gitiles-servlet/src/main/java/com/google/gitiles/doc/DocServlet.java - gitiles - Git at Google

 // Copyright 2015 Google Inc. All Rights Reserved.
 //
 // 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.gitiles.doc;

 import static java.nio.charset.StandardCharsets.UTF_8;
 import static javax.servlet.http.HttpServletResponse.SC_INTERNAL_SERVER_ERROR;
 import static javax.servlet.http.HttpServletResponse.SC_NOT_FOUND;
 import static javax.servlet.http.HttpServletResponse.SC_NOT_MODIFIED;
 import static org.eclipse.jgit.lib.Constants.OBJ_BLOB;
 import static org.eclipse.jgit.lib.FileMode.TYPE_FILE;
 import static org.eclipse.jgit.lib.FileMode.TYPE_MASK;
 import static org.eclipse.jgit.lib.FileMode.TYPE_TREE;

 import com.google.common.base.MoreObjects;
 import com.google.common.base.Strings;
 import com.google.common.hash.Hasher;
 import com.google.common.hash.Hashing;
 import com.google.common.net.HttpHeaders;
 import com.google.gitiles.BaseServlet;
 import com.google.gitiles.FormatType;
 import com.google.gitiles.GitilesAccess;
 import com.google.gitiles.GitilesView;
 import com.google.gitiles.Renderer;
 import com.google.gitiles.ViewFilter;

 import org.eclipse.jgit.errors.IncorrectObjectTypeException;
 import org.eclipse.jgit.http.server.ServletUtils;
 import org.eclipse.jgit.lib.Config;
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.ObjectLoader;
 import org.eclipse.jgit.lib.ObjectReader;
 import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.revwalk.RevTree;
 import org.eclipse.jgit.revwalk.RevWalk;
 import org.eclipse.jgit.treewalk.TreeWalk;
 import org.eclipse.jgit.util.RawParseUtils;
 import org.pegdown.ast.RootNode;

 import java.io.IOException;
 import java.util.HashMap;
 import java.util.Map;

 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;

 public class DocServlet extends BaseServlet {
   private static final long serialVersionUID = 1L;

   private static final String INDEX_MD = "index.md";
   private static final String NAVBAR_MD = "navbar.md";
   private static final String SOY_FILE = "Doc.soy";
   private static final String SOY_TEMPLATE = "gitiles.markdownDoc";

   // Generation of ETag logic. Bump this only if DocServlet logic changes
   // significantly enough to impact cached pages. Soy template and source
   // files are automatically hashed as part of the ETag.
   private static final int ETAG_GEN = 1;

   public DocServlet(GitilesAccess.Factory accessFactory, Renderer renderer) {
     super(renderer, accessFactory);
   }

   @Override
   protected void doGetHtml(HttpServletRequest req, HttpServletResponse res)
       throws IOException {
     Config cfg = getAccess(req).getConfig();
     if (!cfg.getBoolean("markdown", "render", true)) {
       res.setStatus(SC_NOT_FOUND);
       return;
     }

     GitilesView view = ViewFilter.getView(req);
     Repository repo = ServletUtils.getRepository(req);
     RevWalk rw = new RevWalk(repo);
     try {
       String path = view.getPathPart();
       RevTree root;
       try {
         root = rw.parseTree(view.getRevision().getId());
       } catch (IncorrectObjectTypeException e) {
         res.setStatus(SC_NOT_FOUND);
         return;
       }

       SourceFile srcmd = findFile(rw, root, path);
       if (srcmd == null) {
         res.setStatus(SC_NOT_FOUND);
         return;
       }

       SourceFile navmd = findFile(rw, root, NAVBAR_MD);
       String reqEtag = req.getHeader(HttpHeaders.IF_NONE_MATCH);
       String curEtag = etag(srcmd, navmd);
       if (reqEtag != null && reqEtag.equals(curEtag)) {
         res.setStatus(SC_NOT_MODIFIED);
         return;
       }

       view = view.toBuilder().setPathPart(srcmd.path).build();
       int inputLimit = cfg.getInt("markdown", "inputLimit", 5 << 20);
       RootNode doc = GitilesMarkdown.parseFile(
           view, srcmd.path,
           srcmd.read(rw.getObjectReader(), inputLimit));
       if (doc == null) {
         res.setStatus(SC_INTERNAL_SERVER_ERROR);
         return;
       }

