gerrit-httpd/src/main/java/com/google/gerrit/httpd/raw/HostPageServlet.java - gerrit - Git at Google

 // Copyright (C) 2008 The Android Open Source Project
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 // http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.

 package com.google.gerrit.httpd.raw;

 import com.google.gerrit.common.data.GerritConfig;
 import com.google.gerrit.common.data.HostPageData;
 import com.google.gerrit.httpd.HtmlDomUtil;
 import com.google.gerrit.server.CurrentUser;
 import com.google.gerrit.server.IdentifiedUser;
 import com.google.gerrit.server.config.SitePaths;
 import com.google.gwt.user.server.rpc.RPCServletUtils;
 import com.google.gwtexpui.linker.server.Permutation;
 import com.google.gwtexpui.linker.server.PermutationSelector;
 import com.google.gwtjsonrpc.server.JsonServlet;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
 import com.google.inject.Singleton;

 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.ObjectId;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.w3c.dom.Document;
 import org.w3c.dom.Element;

 import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.io.StringWriter;
 import java.security.MessageDigest;
 import java.util.HashMap;
 import java.util.Map;

 import javax.servlet.ServletContext;
 import javax.servlet.ServletException;
 import javax.servlet.http.HttpServlet;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;

 /** Sends the Gerrit host page to clients. */
 @SuppressWarnings("serial")
 @Singleton
 public class HostPageServlet extends HttpServlet {
   private static final Logger log =
       LoggerFactory.getLogger(HostPageServlet.class);
   private static final boolean IS_DEV = Boolean.getBoolean("Gerrit.GwtDevMode");
   private static final String HPD_ID = "gerrit_hostpagedata";

   private final Provider<CurrentUser> currentUser;
   private final GerritConfig config;
   private final HostPageData.Theme signedOutTheme;
   private final HostPageData.Theme signedInTheme;
   private final SitePaths site;
   private final Document template;
   private final String noCacheName;
   private final PermutationSelector selector;
   private volatile Page page;

   @Inject
   HostPageServlet(final Provider<CurrentUser> cu, final SitePaths sp,
       final ThemeFactory themeFactory, final GerritConfig gc,
       final ServletContext servletContext) throws IOException, ServletException {
     currentUser = cu;
     config = gc;
     signedOutTheme = themeFactory.getSignedOutTheme();
     signedInTheme = themeFactory.getSignedInTheme();
     site = sp;

     final String pageName = "HostPage.html";
     template = HtmlDomUtil.parseFile(getClass(), pageName);
     if (template == null) {
       throw new FileNotFoundException("No " + pageName + " in webapp");
     }

     if (HtmlDomUtil.find(template, "gerrit_module") == null) {
       throw new ServletException("No gerrit_module in " + pageName);
     }
     if (HtmlDomUtil.find(template, HPD_ID) == null) {
       throw new ServletException("No " + HPD_ID + " in " + pageName);
     }

     final String src = "gerrit/gerrit.nocache.js";
     selector = new PermutationSelector("gerrit");
     if (IS_DEV) {
       noCacheName = src;
     } else {
       final Element devmode = HtmlDomUtil.find(template, "gerrit_gwtdevmode");
       if (devmode != null) {
         devmode.getParentNode().removeChild(devmode);
       }

       InputStream in = servletContext.getResourceAsStream("/" + src);
       if (in == null) {
         throw new IOException("No " + src + " in webapp root");
       }

       final MessageDigest md = Constants.newMessageDigest();
       try {
         try {
           final byte[] buf = new byte[1024];
           int n;
           while ((n = in.read(buf)) > 0) {
             md.update(buf, 0, n);
           }
         } finally {
           in.close();
         }
       } catch (IOException e) {
         throw new IOException("Failed reading " + src, e);
       }
       final String id = ObjectId.fromRaw(md.digest()).name();
       noCacheName = src + "?content=" + id;
       selector.init(servletContext);
     }

     page = new Page();
   }

   private void json(final Object data, final StringWriter w) {
     JsonServlet.defaultGsonBuilder().create().toJson(data, w);
   }

   private Page get() {
     Page p = page;
     if (p.isStale()) {
       final Page newPage;
       try {
         newPage = new Page();
       } catch (IOException e) {
         log.error("Cannot refresh site header/footer", e);
         return p;
       }
       p = newPage;
       page = p;
     }
     return p;
   }

