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#---------------------------------------------------------------------------
#
# Title : EMESARY inter-object communication
#
# File Type : Implementation File
#
# Description : Provides generic inter-object communication. For an object to receive a message it
# : must first register with an instance of a Transmitter, and provide a Receive method
#
# : To send a message use a Transmitter with an object. That's all there is to it.
#
# References : http://chateau-logic.com/content/emesary-nasal-implementation-flightgear
# : http://www.chateau-logic.com/content/class-based-inter-object-communication
# : http://chateau-logic.com/content/emesary-efficient-inter-object-communication-using-interfaces-and-inheritance
# : http://chateau-logic.com/content/c-wpf-application-plumbing-using-emesary
#
# Author : Richard Harrison (richard@zaretto.com)
#
# Creation Date : 29 January 2016
#
# Version : 4.8
#
# Copyright © 2016 Richard Harrison Released under GPL V2
#
#---------------------------------------------------------------------------
# Classes in this file:
# Transmitter
# Notification
# Recipient
#---------------------------------------------------------------------------*/
var __emesaryUniqueId = 14; # 0-15 are reserved, this way the global transmitter will be 15.
# add registry so we can find a transmitter by name in genericEmesaryGlobalTransmitterTransmit
var _transmitters = Hash.new("transmitters");
var _registerTransmitter = func (key, t) {
_transmitters.set(key, t);
}
var getTransmitter = func (key) {
return _transmitters.get(key);
}
# Transmitters send notifications to all recipients that are registered.
var Transmitter =
{
ReceiptStatus_OK : 0, # Processing completed successfully
ReceiptStatus_Fail : 1, # Processing resulted in at least one failure
ReceiptStatus_Abort : 2, # Fatal error, stop processing any further recipients of this message. Implicitly failed.
ReceiptStatus_Finished : 3, # Definitive completion - do not send message to any further recipients
ReceiptStatus_NotProcessed : 4,# Return value when method doesn't process a message.
ReceiptStatus_Pending : 5, # Message sent with indeterminate return status as processing underway
ReceiptStatus_PendingFinished : 6,# Message definitively handled, status indeterminate. The message will not be sent any further
# create a new transmitter. shouldn't need many of these
# _ident: string; name of the transmitter, used in debug messages
new: func(_ident)
{
if (!isscalar(_ident)) {
logprint(LOG_ALERT, "Transmitter.new: argument must be a scalar!")
}
__emesaryUniqueId += 1;
var new_class = {
parents : [Transmitter],
Recipients : [],
Ident : _ident,
Timestamp : nil,
MaxMilliseconds : 1,
UniqueId: __emesaryUniqueId,
};
_registerTransmitter(_ident, new_class);
return new_class;
},
OverrunDetection: func(max_ms=0){
if (isnum(max_ms) and max_ms) {
if (me.Timestamp == nil)
me.Timestamp = maketimestamp();
me.MaxMilliseconds = max_ms;
logprint(LOG_INFO, "Set overrun detection ",me.Ident, " to ", me.MaxMilliseconds);
return 1;
} else {
# me.Timestamp = nil;
me.MaxMilliseconds = 0;
logprint(LOG_INFO, "Disable overrun detection ",me.Ident);
return 0;
}
},
# Add a recipient to receive notifications from this transmitter
Register: func (recipient)
{
# not inheriting from Recipient is maybe strange but will not crash
if (!isa(recipient, Recipient))
{
logprint(LOG_INFO, "Transmitter.Register: argument is not a Recipient object");
}
#not having a Receive function is an error
if (!isfunc(recipient["Receive"]))
{
logprint(DEV_ALERT, "Transmitter.Register: Error, argument has no Receive method!");
return 0;
}
foreach (var r; me.Recipients)
{
if (r == recipient) {
logprint(DEV_ALERT, "Transmitter.Register: Recipient already registered!");
return 1;
}
}
append(me.Recipients, recipient);
return 1;
},
DeleteAllRecipients: func
{
me.Recipients = [];
