Merge branch 'jn/gitweb-blame'

* jn/gitweb-blame:
  gitweb: Add link to other blame implementation in blame views
  gitweb: Make linking to actions requiring JavaScript a feature
  gitweb.js: fix padLeftStr() and its usage
  gitweb.js: Harden setting blamed commit info in incremental blame
  gitweb.js: fix null object exception in initials calculation
  gitweb: Minify gitweb.js if JSMIN is defined
  gitweb: Create links leading to 'blame_incremental' using JavaScript
  gitweb: Colorize 'blame_incremental' view during processing
  gitweb: Incremental blame (using JavaScript)
  gitweb: Add optional "time to generate page" info in footer

Conflicts:
	Makefile
	gitweb/gitweb.css

4 files changed, 1141 insertions, 87 deletions

diff --git a/gitweb/README b/gitweb/README
index 66c6a9391d..b69b0e5042 100644
--- a/gitweb/README
+++ b/gitweb/README
@@ -92,6 +92,10 @@ You can specify the following configuration variables when building GIT:
    web browsers that support favicons (website icons) may display them
    in the browser's URL bar and next to site name in bookmarks).  Relative
    to base URI of gitweb.  [Default: git-favicon.png]
+ * GITWEB_JS
+   Points to the localtion where you put gitweb.js on your web server
+   (or to be more generic URI of JavaScript code used by gitweb).
+   Relative to base URI of gitweb.  [Default: gitweb.js]
  * GITWEB_CONFIG
    This Perl file will be loaded using 'do' and can be used to override any
    of the options above as well as some other options -- see the "Runtime
diff --git a/gitweb/gitweb.css b/gitweb/gitweb.css
index cb3f0baf05..50067f2e0d 100644
--- a/gitweb/gitweb.css
+++ b/gitweb/gitweb.css
@@ -79,6 +79,13 @@ div.page_footer_text {
 	font-style: italic;
 }
 
+div#generating_info {
+	margin: 4px;
+	font-size: smaller;
+	text-align: center;
+	color: #505050;
+}
+
 div.page_body {
 	padding: 8px;
 	font-family: monospace;
@@ -254,6 +261,11 @@ tr.no-previous td.linenr {
 	font-weight: bold;
 }
 
+/* for 'blame_incremental', during processing */
+tr.color1 { background-color: #f6fff6; }
+tr.color2 { background-color: #f6f6ff; }
+tr.color3 { background-color: #fff6f6; }
+
 td {
 	padding: 2px 5px;
 	font-size: 100%;
@@ -345,6 +357,17 @@ td.mode {
 	font-family: monospace;
 }
 