   @Override
   protected void doGet(final HttpServletRequest req,
       final HttpServletResponse rsp) throws IOException {
     final Page.Content page = get().get(select(req));
     final byte[] raw;

     final CurrentUser user = currentUser.get();
     if (user instanceof IdentifiedUser) {
       final StringWriter w = new StringWriter();
       w.write(HPD_ID + ".account=");
       json(((IdentifiedUser) user).getAccount(), w);
       w.write(";");

       w.write(HPD_ID + ".accountDiffPref=");
       json(((IdentifiedUser) user).getAccountDiffPreference(), w);
       w.write(";");

       w.write(HPD_ID + ".theme=");
       json(signedInTheme, w);
       w.write(";");

       final byte[] userData = w.toString().getBytes("UTF-8");
       raw = concat(page.part1, userData, page.part2);
     } else {
       raw = page.full;
     }

     final byte[] tosend;
     if (RPCServletUtils.acceptsGzipEncoding(req)) {
       rsp.setHeader("Content-Encoding", "gzip");
       tosend = raw == page.full ? page.full_gz : HtmlDomUtil.compress(raw);
     } else {
       tosend = raw;
     }

     rsp.setHeader("Expires", "Fri, 01 Jan 1980 00:00:00 GMT");
     rsp.setHeader("Pragma", "no-cache");
     rsp.setHeader("Cache-Control", "no-cache, must-revalidate");
     rsp.setContentType("text/html");
     rsp.setCharacterEncoding(HtmlDomUtil.ENC);
     rsp.setContentLength(tosend.length);
     final OutputStream out = rsp.getOutputStream();
     try {
       out.write(tosend);
     } finally {
       out.close();
     }
   }

   private Permutation select(final HttpServletRequest req) {
     if ("0".equals(req.getParameter("s"))) {
       // If s=0 is used in the URL, the user has explicitly asked us
       // to not perform selection on the server side, perhaps due to
       // it incorrectly guessing their user agent.
       //
       return null;
     }
     return selector.select(req);
   }

   private static byte[] concat(byte[] p1, byte[] p2, byte[] p3) {
     final byte[] r = new byte[p1.length + p2.length + p3.length];
     int p = 0;
     p = append(p1, r, p);
     p = append(p2, r, p);
     p = append(p3, r, p);
     return r;
   }

   private static int append(byte[] src, final byte[] dst, int p) {
     System.arraycopy(src, 0, dst, p, src.length);
     return p + src.length;
   }

   private static class FileInfo {
     private final File path;
     private final long time;

     FileInfo(final File p) {
       path = p;
       time = path.lastModified();
     }

     boolean isStale() {
       return time != path.lastModified();
     }
   }

   private class Page {
     private final FileInfo css;
     private final FileInfo header;
     private final FileInfo footer;
     private final Map<Permutation, Content> permutations;

