Make hooks/commit-msg available over HTTP

We have to move the old scproot assets into gerrit-server so they
are commonly available to both the SSH and HTTP daemon packages.

Bug: issue 392
Change-Id: Ie0dc95529f26b14535c2e1041863a441333516b3
Signed-off-by: Shawn O. Pearce <sop@google.com>
Reviewed-by: Nico Sallembien <nsallembien@google.com>

gerrit-server/src/main/java/com/google/gerrit/server/config/GerritGlobalModule.java

@@ -59,6 +59,7 @@ import com.google.gerrit.server.patch.PatchListCacheImpl;
 import com.google.gerrit.server.patch.PatchSetInfoFactory;
 import com.google.gerrit.server.project.ProjectCacheImpl;
 import com.google.gerrit.server.project.ProjectState;
+import com.google.gerrit.server.tools.ToolsCatalog;
 import com.google.gerrit.server.util.IdGenerator;
 import com.google.gerrit.server.workflow.FunctionState;
 import com.google.inject.Inject;
@@ -114,6 +115,7 @@ public class GerritGlobalModule extends FactoryModule {
     bind(GitRepositoryManager.class).to(LocalDiskRepositoryManager.class);
     bind(FileTypeRegistry.class).to(MimeUtilFileTypeRegistry.class);
     bind(WorkQueue.class);
+    bind(ToolsCatalog.class);
 
     bind(ReplicationQueue.class).to(PushReplication.class).in(SINGLETON);
     factory(PushAllProjectsOp.Factory.class);

gerrit-server/src/main/java/com/google/gerrit/server/tools/ToolsCatalog.java

@@ -0,0 +1,229 @@
+// Copyright (C) 2010 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.tools;
+
+import com.google.gerrit.common.Version;
+import com.google.inject.Inject;
+import com.google.inject.Singleton;
+
+import org.eclipse.jgit.lib.Constants;
+import org.eclipse.jgit.util.RawParseUtils;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.BufferedReader;
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.SortedMap;
+import java.util.TreeMap;
+
+/**
+ * Listing of all client side tools stored on this server.
+ * <p>
+ * Clients may download these tools through our file server, as they are
+ * packaged with our own software releases.
+ */
+@Singleton
+public class ToolsCatalog {
+  private static final Logger log = LoggerFactory.getLogger(ToolsCatalog.class);
+
+  private final SortedMap<String, Entry> toc;
+
+  @Inject
+  ToolsCatalog() throws IOException {
+    this.toc = readToc();
+  }
+
+  /**
+   * Lookup an entry in the tools catalog.
+   *
+   * @param name path of the item, relative to the root of the catalog.
+   * @return the entry; null if the item is not part of the catalog.
+   */
+  public Entry get(String name) {
+    if (name.startsWith("/")) {
+      name = name.substring(1);
+    }
+    if (name.endsWith("/")) {
+      name = name.substring(0, name.length() - 1);
+    }
+    return toc.get(name);
+  }
+
+  private static SortedMap<String, Entry> readToc() throws IOException {
+    SortedMap<String, Entry> toc = new TreeMap<String, Entry>();
+    final BufferedReader br =
+        new BufferedReader(new InputStreamReader(new ByteArrayInputStream(
+            read("TOC")), "UTF-8"));
+    String line;
+    while ((line = br.readLine()) != null) {
+      if (line.length() > 0 && !line.startsWith("#")) {
+        final Entry e = new Entry(Entry.Type.FILE, line);
+        toc.put(e.getPath(), e);
+      }
+    }
+
+    final List<Entry> all = new ArrayList<Entry>(toc.values());
+    for (Entry e : all) {
+      String path = dirOf(e.getPath());
+      while (path != null) {
+        Entry d = toc.get(path);
+        if (d == null) {
+          d = new Entry(Entry.Type.DIR, 0755, path);
+          toc.put(d.getPath(), d);
+        }
+        d.children.add(e);
+        path = dirOf(path);
+        e = d;
+      }
+    }
+
+    final Entry top = new Entry(Entry.Type.DIR, 0755, "");
+    for (Entry e : toc.values()) {
+      if (dirOf(e.getPath()) == null) {
+        top.children.add(e);
+      }
+    }
+    toc.put(top.getPath(), top);
+
+    return Collections.unmodifiableSortedMap(toc);
+  }
+
+  private static byte[] read(String path) {
+    String name = "root/" + path;
+    InputStream in = ToolsCatalog.class.getResourceAsStream(name);
+    if (in == null) {
+      return null;
+    }
+
+    try {
+      final ByteArrayOutputStream out = new ByteArrayOutputStream();
+      try {
+        final byte[] buf = new byte[8192];
+        int n;
+        while ((n = in.read(buf, 0, buf.length)) > 0) {
+          out.write(buf, 0, n);
+        }
+      } finally {
+        in.close();
+      }
+      return out.toByteArray();
+    } catch (Exception e) {
+      log.debug("Cannot read " + path, e);
+      return null;
+    }
+  }
+
+  private static String dirOf(String path) {
+    final int s = path.lastIndexOf('/');
+    return s < 0 ? null : path.substring(0, s);
+  }
+
+  /** A file served out of the tools root directory. */
+  public static class Entry {
+    public static enum Type {
+      DIR, FILE;
+    }
+
+    private final Type type;
+    private final int mode;
+    private final String path;
+    private final List<Entry> children;
+
+    Entry(Type type, String line) {
+      int s = line.indexOf(' ');
+      String mode = line.substring(0, s);
+      String path = line.substring(s + 1);
+
+      this.type = type;
+      this.mode = Integer.parseInt(mode, 8);
+      this.path = path;
+      if (type == Type.FILE) {
+        this.children = Collections.emptyList();
+      } else {
+        this.children = new ArrayList<Entry>();
+      }
+    }
+
+    Entry(Type type, int mode, String path) {
+      this.type = type;
+      this.mode = mode;
+      this.path = path;
+      this.children = new ArrayList<Entry>();
+    }
+
+    public Type getType() {
+      return type;
+    }
+
+    /** @return the preferred UNIX file mode, e.g. {@code 0755}. */
+    public int getMode() {
+      return mode;
+    }
+
+    /** @return path of the entry, relative to the catalog root. */
+    public String getPath() {
+      return path;
+    }
+
+    /** @return name of the entry, within its parent directory. */
+    public String getName() {
+      final int s = path.lastIndexOf('/');
+      return s < 0 ? path : path.substring(s + 1);
+    }
+
+    /** @return collection of entries below this one, if this is a directory. */
+    public List<Entry> getChildren() {
+      return Collections.unmodifiableList(children);
+    }
+
+    /** @return a copy of the file's contents. */
+    public byte[] getBytes() {
+      byte[] data = read(getPath());
+
+      if (isScript(data)) {
+        // Embed Gerrit's version number into the top of the script.
+        //
+        final String version = Version.getVersion();
+        final int lf = RawParseUtils.nextLF(data, 0);
+        if (version != null && lf < data.length) {
+          byte[] versionHeader =
+              Constants.encode("# From Gerrit Code Review " + version + "\n");
+
+          ByteArrayOutputStream buf = new ByteArrayOutputStream();
+          buf.write(data, 0, lf);
+          buf.write(versionHeader, 0, versionHeader.length);
+          buf.write(data, lf, data.length - lf);
+          data = buf.toByteArray();
+        }
+      }
+
+      return data;
+    }
+
+    private boolean isScript(byte[] data) {
+      return data != null && data.length > 3 //
+          && data[0] == '#' //
+          && data[1] == '!' //
+          && data[2] == '/';
+    }
+  }
+}