document = {} window = {} navigator = {} load("prototype-1.4.0.js"); load("example.js"); load("json.js"); load("jdbc.js"); load("inspect.js"); function callCC(f) { var k = new Continuation(); return f(k); } Savannah = {} Savannah.Servlet = Class.create(); Savannah.Servlet.prototype = { initialize: function () { this.entryPoints = []; this.unwinding = false; this.prng = java.security.SecureRandom.getInstance("SHA1PRNG"); this.sha = java.security.MessageDigest.getInstance("SHA-1"); this._current = new java.lang.ThreadLocal(); }, current: function () { return this._current.get(); }, session: function () { return this.current().sessionData; }, continuationMap: function () { var sess = this.session(); if (!sess.continuations) { sess.continuations = {}; } return sess.continuations; }, addEntryPoint: function (spec, proc) { var parts = spec.split('/'); var r = this.findEntryPoint(spec); if (r) { r.entryPoint[0] = parts; r.entryPoint[1] = proc; } else { this.entryPoints.push([parts, proc]); } }, findEntryPoint: function(path) { var pathParts = path.split('/'); for (var pointIndex = 0; pointIndex < this.entryPoints.length; pointIndex++) { var entryPoint = this.entryPoints[pointIndex]; var entryPointParts = entryPoint[0]; var bindings = {}; var matched = true; if (pathParts.length == entryPointParts.length) { for (var i = 0; (i < pathParts.length); i++) { if (entryPointParts[i][0] == '_') { bindings[entryPointParts[i].substring(1)] = pathParts[i]; } else { if (entryPointParts[i] != pathParts[i]) { matched = false; break; } } } if (matched) { return {entryPoint: entryPoint, bindings: bindings}; } } } return null; }, reply404: function (path) { this.replyError(404, "text/html",

