Improve logging by assigning each RGA its own id number. (This is esp…

…ecially useful since each "welcome" event has the browser creating a new RGA, so there can be more than one even for a single document.)

lib/rga.js

@@ -11,6 +11,7 @@ var MAX_REPLICA_ID_BITS = 16;
 function RGA(id, history, queue) {
   if (typeof id !== "number" || (id | 0) !== id || id < 0 || id >= (1 << MAX_REPLICA_ID_BITS))
     throw new TypeError("RGA constructor: first argument is not a valid id");
+  this._idForLogging = RGA._nextIdForLogging++;
   this.id = id;
   this.left = {next: undefined, timestamp: -1, atom: undefined, removed: false};
   this._index = new Map([[this.left.timestamp, this.left]]);
@@ -30,6 +31,7 @@ function RGA(id, history, queue) {
   }
 }
 
+RGA._nextIdForLogging = 100;
 RGA._logging = false;
 
 RGA._browserQueue = {
@@ -158,7 +160,9 @@ RGA.prototype = {
 
   _log: function () {
     if (RGA._logging)
-      console.log.apply(console, arguments);
+      console.log
+        .bind(console, "{" + this.constructor.name + this._idForLogging + "}:")
+        .apply(undefined, arguments);
   }
 };
 
@@ -309,6 +313,8 @@ RGA.AceEditorRGA = function AceEditorRGA(id, editor, history, queue) {
 
 RGA.AceEditorRGA.prototype = Object.create(RGA.prototype);
 Object.assign(RGA.AceEditorRGA.prototype, {
+  constructor: RGA.AceEditorRGA,
+
   // Return the {row, column} coordinates of the character with timestamp t.
   getRowColumnBefore: function (t) {
     if (t === this.left.timestamp)