       RootNode nav = null;
       if (navmd != null) {
         nav = GitilesMarkdown.parseFile(
             view, navmd.path,
             navmd.read(rw.getObjectReader(), inputLimit));
         if (nav == null) {
           res.setStatus(SC_INTERNAL_SERVER_ERROR);
           return;
         }
       }

       res.setHeader(HttpHeaders.ETAG, curEtag);
       showDoc(req, res, view, nav, doc);
     } finally {
       rw.release();
     }
   }

   private String etag(SourceFile srcmd, SourceFile navmd) {
     byte[] b = new byte[Constants.OBJECT_ID_LENGTH];
     Hasher h = Hashing.sha1().newHasher();
     h.putInt(ETAG_GEN);

     renderer.getTemplateHash(SOY_FILE).writeBytesTo(b, 0, b.length);
     h.putBytes(b);

     if (navmd != null) {
       navmd.id.copyRawTo(b, 0);
       h.putBytes(b);
     }

     srcmd.id.copyRawTo(b, 0);
     h.putBytes(b);
     return h.hash().toString();
   }

   @Override
   protected void setCacheHeaders(HttpServletResponse res) {
     long now = System.currentTimeMillis();
     res.setDateHeader(HttpHeaders.EXPIRES, now);
     res.setDateHeader(HttpHeaders.DATE, now);
     res.setHeader(HttpHeaders.CACHE_CONTROL, "private, max-age=0, must-revalidate");
   }

   private void showDoc(HttpServletRequest req, HttpServletResponse res,
       GitilesView view, RootNode nav, RootNode doc) throws IOException {
     Map<String, Object> data = new HashMap<>();
     data.putAll(Navbar.bannerSoyData(view, nav));
     data.put("pageTitle", MoreObjects.firstNonNull(
         MarkdownUtil.getTitle(doc),
         view.getPathPart()));
     data.put("sourceUrl", GitilesView.show().copyFrom(view).toUrl());
     data.put("logUrl", GitilesView.log().copyFrom(view).toUrl());
     data.put("blameUrl", GitilesView.blame().copyFrom(view).toUrl());
     data.put("navbarHtml", new MarkdownToHtml(view).toSoyHtml(nav));
     data.put("bodyHtml", new MarkdownToHtml(view).toSoyHtml(doc));

     String page = renderer.render(SOY_TEMPLATE, data);
     byte[] raw = page.getBytes(UTF_8);
     res.setContentType(FormatType.HTML.getMimeType());
     res.setCharacterEncoding(UTF_8.name());
     setCacheHeaders(res);
     if (acceptsGzipEncoding(req)) {
       res.setHeader(HttpHeaders.CONTENT_ENCODING, "gzip");
       raw = gzip(raw);
     }
     res.setContentLength(raw.length);
     res.setStatus(HttpServletResponse.SC_OK);
     res.getOutputStream().write(raw);
   }

   private static SourceFile findFile(RevWalk rw, RevTree root, String path) throws IOException {
     if (Strings.isNullOrEmpty(path)) {
       path = INDEX_MD;
     }

     ObjectReader reader = rw.getObjectReader();
     TreeWalk tw = TreeWalk.forPath(reader, path, root);
     if (tw == null) {
       return null;
     }
     if ((tw.getRawMode(0) & TYPE_MASK) == TYPE_TREE) {
       if (findIndexFile(tw)) {
         path = tw.getPathString();
       } else {
         return null;
       }
     }
     if ((tw.getRawMode(0) & TYPE_MASK) == TYPE_FILE) {
       if (!path.endsWith(".md")) {
         return null;
       }
       return new SourceFile(path, tw.getObjectId(0));
     }
     return null;
   }

   private static boolean findIndexFile(TreeWalk tw) throws IOException {
     tw.enterSubtree();
     while (tw.next()) {
       if ((tw.getRawMode(0) & TYPE_MASK) == TYPE_FILE
           && INDEX_MD.equals(tw.getNameString())) {
         return true;
       }
     }
     return false;
   }

   private static class SourceFile {
     final String path;
     final ObjectId id;

     SourceFile(String path, ObjectId id) {
       this.path = path;
       this.id = id;
     }

