add article prefetching, remove history tracking

backend.php

@@ -43,7 +43,7 @@
 
 	$print_exec_time = false;
 
-	if ((!$op || $op == "rpc" || $op == "rss" || $op == "digestSend" ||
+	if ((!$op || $op == "rpc" || $op == "rss" || $op == "view" || $op == "digestSend" ||
 			$op == "globalUpdateFeeds") && !$_REQUEST["noxml"]) {
 		header("Content-Type: application/xml; charset=utf-8");
 	} else {
@@ -141,10 +141,9 @@
 
 	}
 
-	if ($op == "view") {
+	function outputArticleXML($link, $id, $feed_id, $mark_as_read = true) {
 
-		$id = db_escape_string($_GET["id"]);
-		$feed_id = db_escape_string($_GET["feed"]);
+		print "<article id='$id'><![CDATA[";
 
 		$result = db_query($link, "SELECT rtl_content FROM ttrss_feeds
 			WHERE id = '$feed_id' AND owner_uid = " . $_SESSION["uid"]);
@@ -163,9 +162,11 @@
 			$rtl_class = "";
 		}
 
-		$result = db_query($link, "UPDATE ttrss_user_entries 
-			SET unread = false,last_read = NOW() 
-			WHERE ref_id = '$id' AND owner_uid = " . $_SESSION["uid"]);
+		if ($mark_as_read) {
+			$result = db_query($link, "UPDATE ttrss_user_entries 
+				SET unread = false,last_read = NOW() 
+				WHERE ref_id = '$id' AND owner_uid = " . $_SESSION["uid"]);
+		}
 
 		$result = db_query($link, "SELECT title,link,content,feed_id,comments,int_id,
 			SUBSTRING(updated,1,16) as updated,
@@ -289,6 +290,36 @@
 			print "</div>";
 
 		}
+
+		print "]]></article>";
+
+	}
+
+	if ($op == "view") {
+
+		$id = db_escape_string($_GET["id"]);
+		$feed_id = db_escape_string($_GET["feed"]);
+		$cids = split(",", db_escape_string($_GET["cids"]));
+		$mode = db_escape_string($_GET["mode"]);
+
+		print "<reply>";
+
+		// in prefetch mode we only output requested cids, main article 
+		// just gets marked as read (it already exists in client cache)
+
+		if ($mode != "prefetch") {
+			outputArticleXML($link, $id, $feed_id);
+		} else {
+			catchupArticleById($link, $id, 0);
+		}
+
+		foreach ($cids as $cid) {
+			if ($cid) {
+				outputArticleXML($link, $cid, $feed_id, false);
+			}
+		}
+
+		print "</reply>";
 	}
 
 	if ($op == "viewfeed") {

feedlist.js

@@ -46,10 +46,10 @@ function viewfeed(feed, subop, is_cat, subop_param, skip_history, offset) {
 
 		enableHotkeys();
 
-		if (!skip_history) {
+/*		if (!skip_history) {
 			history_push('FEED:' + feed + ':' + subop + ':' + is_cat +
 				':' + subop_param);
-		}
+		} */
 
 		var toolbar_query = Form.serialize("main_toolbar_form");
 		var toolbar_form = document.forms["main_toolbar_form"];

functions.js

@@ -1667,3 +1667,34 @@ function logoutUser() {
 		exception_error("logoutUser", e);
 	}
 }
+
+// this only searches loaded headlines list, not in CDM
+function getRelativePostIds(id) {
+
+	debug("getRelativePostIds: " + id);
+
+	var ids = new Array();
+	var container = document.getElementById("headlinesList");
+
+	if (container) {
+		var rows = container.rows;
+
+		for (var i = 0; i < rows.length; i++) {
+			var r_id = rows[i].id.replace("RROW-", "");
+
+			if (r_id == id) {
+				if (i > 0) ids.push(rows[i-1].id.replace("RROW-", ""));
+				if (i > 1) ids.push(rows[i-2].id.replace("RROW-", ""));
+				if (i > 2) ids.push(rows[i-3].id.replace("RROW-", ""));
+
+				if (i < rows.length) ids.push(rows[i+1].id.replace("RROW-", ""));
+				if (i < rows.length-1) ids.push(rows[i+2].id.replace("RROW-", ""));
+				if (i < rows.length-2) ids.push(rows[i+3].id.replace("RROW-", ""));
+
+				return ids;
+			}
+		}
+	}
+
+	return false;
+}

