query optimizations; split big feed update transaction

[tt-rss.git] / functions.php

<?

	if ($_GET["debug"]) {
		define('DEFAULT_ERROR_LEVEL', E_ALL);
	} else {
		define('DEFAULT_ERROR_LEVEL', E_ERROR | E_WARNING | E_PARSE);
	}

	require_once 'config.php';
	require_once 'db-prefs.php';
	require_once 'compat.php';

	require_once 'magpierss/rss_utils.inc';

	define('MAGPIE_OUTPUT_ENCODING', 'UTF-8');

	function purge_feed($link, $feed_id, $purge_interval, $debug = false) {

		$rows = -1;

		if (DB_TYPE == "pgsql") {
/*			$result = db_query($link, "DELETE FROM ttrss_user_entries WHERE
				marked = false AND feed_id = '$feed_id' AND
				(SELECT date_entered FROM ttrss_entries WHERE
					id = ref_id) < NOW() - INTERVAL '$purge_interval days'"); */

			$result = db_query($link, "DELETE FROM ttrss_user_entries WHERE 
				ttrss_entries.id = ref_id AND 
				marked = false AND 
				feed_id = '$feed_id' AND 
				ttrss_entries.date_entered < NOW() - INTERVAL '$purge_interval days'");

			$rows = pg_affected_rows($result);
			
		} else {
			$result = db_query($link, "DELETE FROM ttrss_user_entries WHERE
				marked = false AND feed_id = '$feed_id' AND
				(SELECT date_entered FROM ttrss_entries WHERE 
					id = ref_id) < DATE_SUB(NOW(), INTERVAL $purge_interval DAY)");
			$rows = mysql_affected_rows($link);

		}

		if ($debug) {
			print "Purged feed $feed_id ($purge_interval): deleted $rows articles\n";
		}
	}

	function global_purge_old_posts($link, $do_output = false, $limit = false) {

		if (DB_TYPE == "mysql") {
			$random_qpart = "RAND()";
		} else {
			$random_qpart = "RANDOM()";
		}

		if ($limit) {
			$limit_qpart = "LIMIT $limit";
		} else {
			$limit_qpart = "";
		}
		
		$result = db_query($link, 
			"SELECT id,purge_interval,owner_uid FROM ttrss_feeds 
				ORDER BY $random_qpart $limit_qpart");

		while ($line = db_fetch_assoc($result)) {

			$feed_id = $line["id"];
			$purge_interval = $line["purge_interval"];
			$owner_uid = $line["owner_uid"];

			if ($purge_interval == 0) {
			
				$tmp_result = db_query($link, 
					"SELECT value FROM ttrss_user_prefs WHERE
						pref_name = 'PURGE_OLD_DAYS' AND owner_uid = '$owner_uid'");

				if (db_num_rows($tmp_result) != 0) {			
					$purge_interval = db_fetch_result($tmp_result, 0, "value");
				}
			}

			if ($do_output) {
//				print "Feed $feed_id: purge interval = $purge_interval\n";
			}

			if ($purge_interval > 0) {
				purge_feed($link, $feed_id, $purge_interval, $do_output);
			}
		}	

		// purge orphaned posts in main content table
		db_query($link, "DELETE FROM ttrss_entries WHERE 
			(SELECT COUNT(int_id) FROM ttrss_user_entries WHERE ref_id = id) = 0");

	}

	function purge_old_posts($link) {

		$user_id = $_SESSION["uid"];
	
		$result = db_query($link, "SELECT id,purge_interval FROM ttrss_feeds 
			WHERE owner_uid = '$user_id'");

		while ($line = db_fetch_assoc($result)) {

			$feed_id = $line["id"];
			$purge_interval = $line["purge_interval"];

			if ($purge_interval == 0) $purge_interval = get_pref($link, 'PURGE_OLD_DAYS');

			if ($purge_interval > 0) {
				purge_feed($link, $feed_id, $purge_interval);
			}
		}	