     Page() throws IOException {
       Document hostDoc = HtmlDomUtil.clone(template);

       css = injectCssFile(hostDoc, "gerrit_sitecss", site.site_css);
       header = injectXmlFile(hostDoc, "gerrit_header", site.site_header);
       footer = injectXmlFile(hostDoc, "gerrit_footer", site.site_footer);

       final HostPageData pageData = new HostPageData();
       pageData.config = config;

       final StringWriter w = new StringWriter();
       w.write("var " + HPD_ID + "=");
       json(pageData, w);
       w.write(";");

       final Element data = HtmlDomUtil.find(hostDoc, HPD_ID);
       asScript(data);
       data.appendChild(hostDoc.createTextNode(w.toString()));
       data.appendChild(hostDoc.createComment(HPD_ID));

       permutations = new HashMap<Permutation, Content>();
       for (Permutation p : selector.getPermutations()) {
         final Document d = HtmlDomUtil.clone(hostDoc);
         Element nocache = HtmlDomUtil.find(d, "gerrit_module");
         nocache.getParentNode().removeChild(nocache);
         p.inject(d);
         permutations.put(p, new Content(d));
       }

       Element nocache = HtmlDomUtil.find(hostDoc, "gerrit_module");
       asScript(nocache);
       nocache.setAttribute("src", noCacheName);
       permutations.put(null, new Content(hostDoc));
     }

     Content get(Permutation p) {
       Content c = permutations.get(p);
       if (c == null) {
         c = permutations.get(null);
       }
       return c;
     }

     boolean isStale() {
       return css.isStale() || header.isStale() || footer.isStale();
     }

     private void asScript(final Element scriptNode) {
       scriptNode.removeAttribute("id");
       scriptNode.setAttribute("type", "text/javascript");
       scriptNode.setAttribute("language", "javascript");
     }

     class Content {
       final byte[] part1;
       final byte[] part2;
       final byte[] full;
       final byte[] full_gz;

       Content(Document hostDoc) throws IOException {
         final String raw = HtmlDomUtil.toString(hostDoc);
         final int p = raw.indexOf("<!--" + HPD_ID);
         if (p < 0) {
           throw new IOException("No tag in transformed host page HTML");
         }
         part1 = raw.substring(0, p).getBytes("UTF-8");
         part2 = raw.substring(raw.indexOf('>', p) + 1).getBytes("UTF-8");

         final StringWriter w = new StringWriter();
         w.write(HPD_ID + ".theme=");
         json(signedOutTheme, w);
         w.write(";");

         final byte[] themeData = w.toString().getBytes("UTF-8");
         full = concat(part1, themeData, part2);
         full_gz = HtmlDomUtil.compress(full);
       }
     }

     private FileInfo injectCssFile(final Document hostDoc, final String id,
         final File src) throws IOException {
       final FileInfo info = new FileInfo(src);
       final Element banner = HtmlDomUtil.find(hostDoc, id);
       if (banner == null) {
         return info;
       }

       while (banner.getFirstChild() != null) {
         banner.removeChild(banner.getFirstChild());
       }

       String css = HtmlDomUtil.readFile(src.getParentFile(), src.getName());
       if (css == null) {
         banner.getParentNode().removeChild(banner);
         return info;
       }

       banner.removeAttribute("id");
       banner.appendChild(hostDoc.createCDATASection("\n" + css + "\n"));
       return info;
     }

     private FileInfo injectXmlFile(final Document hostDoc, final String id,
         final File src) throws IOException {
       final FileInfo info = new FileInfo(src);
       final Element banner = HtmlDomUtil.find(hostDoc, id);
       if (banner == null) {
         return info;
       }

       while (banner.getFirstChild() != null) {
         banner.removeChild(banner.getFirstChild());
       }

       Document html = HtmlDomUtil.parseFile(src);
       if (html == null) {
         banner.getParentNode().removeChild(banner);
         return info;
       }

       final Element content = html.getDocumentElement();
       banner.appendChild(hostDoc.importNode(content, true));
       return info;
     }
   }
 }
	// Copyright (C) 2008 The Android Open Source Project
	//
	// Licensed under the Apache License, Version 2.0 (the "License");
	// you may not use this file except in compliance with the License.
	// You may obtain a copy of the License at
	//
	// http://www.apache.org/licenses/LICENSE-2.0
	//
	// Unless required by applicable law or agreed to in writing, software
	// distributed under the License is distributed on an "AS IS" BASIS,
	// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	// See the License for the specific language governing permissions and
	// limitations under the License.