     String read(ObjectReader reader, int inputLimit) throws IOException {
       ObjectLoader obj = reader.open(id, OBJ_BLOB);
       byte[] raw = obj.getCachedBytes(inputLimit);
       return RawParseUtils.decode(raw);
     }
   }
 }
	// Copyright 2015 Google Inc. All Rights Reserved.
	//
	// 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.gitiles.doc;

	import static java.nio.charset.StandardCharsets.UTF_8;
	import static javax.servlet.http.HttpServletResponse.SC_INTERNAL_SERVER_ERROR;
	import static javax.servlet.http.HttpServletResponse.SC_NOT_FOUND;
	import static javax.servlet.http.HttpServletResponse.SC_NOT_MODIFIED;
	import static org.eclipse.jgit.lib.Constants.OBJ_BLOB;
	import static org.eclipse.jgit.lib.FileMode.TYPE_FILE;
	import static org.eclipse.jgit.lib.FileMode.TYPE_MASK;
	import static org.eclipse.jgit.lib.FileMode.TYPE_TREE;

	import com.google.common.base.MoreObjects;
	import com.google.common.base.Strings;
	import com.google.common.hash.Hasher;
	import com.google.common.hash.Hashing;
	import com.google.common.net.HttpHeaders;
	import com.google.gitiles.BaseServlet;
	import com.google.gitiles.FormatType;
	import com.google.gitiles.GitilesAccess;
	import com.google.gitiles.GitilesView;
	import com.google.gitiles.Renderer;
	import com.google.gitiles.ViewFilter;

	import org.eclipse.jgit.errors.IncorrectObjectTypeException;
	import org.eclipse.jgit.http.server.ServletUtils;
	import org.eclipse.jgit.lib.Config;
	import org.eclipse.jgit.lib.Constants;
	import org.eclipse.jgit.lib.ObjectId;
	import org.eclipse.jgit.lib.ObjectLoader;
	import org.eclipse.jgit.lib.ObjectReader;
	import org.eclipse.jgit.lib.Repository;
	import org.eclipse.jgit.revwalk.RevTree;
	import org.eclipse.jgit.revwalk.RevWalk;
	import org.eclipse.jgit.treewalk.TreeWalk;
	import org.eclipse.jgit.util.RawParseUtils;
	import org.pegdown.ast.RootNode;

	import java.io.IOException;
	import java.util.HashMap;
	import java.util.Map;

	import javax.servlet.http.HttpServletRequest;
	import javax.servlet.http.HttpServletResponse;

	public class DocServlet extends BaseServlet {
	private static final long serialVersionUID = 1L;

	private static final String INDEX_MD = "index.md";
	private static final String NAVBAR_MD = "navbar.md";
	private static final String SOY_FILE = "Doc.soy";
	private static final String SOY_TEMPLATE = "gitiles.markdownDoc";

	// Generation of ETag logic. Bump this only if DocServlet logic changes
	// significantly enough to impact cached pages. Soy template and source
	// files are automatically hashed as part of the ETag.
	private static final int ETAG_GEN = 1;

	public DocServlet(GitilesAccess.Factory accessFactory, Renderer renderer) {
	super(renderer, accessFactory);
	}

	@Override
	protected void doGetHtml(HttpServletRequest req, HttpServletResponse res)
	throws IOException {
	Config cfg = getAccess(req).getConfig();
	if (!cfg.getBoolean("markdown", "render", true)) {
	res.setStatus(SC_NOT_FOUND);
	return;
	}

	GitilesView view = ViewFilter.getView(req);
	Repository repo = ServletUtils.getRepository(req);
	RevWalk rw = new RevWalk(repo);
	try {
	String path = view.getPathPart();
	RevTree root;
	try {
	root = rw.parseTree(view.getRevision().getId());
	} catch (IncorrectObjectTypeException e) {
	res.setStatus(SC_NOT_FOUND);
	return;
	}

	SourceFile srcmd = findFile(rw, root, path);
	if (srcmd == null) {
	res.setStatus(SC_NOT_FOUND);
	return;
	}

	SourceFile navmd = findFile(rw, root, NAVBAR_MD);
	String reqEtag = req.getHeader(HttpHeaders.IF_NONE_MATCH);
	String curEtag = etag(srcmd, navmd);
	if (reqEtag != null && reqEtag.equals(curEtag)) {
	res.setStatus(SC_NOT_MODIFIED);
	return;
	}

	view = view.toBuilder().setPathPart(srcmd.path).build();
	int inputLimit = cfg.getInt("markdown", "inputLimit", 5 << 20);
	RootNode doc = GitilesMarkdown.parseFile(
	view, srcmd.path,
	srcmd.read(rw.getObjectReader(), inputLimit));
	if (doc == null) {
	res.setStatus(SC_INTERNAL_SERVER_ERROR);
	return;
	}