		// purge orphaned posts in main content table
		db_query($link, "DELETE FROM ttrss_entries WHERE 
			(SELECT COUNT(int_id) FROM ttrss_user_entries WHERE ref_id = id) = 0");
	}

	function update_all_feeds($link, $fetch, $user_id = false, $force_daemon = false) {

		if (WEB_DEMO_MODE) return;

		if (!$user_id) {
			$user_id = $_SESSION["uid"];
			purge_old_posts($link);
		}

//		db_query($link, "BEGIN");

		if (MAX_UPDATE_TIME > 0) {
			if (DB_TYPE == "mysql") {
				$q_order = "RAND()";
			} else {
				$q_order = "RANDOM()";
			}
		} else {
			$q_order = "last_updated DESC";
		}

		$result = db_query($link, "SELECT feed_url,id,
			SUBSTRING(last_updated,1,19) AS last_updated,
			update_interval FROM ttrss_feeds WHERE owner_uid = '$user_id'
			ORDER BY $q_order");

		$upd_start = time();

		while ($line = db_fetch_assoc($result)) {
			$upd_intl = $line["update_interval"];

			if (!$upd_intl || $upd_intl == 0) {
				$upd_intl = get_pref($link, 'DEFAULT_UPDATE_INTERVAL', $user_id);
			}

			if ($upd_intl < 0) { 
				// Updates for this feed are disabled
				continue; 
			}

			if ($fetch || (!$line["last_updated"] || 
				time() - strtotime($line["last_updated"]) > ($upd_intl * 60))) {

//				print "<!-- feed: ".$line["feed_url"]." -->";

				update_rss_feed($link, $line["feed_url"], $line["id"], $force_daemon);

				$upd_elapsed = time() - $upd_start;

				if (MAX_UPDATE_TIME > 0 && $upd_elapsed > MAX_UPDATE_TIME) {
					return;
				}
			}
		}

//		db_query($link, "COMMIT");

	}

	function check_feed_favicon($feed_url, $feed, $link) {
		$feed_url = str_replace("http://", "", $feed_url);
		$feed_url = preg_replace("/\/.*$/", "", $feed_url);
		
		$icon_url = "http://$feed_url/favicon.ico";
		$icon_file = ICONS_DIR . "/$feed.ico";

		if (!file_exists($icon_file)) {
				
			error_reporting(0);
			$r = fopen($icon_url, "r");
			error_reporting (DEFAULT_ERROR_LEVEL);

			if ($r) {
				$tmpfname = tempnam(TMP_DIRECTORY, "ttrssicon");
			
				$t = fopen($tmpfname, "w");
				
				while (!feof($r)) {
					$buf = fread($r, 16384);
					fwrite($t, $buf);
				}
				
				fclose($r);
				fclose($t);

				error_reporting(0);
				if (!rename($tmpfname, $icon_file)) {
					unlink($tmpfname);
				}

				chmod($icon_file, 0644);
				
				error_reporting (DEFAULT_ERROR_LEVEL);

			}	
		}
	}

	function update_rss_feed($link, $feed_url, $feed, $ignore_daemon = false) {

		if (WEB_DEMO_MODE) return;

		if (DAEMON_REFRESH_ONLY && !$_GET["daemon"] && !$ignore_daemon) {
			return;			
		}

		$result = db_query($link, "SELECT update_interval,auth_login,auth_pass	
			FROM ttrss_feeds WHERE id = '$feed'");

		$auth_login = db_fetch_result($result, 0, "auth_login");
		$auth_pass = db_fetch_result($result, 0, "auth_pass");

		$update_interval = db_fetch_result($result, 0, "update_interval");

		if ($update_interval < 0) { return; }

		$feed = db_escape_string($feed);

		$fetch_url = $feed_url;

		if ($auth_login && $auth_pass) {
			$url_parts = array();
			preg_match("/(^[^:]*):\/\/(.*)/", $fetch_url, $url_parts);

			if ($url_parts[1] && $url_parts[2]) {
				$fetch_url = $url_parts[1] . "://$auth_login:$auth_pass@" . $url_parts[2];
			}