+/* progress of blame_interactive */
+div#progress_bar {
+	height: 2px;
+	margin-bottom: -2px;
+	background-color: #d8d9d0;
+}
+div#progress_info {
+	float: right;
+	text-align: right;
+}
+
 /* format of (optional) objects size in 'tree' view */
 td.size {
 	font-family: monospace;
diff --git a/gitweb/gitweb.js b/gitweb/gitweb.js
new file mode 100644
index 0000000000..2a25b7cc47
--- /dev/null
+++ b/gitweb/gitweb.js
@@ -0,0 +1,870 @@
+// Copyright (C) 2007, Fredrik Kuivinen <frekui@gmail.com>
+//               2007, Petr Baudis <pasky@suse.cz>
+//          2008-2009, Jakub Narebski <jnareb@gmail.com>
+
+/**
+ * @fileOverview JavaScript code for gitweb (git web interface).
+ * @license GPLv2 or later
+ */
+
+/* ============================================================ */
+/* functions for generic gitweb actions and views */
+
+/**
+ * used to check if link has 'js' query parameter already (at end),
+ * and other reasons to not add 'js=1' param at the end of link
+ * @constant
+ */
+var jsExceptionsRe = /[;?]js=[01]$/;
+
+/**
+ * Add '?js=1' or ';js=1' to the end of every link in the document
+ * that doesn't have 'js' query parameter set already.
+ *
+ * Links with 'js=1' lead to JavaScript version of given action, if it
+ * exists (currently there is only 'blame_incremental' for 'blame')
+ *
+ * @globals jsExceptionsRe
+ */
+function fixLinks() {
+	var allLinks = document.getElementsByTagName("a") || document.links;
+	for (var i = 0, len = allLinks.length; i < len; i++) {
+		var link = allLinks[i];
+		if (!jsExceptionsRe.test(link)) { // =~ /[;?]js=[01]$/;
+			link.href +=
+				(link.href.indexOf('?') === -1 ? '?' : ';') + 'js=1';
+		}
+	}
+}
+
+
+/* ============================================================ */
+
+/*
+ * This code uses DOM methods instead of (nonstandard) innerHTML
+ * to modify page.
+ *
+ * innerHTML is non-standard IE extension, though supported by most
+ * browsers; however Firefox up to version 1.5 didn't implement it in
+ * a strict mode (application/xml+xhtml mimetype).
+ *
+ * Also my simple benchmarks show that using elem.firstChild.data =
+ * 'content' is slightly faster than elem.innerHTML = 'content'.  It
+ * is however more fragile (text element fragment must exists), and
+ * less feature-rich (we cannot add HTML).
+ *
+ * Note that DOM 2 HTML is preferred over generic DOM 2 Core; the
+ * equivalent using DOM 2 Core is usually shown in comments.
+ */
+
+
+/* ============================================================ */
+/* generic utility functions */
+
+
+/**
+ * pad number N with nonbreakable spaces on the left, to WIDTH characters
+ * example: padLeftStr(12, 3, '\u00A0') == '\u00A012'
+ *          ('\u00A0' is nonbreakable space)
+ *
+ * @param {Number|String} input: number to pad
+ * @param {Number} width: visible width of output
+ * @param {String} str: string to prefix to string, e.g. '\u00A0'
+ * @returns {String} INPUT prefixed with (WIDTH - INPUT.length) x STR
+ */
+function padLeftStr(input, width, str) {
+	var prefix = '';
+
+	width -= input.toString().length;
+	while (width > 0) {
+		prefix += str;
+		width--;
+	}
+	return prefix + input;
+}
+
+/**
+ * Pad INPUT on the left to SIZE width, using given padding character CH,
+ * for example padLeft('a', 3, '_') is '__a'.
+ *
+ * @param {String} input: input value converted to string.
+ * @param {Number} width: desired length of output.
+ * @param {String} ch: single character to prefix to string.
+ *
+ * @returns {String} Modified string, at least SIZE length.
+ */
+function padLeft(input, width, ch) {
+	var s = input + "";
+	while (s.length < width) {
+		s = ch + s;
+	}
+	return s;
+}
+
+/**
+ * Create XMLHttpRequest object in cross-browser way
+ * @returns XMLHttpRequest object, or null
+ */
+function createRequestObject() {
+	try {
+		return new XMLHttpRequest();
+	} catch (e) {}
+	try {
+		return window.createRequest();
+	} catch (e) {}
+	try {
+		return new ActiveXObject("Msxml2.XMLHTTP");
+	} catch (e) {}
+	try {
+		return new ActiveXObject("Microsoft.XMLHTTP");
+	} catch (e) {}
+
+	return null;
+}
+
+
+/* ============================================================ */
+/* utility/helper functions (and variables) */
+
+var xhr;        // XMLHttpRequest object
+var projectUrl; // partial query + separator ('?' or ';')
+
+// 'commits' is an associative map. It maps SHA1s to Commit objects.
+var commits = {};
+
+/**
+ * constructor for Commit objects, used in 'blame'
+ * @class Represents a blamed commit
+ * @param {String} sha1: SHA-1 identifier of a commit
+ */
+function Commit(sha1) {
+	if (this instanceof Commit) {
+		this.sha1 = sha1;
+		this.nprevious = 0; /* number of 'previous', effective parents */
+	} else {
+		return new Commit(sha1);
+	}
+}
+
+/* ............................................................ */
+/* progress info, timing, error reporting */
+
+var blamedLines = 0;
+var totalLines  = '???';
+var div_progress_bar;
+var div_progress_info;
+
+/**
+ * Detects how many lines does a blamed file have,
+ * This information is used in progress info
+ *
+ * @returns {Number|String} Number of lines in file, or string '...'
+ */
+function countLines() {
+	var table =
+		document.getElementById('blame_table') ||
+		document.getElementsByTagName('table')[0];
+
+	if (table) {
+		return table.getElementsByTagName('tr').length - 1; // for header
+	} else {
+		return '...';
+	}
+}
+
+/**
+ * update progress info and length (width) of progress bar
+ *
+ * @globals div_progress_info, div_progress_bar, blamedLines, totalLines
+ */
+function updateProgressInfo() {
+	if (!div_progress_info) {
+		div_progress_info = document.getElementById('progress_info');
+	}
+	if (!div_progress_bar) {
+		div_progress_bar = document.getElementById('progress_bar');
+	}
+	if (!div_progress_info && !div_progress_bar) {
+		return;
+	}
+
+	var percentage = Math.floor(100.0*blamedLines/totalLines);
+
+	if (div_progress_info) {
+		div_progress_info.firstChild.data  = blamedLines + ' / ' + totalLines +
+			' (' + padLeftStr(percentage, 3, '\u00A0') + '%)';
+	}
+
+	if (div_progress_bar) {
+		//div_progress_bar.setAttribute('style', 'width: '+percentage+'%;');
+		div_progress_bar.style.width = percentage + '%';
+	}
+}
+
+
+var t_interval_server = '';
+var cmds_server = '';
+var t0 = new Date();
+
+/**
+ * write how much it took to generate data, and to run script
+ *
+ * @globals t0, t_interval_server, cmds_server
+ */
+function writeTimeInterval() {
+	var info_time = document.getElementById('generating_time');
+	if (!info_time || !t_interval_server) {
+		return;
+	}
+	var t1 = new Date();
+	info_time.firstChild.data += ' + (' +
+		t_interval_server + ' sec server blame_data / ' +
+		(t1.getTime() - t0.getTime())/1000 + ' sec client JavaScript)';
+
+	var info_cmds = document.getElementById('generating_cmd');
+	if (!info_time || !cmds_server) {
+		return;
+	}
+	info_cmds.firstChild.data += ' + ' + cmds_server;
+}
+
+/**
+ * show an error message alert to user within page (in prohress info area)
+ * @param {String} str: plain text error message (no HTML)
+ *
+ * @globals div_progress_info
+ */
+function errorInfo(str) {
+	if (!div_progress_info) {
+		div_progress_info = document.getElementById('progress_info');
+	}
+	if (div_progress_info) {
+		div_progress_info.className = 'error';
+		div_progress_info.firstChild.data = str;
+	}
+}
+
+/* ............................................................ */
+/* coloring rows during blame_data (git blame --incremental) run */
+
+/**
+ * used to extract N from 'colorN', where N is a number,
+ * @constant
+ */
+var colorRe = /\bcolor([0-9]*)\b/;
+
+/**
+ * return N if <tr class="colorN">, otherwise return null
+ * (some browsers require CSS class names to begin with letter)
+ *
+ * @param {HTMLElement} tr: table row element to check
+ * @param {String} tr.className: 'class' attribute of tr element
+ * @returns {Number|null} N if tr.className == 'colorN', otherwise null
+ *
+ * @globals colorRe
+ */
+function getColorNo(tr) {
+	if (!tr) {
+		return null;
+	}
+	var className = tr.className;
+	if (className) {
+		var match = colorRe.exec(className);
+		if (match) {
+			return parseInt(match[1], 10);
+		}
+	}
+	return null;
+}
+
+var colorsFreq = [0, 0, 0];
+/**
+ * return one of given possible colors (curently least used one)
+ * example: chooseColorNoFrom(2, 3) returns 2 or 3
+ *
+ * @param {Number[]} arguments: one or more numbers
+ *        assumes that  1 <= arguments[i] <= colorsFreq.length
+ * @returns {Number} Least used color number from arguments
