1 files changed, 150 insertions, 0 deletions
diff --git a/java/com/google/gerrit/index/SiteIndexer.java b/java/com/google/gerrit/index/SiteIndexer.java
new file mode 100644
index 0000000000..c3ab8a42e5
--- /dev/null
+++ b/java/com/google/gerrit/index/SiteIndexer.java
@@ -0,0 +1,150 @@
+// Copyright (C) 2016 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.index;
+
+import static java.nio.charset.StandardCharsets.UTF_8;
+import static java.util.Objects.requireNonNull;
+
+import com.google.common.base.Stopwatch;
+import com.google.common.flogger.FluentLogger;
+import com.google.common.util.concurrent.ListenableFuture;
+import com.google.common.util.concurrent.MoreExecutors;
+import java.io.OutputStream;
+import java.io.OutputStreamWriter;
+import java.io.PrintWriter;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.RejectedExecutionException;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicBoolean;
+import org.eclipse.jgit.lib.ProgressMonitor;
+import org.eclipse.jgit.util.io.NullOutputStream;
+
+public abstract class SiteIndexer<K, V, I extends Index<K, V>> {
+  private static final FluentLogger logger = FluentLogger.forEnclosingClass();
+
+  public static class Result {
+    private final long elapsedNanos;
+    private final boolean success;
+    private final int done;
+    private final int failed;
+
+    public Result(Stopwatch sw, boolean success, int done, int failed) {
+      this.elapsedNanos = sw.elapsed(TimeUnit.NANOSECONDS);
+      this.success = success;
+      this.done = done;
+      this.failed = failed;
+    }
+
+    public boolean success() {
+      return success;
+    }
+
+    public int doneCount() {
+      return done;
+    }
+
+    public int failedCount() {
+      return failed;
+    }
+
+    public long elapsed(TimeUnit timeUnit) {
+      return timeUnit.convert(elapsedNanos, TimeUnit.NANOSECONDS);
+    }
+  }
+
+  protected int totalWork = -1;
+  protected OutputStream progressOut = NullOutputStream.INSTANCE;
+  protected PrintWriter verboseWriter = newPrintWriter(NullOutputStream.INSTANCE);
+
+  public void setTotalWork(int num) {
+    totalWork = num;
+  }
+
+  public void setProgressOut(OutputStream out) {
+    progressOut = requireNonNull(out);
+  }
+
+  public void setVerboseOut(OutputStream out) {
+    verboseWriter = newPrintWriter(requireNonNull(out));
+  }
+
+  public abstract Result indexAll(I index);
+
+  protected final void addErrorListener(
+      ListenableFuture<?> future, String desc, ProgressMonitor progress, AtomicBoolean ok) {
+    future.addListener(
+        new ErrorListener(future, desc, progress, ok), MoreExecutors.directExecutor());
+  }
+
+  protected PrintWriter newPrintWriter(OutputStream out) {
+    return new PrintWriter(new OutputStreamWriter(out, UTF_8));
+  }
+
+  private static class ErrorListener implements Runnable {
+    private final ListenableFuture<?> future;
+    private final String desc;
+    private final ProgressMonitor progress;
+    private final AtomicBoolean ok;
+
+    private ErrorListener(
+        ListenableFuture<?> future, String desc, ProgressMonitor progress, AtomicBoolean ok) {
+      this.future = future;
+      this.desc = desc;
+      this.progress = progress;
+      this.ok = ok;
+    }
+
+    @Override
+    public void run() {
+      try {
+        future.get();
+      } catch (RejectedExecutionException e) {
+        // Server shutdown, don't spam the logs.
+        failSilently();
+      } catch (ExecutionException | InterruptedException e) {
+        fail(e);
+      } catch (RuntimeException e) {
+        failAndThrow(e);
+      } catch (Error e) {
+        // Can't join with RuntimeException because "RuntimeException |
+        // Error" becomes Throwable, which messes with signatures.
+        failAndThrow(e);
+      } finally {
+        synchronized (progress) {
+          progress.update(1);
+        }
+      }
+    }
+
+    private void failSilently() {
+      ok.set(false);
+    }
+
+    private void fail(Throwable t) {
+      logger.atSevere().withCause(t).log("Failed to index %s", desc);
+      ok.set(false);
+    }
+
+    private void failAndThrow(RuntimeException e) {
+      fail(e);
+      throw e;
+    }
+
+    private void failAndThrow(Error e) {
+      fail(e);
+      throw e;
+    }
+  }
+}