		}
		error_reporting(0);
		$rss = fetch_rss($fetch_url);

		error_reporting (DEFAULT_ERROR_LEVEL);

		$feed = db_escape_string($feed);

		if ($rss) {

//			db_query($link, "BEGIN");

			$result = db_query($link, "SELECT title,icon_url,site_url,owner_uid
				FROM ttrss_feeds WHERE id = '$feed'");

			$registered_title = db_fetch_result($result, 0, "title");
			$orig_icon_url = db_fetch_result($result, 0, "icon_url");
			$orig_site_url = db_fetch_result($result, 0, "site_url");

			$owner_uid = db_fetch_result($result, 0, "owner_uid");

			if (get_pref($link, 'ENABLE_FEED_ICONS', $owner_uid)) {	
				check_feed_favicon($feed_url, $feed, $link);
			}

			if (!$registered_title || $registered_title == "[Unknown]") {
				$feed_title = db_escape_string($rss->channel["title"]);
				db_query($link, "UPDATE ttrss_feeds SET 
					title = '$feed_title' WHERE id = '$feed'");
			}

			$site_url = $rss->channel["link"];
			// weird, weird Magpie
			if (!$site_url) $site_url = db_escape_string($rss->channel["link_"]);

			if ($site_url && $orig_site_url != db_escape_string($site_url)) {
				db_query($link, "UPDATE ttrss_feeds SET 
					site_url = '$site_url' WHERE id = '$feed'");
			}

//			print "I: " . $rss->channel["image"]["url"];

			$icon_url = $rss->image["url"];

			if ($icon_url && !$orig_icon_url != db_escape_string($icon_url)) {
				$icon_url = db_escape_string($icon_url);
				db_query($link, "UPDATE ttrss_feeds SET icon_url = '$icon_url' WHERE id = '$feed'");
			}


			$filters = array();

			$result = db_query($link, "SELECT reg_exp,
				ttrss_filter_types.name AS name,
				ttrss_filter_actions.name AS action
				FROM ttrss_filters,ttrss_filter_types,ttrss_filter_actions WHERE 					
					owner_uid = $owner_uid AND
					ttrss_filter_types.id = filter_type AND
					ttrss_filter_actions.id = action_id AND
				(feed_id IS NULL OR feed_id = '$feed')");

			while ($line = db_fetch_assoc($result)) {
				if (!$filters[$line["name"]]) $filters[$line["name"]] = array();

				$filter["reg_exp"] = $line["reg_exp"];
				$filter["action"] = $line["action"];
				
				array_push($filters[$line["name"]], $filter);
			}

			$iterator = $rss->items;

			if (!$iterator || !is_array($iterator)) $iterator = $rss->entries;
			if (!$iterator || !is_array($iterator)) $iterator = $rss;

			if (!is_array($iterator)) {
				db_query($link, "UPDATE ttrss_feeds 
					SET last_error = 'CrazyBug 001: Can\'t find iterator :(' 
						WHERE id = '$feed'");
				return; // WTF?
			}

			foreach ($iterator as $item) {
	
				$entry_guid = $item["id"];
	
				if (!$entry_guid) $entry_guid = $item["guid"];
				if (!$entry_guid) $entry_guid = $item["link"];

				if (!$entry_guid) continue;

				$entry_timestamp = "";

				$rss_2_date = $item['pubdate'];
				$rss_1_date = $item['dc']['date'];
				$atom_date = $item['issued'];
				if (!$atom_date) $atom_date = $item['updated'];
			
				if ($atom_date != "") $entry_timestamp = parse_w3cdtf($atom_date);
				if ($rss_1_date != "") $entry_timestamp = parse_w3cdtf($rss_1_date);
				if ($rss_2_date != "") $entry_timestamp = strtotime($rss_2_date);
				
				if ($entry_timestamp == "") {
					$entry_timestamp = time();
					$no_orig_date = 'true';
				} else {
					$no_orig_date = 'false';
				}

				$entry_timestamp_fmt = strftime("%Y/%m/%d %H:%M:%S", $entry_timestamp);