+ * @globals colorsFreq
+ */
+function chooseColorNoFrom() {
+	// choose the color which is least used
+	var colorNo = arguments[0];
+	for (var i = 1; i < arguments.length; i++) {
+		if (colorsFreq[arguments[i]-1] < colorsFreq[colorNo-1]) {
+			colorNo = arguments[i];
+		}
+	}
+	colorsFreq[colorNo-1]++;
+	return colorNo;
+}
+
+/**
+ * given two neigbour <tr> elements, find color which would be different
+ * from color of both of neighbours; used to 3-color blame table
+ *
+ * @param {HTMLElement} tr_prev
+ * @param {HTMLElement} tr_next
+ * @returns {Number} color number N such that
+ * colorN != tr_prev.className && colorN != tr_next.className
+ */
+function findColorNo(tr_prev, tr_next) {
+	var color_prev = getColorNo(tr_prev);
+	var color_next = getColorNo(tr_next);
+
+
+	// neither of neighbours has color set
+	// THEN we can use any of 3 possible colors
+	if (!color_prev && !color_next) {
+		return chooseColorNoFrom(1,2,3);
+	}
+
+	// either both neighbours have the same color,
+	// or only one of neighbours have color set
+	// THEN we can use any color except given
+	var color;
+	if (color_prev === color_next) {
+		color = color_prev; // = color_next;
+	} else if (!color_prev) {
+		color = color_next;
+	} else if (!color_next) {
+		color = color_prev;
+	}
+	if (color) {
+		return chooseColorNoFrom((color % 3) + 1, ((color+1) % 3) + 1);
+	}
+
+	// neighbours have different colors
+	// THEN there is only one color left
+	return (3 - ((color_prev + color_next) % 3));
+}
+
+/* ............................................................ */
+/* coloring rows like 'blame' after 'blame_data' finishes */
+
+/**
+ * returns true if given row element (tr) is first in commit group
+ * to be used only after 'blame_data' finishes (after processing)
+ *
+ * @param {HTMLElement} tr: table row
+ * @returns {Boolean} true if TR is first in commit group
+ */
+function isStartOfGroup(tr) {
+	return tr.firstChild.className === 'sha1';
+}
+
+/**
+ * change colors to use zebra coloring (2 colors) instead of 3 colors
+ * concatenate neighbour commit groups belonging to the same commit
+ *
+ * @globals colorRe
+ */
+function fixColorsAndGroups() {
+	var colorClasses = ['light', 'dark'];
+	var linenum = 1;
+	var tr, prev_group;
+	var colorClass = 0;
+	var table =
+		document.getElementById('blame_table') ||
+		document.getElementsByTagName('table')[0];
+
+	while ((tr = document.getElementById('l'+linenum))) {
+	// index origin is 0, which is table header; start from 1
+	//while ((tr = table.rows[linenum])) { // <- it is slower
+		if (isStartOfGroup(tr, linenum, document)) {
+			if (prev_group &&
+			    prev_group.firstChild.firstChild.href ===
+			            tr.firstChild.firstChild.href) {
+				// we have to concatenate groups
+				var prev_rows = prev_group.firstChild.rowSpan || 1;
+				var curr_rows =         tr.firstChild.rowSpan || 1;
+				prev_group.firstChild.rowSpan = prev_rows + curr_rows;
+				//tr.removeChild(tr.firstChild);
+				tr.deleteCell(0); // DOM2 HTML way
+			} else {
+				colorClass = (colorClass + 1) % 2;
+				prev_group = tr;
+			}
+		}
+		var tr_class = tr.className;
+		tr.className = tr_class.replace(colorRe, colorClasses[colorClass]);
+		linenum++;
+	}
+}
+
+/* ............................................................ */
+/* time and data */
+
+/**
+ * used to extract hours and minutes from timezone info, e.g '-0900'
+ * @constant
+ */
+var tzRe = /^([+-][0-9][0-9])([0-9][0-9])$/;
+
+/**
+ * return date in local time formatted in iso-8601 like format
+ * 'yyyy-mm-dd HH:MM:SS +/-ZZZZ' e.g. '2005-08-07 21:49:46 +0200'
+ *
+ * @param {Number} epoch: seconds since '00:00:00 1970-01-01 UTC'
+ * @param {String} timezoneInfo: numeric timezone '(+|-)HHMM'
+ * @returns {String} date in local time in iso-8601 like format
+ *
+ * @globals tzRe
+ */
+function formatDateISOLocal(epoch, timezoneInfo) {
+	var match = tzRe.exec(timezoneInfo);
+	// date corrected by timezone
+	var localDate = new Date(1000 * (epoch +
+		(parseInt(match[1],10)*3600 + parseInt(match[2],10)*60)));
+	var localDateStr = // e.g. '2005-08-07'
+		localDate.getUTCFullYear()                 + '-' +
+		padLeft(localDate.getUTCMonth()+1, 2, '0') + '-' +
+		padLeft(localDate.getUTCDate(),    2, '0');
+	var localTimeStr = // e.g. '21:49:46'
+		padLeft(localDate.getUTCHours(),   2, '0') + ':' +
+		padLeft(localDate.getUTCMinutes(), 2, '0') + ':' +
+		padLeft(localDate.getUTCSeconds(), 2, '0');
+
+	return localDateStr + ' ' + localTimeStr + ' ' + timezoneInfo;
+}
+
+/* ............................................................ */
+/* unquoting/unescaping filenames */
+
+/**#@+
+ * @constant
+ */
+var escCodeRe = /\\([^0-7]|[0-7]{1,3})/g;
+var octEscRe = /^[0-7]{1,3}$/;
+var maybeQuotedRe = /^\"(.*)\"$/;
+/**#@-*/
+
+/**
+ * unquote maybe git-quoted filename
+ * e.g. 'aa' -> 'aa', '"a\ta"' -> 'a	a'
+ *
+ * @param {String} str: git-quoted string
+ * @returns {String} Unquoted and unescaped string
+ *
+ * @globals escCodeRe, octEscRe, maybeQuotedRe
+ */
+function unquote(str) {
+	function unq(seq) {
+		var es = {
+			// character escape codes, aka escape sequences (from C)
+			// replacements are to some extent JavaScript specific
+			t: "\t",   // tab            (HT, TAB)
+			n: "\n",   // newline        (NL)
+			r: "\r",   // return         (CR)
+			f: "\f",   // form feed      (FF)
+			b: "\b",   // backspace      (BS)
+			a: "\x07", // alarm (bell)   (BEL)
+			e: "\x1B", // escape         (ESC)
+			v: "\v"    // vertical tab   (VT)
+		};
+
+		if (seq.search(octEscRe) !== -1) {
+			// octal char sequence
+			return String.fromCharCode(parseInt(seq, 8));
+		} else if (seq in es) {
+			// C escape sequence, aka character escape code
+			return es[seq];
+		}
+		// quoted ordinary character
+		return seq;
+	}
+
+	var match = str.match(maybeQuotedRe);
+	if (match) {
+		str = match[1];
+		// perhaps str = eval('"'+str+'"'); would be enough?
+		str = str.replace(escCodeRe,
+			function (substr, p1, offset, s) { return unq(p1); });
+	}
+	return str;
+}
+
+/* ============================================================ */
+/* main part: parsing response */
+
+/**
+ * Function called for each blame entry, as soon as it finishes.
+ * It updates page via DOM manipulation, adding sha1 info, etc.
+ *
+ * @param {Commit} commit: blamed commit
+ * @param {Object} group: object representing group of lines,
+ *                        which blame the same commit (blame entry)
+ *
+ * @globals blamedLines
+ */
+function handleLine(commit, group) {
+	/*
+	   This is the structure of the HTML fragment we are working
+	   with:
+
+	   <tr id="l123" class="">
+	     <td class="sha1" title=""><a href=""> </a></td>
+	     <td class="linenr"><a class="linenr" href="">123</a></td>
+	     <td class="pre"># times (my ext3 doesn&#39;t).</td>
+	   </tr>
+	*/
+
+	var resline = group.resline;
+
+	// format date and time string only once per commit
+	if (!commit.info) {
+		/* e.g. 'Kay Sievers, 2005-08-07 21:49:46 +0200' */
+		commit.info = commit.author + ', ' +
+			formatDateISOLocal(commit.authorTime, commit.authorTimezone);
+	}
+
+	// color depends on group of lines, not only on blamed commit
+	var colorNo = findColorNo(
+		document.getElementById('l'+(resline-1)),
+		document.getElementById('l'+(resline+group.numlines))
+	);
+
+	// loop over lines in commit group
+	for (var i = 0; i < group.numlines; i++, resline++) {
+		var tr = document.getElementById('l'+resline);
+		if (!tr) {
+			break;
+		}
+		/*
+			<tr id="l123" class="">
+			  <td class="sha1" title=""><a href=""> </a></td>
+			  <td class="linenr"><a class="linenr" href="">123</a></td>
+			  <td class="pre"># times (my ext3 doesn&#39;t).</td>
+			</tr>
+		*/
+		var td_sha1  = tr.firstChild;
+		var a_sha1   = td_sha1.firstChild;
+		var a_linenr = td_sha1.nextSibling.firstChild;
+
+		/* <tr id="l123" class=""> */
+		var tr_class = '';
+		if (colorNo !== null) {
+			tr_class = 'color'+colorNo;
+		}
+		if (commit.boundary) {
+			tr_class += ' boundary';
+		}
+		if (commit.nprevious === 0) {
+			tr_class += ' no-previous';
+		} else if (commit.nprevious > 1) {
+			tr_class += ' multiple-previous';
+		}
+		tr.className = tr_class;
+
+		/* <td class="sha1" title="?" rowspan="?"><a href="?">?</a></td> */
+		if (i === 0) {
+			td_sha1.title = commit.info;
+			td_sha1.rowSpan = group.numlines;
+
+			a_sha1.href = projectUrl + 'a=commit;h=' + commit.sha1;
+			if (a_sha1.firstChild) {
+				a_sha1.firstChild.data = commit.sha1.substr(0, 8);
+			} else {
+				a_sha1.appendChild(