	package com.google.gerrit.httpd.raw;

	import com.google.gerrit.common.data.GerritConfig;
	import com.google.gerrit.common.data.HostPageData;
	import com.google.gerrit.httpd.HtmlDomUtil;
	import com.google.gerrit.server.CurrentUser;
	import com.google.gerrit.server.IdentifiedUser;
	import com.google.gerrit.server.config.SitePaths;
	import com.google.gwt.user.server.rpc.RPCServletUtils;
	import com.google.gwtexpui.linker.server.Permutation;
	import com.google.gwtexpui.linker.server.PermutationSelector;
	import com.google.gwtjsonrpc.server.JsonServlet;
	import com.google.inject.Inject;
	import com.google.inject.Provider;
	import com.google.inject.Singleton;

	import org.eclipse.jgit.lib.Constants;
	import org.eclipse.jgit.lib.ObjectId;
	import org.slf4j.Logger;
	import org.slf4j.LoggerFactory;
	import org.w3c.dom.Document;
	import org.w3c.dom.Element;

	import java.io.File;
	import java.io.FileNotFoundException;
	import java.io.IOException;
	import java.io.InputStream;
	import java.io.OutputStream;
	import java.io.StringWriter;
	import java.security.MessageDigest;
	import java.util.HashMap;
	import java.util.Map;

	import javax.servlet.ServletContext;
	import javax.servlet.ServletException;
	import javax.servlet.http.HttpServlet;
	import javax.servlet.http.HttpServletRequest;
	import javax.servlet.http.HttpServletResponse;

	/** Sends the Gerrit host page to clients. */
	@SuppressWarnings("serial")
	@Singleton
	public class HostPageServlet extends HttpServlet {
	private static final Logger log =
	LoggerFactory.getLogger(HostPageServlet.class);
	private static final boolean IS_DEV = Boolean.getBoolean("Gerrit.GwtDevMode");
	private static final String HPD_ID = "gerrit_hostpagedata";

	private final Provider<CurrentUser> currentUser;
	private final GerritConfig config;
	private final HostPageData.Theme signedOutTheme;
	private final HostPageData.Theme signedInTheme;
	private final SitePaths site;
	private final Document template;
	private final String noCacheName;
	private final PermutationSelector selector;
	private volatile Page page;

	@Inject
	HostPageServlet(final Provider<CurrentUser> cu, final SitePaths sp,
	final ThemeFactory themeFactory, final GerritConfig gc,
	final ServletContext servletContext) throws IOException, ServletException {
	currentUser = cu;
	config = gc;
	signedOutTheme = themeFactory.getSignedOutTheme();
	signedInTheme = themeFactory.getSignedInTheme();
	site = sp;

	final String pageName = "HostPage.html";
	template = HtmlDomUtil.parseFile(getClass(), pageName);
	if (template == null) {
	throw new FileNotFoundException("No " + pageName + " in webapp");
	}

	if (HtmlDomUtil.find(template, "gerrit_module") == null) {
	throw new ServletException("No gerrit_module in " + pageName);
	}
	if (HtmlDomUtil.find(template, HPD_ID) == null) {
	throw new ServletException("No " + HPD_ID + " in " + pageName);
	}

	final String src = "gerrit/gerrit.nocache.js";
	selector = new PermutationSelector("gerrit");
	if (IS_DEV) {
	noCacheName = src;
	} else {
	final Element devmode = HtmlDomUtil.find(template, "gerrit_gwtdevmode");
	if (devmode != null) {
	devmode.getParentNode().removeChild(devmode);
	}