	RootNode nav = null;
	if (navmd != null) {
	nav = GitilesMarkdown.parseFile(
	view, navmd.path,
	navmd.read(rw.getObjectReader(), inputLimit));
	if (nav == null) {
	res.setStatus(SC_INTERNAL_SERVER_ERROR);
	return;
	}
	}

	res.setHeader(HttpHeaders.ETAG, curEtag);
	showDoc(req, res, view, nav, doc);
	} finally {
	rw.release();
	}
	}

	private String etag(SourceFile srcmd, SourceFile navmd) {
	byte[] b = new byte[Constants.OBJECT_ID_LENGTH];
	Hasher h = Hashing.sha1().newHasher();
	h.putInt(ETAG_GEN);

	renderer.getTemplateHash(SOY_FILE).writeBytesTo(b, 0, b.length);
	h.putBytes(b);

	if (navmd != null) {
	navmd.id.copyRawTo(b, 0);
	h.putBytes(b);
	}

	srcmd.id.copyRawTo(b, 0);
	h.putBytes(b);
	return h.hash().toString();
	}

	@Override
	protected void setCacheHeaders(HttpServletResponse res) {
	long now = System.currentTimeMillis();
	res.setDateHeader(HttpHeaders.EXPIRES, now);
	res.setDateHeader(HttpHeaders.DATE, now);
	res.setHeader(HttpHeaders.CACHE_CONTROL, "private, max-age=0, must-revalidate");
	}

	private void showDoc(HttpServletRequest req, HttpServletResponse res,
	GitilesView view, RootNode nav, RootNode doc) throws IOException {
	Map<String, Object> data = new HashMap<>();
	data.putAll(Navbar.bannerSoyData(view, nav));
	data.put("pageTitle", MoreObjects.firstNonNull(
	MarkdownUtil.getTitle(doc),
	view.getPathPart()));
	data.put("sourceUrl", GitilesView.show().copyFrom(view).toUrl());
	data.put("logUrl", GitilesView.log().copyFrom(view).toUrl());
	data.put("blameUrl", GitilesView.blame().copyFrom(view).toUrl());
	data.put("navbarHtml", new MarkdownToHtml(view).toSoyHtml(nav));
	data.put("bodyHtml", new MarkdownToHtml(view).toSoyHtml(doc));

	String page = renderer.render(SOY_TEMPLATE, data);
	byte[] raw = page.getBytes(UTF_8);
	res.setContentType(FormatType.HTML.getMimeType());
	res.setCharacterEncoding(UTF_8.name());
	setCacheHeaders(res);
	if (acceptsGzipEncoding(req)) {
	res.setHeader(HttpHeaders.CONTENT_ENCODING, "gzip");
	raw = gzip(raw);
	}
	res.setContentLength(raw.length);
	res.setStatus(HttpServletResponse.SC_OK);
	res.getOutputStream().write(raw);
	}

	private static SourceFile findFile(RevWalk rw, RevTree root, String path) throws IOException {
	if (Strings.isNullOrEmpty(path)) {
	path = INDEX_MD;
	}

	ObjectReader reader = rw.getObjectReader();
	TreeWalk tw = TreeWalk.forPath(reader, path, root);
	if (tw == null) {
	return null;
	}
	if ((tw.getRawMode(0) & TYPE_MASK) == TYPE_TREE) {
	if (findIndexFile(tw)) {
	path = tw.getPathString();
	} else {
	return null;
	}
	}
	if ((tw.getRawMode(0) & TYPE_MASK) == TYPE_FILE) {
	if (!path.endsWith(".md")) {
	return null;
	}
	return new SourceFile(path, tw.getObjectId(0));
	}
	return null;
	}

	private static boolean findIndexFile(TreeWalk tw) throws IOException {
	tw.enterSubtree();
	while (tw.next()) {
	if ((tw.getRawMode(0) & TYPE_MASK) == TYPE_FILE
	&& INDEX_MD.equals(tw.getNameString())) {
	return true;
	}
	}
	return false;
	}

	private static class SourceFile {
	final String path;
	final ObjectId id;

	SourceFile(String path, ObjectId id) {
	this.path = path;
	this.id = id;
	}

	String read(ObjectReader reader, int inputLimit) throws IOException {
	ObjectLoader obj = reader.open(id, OBJ_BLOB);
	byte[] raw = obj.getCachedBytes(inputLimit);
	return RawParseUtils.decode(raw);
	}
	}
	}