+					document.createTextNode(commit.sha1.substr(0, 8)));
+			}
+			if (group.numlines >= 2) {
+				var fragment = document.createDocumentFragment();
+				var br   = document.createElement("br");
+				var match = commit.author.match(/\b([A-Z])\B/g);
+				if (match) {
+					var text = document.createTextNode(
+							match.join(''));
+				}
+				if (br && text) {
+					var elem = fragment || td_sha1;
+					elem.appendChild(br);
+					elem.appendChild(text);
+					if (fragment) {
+						td_sha1.appendChild(fragment);
+					}
+				}
+			}
+		} else {
+			//tr.removeChild(td_sha1); // DOM2 Core way
+			tr.deleteCell(0); // DOM2 HTML way
+		}
+
+		/* <td class="linenr"><a class="linenr" href="?">123</a></td> */
+		var linenr_commit =
+			('previous' in commit ? commit.previous : commit.sha1);
+		var linenr_filename =
+			('file_parent' in commit ? commit.file_parent : commit.filename);
+		a_linenr.href = projectUrl + 'a=blame_incremental' +
+			';hb=' + linenr_commit +
+			';f='  + encodeURIComponent(linenr_filename) +
+			'#l' + (group.srcline + i);
+
+		blamedLines++;
+
+		//updateProgressInfo();
+	}
+}
+
+// ----------------------------------------------------------------------
+
+var inProgress = false;   // are we processing response
+
+/**#@+
+ * @constant
+ */
+var sha1Re = /^([0-9a-f]{40}) ([0-9]+) ([0-9]+) ([0-9]+)/;
+var infoRe = /^([a-z-]+) ?(.*)/;
+var endRe  = /^END ?([^ ]*) ?(.*)/;
+/**@-*/
+
+var curCommit = new Commit();
+var curGroup  = {};
+
+var pollTimer = null;
+
+/**
+ * Parse output from 'git blame --incremental [...]', received via
+ * XMLHttpRequest from server (blamedataUrl), and call handleLine
+ * (which updates page) as soon as blame entry is completed.
+ *
+ * @param {String[]} lines: new complete lines from blamedata server
+ *
+ * @globals commits, curCommit, curGroup, t_interval_server, cmds_server
+ * @globals sha1Re, infoRe, endRe
+ */
+function processBlameLines(lines) {
+	var match;
+
+	for (var i = 0, len = lines.length; i < len; i++) {
+
+		if ((match = sha1Re.exec(lines[i]))) {
+			var sha1 = match[1];
+			var srcline  = parseInt(match[2], 10);
+			var resline  = parseInt(match[3], 10);
+			var numlines = parseInt(match[4], 10);
+
+			var c = commits[sha1];
+			if (!c) {
+				c = new Commit(sha1);
+				commits[sha1] = c;
+			}
+			curCommit = c;
+
+			curGroup.srcline = srcline;
+			curGroup.resline = resline;
+			curGroup.numlines = numlines;
+
+		} else if ((match = infoRe.exec(lines[i]))) {
+			var info = match[1];
+			var data = match[2];
+			switch (info) {
+			case 'filename':
+				curCommit.filename = unquote(data);
+				// 'filename' information terminates the entry
+				handleLine(curCommit, curGroup);
+				updateProgressInfo();
+				break;
+			case 'author':
+				curCommit.author = data;
+				break;
+			case 'author-time':
+				curCommit.authorTime = parseInt(data, 10);
+				break;
+			case 'author-tz':
+				curCommit.authorTimezone = data;
+				break;
+			case 'previous':
+				curCommit.nprevious++;
+				// store only first 'previous' header
+				if (!'previous' in curCommit) {
+					var parts = data.split(' ', 2);
+					curCommit.previous    = parts[0];
+					curCommit.file_parent = unquote(parts[1]);
+				}
+				break;
+			case 'boundary':
+				curCommit.boundary = true;
+				break;
+			} // end switch
+
+		} else if ((match = endRe.exec(lines[i]))) {
+			t_interval_server = match[1];
+			cmds_server = match[2];
+
+		} else if (lines[i] !== '') {
+			// malformed line
+
+		} // end if (match)
+
+	} // end for (lines)
+}
+
+/**
+ * Process new data and return pointer to end of processed part
+ *
+ * @param {String} unprocessed: new data (from nextReadPos)
+ * @param {Number} nextReadPos: end of last processed data
+ * @return {Number} end of processed data (new value for nextReadPos)
+ */
+function processData(unprocessed, nextReadPos) {
+	var lastLineEnd = unprocessed.lastIndexOf('\n');
+	if (lastLineEnd !== -1) {
+		var lines = unprocessed.substring(0, lastLineEnd).split('\n');
+		nextReadPos += lastLineEnd + 1 /* 1 == '\n'.length */;
+
+		processBlameLines(lines);
+	} // end if
+
+	return nextReadPos;
+}
+
+/**
+ * Handle XMLHttpRequest errors
+ *
+ * @param {XMLHttpRequest} xhr: XMLHttpRequest object
+ *
+ * @globals pollTimer, commits, inProgress
+ */
+function handleError(xhr) {
+	errorInfo('Server error: ' +
+		xhr.status + ' - ' + (xhr.statusText || 'Error contacting server'));
+
+	clearInterval(pollTimer);
+	commits = {}; // free memory
+
+	inProgress = false;
+}
+
+/**
+ * Called after XMLHttpRequest finishes (loads)
+ *
+ * @param {XMLHttpRequest} xhr: XMLHttpRequest object (unused)
+ *
+ * @globals pollTimer, commits, inProgress
+ */
+function responseLoaded(xhr) {
+	clearInterval(pollTimer);
+
+	fixColorsAndGroups();
+	writeTimeInterval();
+	commits = {}; // free memory
+
+	inProgress = false;
+}
+
+/**
+ * handler for XMLHttpRequest onreadystatechange event
+ * @see startBlame
+ *
+ * @globals xhr, inProgress
+ */
+function handleResponse() {
+
+	/*
+	 * xhr.readyState
+	 *
+	 *  Value  Constant (W3C)    Description
+	 *  -------------------------------------------------------------------
+	 *  0      UNSENT            open() has not been called yet.
+	 *  1      OPENED            send() has not been called yet.
+	 *  2      HEADERS_RECEIVED  send() has been called, and headers
+	 *                           and status are available.
+	 *  3      LOADING           Downloading; responseText holds partial data.
+	 *  4      DONE              The operation is complete.
+	 */
+
+	if (xhr.readyState !== 4 && xhr.readyState !== 3) {
+		return;
+	}
+
+	// the server returned error
+	if (xhr.readyState === 3 && xhr.status !== 200) {
+		return;
+	}
+	if (xhr.readyState === 4 && xhr.status !== 200) {
+		handleError(xhr);
+		return;
+	}
+
+	// In konqueror xhr.responseText is sometimes null here...
+	if (xhr.responseText === null) {
+		return;
+	}
+
+	// in case we were called before finished processing
+	if (inProgress) {
+		return;
+	} else {
+		inProgress = true;
+	}
+
+	// extract new whole (complete) lines, and process them
+	while (xhr.prevDataLength !== xhr.responseText.length) {
+		if (xhr.readyState === 4 &&
+		    xhr.prevDataLength === xhr.responseText.length) {
+			break;
+		}
+
+		xhr.prevDataLength = xhr.responseText.length;
+		var unprocessed = xhr.responseText.substring(xhr.nextReadPos);
+		xhr.nextReadPos = processData(unprocessed, xhr.nextReadPos);
+	} // end while
+
+	// did we finish work?
+	if (xhr.readyState === 4 &&
+	    xhr.prevDataLength === xhr.responseText.length) {
+		responseLoaded(xhr);
+	}
+
+	inProgress = false;
+}
+
+// ============================================================
+// ------------------------------------------------------------
+
+/**
+ * Incrementally update line data in blame_incremental view in gitweb.
+ *
+ * @param {String} blamedataUrl: URL to server script generating blame data.
+ * @param {String} bUrl: partial URL to project, used to generate links.
+ *
+ * Called from 'blame_incremental' view after loading table with
+ * file contents, a base for blame view.
+ *
+ * @globals xhr, t0, projectUrl, div_progress_bar, totalLines, pollTimer
+*/
+function startBlame(blamedataUrl, bUrl) {
+
+	xhr = createRequestObject();
+	if (!xhr) {
+		errorInfo('ERROR: XMLHttpRequest not supported');
+		return;
+	}
+
+	t0 = new Date();
+	projectUrl = bUrl + (bUrl.indexOf('?') === -1 ? '?' : ';');
+	if ((div_progress_bar = document.getElementById('progress_bar'))) {
+		//div_progress_bar.setAttribute('style', 'width: 100%;');
+		div_progress_bar.style.cssText = 'width: 100%;';
+	}
+	totalLines = countLines();
+	updateProgressInfo();
+
+	/* add extra properties to xhr object to help processing response */
+	xhr.prevDataLength = -1;  // used to detect if we have new data
+	xhr.nextReadPos = 0;      // where unread part of response starts
+
+	xhr.onreadystatechange = handleResponse;
+	//xhr.onreadystatechange = function () { handleResponse(xhr); };
+
+	xhr.open('GET', blamedataUrl);
+	xhr.setRequestHeader('Accept', 'text/plain');
+	xhr.send(null);
+
+	// not all browsers call onreadystatechange event on each server flush
+	// poll response using timer every second to handle this issue
+	pollTimer = setInterval(xhr.onreadystatechange, 1000);
+}
+
+// end of gitweb.js
diff --git a/gitweb/gitweb.perl b/gitweb/gitweb.perl
index f94536c680..7e477af956 100755
--- a/gitweb/gitweb.perl
+++ b/gitweb/gitweb.perl
@@ -18,6 +18,12 @@ use File::Find qw();
 use File::Basename qw(basename);
 binmode STDOUT, ':utf8';
 