				$entry_title = $item["title"];

				// strange Magpie workaround
				$entry_link = $item["link_"];
				if (!$entry_link) $entry_link = $item["link"];

				if (!$entry_title) continue;
				if (!$entry_link) continue;

				$entry_content = $item["content:escaped"];

				if (!$entry_content) $entry_content = $item["content:encoded"];
				if (!$entry_content) $entry_content = $item["content"];
				if (!$entry_content) $entry_content = $item["summary"];
				if (!$entry_content) $entry_content = $item["description"];

//				if (!$entry_content) continue;

				// WTF
				if (is_array($entry_content)) {
					$entry_content = $entry_content["encoded"];
					if (!$entry_content) $entry_content = $entry_content["escaped"];
				}

//				print_r($item);
//				print_r(htmlspecialchars($entry_content));
//				print "<br>";

				$entry_content_unescaped = $entry_content;
				$content_hash = "SHA1:" . sha1(strip_tags($entry_content));

				$entry_comments = $item["comments"];

				$entry_author = db_escape_string($item['dc']['creator']);

				$entry_guid = db_escape_string($entry_guid);

				$result = db_query($link, "SELECT id FROM	ttrss_entries 
					WHERE guid = '$entry_guid'");

				$entry_content = db_escape_string($entry_content);
				$entry_title = db_escape_string($entry_title);
				$entry_link = db_escape_string($entry_link);
				$entry_comments = db_escape_string($entry_comments);

				$num_comments = db_escape_string($item["slash"]["comments"]);

				if (!$num_comments) $num_comments = 0;

				db_query($link, "BEGIN");

				if (db_num_rows($result) == 0) {

					// base post entry does not exist, create it

					$result = db_query($link,
						"INSERT INTO ttrss_entries 
							(title,
							guid,
							link,
							updated,
							content,
							content_hash,
							no_orig_date,
							date_entered,
							comments,
							num_comments,
							author)
						VALUES
							('$entry_title', 
							'$entry_guid', 
							'$entry_link',
							'$entry_timestamp_fmt', 
							'$entry_content', 
							'$content_hash',
							$no_orig_date, 
							NOW(), 
							'$entry_comments',
							'$num_comments',
							'$entry_author')");
				} else {
					// we keep encountering the entry in feeds, so we need to
					// update date_entered column so that we don't get horrible
					// dupes when the entry gets purged and reinserted again e.g.
					// in the case of SLOW SLOW OMG SLOW updating feeds

					$base_entry_id = db_fetch_result($result, 0, "id");

					db_query($link, "UPDATE ttrss_entries SET date_entered = NOW()
						WHERE id = '$base_entry_id'");
				}

				// now it should exist, if not - bad luck then

				$result = db_query($link, "SELECT 
						id,content_hash,no_orig_date,title,
						substring(date_entered,1,19) as date_entered,
						substring(updated,1,19) as updated,
						num_comments
					FROM 
						ttrss_entries 
					WHERE guid = '$entry_guid'");

				if (db_num_rows($result) == 1) {

					// this will be used below in update handler
					$orig_content_hash = db_fetch_result($result, 0, "content_hash");
					$orig_title = db_fetch_result($result, 0, "title");
					$orig_num_comments = db_fetch_result($result, 0, "num_comments");
					$orig_date_entered = strtotime(db_fetch_result($result, 
						0, "date_entered"));

					$ref_id = db_fetch_result($result, 0, "id");

					// check for user post link to main table

					// do we allow duplicate posts with same GUID in different feeds?
					if (get_pref($link, "ALLOW_DUPLICATE_POSTS", $owner_uid)) {
						$dupcheck_qpart = "AND feed_id = '$feed'";
					} else { 
						$dupcheck_qpart = "";
					}

//					error_reporting(0);

					$filter_name = get_filter_name($entry_title, $entry_content, 
						$entry_link, $filters);

					if ($filter_name == "filter") {
						continue;
					}

//					error_reporting (DEFAULT_ERROR_LEVEL);

