Class: SolverWorldModel

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

Constant Summary collapse

KEEP_ALIVE =

Message constants

0
TYPE_ANNOUNCE = 
1
START_TRANSIENT = 
2
STOP_TRANSIENT = 
3
SOLVER_DATA = 
4
CREATE_URI = 
5
EXPIRE_URI = 
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DELETE_URI = 
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EXPIRE_ATTRIBUTE = 
8
DELETE_ATTRIBUTE = 
9

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(host, port, origin, start_transient_callback = nil, stop_transient_callback = nil) ⇒ SolverWorldModel

Returns a new instance of SolverWorldModel.



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# File 'lib/libowl/solver_world_model.rb', line 91

def initialize(host, port, origin, start_transient_callback = nil, stop_transient_callback = nil)
  @origin = origin
  @connected = false
  @host = host
  @port = port
  @socket = TCPSocket.open(host, port)
  handshake = ""
  ver_string = "GRAIL world model protocol"
  #The handshake is the length of the message, the protocol string, and the version (0).
  handshake << [ver_string.length].pack('N') << ver_string << "\x00\x00"
  #Receive a handshake and then send one
  @socket.send(handshake, 0)
  inshake = @socket.recvfrom(handshake.length)[0]
  while (inshake.length < handshake.length)
    puts "Waiting for #{handshake.length - inshake.length} byte more of handshake."
    inshake += @socket.recvfrom(handshake.length - inshake.length)[0]
  end

  @connected = true
  for i in 1..handshake.length
    if handshake[i] != inshake[i]
      puts "Handshake failure!"
      puts "For byte i we sent #{handshake[i]} but got #{inshake[i]}"
      @connected = false
    end
  end

  @name_to_alias = {}
  @alias_to_name = {}

  @start_transient_callback = start_transient_callback
  @stop_transient_callback = stop_transient_callback
end

Instance Attribute Details

#alias_to_name ⇒ Object

Returns the value of attribute alias_to_name.



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# File 'lib/libowl/solver_world_model.rb', line 24

def alias_to_name
  @alias_to_name
end

#connected ⇒ Object

Returns the value of attribute connected.



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# File 'lib/libowl/solver_world_model.rb', line 24

def connected
  @connected
end

#name_to_alias ⇒ Object

Returns the value of attribute name_to_alias.



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# File 'lib/libowl/solver_world_model.rb', line 24

def name_to_alias
  @name_to_alias
end

Instance Method Details

#addSolutionTypes(attributes) ⇒ Object

Add some SolutionType objects to the known list



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# File 'lib/libowl/solver_world_model.rb', line 126

def addSolutionTypes(attributes)
  new_aliases = []
  attributes.each { |attr|
    if (@name_to_alias[attr.name] == nil)
      new_alias = @name_to_alias.length
      @name_to_alias[attr.name] = new_alias
      @alias_to_name[new_alias] = attr.name
      new_aliases.push([attr.name, new_alias])
    end
  }
  if (new_aliases.length > 0)
    makeTypeAnnounce(new_aliases)
  end
end

#createURI(uri, creation_time) ⇒ Object

Create an object with the given name in the world model.



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# File 'lib/libowl/solver_world_model.rb', line 187

def createURI(uri, creation_time)
  buff = [CREATE_URI].pack('C')
  buff += strToSizedUTF16(uri)
  buff += packuint64(creation_time)
  buff += strToUnicode(@origin)
  #Send the message with its length prepended to the front
  @socket.send("#{[buff.length].pack('N')}#{buff}", 0)
end

#decodeStartTransient(inbuff) ⇒ Object

Decode a start transient message



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# File 'lib/libowl/solver_world_model.rb', line 56

def decodeStartTransient(inbuff)
  num_aliases = inbuff.unpack('N')[0]
  rest = inbuff[4, inbuff.length - 1]
  new_trans_requests = []
  for i in 1..num_aliases do
    type_alias = rest.unpack('N')[0]
    total_expressions = rest.unpack('N')[0]
    t_request = TransientRequest.new(type_alias, [])
    for j in 1..total_expressions do
      exp, rest = splitURIFromRest(rest[4, rest.length - 1])
      t_request.expressions.push(exp)
    end
    new_trans_requests.push(t_request)
  end
  return new_trans_requests
end