+our $t0;
+if (eval { require Time::HiRes; 1; }) {
+	$t0 = [Time::HiRes::gettimeofday()];
+}
+our $number_of_git_cmds = 0;
+
 BEGIN {
 	CGI->compile() if $ENV{'MOD_PERL'};
 }
@@ -90,6 +96,8 @@ our $stylesheet = undef;
 our $logo = "++GITWEB_LOGO++";
 # URI of GIT favicon, assumed to be image/png type
 our $favicon = "++GITWEB_FAVICON++";
+# URI of gitweb.js (JavaScript code for gitweb)
+our $javascript = "++GITWEB_JS++";
 
 # URI and label (title) of GIT logo link
 #our $logo_url = "http://www.kernel.org/pub/software/scm/git/docs/";
@@ -417,6 +425,20 @@ our %feature = (
 		'sub' => \&feature_avatar,
 		'override' => 0,
 		'default' => ['']},
+
+	# Enable displaying how much time and how many git commands
+	# it took to generate and display page.  Disabled by default.
+	# Project specific override is not supported.
+	'timed' => {
+		'override' => 0,
+		'default' => [0]},
+
+	# Enable turning some links into links to actions which require
+	# JavaScript to run (like 'blame_incremental').  Not enabled by
+	# default.  Project specific override is currently not supported.
+	'javascript-actions' => {
+		'override' => 0,
+		'default' => [0]},
 );
 