},
# Stops a recipient from receiving notifications from this transmitter.
DeRegister: func(todelete_recipient)
{
var out_idx = 0;
var element_deleted = 0;
for (var idx = 0; idx < size(me.Recipients); idx += 1)
{
if (me.Recipients[idx] != todelete_recipient)
{
me.Recipients[out_idx] = me.Recipients[idx];
out_idx = out_idx + 1;
}
else
element_deleted = 1;
}
if (element_deleted)
pop(me.Recipients);
},
RecipientCount: func
{
return size(me.Recipients);
},
PrintRecipients: func
{
print("Emesary: Recipient list for ",me.Ident,"(",me.UniqueId,")");
for (var idx = 0; idx < size(me.Recipients); idx += 1)
print("Emesary: Recipient[",idx,"] ",me.Recipients[idx].Ident," (",me.Recipients[idx].UniqueId,")");
},
# Notify all registered recipients. Stop when receipt status of abort or finished are received.
# The receipt status from this method will be
# - OK > message handled
# - Fail > message not handled. A status of Abort from a recipient will result in our status
# being fail as Abort means that the message was not and cannot be handled, and
# allows for usages such as access controls.
# message: hash; Notification passed to the Receive() method of registered recipients
NotifyAll: func(message)
{
if (!isa(message, Notification))
{
logprint(DEV_ALERT, "Transmitter.NotifyAll: argument must be a Notification!");
return Transmitter.ReceiptStatus_NotProcessed;
}
me._return_status = Transmitter.ReceiptStatus_NotProcessed;
me.TimeTaken = 0;
foreach (var recipient; me.Recipients)
{
if (recipient.RecipientActive)
{
me._rstat = nil;
if (me.MaxMilliseconds > 0 and me.Timestamp != nil)
me.Timestamp.stamp();
message.Timestamp = me.Timestamp;
call(func {me._rstat = recipient.Receive(message);},nil,nil,nil,var err = []);
if (size(err)){
foreach(var line; err) {
print(line);
}
logprint(LOG_ALERT, "Recipient ",recipient.Ident,
" has been removed from transmitter (", me.Ident,
") because of the above error");
me.DeRegister(recipient);
#need to break the foreach due to having modified what its iterating over.
return Transmitter.ReceiptStatus_Abort;
}
if (me.Timestamp != nil) {
recipient.TimeTaken = me.Timestamp.elapsedUSec()/1000.0;
me.TimeTaken += recipient.TimeTaken;
}
if(me._rstat == Transmitter.ReceiptStatus_Fail)
{
me._return_status = Transmitter.ReceiptStatus_Fail;
}
elsif(me._rstat == Transmitter.ReceiptStatus_Pending)
{
me._return_status = Transmitter.ReceiptStatus_Pending;
}
elsif(me._rstat == Transmitter.ReceiptStatus_PendingFinished)
{
return me._rstat;
}
# elsif(rstat == Transmitter.ReceiptStatus_NotProcessed)
# {
# ;
# }
elsif(me._rstat == Transmitter.ReceiptStatus_OK)
{
if (me._return_status == Transmitter.ReceiptStatus_NotProcessed)
me._return_status = me._rstat;
}
elsif(me._rstat == Transmitter.ReceiptStatus_Abort)
{
# this is a final results, e.g. no more recipients will be
# notified but the result is returned as NotifyAll result.
return Transmitter.ReceiptStatus_Abort;
}
elsif(me._rstat == Transmitter.ReceiptStatus_Finished)
{
# this is a final results, e.g. no more recipients will be
# notified but the result is returned as NotifyAll result.
return Transmitter.ReceiptStatus_OK;
}
}
}
if (me.MaxMilliseconds and me.TimeTaken > me.MaxMilliseconds) {
logprint(LOG_WARN, sprintf("Overrun: %s ['%s'] %1.2fms max (%d)",
me.Ident, message.NotificationType, me.TimeTaken, me.MaxMilliseconds));
foreach (var recipient; me.Recipients) {
if (recipient.TimeTaken) {
logprint(LOG_WARN, sprintf(" -- Recipient %25s %7.2f ms",
recipient.Ident, recipient.TimeTaken));
}
}
}
return me._return_status;
},
# Returns true if a return value from NotifyAll is to be considered a failure.
IsFailed: func(receiptStatus)
