Dissolve gerrit-server top-level directory

Change-Id: I538512dfe0f1bea774c01fdd45fa410a45634011

java/com/google/gerrit/server/documentation/Constants.java

@@ -0,0 +1,26 @@
+// Copyright (C) 2013 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.server.documentation;
+
+public class Constants {
+  public static final String PACKAGE = "com/google/gerrit/server/documentation";
+  public static final String INDEX_ZIP = "index.zip";
+
+  public static final String DOC_FIELD = "doc";
+  public static final String TITLE_FIELD = "title";
+  public static final String URL_FIELD = "url";
+
+  private Constants() {}
+}

java/com/google/gerrit/server/documentation/MarkdownFormatter.java

@@ -0,0 +1,158 @@
+// Copyright (C) 2012 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.server.documentation;
+
+import static java.nio.charset.StandardCharsets.UTF_8;
+import static org.pegdown.Extensions.ALL;
+import static org.pegdown.Extensions.HARDWRAPS;
+import static org.pegdown.Extensions.SUPPRESS_ALL_HTML;
+
+import com.google.common.base.Strings;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.UnsupportedEncodingException;
+import java.net.URL;
+import java.nio.charset.Charset;
+import java.util.concurrent.atomic.AtomicBoolean;
+import org.apache.commons.lang.StringEscapeUtils;
+import org.eclipse.jgit.util.RawParseUtils;
+import org.eclipse.jgit.util.TemporaryBuffer;
+import org.pegdown.LinkRenderer;
+import org.pegdown.PegDownProcessor;
+import org.pegdown.ToHtmlSerializer;
+import org.pegdown.ast.HeaderNode;
+import org.pegdown.ast.Node;
+import org.pegdown.ast.RootNode;
+import org.pegdown.ast.TextNode;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class MarkdownFormatter {
+  private static final Logger log = LoggerFactory.getLogger(MarkdownFormatter.class);
+
+  private static final String defaultCss;
+
+  static {
+    AtomicBoolean file = new AtomicBoolean();
+    String src;
+    try {
+      src = readPegdownCss(file);
+    } catch (IOException err) {
+      log.warn("Cannot load pegdown.css", err);
+      src = "";
+    }
+    defaultCss = file.get() ? null : src;
+  }
+
+  private static String readCSS() {
+    if (defaultCss != null) {
+      return defaultCss;
+    }
+    try {
+      return readPegdownCss(new AtomicBoolean());
+    } catch (IOException err) {
+      log.warn("Cannot load pegdown.css", err);
+      return "";
+    }
+  }
+
+  private boolean suppressHtml;
+  private String css;
+
+  public MarkdownFormatter suppressHtml() {
+    suppressHtml = true;
+    return this;
+  }
+
+  public MarkdownFormatter setCss(String css) {
+    this.css = StringEscapeUtils.escapeHtml(css);
+    return this;
+  }
+
+  public byte[] markdownToDocHtml(String md, String charEnc) throws UnsupportedEncodingException {
+    RootNode root = parseMarkdown(md);
+    String title = findTitle(root);
+
+    StringBuilder html = new StringBuilder();
+    html.append("<html>");
+    html.append("<head>");
+    if (!Strings.isNullOrEmpty(title)) {
+      html.append("<title>").append(title).append("</title>");
+    }
+    html.append("<style type=\"text/css\">\n");
+    if (css != null) {
+      html.append(css);
+    } else {
+      html.append(readCSS());
+    }
+    html.append("\n</style>");
+    html.append("</head>");
+    html.append("<body>\n");
+    html.append(new ToHtmlSerializer(new LinkRenderer()).toHtml(root));
+    html.append("\n</body></html>");
+    return html.toString().getBytes(charEnc);
+  }
+
+  public String extractTitleFromMarkdown(byte[] data, String charEnc) {
+    String md = RawParseUtils.decode(Charset.forName(charEnc), data);
+    return findTitle(parseMarkdown(md));
+  }
+
+  private String findTitle(Node root) {
+    if (root instanceof HeaderNode) {
+      HeaderNode h = (HeaderNode) root;
+      if (h.getLevel() == 1 && h.getChildren() != null && !h.getChildren().isEmpty()) {
+        StringBuilder b = new StringBuilder();
+        for (Node n : root.getChildren()) {
+          if (n instanceof TextNode) {
+            b.append(((TextNode) n).getText());
+          }
+        }
+        return b.toString();
+      }
+    }
+
+    for (Node n : root.getChildren()) {
+      String title = findTitle(n);
+      if (title != null) {
+        return title;
+      }
+    }
+    return null;
+  }
+
+  private RootNode parseMarkdown(String md) {
+    int options = ALL & ~(HARDWRAPS);
+    if (suppressHtml) {
+      options |= SUPPRESS_ALL_HTML;
+    }
+    return new PegDownProcessor(options).parseMarkdown(md.toCharArray());
+  }
+
+  private static String readPegdownCss(AtomicBoolean file) throws IOException {
+    String name = "pegdown.css";
+    URL url = MarkdownFormatter.class.getResource(name);
+    if (url == null) {
+      throw new FileNotFoundException("Resource " + name);
+    }
+    file.set("file".equals(url.getProtocol()));
+    try (InputStream in = url.openStream();
+        TemporaryBuffer.Heap tmp = new TemporaryBuffer.Heap(128 * 1024)) {
+      tmp.copy(in);
+      return new String(tmp.toByteArray(), UTF_8);
+    }
+  }
+}