 sub gitweb_get_feature {
@@ -531,6 +553,7 @@ if (-e $GITWEB_CONFIG) {
 
 # version of the core git binary
 our $git_version = qx("$GIT" --version) =~ m/git version (.*)$/ ? $1 : "unknown";
+$number_of_git_cmds++;
 
 $projects_list ||= $projectroot;
 
@@ -568,12 +591,16 @@ our @cgi_param_mapping = (
 	snapshot_format => "sf",
 	extra_options => "opt",
 	search_use_regexp => "sr",
+	# this must be last entry (for manipulation from JavaScript)
+	javascript => "js"
 );
 our %cgi_param_mapping = @cgi_param_mapping;
 
 # we will also need to know the possible actions, for validation
 our %actions = (
 	"blame" => \&git_blame,
+	"blame_incremental" => \&git_blame_incremental,
+	"blame_data" => \&git_blame_data,
 	"blobdiff" => \&git_blobdiff,
 	"blobdiff_plain" => \&git_blobdiff_plain,
 	"blob" => \&git_blob,
@@ -2006,6 +2033,7 @@ sub get_feed_info {
 
 # returns path to the core git executable and the --git-dir parameter as list
 sub git_cmd {
+	$number_of_git_cmds++;
 	return $GIT, '--git-dir='.$git_dir;
 }
 
@@ -3281,10 +3309,36 @@ sub git_footer_html {
 	}
 	print "</div>\n"; # class="page_footer"
 
+	if (defined $t0 && gitweb_check_feature('timed')) {
+		print "<div id=\"generating_info\">\n";
+		print 'This page took '.
+		      '<span id="generating_time" class="time_span">'.
+		      Time::HiRes::tv_interval($t0, [Time::HiRes::gettimeofday()]).
+		      ' seconds </span>'.
+		      ' and '.
+		      '<span id="generating_cmd">'.
+		      $number_of_git_cmds.
+		      '</span> git commands '.
+		      " to generate.\n";
+		print "</div>\n"; # class="page_footer"
+	}
+
 	if (-f $site_footer) {
 		insert_file($site_footer);
 	}
 
+	print qq!<script type="text/javascript" src="$javascript"></script>\n!;
+	if ($action eq 'blame_incremental') {
+		print qq!<script type="text/javascript">\n!.
+		      qq!startBlame("!. href(action=>"blame_data", -replay=>1) .qq!",\n!.
+		      qq!           "!. href() .qq!");\n!.
+		      qq!</script>\n!;
+	} elsif (gitweb_check_feature('javascript-actions')) {
+		print qq!<script type="text/javascript">\n!.
+		      qq!window.onload = fixLinks;\n!.
+		      qq!</script>\n!;
+	}
+
 	print "</body>\n" .
 	      "</html>";
 }
@@ -4881,7 +4935,13 @@ sub git_tag {
 	git_footer_html();
 }
 
-sub git_blame {
+sub git_blame_common {
+	my $format = shift || 'porcelain';
+	if ($format eq 'porcelain' && $cgi->param('js')) {
+		$format = 'incremental';
+		$action = 'blame_incremental'; # for page title etc
+	}
+
 	# permissions
 	gitweb_check_feature('blame')
 		or die_error(403, "Blame view not allowed");
@@ -4903,123 +4963,220 @@ sub git_blame {
 		}
 	}
 