{
# Failed is either Fail or Abort.
# NotProcessed isn't a failure because it hasn't been processed.
if (receiptStatus == Transmitter.ReceiptStatus_Fail or receiptStatus == Transmitter.ReceiptStatus_Abort)
return 1;
return 0;
}
};
var QueuedTransmitter =
{
new: func(_ident){
var new_class = { parents:[QueuedTransmitter], base:emesary.Transmitter};
new_class = emesary.Transmitter.new(_ident);
new_class.baseNotifyAll = new_class.NotifyAll;
new_class.Q = [];
new_class.NotifyAll = func(message){
append(me.Q, message);
return emesary.Transmitter.ReceiptStatus_Pending;
};
new_class.Process = func {
foreach (var m ; me.Q)
me.baseNotifyAll(m);
me.Q = [];
return emesary.Transmitter.ReceiptStatus_PendingFinished;
};
new_class.size = func {
return size(me.Q);
}
return new_class;
}
};
#---------------------------------------------------------------------------
# Notification - base class
# By convention a Notification has a type and a value. Derived classes can add
# extra properties or methods.
#
# NotificationType: Notification Type
# Ident: Can be an ident, or for simple messages a value that needs transmitting.
# IsDistinct: non zero if this message supercedes previous messages of this type.
# Distinct messages are usually sent often and self contained
# (i.e. no relative state changes such as toggle value)
# Messages that indicate an event (such as after a pilot action)
# will usually be non-distinct. So an example would be gear/up down
# or ATC acknowledgements that all need to be transmitted
# The IsDistinct is important for any messages that are bridged over MP as
# only the most recently sent distinct message will be transmitted over MP.
# Example:
# position update, where only current position is relevant -> IsDistinct=1;
# 0 = queue all messages for MP bridging
# 1 = queue only latest message (replace any old message of same type+ident)
#
var TypeIdUnspecified = 1;
var NotificationAutoTypeId = 1;
var Notification =
{
new: func(_type, _ident, _typeid=0)
{
if (!isscalar(_type)) {
logprint(DEV_ALERT, "Notification.new: _type must be a scalar!");
return nil;
}
if (!isscalar(_ident)) {
logprint(DEV_ALERT, "Notification.new: _ident is not scalar but ", typeof(_ident));
return nil;
}
if (_typeid == 0) {
NotificationAutoTypeId += 1;
# IDs >= 16 are reserved; see http://wiki.flightgear.org/Emesary_Notifications
if (NotificationAutoTypeId == 16) {
logprint(LOG_ALERT, "Notification: AutoTypeID limit exceeded: "~NotificationAutoTypeId);
return nil;
}
_typeid = NotificationAutoTypeId;
}
var new_class = {
parents: [Notification],
NotificationType: _type,
Ident: _ident,
IsDistinct: 1, #1: MP bridge only latest notification
FromIncomingBridge: 0,
Callsign: nil,
TypeId: _typeid, # used in MP bridged
};
return new_class;
},
setType: func(_type) {
if (!isscalar(_type)) {
logprint(DEV_ALERT, "Notification.new: _type must be a scalar!");
return nil;
}
me.NotificationType = _type;
return me;
},
setIdent: func(_ident) {
if (!isscalar(_ident)) {
logprint(DEV_ALERT, "Notification.new: _ident is not scalar but ", typeof(_ident));
return nil;
}
me.Ident = _ident;
return me;
},
GetBridgeMessageNotificationTypeKey: func {
return me.NotificationType~"."~me.Ident;
},
};
#---------------------------------------------------------------------------
# Recipient - base class for receiving notifications.
#
# You have to implement the Receive method
# The Receive method must return a sensible ReceiptStatus_* code
var Recipient =
{
new: func(_ident)
{
if (_ident == nil or _ident == "")
{
_ident = id(new_class);
logprint(LOG_WARN, "Emesary Error: Ident required when creating a recipient, defaulting to ", _ident);
}
__emesaryUniqueId += 1;
var new_class = {
parents: [Recipient],
Ident: _ident,
RecipientActive: 1,
UniqueId: __emesaryUniqueId,
};
return new_class;
},
Receive: func(notification)
{
logprint(DEV_ALERT, "Emesary Error: Receive function not implemented in recipient ", me.Ident);
return Transmitter.ReceiptStatus_NotProcessed;
},
setReceive: func(f)
{
if (isfunc(f)) { me.Receive = f; }
else { logprint(DEV_ALERT, "Recipient.addReceive: argument must be a function!"); }
return me;
},
};
