1 files changed, 142 insertions, 0 deletions
diff --git a/java/com/google/gerrit/server/util/SystemLog.java b/java/com/google/gerrit/server/util/SystemLog.java
new file mode 100644
index 0000000000..ec2f3863a7
--- /dev/null
+++ b/java/com/google/gerrit/server/util/SystemLog.java
@@ -0,0 +1,142 @@
+// Copyright (C) 2014 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.util;
+
+import static java.nio.charset.StandardCharsets.UTF_8;
+
+import com.google.common.base.Strings;
+import com.google.common.flogger.FluentLogger;
+import com.google.gerrit.common.Die;
+import com.google.gerrit.server.config.GerritServerConfig;
+import com.google.gerrit.server.config.SitePaths;
+import com.google.inject.Inject;
+import com.google.inject.Singleton;
+import java.io.IOException;
+import java.nio.file.Path;
+import org.apache.log4j.Appender;
+import org.apache.log4j.AsyncAppender;
+import org.apache.log4j.DailyRollingFileAppender;
+import org.apache.log4j.FileAppender;
+import org.apache.log4j.Layout;
+import org.apache.log4j.LogManager;
+import org.apache.log4j.Logger;
+import org.apache.log4j.helpers.OnlyOnceErrorHandler;
+import org.apache.log4j.spi.ErrorHandler;
+import org.apache.log4j.spi.LoggingEvent;
+import org.eclipse.jgit.lib.Config;
+
+@Singleton
+public class SystemLog {
+  private static final FluentLogger logger = FluentLogger.forEnclosingClass();
+
+  public static final String LOG4J_CONFIGURATION = "log4j.configuration";
+
+  private final SitePaths site;
+  private final int asyncLoggingBufferSize;
+  private final boolean rotateLogs;
+
+  @Inject
+  public SystemLog(SitePaths site, @GerritServerConfig Config config) {
+    this.site = site;
+    this.asyncLoggingBufferSize = config.getInt("core", "asyncLoggingBufferSize", 64);
+    this.rotateLogs = config.getBoolean("log", "rotate", true);
+  }
+
+  public static boolean shouldConfigure() {
+    return Strings.isNullOrEmpty(System.getProperty(LOG4J_CONFIGURATION));
+  }
+
+  public static Appender createAppender(Path logdir, String name, Layout layout, boolean rotate) {
+    final FileAppender dst = rotate ? new DailyRollingFileAppender() : new FileAppender();
+    dst.setName(name);
+    dst.setLayout(layout);
+    dst.setEncoding(UTF_8.name());
+    dst.setFile(resolve(logdir).resolve(name).toString());
+    dst.setImmediateFlush(true);
+    dst.setAppend(true);
+    dst.setErrorHandler(new DieErrorHandler());
+    dst.activateOptions();
+    dst.setErrorHandler(new OnlyOnceErrorHandler());
+    return dst;
+  }
+
+  public AsyncAppender createAsyncAppender(String name, Layout layout) {
+    return createAsyncAppender(name, layout, rotateLogs);
+  }
+
+  private AsyncAppender createAsyncAppender(String name, Layout layout, boolean rotate) {
+    return createAsyncAppender(name, layout, rotate, false);
+  }
+
+  public AsyncAppender createAsyncAppender(
+      String name, Layout layout, boolean rotate, boolean forPlugin) {
+    AsyncAppender async = new AsyncAppender();
+    async.setName(name);
+    async.setBlocking(true);
+    async.setBufferSize(asyncLoggingBufferSize);
+    async.setLocationInfo(false);
+
+    if (forPlugin || shouldConfigure()) {
+      async.addAppender(createAppender(site.logs_dir, name, layout, rotate));
+    } else {
+      Appender appender = LogManager.getLogger(name).getAppender(name);
+      if (appender != null) {
+        async.addAppender(appender);
+      } else {
+        logger.atWarning().log(
+            "No appender with the name: %s was found. %s logging is disabled", name, name);
+      }
+    }
+    async.activateOptions();
+    return async;
+  }
+
+  private static Path resolve(Path p) {
+    try {
+      return p.toRealPath().normalize();
+    } catch (IOException e) {
+      return p.toAbsolutePath().normalize();
+    }
+  }
+
+  private static final class DieErrorHandler implements ErrorHandler {
+    @Override
+    public void error(String message, Exception e, int errorCode, LoggingEvent event) {
+      error(e != null ? e.getMessage() : message);
+    }
+
+    @Override
+    public void error(String message, Exception e, int errorCode) {
+      error(e != null ? e.getMessage() : message);
+    }
+
+    @Override
+    public void error(String message) {
+      throw new Die("Cannot open log file: " + message);
+    }
+
+    @Override
+    public void activateOptions() {}
+
+    @Override
+    public void setAppender(Appender appender) {}
+
+    @Override
+    public void setBackupAppender(Appender appender) {}
+
+    @Override
+    public void setLogger(Logger logger) {}
+  }
+}