java/com/google/gerrit/server/documentation/QueryDocumentationExecutor.java

@@ -0,0 +1,149 @@
+// Copyright (C) 2013 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.server.documentation;
+
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.Lists;
+import com.google.inject.Inject;
+import com.google.inject.Singleton;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.List;
+import java.util.Map;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipInputStream;
+import org.apache.lucene.analysis.standard.StandardAnalyzer;
+import org.apache.lucene.document.Document;
+import org.apache.lucene.index.DirectoryReader;
+import org.apache.lucene.index.IndexReader;
+import org.apache.lucene.queryparser.simple.SimpleQueryParser;
+import org.apache.lucene.search.IndexSearcher;
+import org.apache.lucene.search.Query;
+import org.apache.lucene.search.ScoreDoc;
+import org.apache.lucene.search.TopDocs;
+import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IndexOutput;
+import org.apache.lucene.store.RAMDirectory;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+@Singleton
+public class QueryDocumentationExecutor {
+  private static final Logger log = LoggerFactory.getLogger(QueryDocumentationExecutor.class);
+
+  private static Map<String, Float> WEIGHTS =
+      ImmutableMap.of(
+          Constants.TITLE_FIELD, 2.0f,
+          Constants.DOC_FIELD, 1.0f);
+
+  private IndexSearcher searcher;
+  private SimpleQueryParser parser;
+
+  public static class DocResult {
+    public String title;
+    public String url;
+    public String content;
+  }
+
+  @Inject
+  public QueryDocumentationExecutor() {
+    try {
+      Directory dir = readIndexDirectory();
+      if (dir == null) {
+        searcher = null;
+        parser = null;
+        return;
+      }
+      IndexReader reader = DirectoryReader.open(dir);
+      searcher = new IndexSearcher(reader);
+      parser = new SimpleQueryParser(new StandardAnalyzer(), WEIGHTS);
+    } catch (IOException e) {
+      log.error("Cannot initialize documentation full text index", e);
+      searcher = null;
+      parser = null;
+    }
+  }
+
+  public List<DocResult> doQuery(String q) throws DocQueryException {
+    if (!isAvailable()) {
+      throw new DocQueryException("Documentation search not available");
+    }
+    Query query = parser.parse(q);
+    try {
+      // TODO(fishywang): Currently as we don't have much documentation, we just use MAX_VALUE here
+      // and skipped paging. Maybe add paging later.
+      TopDocs results = searcher.search(query, Integer.MAX_VALUE);
+      ScoreDoc[] hits = results.scoreDocs;
+      int totalHits = results.totalHits;
+
+      List<DocResult> out = Lists.newArrayListWithCapacity(totalHits);
+      for (int i = 0; i < totalHits; i++) {
+        DocResult result = new DocResult();
+        Document doc = searcher.doc(hits[i].doc);
+        result.url = doc.get(Constants.URL_FIELD);
+        result.title = doc.get(Constants.TITLE_FIELD);
+        out.add(result);
+      }
+      return out;
+    } catch (IOException e) {
+      throw new DocQueryException(e);
+    }
+  }
+
+  protected Directory readIndexDirectory() throws IOException {
+    Directory dir = new RAMDirectory();
+    byte[] buffer = new byte[4096];
+    InputStream index = getClass().getResourceAsStream(Constants.INDEX_ZIP);
+    if (index == null) {
+      log.warn("No index available");
+      return null;
+    }
+
+    try (ZipInputStream zip = new ZipInputStream(index)) {
+      ZipEntry entry;
+      while ((entry = zip.getNextEntry()) != null) {
+        try (IndexOutput out = dir.createOutput(entry.getName(), null)) {
+          int count;
+          while ((count = zip.read(buffer)) != -1) {
+            out.writeBytes(buffer, count);
+          }
+        }
+      }
+    }
+    // We must NOT call dir.close() here, as DirectoryReader.open() expects an opened directory.
+    return dir;
+  }
+
+  public boolean isAvailable() {
+    return parser != null && searcher != null;
+  }
+
+  @SuppressWarnings("serial")
+  public static class DocQueryException extends Exception {
+    DocQueryException() {}
+
+    DocQueryException(String msg) {
+      super(msg);
+    }
+
+    DocQueryException(String msg, Throwable e) {
+      super(msg, e);
+    }
+
+    DocQueryException(Throwable e) {
+      super(e);
+    }
+  }
+}