#
# Instantiate a Global Transmitter, this is a convenience and a known starting point.
# Generally most classes will use this transmitters, however other transmitters
# can be created and merely use the global transmitter to discover each other.
var GlobalTransmitter = Transmitter.new("GlobalTransmitter");
#
# Base method of transferring all numeric based values.
# Using the same techinque as base64 - except this is base248 because we can use a much wider range of characters.
#
var BinaryAsciiTransfer =
{
#excluded chars 32 (<space>), 33 (!), 35 (#), 36($), 126 (~), 127 (<del>)
alphabet :
chr(1) ~chr(2) ~chr(3) ~chr(4) ~chr(5) ~chr(6) ~chr(7) ~chr(8) ~chr(9)
~chr(10)~chr(11)~chr(12)~chr(13)~chr(14)~chr(15)~chr(16)~chr(17)~chr(18)~chr(19)
~chr(20)~chr(21)~chr(22)~chr(23)~chr(24)~chr(25)~chr(26)~chr(27)~chr(28)~chr(29)
~chr(30)~chr(31) ~chr(34)
~"%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}"
~chr(128)~chr(129)
~chr(130)~chr(131)~chr(132)~chr(133)~chr(134)~chr(135)~chr(136)~chr(137)~chr(138)~chr(139)
~chr(140)~chr(141)~chr(142)~chr(143)~chr(144)~chr(145)~chr(146)~chr(147)~chr(148)~chr(149)
~chr(150)~chr(151)~chr(152)~chr(153)~chr(154)~chr(155)~chr(156)~chr(157)~chr(158)~chr(159)
~chr(160)~chr(161)~chr(162)~chr(163)~chr(164)~chr(165)~chr(166)~chr(167)~chr(168)~chr(169)
~chr(170)~chr(171)~chr(172)~chr(173)~chr(174)~chr(175)~chr(176)~chr(177)~chr(178)~chr(179)
~chr(180)~chr(181)~chr(182)~chr(183)~chr(184)~chr(185)~chr(186)~chr(187)~chr(188)~chr(189)
~chr(190)~chr(191)~chr(192)~chr(193)~chr(194)~chr(195)~chr(196)~chr(197)~chr(198)~chr(199)
~chr(200)~chr(201)~chr(202)~chr(203)~chr(204)~chr(205)~chr(206)~chr(207)~chr(208)~chr(209)
~chr(210)~chr(211)~chr(212)~chr(213)~chr(214)~chr(215)~chr(216)~chr(217)~chr(218)~chr(219)
~chr(220)~chr(221)~chr(222)~chr(223)~chr(224)~chr(225)~chr(226)~chr(227)~chr(228)~chr(229)
~chr(230)~chr(231)~chr(232)~chr(233)~chr(234)~chr(235)~chr(236)~chr(237)~chr(238)~chr(239)
~chr(240)~chr(241)~chr(242)~chr(243)~chr(244)~chr(245)~chr(246)~chr(247)~chr(248)~chr(249)
~chr(250)~chr(251)~chr(252)~chr(253)~chr(254)~chr(255),
# base248: powers of 2 (i.e. po2(x) = f(248 ^ x);
# 0 based list so the first item is really[1]; i.e. 124 which is 248/2 as po2 is the magnitude excluding sign
po2: [1, 124, 30752, 7626496, 1891371008, 469060009984, 116326882476032, 28849066854055936],
_base: 248,
spaces: " ",
empty_encoding: chr(1)~chr(1)~chr(1)~chr(1)~chr(1)~chr(1)~chr(1)~chr(1)~chr(1)~chr(1)~chr(1),
encodeNumeric : func(_num,length,factor)
{
#print(BinaryAsciiTransfer.po2[1]);
var irange = int(BinaryAsciiTransfer.po2[length] / factor);
var scale = int(irange / factor);
#print("EC ",irange, " sc=",scale);
var num = int(_num / factor);
if (num < -scale) num = -scale;
else if (num > scale) num = scale;