					$result = db_query($link,
						"SELECT ref_id FROM ttrss_user_entries WHERE
							ref_id = '$ref_id' AND owner_uid = '$owner_uid'
							$dupcheck_qpart");
							
					// okay it doesn't exist - create user entry
					if (db_num_rows($result) == 0) {

						if ($filter_name != 'catchup') {
							$unread = 'true';
							$last_read_qpart = 'NULL';
						} else {
							$unread = 'false';
							$last_read_qpart = 'NOW()';
						}						
						
						$result = db_query($link,
							"INSERT INTO ttrss_user_entries 
								(ref_id, owner_uid, feed_id, unread, last_read) 
							VALUES ('$ref_id', '$owner_uid', '$feed', $unread,
								$last_read_qpart)");
					}
					
					$post_needs_update = false;

					if (get_pref($link, "UPDATE_POST_ON_CHECKSUM_CHANGE", $owner_uid) &&
						($content_hash != $orig_content_hash)) {
						$post_needs_update = true;
					}

					if ($orig_title != $entry_title) {
						$post_needs_update = true;
					}

					if ($orig_num_comments != $num_comments) {
						$post_needs_update = true;
					}

//					this doesn't seem to be very reliable
//
//					if ($orig_timestamp != $entry_timestamp && !$orig_no_orig_date) {
//						$post_needs_update = true;
//					}

					// if post needs update, update it and mark all user entries 
					// linking to this post as updated					
					if ($post_needs_update) {

//						print "<!-- post $orig_title needs update : $post_needs_update -->";

						db_query($link, "UPDATE ttrss_entries 
							SET title = '$entry_title', content = '$entry_content',
								num_comments = '$num_comments'
							WHERE id = '$ref_id'");

						db_query($link, "UPDATE ttrss_user_entries 
							SET last_read = null WHERE ref_id = '$ref_id' AND unread = false");

					}
				}

				db_query($link, "COMMIT");

				/* taaaags */
				// <a href="http://technorati.com/tag/Xorg" rel="tag">Xorg</a>, //

				$entry_tags = null;

				preg_match_all("/<a.*?href=.http:\/\/.*?technorati.com\/tag\/([^\"\'>]+)/i", 
					$entry_content_unescaped, $entry_tags);

//				print "<br>$entry_title : $entry_content_unescaped<br>";
//				print_r($entry_tags);
//				print "<br>";

				$entry_tags = $entry_tags[1];

				if (count($entry_tags) > 0) {
				
					db_query($link, "BEGIN");
			
					$result = db_query($link, "SELECT id,int_id 
						FROM ttrss_entries,ttrss_user_entries 
						WHERE guid = '$entry_guid' 
						AND feed_id = '$feed' AND ref_id = id
						AND owner_uid = '$owner_uid'");

					if (db_num_rows($result) == 1) {

						$entry_id = db_fetch_result($result, 0, "id");
						$entry_int_id = db_fetch_result($result, 0, "int_id");
						
						foreach ($entry_tags as $tag) {
							$tag = db_escape_string(strtolower($tag));

							$tag = str_replace("+", " ", $tag);	
							$tag = str_replace("technorati tag: ", "", $tag);
	
							$result = db_query($link, "SELECT id FROM ttrss_tags		
								WHERE tag_name = '$tag' AND post_int_id = '$entry_int_id' AND 
								owner_uid = '$owner_uid' LIMIT 1");
	
	//						print db_fetch_result($result, 0, "id");
	
							if ($result && db_num_rows($result) == 0) {
								
	//							print "tagging $entry_id as $tag<br>";
	
								db_query($link, "INSERT INTO ttrss_tags 
									(owner_uid,tag_name,post_int_id)
									VALUES ('$owner_uid','$tag', '$entry_int_id')");
							}							
						}
					}
					db_query($link, "COMMIT");
				} 
			} 

			db_query($link, "UPDATE ttrss_feeds 
				SET last_updated = NOW(), last_error = '' WHERE id = '$feed'");

//			db_query($link, "COMMIT");