#decodeStopTransient(inbuff) ⇒ Object

Decode a stop transient message



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# File 'lib/libowl/solver_world_model.rb', line 74

def decodeStopTransient(inbuff)
  num_aliases = inbuff.unpack('N')[0]
  rest = inbuff[4, inbuff.length - 1]
  new_trans_requests = []
  for i in 1..num_aliases do
    type_alias = rest.unpack('N')[0]
    total_expressions = rest.unpack('N')[0]
    t_request = TransientRequest.new(type_alias, [])
    for j in 1..total_expressions do
      exp, rest = splitURIFromRest(rest[4, rest.length - 1])
      t_request.expressions.push(exp)
    end
    new_trans_requests.push(t_request)
  end
  return new_trans_requests
end

#deleteURI(uri) ⇒ Object

Delete an object in the world model.



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# File 'lib/libowl/solver_world_model.rb', line 210

def deleteURI(uri)
  buff = [DELETE_URI].pack('C')
  buff += strToSizedUTF16(uri)
  buff += strToUnicode(@origin)
  #Send the message with its length prepended to the front
  @socket.send("#{[buff.length].pack('N')}#{buff}", 0)
end

#expireURI(uri, expiration_time) ⇒ Object

Expire the object with the given name in the world model, indicating that it is no longer valid after the given time.



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# File 'lib/libowl/solver_world_model.rb', line 199

def expireURI(uri, expiration_time)
  buff = [EXPIRE_URI].pack('C')
  buff += strToSizedUTF16(uri)
  buff += packuint64(expiration_time)
  buff += strToUnicode(@origin)
  #Send the message with its length prepended to the front
  @socket.send("#{[buff.length].pack('N')}#{buff}", 0)
end

#handleMessage ⇒ Object

Handle a message of currently unknown type



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# File 'lib/libowl/solver_world_model.rb', line 37

def handleMessage()
  #Get the message length as n unsigned integer
  inlen = (@socket.recvfrom(4)[0]).unpack('N')[0]
  inbuff = @socket.recvfrom(inlen)[0]
  #Byte that indicates message type
  control = inbuff.unpack('C')[0]
  if control == START_TRANSIENT
    if (@start_transient_callback != nil)
      @start_transient_callback.call(decodeStartTransient(inbuff[1, inbuff.length - 1]))
    end
  elsif control == STOP_TRANSIENT
    if (@stop_transient_callback != nil)
      @stop_transient_callback.call(decodeStopTransient(inbuff[1, inbuff.length - 1]))
    end
  end
  return control
end

#makeTypeAnnounce(type_pairs) ⇒ Object 



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# File 'lib/libowl/solver_world_model.rb', line 141

def makeTypeAnnounce(type_pairs)
  buff = [TYPE_ANNOUNCE].pack('C') + [type_pairs.length].pack('N')
  for pair in type_pairs do
    #TODO Not supporting transient types for now so always write a zero
    #for the transient on/off byte
    buff += [pair[1]].pack('N') + strToSizedUTF16(pair[0]) + [0].pack('C')
  end
  #Add the origin string to the end of the message
  buff += strToUnicode(@origin)
  @socket.send("#{[buff.length].pack('N')}#{buff}", 0)
end

#pushData(wmdata_vector, create_uris = false) ⇒ Object

Push URI attributes, automatically declaring new solution types as non-stremaing types if they were not previously declared.



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# File 'lib/libowl/solver_world_model.rb', line 156

def pushData(wmdata_vector, create_uris = false)
  buff = [SOLVER_DATA].pack('C')
  if (create_uris)
    buff += [1].pack('C')
  else
    buff += [0].pack('C')
  end

  #Push back the total number of solutions
  total_solns = wmdata_vector.inject(0){|sum, wmdata|
    sum + wmdata.attributes.length
  }
  buff += [total_solns].pack('N')

  #Now create each solution and push it back into the buffer
  wmdata_vector.each{|wmdata|
    #First make sure all of the solutions types have been declared
    addSolutionTypes(wmdata.attributes)
    #Now push back this attribute's data using an alias for the name
    wmdata.attributes.each{|attr|
      buff += [@name_to_alias[attr.name]].pack('N') +
        packuint64(attr.creation) +
        strToSizedUTF16(wmdata.uri) + [attr.data.length].pack('N') + attr.data
    }
  }
  #Send the message with its length prepended to the front
  @socket.send("#{[buff.length].pack('N')}#{buff}", 0)
end