num = int(num + irange);
if (num == 0)
return substr(BinaryAsciiTransfer.empty_encoding,0,length);
var arr="";
while (num > 0 and length > 0) {
var num0 = num;
num = int(num / BinaryAsciiTransfer._base);
rem = num0-(num*BinaryAsciiTransfer._base);
arr =substr(BinaryAsciiTransfer.alphabet, rem,1) ~ arr;
length -= 1;
}
if (length>0)
arr = substr(BinaryAsciiTransfer.spaces,0,length)~arr;
return arr;
},
retval : {value:0, pos:0},
decodeNumeric : func(str, length, factor, pos)
{
var irange = int(BinaryAsciiTransfer.po2[length]/factor);
var power = length-1;
BinaryAsciiTransfer.retval.value = 0;
BinaryAsciiTransfer.retval.pos = pos;
while (length > 0 and power > 0) {
var c = substr(str,BinaryAsciiTransfer.retval.pos,1);
if (c != " ") break;
power = power -1;
length = length-1;
BinaryAsciiTransfer.retval.pos = BinaryAsciiTransfer.retval.pos + 1;
}
while (length >= 0 and power >= 0) {
var c = substr(str,BinaryAsciiTransfer.retval.pos,1);
# spaces are used as padding so ignore them.
if (c != " ") {
var cc = find(c,BinaryAsciiTransfer.alphabet);
if (cc < 0)
{
print("Emesary: BinaryAsciiTransfer.decodeNumeric: Bad encoding ");
return BinaryAsciiTransfer.retval;
}
BinaryAsciiTransfer.retval.value += int(cc * math.exp(math.ln(BinaryAsciiTransfer._base) * power));
power = power - 1;
}
length = length-1;
BinaryAsciiTransfer.retval.pos = BinaryAsciiTransfer.retval.pos + 1;
}
BinaryAsciiTransfer.retval.value -= irange;
BinaryAsciiTransfer.retval.value = BinaryAsciiTransfer.retval.value * factor;
return BinaryAsciiTransfer.retval;
},
encodeInt : func(num,length){
return me.encodeNumeric(num, length, 1.0);
},
decodeInt : func(str, length, pos){
return me.decodeNumeric(str, length, 1.0, pos);
}
};
var TransferString =
{
MaxLength:16,
#
# just to pack a valid range and keep the lower and very upper control codes for seperators
# that way we don't need to do anything special to encode the string.
getalphanumericchar : func(v)
{
if (find(v,BinaryAsciiTransfer.alphabet) > 0)#"-./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_abcdefghijklmnopqrstuvwxyz") > 0)
return v;
return nil;
},
encode : func(v)
{
if (v==nil)
return "0";
var l = size(v);
if (l > TransferString.MaxLength)
l = TransferString.MaxLength;
var rv = "";
var actual_len = 0;
for(var ii = 0; ii < l; ii = ii + 1)
{
ev = TransferString.getalphanumericchar(substr(v,ii,1));
if (ev != nil) {
rv = rv ~ ev;
actual_len = actual_len + 1;
}
}
rv = BinaryAsciiTransfer.encodeNumeric(l,1,1.0) ~ rv;
return rv;
},
decode : func(v,pos)
{
var dv = BinaryAsciiTransfer.decodeNumeric(v,1,1.0,pos);
var length = dv.value;
if (length == 0){
dv.value = "";
return dv;
}
var rv = substr(v,dv.pos,length);
dv.pos = dv.pos + length;
dv.value = rv;
return dv;
}
};
