename.split(".")
  @filename = "#{@filename[0]}.db"
  # Checks if file exists
  unless Dir.entries('.').detect {|f| f.match "#{@filename}"}
    @db_file = File.new(@filename, "w")
    @db_file.close
  end
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(keyname, *value) ⇒ Object 



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# File 'lib/keydb.rb', line 79

def method_missing(keyname, *value)
  # Converts the keyname (method) to a string
  keyname = keyname.to_s
  # Checks if it is an accessor method
  if keyname =~ /=/
    keyname.gsub!("=", "")
    value = value[0]
    # Validates the keyname
    if keyname =~ /\/\/\/|\(---\)|-\*\*\*-/
      raise "Invalid Keyname!"
      return
    end
    File.open(@filename, "r").each_line do |line|
      if Marshal.load(line).split("///")[0] == keyname
        # Checks key for uniqueness
        raise "Keynames must be unique"
        return
      end
    end
    @db_file = File.open(@filename, "a")
    # Writes key
    @db_file.write(Marshal.dump("#{keyname}///#{value}"))
    @db_file.write("\n")
    @db_file.close
  else
    File.open(@filename, "r").each_line do |line|
      # Checks if key has been deleted
      if Marshal.load(line).split("(---)")[1] == keyname
        return "Key has been deleted"
      # Checks for a changekey sequence
      elsif Marshal.load(line).split("-***-")[1] == keyname
        return Marshal.load(line).split("-***-")[2]
      end
    end
    File.open(@filename, "r").each_line do |line|
      line = Marshal.load(line)
      # Returns unchanged, undeleted keys
      if line.split("///")[0] == keyname
        return line.split("///")[1]
      end
    end
  end 
end

Instance Attribute Details

#filename ⇒ Object (readonly)

Makes filename and version into attributes



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# File 'lib/keydb.rb', line 4

def filename
  @filename
end

#version ⇒ Object (readonly)

Makes filename and version into attributes



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# File 'lib/keydb.rb', line 4

def version
  @version
end

Instance Method Details

#change_key(keyname, value) ⇒ Object 



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# File 'lib/keydb.rb', line 19

def change_key keyname, value
  @db_file = File.open(@filename, "a")
  # Writes a changekey sequence
  @db_file.write(Marshal.dump("CK-***-#{keyname}-***-#{value}"))
  @db_file.write("\n")
  @db_file.close
end

#delete_db ⇒ Object 



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# File 'lib/keydb.rb', line 68

def delete_db
  # Deletes the database
  system("rm #{@filename}")
end

#delete_key(keyname) ⇒ Object 



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# File 'lib/keydb.rb', line 27

def delete_key keyname
  @db_file = File.open(@filename, "a")
  # Writes a deletekey sequence
  @db_file.write(Marshal.dump("DK(---)#{keyname}"))
  @db_file.write("\n")
  @db_file.close
end

#keys ⇒ Object 



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# File 'lib/keydb.rb', line 40

def keys
  # Creates a new array of keys to ignore
  to_ignore = Array.new
  File.open(@filename).each_line do |line|
    if Marshal.load(line).split("(---)")[1] != nil
      # Pushes deleted keys
      to_ignore.push(Marshal.load(line).split("(---)")[1])
    elsif Marshal.load(line).split("-***-")[1] != nil
      # Pushes changed keys
      to_ignore.push(Marshal.load(line).split("-***-")[1])
    end
  end
  puts to_ignore
  File.open(@filename).each_line do |line|
    line = Marshal.load(line)
    @keys_and_vals = line.split('///')
    # Checks if key is ignored
    if line.split("(---)").length == 2 or to_ignore.include? line.split("///")[0]
      print
    elsif to_ignore.include? line.split("-***-")[1] 
      print  
    else
      # Prints valid keys
      puts @keys_and_vals[0]
    end
  end
end

#to_s ⇒ Object 



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# File 'lib/keydb.rb', line 35

def to_s
  # Returns a string representation
  return "KeyDB-#{@filename}"
end

#wipe_db ⇒ Object 



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# File 'lib/keydb.rb', line 73

def wipe_db
  # Creates a new, clean database
  delete_db
  File.new(@filename, "w")
end