		} else {
			$error_msg = db_escape_string(magpie_error());
			db_query($link, 
				"UPDATE ttrss_feeds SET last_error = '$error_msg', 
					last_updated = NOW() WHERE id = '$feed'");
		}

	}

	function print_select($id, $default, $values, $attributes = "") {
		print "<select id=\"$id\" $attributes>";
		foreach ($values as $v) {
			if ($v == $default)
				$sel = " selected";
			 else
			 	$sel = "";
			
			print "<option$sel>$v</option>";
		}
		print "</select>";
	}

	function get_filter_name($title, $content, $link, $filters) {

		if ($filters["title"]) {
			foreach ($filters["title"] as $filter) {
				$reg_exp = $filter["reg_exp"];			
				if (preg_match("/$reg_exp/i", $title)) {
					return $filter["action"];
				}
			}
		}

		if ($filters["content"]) {
			foreach ($filters["content"] as $filter) {
				$reg_exp = $filter["reg_exp"];			
				if (preg_match("/$reg_exp/i", $content)) {
					return $filter["action"];
				}		
			}
		}

		if ($filters["both"]) {
			foreach ($filters["both"] as $filter) {			
				$reg_exp = $filter["reg_exp"];		
				if (preg_match("/$reg_exp/i", $title) || 
					preg_match("/$reg_exp/i", $content)) {
					return $filter["action"];
				}
			}
		}

		if ($filters["link"]) {
			$reg_exp = $filter["reg_exp"];
			foreach ($filters["link"] as $filter) {
				$reg_exp = $filter["reg_exp"];
				if (preg_match("/$reg_exp/i", $link)) {
					return $filter["action"];
				}
			}
		}

		return false;
	}

	function printFeedEntry($feed_id, $class, $feed_title, $unread, $icon_file, $link) {

		if (file_exists($icon_file) && filesize($icon_file) > 0) {
				$feed_icon = "<img id=\"FIMG-$feed_id\" src=\"$icon_file\">";
		} else {
			$feed_icon = "<img id=\"FIMG-$feed_id\" src=\"images/blank_icon.gif\">";
		}

		$feed = "<a href=\"javascript:viewfeed('$feed_id', 0);\">$feed_title</a>";

		print "<li id=\"FEEDR-$feed_id\" class=\"$class\">";
		if (get_pref($link, 'ENABLE_FEED_ICONS')) {
			print "$feed_icon";
		}

		print "<span id=\"FEEDN-$feed_id\">$feed</span>";

		if ($unread != 0) {
			$fctr_class = "";
		} else {
			$fctr_class = "class=\"invisible\"";
		}

		print "<span $fctr_class id=\"FEEDCTR-$feed_id\">
			 (<span id=\"FEEDU-$feed_id\">$unread</span>)</span>";
		
		print "</li>";

	}

	function getmicrotime() {
		list($usec, $sec) = explode(" ",microtime());
		return ((float)$usec + (float)$sec);
	}

	function print_radio($id, $default, $values, $attributes = "") {
		foreach ($values as $v) {
		
			if ($v == $default)
				$sel = "checked";
			 else
			 	$sel = "";

			if ($v == "Yes") {
				$sel .= " value=\"1\"";
			} else {
				$sel .= " value=\"0\"";
			}
			
			print "<input class=\"noborder\" 
				type=\"radio\" $sel $attributes name=\"$id\">&nbsp;$v&nbsp;";

		}
	}

	function initialize_user_prefs($link, $uid) {

		$uid = db_escape_string($uid);

		db_query($link, "BEGIN");

		$result = db_query($link, "SELECT pref_name,def_value FROM ttrss_prefs");
		
		$u_result = db_query($link, "SELECT pref_name 
			FROM ttrss_user_prefs WHERE owner_uid = '$uid'");

		$active_prefs = array();

		while ($line = db_fetch_assoc($u_result)) {
			array_push($active_prefs, $line["pref_name"]);			
		}

		while ($line = db_fetch_assoc($result)) {
			if (array_search($line["pref_name"], $active_prefs) === FALSE) {
//				print "adding " . $line["pref_name"] . "<br>";

				db_query($link, "INSERT INTO ttrss_user_prefs
					(owner_uid,pref_name,value) VALUES 
					('$uid', '".$line["pref_name"]."','".$line["def_value"]."')");