#
# encode an int into a specified number of characters.
var TransferInt =
{
encode : func(v, length)
{
return BinaryAsciiTransfer.encodeNumeric(v,length, 1.0);
},
decode : func(v, length, pos)
{
return BinaryAsciiTransfer.decodeNumeric(v,length, 1.0, pos);
}
};
var TransferFixedDouble =
{
encode : func(v, length, factor)
{
return BinaryAsciiTransfer.encodeNumeric(int(v), length, factor);
},
decode : func(v, length, factor, pos)
{
return BinaryAsciiTransfer.decodeNumeric(v, length, pos, factor);
}
};
var TransferNorm =
{
powers: [1,10.0, 100.0, 1000.0, 10000.0, 100000.0, 1000000.0, 10000000.0, 100000000.0, 1000000000.0, 10000000000.0, 100000000000.0],
encode : func(v, length)
{
return BinaryAsciiTransfer.encodeNumeric(int(v * BinaryAsciiTransfer.po2[length]),length, 1.0);
},
decode : func(v, length, pos)
{
dv = BinaryAsciiTransfer.decodeNumeric(v, length, 1.0, pos);
dv.value = (dv.value/BinaryAsciiTransfer.po2[length]);
return dv;
}
};
var TransferByte =
{
encode : func(v)
{
return BinaryAsciiTransfer.encodeNumeric(v,1, 1.0);
},
decode : func(v, pos)
{
return BinaryAsciiTransfer.decodeNumeric(v, 1, 1.0, pos);
}
};
var TransferCoord =
{
# 28 bits = 268435456 (268 435 456)
# to transfer lat lon (360 degree range) 268435456/360=745654
# we could use different factors for lat lon due to the differing range, however
# this will be fine.
# 1 degree = 110574 meters;
encode : func(v)
{
return BinaryAsciiTransfer.encodeNumeric((v.lat()+90)*745654,5, 1.0)
~ BinaryAsciiTransfer.encodeNumeric((v.lon()+180)*745654,5, 1.0)
~ TransferNumeric.encode(v.alt(), 3, 1.0);
},
decode : func(v,pos)
{
var dv = BinaryAsciiTransfer.decodeNumeric(v,5, 1.0 ,pos);
var lat = (dv.value / 745654)-90;
dv = BinaryAsciiTransfer.decodeNumeric(v,5, 1.0 ,dv.pos);
var lon = (dv.value / 745654)-180;
dv = TransferNumeric.decode(v, 3, 1.0 ,dv.pos);
var alt =dv.value;
dv.value = geo.Coord.new().set_latlon(lat, lon).set_alt(alt);
return dv;
}
};
# genericEmesaryGlobalTransmitterTransmit allowes to use the emesary.GlobalTransmitter via fgcommand
# which in turn allows using it in XML bindings, e.g.
# <binding>
# <command>emesary-transmit</command>
# <type>cockpit-switch</type>
# <ident>eicas-page-select</ident>
# <page>hydraulic</page>
# </binding>
#
var genericEmesaryGlobalTransmitterTransmit = func(node)
{
var transmitter = emesary.GlobalTransmitter;
var t = node.getNode("transmitter",1).getValue();
if (t != nil) {
transmitter = emesary.getTransmitter(t);
if (transmitter == nil) {
logprint(LOG_WARN, "Invalid transmitter "~t);
return;
}
}
var type = node.getNode("type").getValue();
if (type == nil) {
logprint(LOG_WARN, "emesary-transmit requires a type");
return;
}
var ident = node.getNode("ident").getValue();
if (ident == nil) {
logprint(LOG_WARN, "emesary-transmit requires an ident");
return;
}
var typeid = node.getNode("typeid",1).getValue() or 0;
if (typeid == 0) {
typeid = TypeIdUnspecified;
logprint(LOG_WARN, "emesary-transmit using generic typeid ", typeid);
}
var message = emesary.Notification.new(type, ident, typeid);
node.removeChild("type");
node.removeChild("id");
node.removeChild("typeid");
# add remaining nodes to the message hash
var children = node.getValues();
if (children != nil) {
foreach (var key; keys(children)) {
message[key] = children[key];
}
}
transmitter.NotifyAll(message);
};
removecommand("emesary-transmit"); #in case of reload
addcommand("emesary-transmit", genericEmesaryGlobalTransmitterTransmit);
#setprop("/sim/startup/terminal-ansi-colors",0);
#for(i=-1;i<=1;i+=0.1)
#print ("i ",i, " --> ", (TransferNorm.decode(TransferNorm.encode(i,2), 2,0)).value);
#debug.dump(TransferNorm.decode(TransferNorm.encode(-1,2), 2,0));
#debug.dump(TransferNorm.decode(TransferNorm.encode(0,2), 2,0));
#debug.dump(TransferNorm.decode(TransferNorm.encode(1,2), 2,0));