From: Scott Worley Date: Fri, 3 Aug 2012 18:30:52 +0000 (-0700) Subject: Keep messages sorted by timestamp X-Git-Url: http://git.scottworley.com/reliable-chat/commitdiff_plain/7f54ca0afcd01093cafcee969b6272ec5c05f542 Keep messages sorted by timestamp This causes messages that appear on some servers and not others to be correctly interleaved on initial load. Note: this is incomplete. rcupdatemessagetime() can break history's always-in-sorted-order invariant by changing Time after messages have been inserted. Fixing this is next. Consider replacing rcaddmessagetohistory()'s simple backwards linear scan with a binary search in the unlikely event that its performance is ever noticed. --- diff --git a/webclient/rc.html b/webclient/rc.html index f3abaf3..c3284da 100644 --- a/webclient/rc.html +++ b/webclient/rc.html @@ -82,6 +82,7 @@ var session = Math.random(); // For outgoing message IDs var since = {}; // server -> time: For fetch?since= var seen = {}; // seen_key -> message + var history = []; // List of messages sorted by Time // Messages have these fields: // Time: The timestamp. Median of ServerTimes // ID: Some unique string for deduping @@ -133,11 +134,29 @@ } function rcaddmessagetohistory(message) { - message.UI = document.createElement("div"); + var message_i; + if (message.Time) { + for (var i = history.length - 1; ; i--) { + if (i < 0 || (history[i].Time && message.Time >= history[i].Time)) { + message_i = i+1; + history.splice(message_i, 0, message); + break; + } + } + } else { + history.push(message); + message_i = history.length-1; + } + var text = (message.Time ? rcformattime(message.Time) : "") + " " + message.Text; + message.UI = document.createElement("div"); message.UI.appendChild(document.createTextNode(text)); var h = document.getElementById("history"); - h.appendChild(message.UI); + if (message_i + 1 < history.length) { + h.insertBefore(message.UI, history[message_i + 1].UI); + } else { + h.appendChild(message.UI); + } window.scrollTo(0, document.body.scrollHeight); } @@ -223,11 +242,11 @@ } function rcsend(d, message) { - var id = new Date().getTime() + "-" + session + "-" + Math.random(); - seen[make_seen_key(id, message)] = message; + message.ID = new Date().getTime() + "-" + session + "-" + Math.random(); + seen[make_seen_key(message.ID, message.Text)] = message; var path = "/speak" + - "?id=" + encodeURIComponent(id) + - "&text=" + encodeURIComponent(message); + "?id=" + encodeURIComponent(message.ID) + + "&text=" + encodeURIComponent(message.Text); for (var i in servers) { var uri = rcserverbase(servers[i]) + path; var img = document.createElement("img"); @@ -249,7 +268,7 @@ message = "<" + rcnick() + "> " + input; } - var m = {'Text': message}; + var m = {'Text': message, 'ServerTimes': {}}; rcaddmessagetohistory(m); rcsend(m.UI, m); }