			}
		}

		db_query($link, "COMMIT");

	}
	
	function authenticate_user($link, $login, $password) {

		$pwd_hash = 'SHA1:' . sha1($password);

		$result = db_query($link, "SELECT id,login,access_level FROM ttrss_users WHERE 
			login = '$login' AND pwd_hash = '$pwd_hash'");

		if (db_num_rows($result) == 1) {
			$_SESSION["uid"] = db_fetch_result($result, 0, "id");
			$_SESSION["name"] = db_fetch_result($result, 0, "login");
			$_SESSION["access_level"] = db_fetch_result($result, 0, "access_level");

			db_query($link, "UPDATE ttrss_users SET last_login = NOW() WHERE id = " . 
				$_SESSION["uid"]);

			$user_theme = get_user_theme_path($link);

			$_SESSION["theme"] = $user_theme;
			$_SESSION["ip_address"] = $_SERVER["REMOTE_ADDR"];

			initialize_user_prefs($link, $_SESSION["uid"]);

			return true;
		}

		return false;

	}

	function make_password($length = 8) {

		$password = "";
		$possible = "0123456789abcdfghjkmnpqrstvwxyzABCDFGHJKMNPQRSTVWXYZ"; 
		
   	$i = 0; 
    
		while ($i < $length) { 
			$char = substr($possible, mt_rand(0, strlen($possible)-1), 1);
        
			if (!strstr($password, $char)) { 
				$password .= $char;
				$i++;
			}
		}
		return $password;
	}

	// this is called after user is created to initialize default feeds, labels
	// or whatever else
	
	// user preferences are checked on every login, not here

	function initialize_user($link, $uid) {

		db_query($link, "insert into ttrss_labels (owner_uid,sql_exp,description) 
			values ('$uid','unread = true', 'Unread articles')");

		db_query($link, "insert into ttrss_labels (owner_uid,sql_exp,description) 
			values ('$uid','last_read is null and unread = false', 'Updated articles')");
		
		db_query($link, "insert into ttrss_feeds (owner_uid,title,feed_url)
			values ('$uid', 'Tiny Tiny RSS: New Releases',
			'http://tt-rss.spb.ru/releases.rss')");

	}

	function logout_user() {
		session_destroy();
		if (isset($_COOKIE[session_name()])) {
		   setcookie(session_name(), '', time()-42000, '/');
		}
	}

	function get_script_urlpath() {
		return preg_replace('/\/[^\/]*$/', "", $_SERVER["REQUEST_URI"]);
	}

	function get_login_redirect() {
		$server = $_SERVER["SERVER_NAME"];

		if (ENABLE_LOGIN_SSL) {
			$protocol = "https";
		} else {
			$protocol = "http";
		}		

		$url_path = get_script_urlpath();

		$redirect_uri = "$protocol://$server$url_path/login.php";

		return $redirect_uri;
	}

	function validate_session($link) {
		if (SESSION_CHECK_ADDRESS && !DATABASE_BACKED_SESSIONS && $_SESSION["uid"]) {
			if ($_SESSION["ip_address"]) {
				if ($_SESSION["ip_address"] != $_SERVER["REMOTE_ADDR"]) {
					return false;
				}
			}
		}
		return true;
	}

	function basic_nosid_redirect_check() {
		if (!SINGLE_USER_MODE) {
			if (!$_COOKIE["ttrss_sid"]) {
				$redirect_uri = get_login_redirect();
				$return_to = preg_replace('/.*?\//', '', $_SERVER["REQUEST_URI"]);
				header("Location: $redirect_uri?rt=$return_to");
				exit;
			}
		}
	}

	function login_sequence($link) {
		if (!SINGLE_USER_MODE) {

			if (!validate_session($link)) {
				logout_user();
				$redirect_uri = get_login_redirect();
				$return_to = preg_replace('/.*?\//', '', $_SERVER["REQUEST_URI"]);
				header("Location: $redirect_uri?rt=$return_to");
				exit;
			}