functions.php

@@ -2811,6 +2811,23 @@
 		}
 	}
 
+	function catchupArticleById($link, $id, $cmode) {
+
+		if ($cmode == 0) {
+			db_query($link, "UPDATE ttrss_user_entries SET 
+			unread = false,last_read = NOW()
+			WHERE ref_id = '$id' AND owner_uid = " . $_SESSION["uid"]);
+		} else if ($cmode == 1) {
+			db_query($link, "UPDATE ttrss_user_entries SET 
+			unread = true
+			WHERE ref_id = '$id' AND owner_uid = " . $_SESSION["uid"]);
+		} else {
+			db_query($link, "UPDATE ttrss_user_entries SET 
+			unread = NOT unread,last_read = NOW()
+			WHERE ref_id = '$id' AND owner_uid = " . $_SESSION["uid"]);
+		}
+	}
+
 	function escape_for_form($s) {
 		return htmlspecialchars(db_unescape_string($s));
 	}

tt-rss.js

@@ -21,7 +21,7 @@ var xmlhttp_ctr = Ajax.getTransport();
 
 var init_params = new Object();
 
-var op_history = new Array();
+//var op_history = new Array();
 
 function tagsAreDisplayed() {
 	return display_tags;
@@ -696,7 +696,7 @@ function feedEditSave() {
 		exception_error("feedEditSave (main)", e);
 	} 
 }
-
+/*
 function localHotkeyHandler(e) {
 
 	var keycode;
@@ -756,7 +756,7 @@ function localHotkeyHandler(e) {
 	}	
 
 	debug("LKP=" + keycode);
-}
+} 
 
 function history_push(op) {
 	debug("history_push: " + op);
@@ -776,4 +776,4 @@ function history_pop() {
 function history_clear() {
 	debug("history_clear");
 	op_history.clear();
-}
+} */

viewfeed.js

@@ -16,6 +16,8 @@ var _reload_feedlist_after_view = false;
 var _cdm_wd_timeout = false;
 var _cdm_wd_vishist = new Array();
 
+var article_cache = new Array();
+
 function catchup_callback() {
 	if (xmlhttp_rpc.readyState == 4) {
 		try {
@@ -66,14 +68,49 @@ function headlines_callback() {
 	}
 }
 
-function article_callback() {
-	if (xmlhttp.readyState == 4) {
-		debug("article_callback");
+function render_article(article) {
+	try {
 		var f = document.getElementById("content-frame");
 		try {
 			f.scrollTop = 0;
 		} catch (e) { };
-		f.innerHTML = xmlhttp.responseText;
+
+		f.innerHTML = article;
+
+	} catch (e) {
+		exception_error("render_article", e);
+	}
+}
+
+function article_callback() {
+	if (xmlhttp.readyState == 4) {
+		debug("article_callback");
+
+		try {
+			if (xmlhttp.responseXML) {
+				var reply = xmlhttp.responseXML.firstChild.firstChild;
+
+				var articles = xmlhttp.responseXML.getElementsByTagName("article");
+
+				for (var i = 0; i < articles.length; i++) {
+					var a_id = articles[i].getAttribute("id");
+
+					debug("found id: " + a_id);
+
+					if (a_id == active_post_id) {
+						debug("active article, rendering...");					
+						render_article(articles[i].firstChild.nodeValue);
+					}
+
+					cache_inject(a_id, articles[i].firstChild.nodeValue);
+				}
+			
+			} else {
+				debug("article_callback: returned no XML object");
+			}
+		} catch (e) {
+			exception_error("article_callback", e);
+		}
 
 		var date = new Date();
 		last_article_view = date.getTime() / 1000;
@@ -100,9 +137,13 @@ function view(id, feed_id, skip_history) {
 
 		active_real_feed_id = feed_id;
 