-	# run git-blame --porcelain
-	open my $fd, "-|", git_cmd(), "blame", '-p',
-		$hash_base, '--', $file_name
-		or die_error(500, "Open git-blame failed");
+	my $fd;
+	if ($format eq 'incremental') {
+		# get file contents (as base)
+		open $fd, "-|", git_cmd(), 'cat-file', 'blob', $hash
+			or die_error(500, "Open git-cat-file failed");
+	} elsif ($format eq 'data') {
+		# run git-blame --incremental
+		open $fd, "-|", git_cmd(), "blame", "--incremental",
+			$hash_base, "--", $file_name
+			or die_error(500, "Open git-blame --incremental failed");
+	} else {
+		# run git-blame --porcelain
+		open $fd, "-|", git_cmd(), "blame", '-p',
+			$hash_base, '--', $file_name
+			or die_error(500, "Open git-blame --porcelain failed");
+	}
+
+	# incremental blame data returns early
+	if ($format eq 'data') {
+		print $cgi->header(
+			-type=>"text/plain", -charset => "utf-8",
+			-status=> "200 OK");
+		local $| = 1; # output autoflush
+		print while <$fd>;
+		close $fd
+			or print "ERROR $!\n";
+
+		print 'END';
+		if (defined $t0 && gitweb_check_feature('timed')) {
+			print ' '.
+			      Time::HiRes::tv_interval($t0, [Time::HiRes::gettimeofday()]).
+			      ' '.$number_of_git_cmds;
+		}
+		print "\n";
+
+		return;
+	}
 
 	# page header
 	git_header_html();
 	my $formats_nav =
 		$cgi->a({-href => href(action=>"blob", -replay=>1)},
 		        "blob") .
+		" | ";
+	if ($format eq 'incremental') {
+		$formats_nav .=
+			$cgi->a({-href => href(action=>"blame", javascript=>0, -replay=>1)},
+			        "blame") . " (non-incremental)";
+	} else {
+		$formats_nav .=
+			$cgi->a({-href => href(action=>"blame_incremental", -replay=>1)},
+			        "blame") . " (incremental)";
+	}
+	$formats_nav .=
 		" | " .
 		$cgi->a({-href => href(action=>"history", -replay=>1)},
 		        "history") .
 		" | " .
-		$cgi->a({-href => href(action=>"blame", file_name=>$file_name)},
+		$cgi->a({-href => href(action=>$action, file_name=>$file_name)},
 		        "HEAD");
 	git_print_page_nav('','', $hash_base,$co{'tree'},$hash_base, $formats_nav);
 	git_print_header_div('commit', esc_html($co{'title'}), $hash_base);
 	git_print_page_path($file_name, $ftype, $hash_base);
 
 	# page body
+	if ($format eq 'incremental') {
+		print "<noscript>\n<div class=\"error\"><center><b>\n".
+		      "This page requires JavaScript to run.\n Use ".
+		      $cgi->a({-href => href(action=>'blame',javascript=>0,-replay=>1)},
+		              'this page').
+		      " instead.\n".
+		      "</b></center></div>\n</noscript>\n";
+
+		print qq!<div id="progress_bar" style="width: 100%; background-color: yellow"></div>\n!;
+	}
+
+	print qq!<div class="page_body">\n!;
+	print qq!<div id="progress_info">... / ...</div>\n!
+		if ($format eq 'incremental');
+	print qq!<table id="blame_table" class="blame" width="100%">\n!.
+	      #qq!<col width="5.5em" /><col width="2.5em" /><col width="*" />\n!.
+	      qq!<thead>\n!.
+	      qq!<tr><th>Commit</th><th>Line</th><th>Data</th></tr>\n!.
+	      qq!</thead>\n!.
+	      qq!<tbody>\n!;
+
 	my @rev_color = qw(light dark);
 	my $num_colors = scalar(@rev_color);
 	my $current_color = 0;
-	my %metainfo = ();
 