			if (!USE_HTTP_AUTH) {
				if (!$_SESSION["uid"]) {
					$redirect_uri = get_login_redirect();
					$return_to = preg_replace('/.*?\//', '', $_SERVER["REQUEST_URI"]);
					header("Location: $redirect_uri?rt=$return_to");
					exit;
				}
			} else {
				if (!$_SESSION["uid"]) {
					if (!$_SERVER["PHP_AUTH_USER"]) {

						header('WWW-Authenticate: Basic realm="Tiny Tiny RSS"');
						header('HTTP/1.0 401 Unauthorized');
						exit;
						
					} else {
						$auth_result = authenticate_user($link, 
							$_SERVER["PHP_AUTH_USER"], $_SERVER["PHP_AUTH_PW"]);

						if (!$auth_result) {
							header('WWW-Authenticate: Basic realm="Tiny Tiny RSS"');
							header('HTTP/1.0 401 Unauthorized');
							exit;
						}
					}
				}				
			}
		} else {
			$_SESSION["uid"] = 1;
			$_SESSION["name"] = "admin";
			initialize_user_prefs($link, 1); 
		}
	}

	function truncate_string($str, $max_len) {
		if (mb_strlen($str, "utf-8") > $max_len - 3) {
			return mb_substr($str, 0, $max_len, "utf-8") . "...";
		} else {
			return $str;
		}
	}

	function get_user_theme_path($link) {
		$result = db_query($link, "SELECT theme_path 
			FROM 
				ttrss_themes,ttrss_users
			WHERE ttrss_themes.id = theme_id AND ttrss_users.id = " . $_SESSION["uid"]);
		if (db_num_rows($result) != 0) {
			return db_fetch_result($result, 0, "theme_path");
		} else {
			return null;
		}
	}

	function smart_date_time($timestamp) {
		if (date("Y.m.d", $timestamp) == date("Y.m.d")) {
			return date("G:i", $timestamp);
		} else if (date("Y", $timestamp) == date("Y")) {
			return date("M d, G:i", $timestamp);
		} else {
			return date("Y/m/d G:i", $timestamp);
		}
	}

	function smart_date($timestamp) {
		if (date("Y.m.d", $timestamp) == date("Y.m.d")) {
			return "Today";
		} else if (date("Y", $timestamp) == date("Y")) {
			return date("D m", $timestamp);
		} else {
			return date("Y/m/d", $timestamp);
		}
	}

	function sql_bool_to_string($s) {
		if ($s == "t" || $s == "1") {
			return "true";
		} else {
			return "false";
		}
	}

	function sql_bool_to_bool($s) {
		if ($s == "t" || $s == "1") {
			return true;
		} else {
			return false;
		}
	}
	

	function toggleEvenOdd($a) {
		if ($a == "even") 
			return "odd";
		else
			return "even";
	}

	function sanity_check($link) {

		$error_code = 0;
		$result = db_query($link, "SELECT schema_version FROM ttrss_version");
		$schema_version = db_fetch_result($result, 0, "schema_version");

		if ($schema_version != SCHEMA_VERSION) {
			$error_code = 5;
		}

		if ($error_code != 0) {
			print "<error error-code='$error_code'/>";
			return false;
		} else {
			return true;
		} 
	}

	function file_is_locked($filename) {
		error_reporting(0);
		$fp = fopen($filename, "r");
		error_reporting(DEFAULT_ERROR_LEVEL);
		if ($fp) {
			if (flock($fp, LOCK_EX | LOCK_NB)) {
				flock($fp, LOCK_UN);
				fclose($fp);
				return false;
			}
			fclose($fp);
			return true;
		}
		return false;
	}

	function make_lockfile($filename) {
		$fp = fopen($filename, "w");

		if (flock($fp, LOCK_EX | LOCK_NB)) {		
			return $fp;
		} else {
			return false;
		}
	}

?>