-		if (!skip_history) {
+		var cached_article = cache_find(id);
+
+		debug("cache check result: " + (cached_article != false));
+
+/*		if (!skip_history) {
 			history_push("ARTICLE:" + id + ":" + feed_id);
-		}
+		} */
 	
 		enableHotkeys();
 	
@@ -119,11 +160,15 @@ function view(id, feed_id, skip_history) {
 			xmlhttp.abort();
 		}
 
-		if (xmlhttp_ready(xmlhttp)) {
+		if (cached_article || xmlhttp_ready(xmlhttp)) {
 
 			cleanSelected("headlinesList");
 
 			var crow = document.getElementById("RROW-" + active_post_id);
+
+			var article_is_unread = crow.className.match("Unread");
+			debug("article is unread: " + article_is_unread);			
+
 			crow.className = crow.className.replace("Unread", "");
 
 			var upd_img_pic = document.getElementById("FUPDPIC-" + active_post_id);
@@ -135,15 +180,55 @@ function view(id, feed_id, skip_history) {
 			selectTableRowsByIdPrefix('headlinesList', 'RROW-', 'RCHK-', false);
 			markHeadline(active_post_id);
 
+			var neighbor_ids = getRelativePostIds(active_post_id);
+
+			/* only request uncached articles */
+
+			var cids_to_request = Array();
+
+			for (var i = 0; i < neighbor_ids.length; i++) {
+				if (!cache_check(neighbor_ids[i])) {
+					cids_to_request.push(neighbor_ids[i]);
+				}
+			}
+
+			debug("additional ids: " + cids_to_request.toString());			
+
 			var date = new Date();
 			var timestamp = Math.round(date.getTime() / 1000);
 			query = query + "&ts=" + timestamp;
 
-			notify_progress("Loading, please wait...");
+			query = query + "&cids=" + cids_to_request.toString();
+
+			if (!cached_article) {
+
+				notify_progress("Loading, please wait...");
+
+				debug(query);
+
+				xmlhttp.open("GET", query, true);
+				xmlhttp.onreadystatechange=article_callback;
+				xmlhttp.send(null);
+			} else if (cached_article && article_is_unread) {
+
+				query = query + "&mode=prefetch";
+
+				debug(query);
+
+				xmlhttp.open("GET", query, true);
+				xmlhttp.onreadystatechange=article_callback;
+				xmlhttp.send(null);
+
+				render_article(cached_article);
+
+			} else if (cached_article) {
+
+				render_article(cached_article);
+
+			}
+
+			cache_expire();
 
-			xmlhttp.open("GET", query, true);
-			xmlhttp.onreadystatechange=article_callback;
-			xmlhttp.send(null);
 		} else {
 			debug("xmlhttp busy (@view)");
 			printLockingError();
@@ -650,3 +735,37 @@ function cdmWatchdog() {
 	}
 
 }
+
+
+function cache_inject(id, article) {
+	if (!article_cache[id]) {
+		debug("cache_article: miss: " + id);
+
+		var cache_obj = new Array();
+
+		var d = new Date();
+		cache_obj["entered"] = d.getTime() / 1000;
+		cache_obj["data"] = article;
+
+		article_cache[id] = cache_obj;
+
+	} else {
+		debug("cache_article: hit: " + id);
+	}
+}
+
+function cache_find(id) {
+	if (typeof article_cache[id] != 'undefined') {
+		return article_cache[id]["data"];
+	} else {
+		return false;
+	}
+}
+
+function cache_check(id) {
+	return typeof article_cache[id] != 'undefined';
+}
+
+function cache_expire() {
+	/* TODO */
+}