-	print <<HTML;
-<div class="page_body">
-<table class="blame">
-<tr><th>Commit</th><th>Line</th><th>Data</th></tr>
-HTML
- LINE:
-	while (my $line = <$fd>) {
-		chomp $line;
-		# the header: <SHA-1> <src lineno> <dst lineno> [<lines in group>]
-		# no <lines in group> for subsequent lines in group of lines
-		my ($full_rev, $orig_lineno, $lineno, $group_size) =
-		   ($line =~ /^([0-9a-f]{40}) (\d+) (\d+)(?: (\d+))?$/);
-		if (!exists $metainfo{$full_rev}) {
-			$metainfo{$full_rev} = { 'nprevious' => 0 };
-		}
-		my $meta = $metainfo{$full_rev};
-		my $data;
-		while ($data = <$fd>) {
-			chomp $data;
-			last if ($data =~ s/^\t//); # contents of line
-			if ($data =~ /^(\S+)(?: (.*))?$/) {
-				$meta->{$1} = $2 unless exists $meta->{$1};
+	if ($format eq 'incremental') {
+		my $color_class = $rev_color[$current_color];
+
+		#contents of a file
+		my $linenr = 0;
+	LINE:
+		while (my $line = <$fd>) {
+			chomp $line;
+			$linenr++;
+
+			print qq!<tr id="l$linenr" class="$color_class">!.
+			      qq!<td class="sha1"><a href=""> </a></td>!.
+			      qq!<td class="linenr">!.
+			      qq!<a class="linenr" href="">$linenr</a></td>!;
+			print qq!<td class="pre">! . esc_html($line) . "</td>\n";
+			print qq!</tr>\n!;
+		}
+
+	} else { # porcelain, i.e. ordinary blame
+		my %metainfo = (); # saves information about commits
+
+		# blame data
+	LINE:
+		while (my $line = <$fd>) {
+			chomp $line;
+			# the header: <SHA-1> <src lineno> <dst lineno> [<lines in group>]
+			# no <lines in group> for subsequent lines in group of lines
+			my ($full_rev, $orig_lineno, $lineno, $group_size) =
+			   ($line =~ /^([0-9a-f]{40}) (\d+) (\d+)(?: (\d+))?$/);
+			if (!exists $metainfo{$full_rev}) {
+				$metainfo{$full_rev} = { 'nprevious' => 0 };
 			}
-			if ($data =~ /^previous /) {
-				$meta->{'nprevious'}++;
+			my $meta = $metainfo{$full_rev};
+			my $data;
+			while ($data = <$fd>) {
+				chomp $data;
+				last if ($data =~ s/^\t//); # contents of line
+				if ($data =~ /^(\S+)(?: (.*))?$/) {
+					$meta->{$1} = $2 unless exists $meta->{$1};
+				}
+				if ($data =~ /^previous /) {
+					$meta->{'nprevious'}++;
+				}
 			}
-		}
-		my $short_rev = substr($full_rev, 0, 8);
-		my $author = $meta->{'author'};
-		my %date =
-			parse_date($meta->{'author-time'}, $meta->{'author-tz'});
-		my $date = $date{'iso-tz'};
-		if ($group_size) {
-			$current_color = ($current_color + 1) % $num_colors;
-		}
-		my $tr_class = $rev_color[$current_color];
-		$tr_class .= ' boundary' if (exists $meta->{'boundary'});
-		$tr_class .= ' no-previous' if ($meta->{'nprevious'} == 0);
-		$tr_class .= ' multiple-previous' if ($meta->{'nprevious'} > 1);
-		print "<tr id=\"l$lineno\" class=\"$tr_class\">\n";
-		if ($group_size) {
-			print "<td class=\"sha1\"";
-			print " title=\"". esc_html($author) . ", $date\"";
-			print " rowspan=\"$group_size\"" if ($group_size > 1);
-			print ">";
-			print $cgi->a({-href => href(action=>"commit",
-			                             hash=>$full_rev,
-			                             file_name=>$file_name)},
-			              esc_html($short_rev));
-			if ($group_size >= 2) {
-				my @author_initials = ($author =~ /\b([[:upper:]])\B/g);
-				if (@author_initials) {
-					print "<br />" .
-					      esc_html(join('', @author_initials));
-					#           or join('.', ...)
+			my $short_rev = substr($full_rev, 0, 8);
+			my $author = $meta->{'author'};
+			my %date =
+				parse_date($meta->{'author-time'}, $meta->{'author-tz'});
+			my $date = $date{'iso-tz'};
+			if ($group_size) {
+				$current_color = ($current_color + 1) % $num_colors;
+			}
+			my $tr_class = $rev_color[$current_color];
+			$tr_class .= ' boundary' if (exists $meta->{'boundary'});
+			$tr_class .= ' no-previous' if ($meta->{'nprevious'} == 0);
+			$tr_class .= ' multiple-previous' if ($meta->{'nprevious'} > 1);
+			print "<tr id=\"l$lineno\" class=\"$tr_class\">\n";
+			if ($group_size) {
+				print "<td class=\"sha1\"";
+				print " title=\"". esc_html($author) . ", $date\"";
+				print " rowspan=\"$group_size\"" if ($group_size > 1);
+				print ">";
+				print $cgi->a({-href => href(action=>"commit",
+				                             hash=>$full_rev,
+				                             file_name=>$file_name)},
+				              esc_html($short_rev));
+				if ($group_size >= 2) {
+					my @author_initials = ($author =~ /\b([[:upper:]])\B/g);
+					if (@author_initials) {
+						print "<br />" .
+						      esc_html(join('', @author_initials));
+						#           or join('.', ...)
+					}
 				}
+				print "</td>\n";
 			}
-			print "</td>\n";
-		}
-		# 'previous' <sha1 of parent commit> <filename at commit>
-		if (exists $meta->{'previous'} &&
-		    $meta->{'previous'} =~ /^([a-fA-F0-9]{40}) (.*)$/) {
-			$meta->{'parent'} = $1;
-			$meta->{'file_parent'} = unquote($2);
-		}
-		my $linenr_commit =
-			exists($meta->{'parent'}) ?
-			$meta->{'parent'} : $full_rev;
-		my $linenr_filename =
-			exists($meta->{'file_parent'}) ?
-			$meta->{'file_parent'} : unquote($meta->{'filename'});
-		my $blamed = href(action => 'blame',
-		                  file_name => $linenr_filename,
-		                  hash_base => $linenr_commit);
-		print "<td class=\"linenr\">";
-		print $cgi->a({ -href => "$blamed#l$orig_lineno",
-		                -class => "linenr" },
-		              esc_html($lineno));
-		print "</td>";
-		print "<td class=\"pre\">" . esc_html($data) . "</td>\n";
-		print "</tr>\n";
+			# 'previous' <sha1 of parent commit> <filename at commit>
+			if (exists $meta->{'previous'} &&
+			    $meta->{'previous'} =~ /^([a-fA-F0-9]{40}) (.*)$/) {
+				$meta->{'parent'} = $1;
+				$meta->{'file_parent'} = unquote($2);
+			}
+			my $linenr_commit =
+				exists($meta->{'parent'}) ?
+				$meta->{'parent'} : $full_rev;
+			my $linenr_filename =
+				exists($meta->{'file_parent'}) ?
+				$meta->{'file_parent'} : unquote($meta->{'filename'});
+			my $blamed = href(action => 'blame',
+			                  file_name => $linenr_filename,
+			                  hash_base => $linenr_commit);
+			print "<td class=\"linenr\">";
+			print $cgi->a({ -href => "$blamed#l$orig_lineno",
+			                -class => "linenr" },
+			              esc_html($lineno));
+			print "</td>";
+			print "<td class=\"pre\">" . esc_html($data) . "</td>\n";
+			print "</tr>\n";
+		} # end while
+
 	}
-	print "</table>\n";
-	print "</div>";
+
+	# footer
+	print "</tbody>\n".
+	      "</table>\n"; # class="blame"
+	print "</div>\n";   # class="blame_body"
 	close $fd
 		or print "Reading blob failed\n";
 
-	# page footer
 	git_footer_html();
 }
 
+sub git_blame {
+	git_blame_common();
+}
+
+sub git_blame_incremental {
+	git_blame_common('incremental');
+}
+
+sub git_blame_data {
+	git_blame_common('data');
+}
+
 sub git_tags {
 	my $head = git_get_head_hash($project);
 	git_header_html();