Error 404: path {path}

); }, callEntryPoint: function(path) { var r = this.findEntryPoint(path); if (r) { return r.entryPoint[1](this, r.bindings); } else { this.reply404(path); } }, reply: function (contentType, content) { var resp = this.current().response; var os = resp.getOutputStream(); resp.setContentType(contentType); os.print(content); os.flush(); }, replyText: function (content) { return this.reply("text/plain", content); }, replyHtml: function (content) { return this.reply("text/html", content); }, replyJson: function (content) { return this.reply("application/x-json", JSON.stringify(content)); }, replyError: function (code, contentType, content) { this.current().response.setStatus(code); return this.reply(contentType, content); }, newContinuationId: function () { var bytes = this.sha.digest(new java.lang.String(this.prng.nextInt().toString()).getBytes()); var s = []; for (var i = 0; i < bytes.length; i++) { var bb = ((bytes[i] + 256) & 255).toString(16).toUpperCase(); if (bb.length == 1) { bb = "0" + bb; } s.push(bb); } return "k" + s.join(""); }, recordContinuation: function(k_id, k) { this.continuationMap()[k_id] = { cont: k, savedChain: this.saveStateChain() }; }, unwindToDispatcher: function () { this.unwinding = true; throw ""; }, isUnwinding: function () { return this.unwinding; }, sendAndSuspend: function(replier) { var k_id = this.newContinuationId(); var k_url = this.current().path_base + ";" + k_id; var k = new Continuation(); this.recordContinuation(k_id, k); replier(k_url); this.unwindToDispatcher(); }, sendAndDispatch: function(replier) { var actionMap = {}; var k = callCC(function (cc) { return cc }); if (k instanceof Continuation) { function procToUrl(proc) { var k_id = this.newContinuationId(); var k_url = this.current().path_base + ";" + k_id; actionMap[k_id] = proc; this.recordContinuation(k_id, k); return k_url; } replier(procToUrl.bind(this)); this.unwindToDispatcher(); } else { var k_id = this.current().invoked_k; return actionMap[k_id](k); } }, saveStateChain: function () { var curr = this.current().stateChain; var acc = null; while (curr != null) { acc = { holder: curr.holder, value: curr.holder.value, next: acc }; curr = curr.next; } return acc; }, restoreStateChain: function (savedChain) { var curr = savedChain; var acc = null; while (curr != null) { acc = { holder: curr.holder, next: acc }; curr.holder.value = curr.value; curr = curr.next; } this.current().stateChain = acc; }, withState: function (initValue, proc) { var h = new Savannah.StateHolder(this, initValue); try { return proc(h); } finally { if (!this.isUnwinding()) { h.forget(); } } }, extractContinuationId: function(path) { var m = /(.*);([^?;]+)/(path); if (m) { return [m[1], m[2]]; } else { return [path, null]; } }, handleRequest: function (req, resp) { var pathInfo = String(req.getRequestURI()); if (pathInfo == null) { pathInfo = "/"; } var path_parts = this.extractContinuationId(pathInfo); this.current().path_base = path_parts[0]; var k_id = path_parts[1]; this.current().invoked_k = k_id; if (k_id) { // TODO: expire continuations var entry = this.continuationMap()[k_id]; if (entry) { this.restoreStateChain(entry.savedChain); return entry.cont([req, resp]); } } this.current().stateChain = null; this.callEntryPoint(path_parts[0]); }, ProcessGet: function (req, resp) { this.unwinding = false; var oldCurrent = this._current.get(); var newCurrent = { request: req, response: resp }; try { this._current.set(newCurrent); var s = req.getSession(); var sd = s.getAttribute("savannahSessionData"); if (sd == null) { sd = {}; s.setAttribute("savannahSessionData", sd); } this.current().sessionData = sd; this.handleRequest(req, resp); } catch (e) { if (e == "") { this.unwinding = false; } else { print("ERROR-IN-SAVANNAH-SERVLET:: " + e); this.replyHtml( Exception in SavannahServlet 
{e.toString()}
); } } this._current.set(oldCurrent); }, }; Savannah.StateHolder = Class.create(); Savannah.StateHolder.prototype = { initialize: function (servlet, initValue) { this.value = initValue; this.servlet = servlet; this.servlet.current().stateChain = { holder: this, next: this.servlet.current().stateChain }; }, forget: function () { var prev = null; var curr = this.servlet.current().stateChain; while (curr != null) { if (curr.holder == this) { if (prev == null) { this.servlet.current().stateChain = curr.next; } else { prev.next = curr.next; } return; } } throw "Savannah.StateHolder.alreadyForgotten"; } } //=========================================================================== if (typeof s != 'undefined') { s.stop(); } sv = new Savannah.Servlet(); s = startServer(8080); addServlet(s, "/", makeServlet({ProcessGet: sv.ProcessGet.bind(sv)})); Bean = { displayProperty: function (b, selector) { if (typeof selector == 'function') { return (selector.bind(b))(); } else { var v = b[selector]; if (typeof v == 'function') { return (v.bind(b))(); } else { return v; } } }, toTable: function (b, selectors) { var f = ; selectors.each(function (selector) { f.table += ; }); return f; }, } function doc(title, body) { return {title}{body}; } sv.addEntryPoint ("/", function (servlet, bindings) { print("FRESH: " + JSON.stringify(bindings)); servlet.sendAndSuspend(function (k_url) { servlet.replyHtml(doc("Step 1",

Next {new Date()}

))}); servlet.sendAndSuspend(function (k_url) { servlet.replyHtml(doc("Step 1.5",

Next Intermediate!

))}); servlet.replyHtml(doc("Step 2", <> Hello

{JSON.stringify(servlet.current())}

)); }); sv.addEntryPoint ("/bean", function (servlet, bindings) { servlet.replyHtml(doc("Bean Bindings", Bean.toTable(servlet.current().request, ["getRequestURI", "getRequestURL", "getPathInfo", ]))); }); sv.addEntryPoint ("/count", function (servlet, bindings) { var finalC = servlet.withState (10, function (c) { while (servlet.sendAndDispatch (function (embedUrl) { servlet.replyHtml (doc("Counter", <>

{c.value}

More; Less; Stop;

)); })) {} return c.value; }); servlet.replyHtml(doc("Bye!",

Bye! {finalC}

)); }); staticFiles = { "style.css": ["text/css", null], "prototype-1.4.0.js": ["text/javascript", null], } sv.addEntryPoint ("/static/_filename", function (servlet, bindings) { var entry = staticFiles[bindings.filename]; if (entry) { servlet.reply(entry[0], readFile(entry[1] || bindings.filename)); } else { servlet.reply404("static/" + bindings.filename); } });
{selector} {Bean.displayProperty(b, selector)}