	InputStream in = servletContext.getResourceAsStream("/" + src);
	if (in == null) {
	throw new IOException("No " + src + " in webapp root");
	}

	final MessageDigest md = Constants.newMessageDigest();
	try {
	try {
	final byte[] buf = new byte[1024];
	int n;
	while ((n = in.read(buf)) > 0) {
	md.update(buf, 0, n);
	}
	} finally {
	in.close();
	}
	} catch (IOException e) {
	throw new IOException("Failed reading " + src, e);
	}
	final String id = ObjectId.fromRaw(md.digest()).name();
	noCacheName = src + "?content=" + id;
	selector.init(servletContext);
	}

	page = new Page();
	}

	private void json(final Object data, final StringWriter w) {
	JsonServlet.defaultGsonBuilder().create().toJson(data, w);
	}

	private Page get() {
	Page p = page;
	if (p.isStale()) {
	final Page newPage;
	try {
	newPage = new Page();
	} catch (IOException e) {
	log.error("Cannot refresh site header/footer", e);
	return p;
	}
	p = newPage;
	page = p;
	}
	return p;
	}

	@Override
	protected void doGet(final HttpServletRequest req,
	final HttpServletResponse rsp) throws IOException {
	final Page.Content page = get().get(select(req));
	final byte[] raw;

	final CurrentUser user = currentUser.get();
	if (user instanceof IdentifiedUser) {
	final StringWriter w = new StringWriter();
	w.write(HPD_ID + ".account=");
	json(((IdentifiedUser) user).getAccount(), w);
	w.write(";");

	w.write(HPD_ID + ".accountDiffPref=");
	json(((IdentifiedUser) user).getAccountDiffPreference(), w);
	w.write(";");

	w.write(HPD_ID + ".theme=");
	json(signedInTheme, w);
	w.write(";");

	final byte[] userData = w.toString().getBytes("UTF-8");
	raw = concat(page.part1, userData, page.part2);
	} else {
	raw = page.full;
	}

	final byte[] tosend;
	if (RPCServletUtils.acceptsGzipEncoding(req)) {
	rsp.setHeader("Content-Encoding", "gzip");
	tosend = raw == page.full ? page.full_gz : HtmlDomUtil.compress(raw);
	} else {
	tosend = raw;
	}

	rsp.setHeader("Expires", "Fri, 01 Jan 1980 00:00:00 GMT");
	rsp.setHeader("Pragma", "no-cache");
	rsp.setHeader("Cache-Control", "no-cache, must-revalidate");
	rsp.setContentType("text/html");
	rsp.setCharacterEncoding(HtmlDomUtil.ENC);
	rsp.setContentLength(tosend.length);
	final OutputStream out = rsp.getOutputStream();
	try {
	out.write(tosend);
	} finally {
	out.close();
	}
	}

	private Permutation select(final HttpServletRequest req) {
	if ("0".equals(req.getParameter("s"))) {
	// If s=0 is used in the URL, the user has explicitly asked us
	// to not perform selection on the server side, perhaps due to
	// it incorrectly guessing their user agent.
	//
	return null;
	}
	return selector.select(req);
	}

	private static byte[] concat(byte[] p1, byte[] p2, byte[] p3) {
	final byte[] r = new byte[p1.length + p2.length + p3.length];
	int p = 0;
	p = append(p1, r, p);
	p = append(p2, r, p);
	p = append(p3, r, p);
	return r;
	}

	private static int append(byte[] src, final byte[] dst, int p) {
	System.arraycopy(src, 0, dst, p, src.length);
	return p + src.length;
	}

	private static class FileInfo {
	private final File path;
	private final long time;

	FileInfo(final File p) {
	path = p;
	time = path.lastModified();
	}

	boolean isStale() {
	return time != path.lastModified();
	}
	}

	private class Page {
	private final FileInfo css;
	private final FileInfo header;
	private final FileInfo footer;
	private final Map<Permutation, Content> permutations;

