gitweb: Split JavaScript for maintability, combining on build

Split originally single gitweb.js file into smaller files, each
dealing with single issue / area of responsibility.  This move should
make gitweb's JavaScript code easier to maintain.

For better webapp performance it is recommended[1][2][3] to combine
JavaScript files.  Do it during build time (in gitweb/Makefile), by
straight concatenation of files into gitweb.js file (which is now
ignored as being generated).  This means that there are no changes to
gitweb script itself - it still uses gitweb.js or gitweb.min.js, but
now generated.

[1]: http://developer.yahoo.com/performance/rules.html
     "Minimize HTTP Requests" section
[2]: http://code.google.com/speed/articles/include-scripts-properly.html
     "1. Combine external JavaScript files"
[3]: http://javascript-reference.info/speed-up-your-javascript-load-time.htm
     "Combine Your Files" section.

See also new gitweb/static/js/README file.

Inspired-by-patch-by: John 'Warthog9' Hawley <warthog9@eaglescrag.net>
Signed-off-by: Jakub Narebski <jnareb@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 687 insertions, 0 deletions

diff --git a/gitweb/static/js/blame_incremental.js b/gitweb/static/js/blame_incremental.js
new file mode 100644
index 0000000000..f63f78b9ec
--- /dev/null
+++ b/gitweb/static/js/blame_incremental.js
@@ -0,0 +1,687 @@
+// Copyright (C) 2007, Fredrik Kuivinen <frekui@gmail.com>
+//               2007, Petr Baudis <pasky@suse.cz>
+//          2008-2011, Jakub Narebski <jnareb@gmail.com>
+
+/**
+ * @fileOverview JavaScript side of Ajax-y 'blame_incremental' view in gitweb
+ * @license GPLv2 or later
+ */
+
+
+/*
+ * 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.
+ */
+
+
+/* ============================================================ */
+/* 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++;
+	}
+}
+
+
+/* ============================================================ */
+/* 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
+	// try ... catch block is to work around bug in IE8
+	try {
+		if (xhr.readyState === 3 && xhr.status !== 200) {
+			return;
+		}
+	} catch (e) {
+		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 blame_incremental.js */