	Page() throws IOException {
	Document hostDoc = HtmlDomUtil.clone(template);

	css = injectCssFile(hostDoc, "gerrit_sitecss", site.site_css);
	header = injectXmlFile(hostDoc, "gerrit_header", site.site_header);
	footer = injectXmlFile(hostDoc, "gerrit_footer", site.site_footer);

	final HostPageData pageData = new HostPageData();
	pageData.config = config;

	final StringWriter w = new StringWriter();
	w.write("var " + HPD_ID + "=");
	json(pageData, w);
	w.write(";");

	final Element data = HtmlDomUtil.find(hostDoc, HPD_ID);
	asScript(data);
	data.appendChild(hostDoc.createTextNode(w.toString()));
	data.appendChild(hostDoc.createComment(HPD_ID));

	permutations = new HashMap<Permutation, Content>();
	for (Permutation p : selector.getPermutations()) {
	final Document d = HtmlDomUtil.clone(hostDoc);
	Element nocache = HtmlDomUtil.find(d, "gerrit_module");
	nocache.getParentNode().removeChild(nocache);
	p.inject(d);
	permutations.put(p, new Content(d));
	}

	Element nocache = HtmlDomUtil.find(hostDoc, "gerrit_module");
	asScript(nocache);
	nocache.setAttribute("src", noCacheName);
	permutations.put(null, new Content(hostDoc));
	}

	Content get(Permutation p) {
	Content c = permutations.get(p);
	if (c == null) {
	c = permutations.get(null);
	}
	return c;
	}

	boolean isStale() {
	return css.isStale() \|\| header.isStale() \|\| footer.isStale();
	}

	private void asScript(final Element scriptNode) {
	scriptNode.removeAttribute("id");
	scriptNode.setAttribute("type", "text/javascript");
	scriptNode.setAttribute("language", "javascript");
	}

	class Content {
	final byte[] part1;
	final byte[] part2;
	final byte[] full;
	final byte[] full_gz;

	Content(Document hostDoc) throws IOException {
	final String raw = HtmlDomUtil.toString(hostDoc);
	final int p = raw.indexOf("<!--" + HPD_ID);
	if (p < 0) {
	throw new IOException("No tag in transformed host page HTML");
	}
	part1 = raw.substring(0, p).getBytes("UTF-8");
	part2 = raw.substring(raw.indexOf('>', p) + 1).getBytes("UTF-8");

	final StringWriter w = new StringWriter();
	w.write(HPD_ID + ".theme=");
	json(signedOutTheme, w);
	w.write(";");

	final byte[] themeData = w.toString().getBytes("UTF-8");
	full = concat(part1, themeData, part2);
	full_gz = HtmlDomUtil.compress(full);
	}
	}

	private FileInfo injectCssFile(final Document hostDoc, final String id,
	final File src) throws IOException {
	final FileInfo info = new FileInfo(src);
	final Element banner = HtmlDomUtil.find(hostDoc, id);
	if (banner == null) {
	return info;
	}

	while (banner.getFirstChild() != null) {
	banner.removeChild(banner.getFirstChild());
	}

	String css = HtmlDomUtil.readFile(src.getParentFile(), src.getName());
	if (css == null) {
	banner.getParentNode().removeChild(banner);
	return info;
	}

	banner.removeAttribute("id");
	banner.appendChild(hostDoc.createCDATASection("\n" + css + "\n"));
	return info;
	}

	private FileInfo injectXmlFile(final Document hostDoc, final String id,
	final File src) throws IOException {
	final FileInfo info = new FileInfo(src);
	final Element banner = HtmlDomUtil.find(hostDoc, id);
	if (banner == null) {
	return info;
	}

	while (banner.getFirstChild() != null) {
	banner.removeChild(banner.getFirstChild());
	}

	Document html = HtmlDomUtil.parseFile(src);
	if (html == null) {
	banner.getParentNode().removeChild(banner);
	return info;
	}

	final Element content = html.getDocumentElement();
	banner.appendChild(hostDoc.importNode(content, true));
	return info;
	}
	}
	}