Add m-esr52 at 52.6.0

10 files changed, 741 insertions, 0 deletions

diff --git a/mobile/android/services/src/main/java/org/mozilla/gecko/background/common/log/Logger.java b/mobile/android/services/src/main/java/org/mozilla/gecko/background/common/log/Logger.java
new file mode 100644
index 000000000..2575717eb
--- /dev/null
+++ b/mobile/android/services/src/main/java/org/mozilla/gecko/background/common/log/Logger.java
@@ -0,0 +1,232 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.background.common.log;
+
+import java.io.PrintWriter;
+import java.util.Iterator;
+import java.util.LinkedHashSet;
+import java.util.Set;
+
+import org.mozilla.gecko.background.common.GlobalConstants;
+import org.mozilla.gecko.background.common.log.writers.AndroidLevelCachingLogWriter;
+import org.mozilla.gecko.background.common.log.writers.AndroidLogWriter;
+import org.mozilla.gecko.background.common.log.writers.LogWriter;
+import org.mozilla.gecko.background.common.log.writers.PrintLogWriter;
+import org.mozilla.gecko.background.common.log.writers.SimpleTagLogWriter;
+import org.mozilla.gecko.background.common.log.writers.ThreadLocalTagLogWriter;
+
+import android.util.Log;
+
+/**
+ * Logging helper class. Serializes all log operations (by synchronizing).
+ */
+public class Logger {
+  public static final String LOGGER_TAG = "Logger";
+  public static final String DEFAULT_LOG_TAG = "GeckoLogger";
+
+  // For extra debugging.
+  public static boolean LOG_PERSONAL_INFORMATION = false;
+
+  /**
+   * Allow each thread to use its own global log tag. This allows
+   * independent services to log as different sources.
+   *
+   * When your thread sets up logging, it should do something like the following:
+   *
+   *   Logger.setThreadLogTag("MyTag");
+   *
+   * The value is inheritable, so worker threads and such do not need to
+   * set the same log tag as their parent.
+   */
+  private static final InheritableThreadLocal<String> logTag = new InheritableThreadLocal<String>() {
+    @Override
+    protected String initialValue() {
+      return DEFAULT_LOG_TAG;
+    }
+  };
+
+  public static void setThreadLogTag(final String logTag) {
+    Logger.logTag.set(logTag);
+  }
+  public static String getThreadLogTag() {
+    return Logger.logTag.get();
+  }
+
+  /**
+   * Current set of writers to which we will log.
+   * <p>
+   * We want logging to be available while running tests, so we initialize
+   * this set statically.
+   */
+  protected final static Set<LogWriter> logWriters;
+  static {
+    final Set<LogWriter> defaultWriters = Logger.defaultLogWriters();
+    logWriters = new LinkedHashSet<LogWriter>(defaultWriters);
+  }
+
+  /**
+   * Default set of log writers to log to.
+   */
+  public final static Set<LogWriter> defaultLogWriters() {
+    final String processedPackage = GlobalConstants.BROWSER_INTENT_PACKAGE.replace("org.mozilla.", "");
+
+    final Set<LogWriter> defaultLogWriters = new LinkedHashSet<LogWriter>();
+
+    final LogWriter log = new AndroidLogWriter();
+    final LogWriter cache = new AndroidLevelCachingLogWriter(log);
+
+    final LogWriter single = new SimpleTagLogWriter(processedPackage, new ThreadLocalTagLogWriter(Logger.logTag, cache));
+
+    defaultLogWriters.add(single);
+    return defaultLogWriters;
+  }
+
+  public static synchronized void startLoggingTo(LogWriter logWriter) {
+    logWriters.add(logWriter);
+  }
+
+  public static synchronized void startLoggingToWriters(Set<LogWriter> writers) {
+    logWriters.addAll(writers);
+  }
+
+  public static synchronized void stopLoggingTo(LogWriter logWriter) {
+    try {
+      logWriter.close();
+    } catch (Exception e) {
+      Log.e(LOGGER_TAG, "Got exception closing and removing LogWriter " + logWriter + ".", e);
+    }
+    logWriters.remove(logWriter);
+  }
+
+  public static synchronized void stopLoggingToAll() {
+    for (LogWriter logWriter : logWriters) {
+      try {
+        logWriter.close();
+      } catch (Exception e) {
+        Log.e(LOGGER_TAG, "Got exception closing and removing LogWriter " + logWriter + ".", e);
+      }
+    }
+    logWriters.clear();
+  }
+
+  /**
+   * Write to only the default log writers.
+   */
+  public static synchronized void resetLogging() {
+    stopLoggingToAll();
+    logWriters.addAll(Logger.defaultLogWriters());
+  }
+
+  /**
+   * Start writing log output to stdout.
+   * <p>
+   * Use <code>resetLogging</code> to stop logging to stdout.
+   */
+  public static synchronized void startLoggingToConsole() {
+    setThreadLogTag("Test");
+    startLoggingTo(new PrintLogWriter(new PrintWriter(System.out, true)));
+  }
+
+  // Synchronized version for other classes to use.
+  public static synchronized boolean shouldLogVerbose(String logTag) {
+    for (LogWriter logWriter : logWriters) {
+      if (logWriter.shouldLogVerbose(logTag)) {
+        return true;
+      }
+    }
+    return false;
+  }
+
+  public static void error(String tag, String message) {
+    Logger.error(tag, message, null);
+  }
+
+  public static void warn(String tag, String message) {
+    Logger.warn(tag, message, null);
+  }
+
+  public static void info(String tag, String message) {
+    Logger.info(tag, message, null);
+  }
+
+  public static void debug(String tag, String message) {
+    Logger.debug(tag, message, null);
+  }
+
+  public static void trace(String tag, String message) {
+    Logger.trace(tag, message, null);
+  }
+
+  public static void pii(String tag, String message) {
+    if (LOG_PERSONAL_INFORMATION) {
+      Logger.debug(tag, "$$PII$$: " + message);
+    }
+  }
+
+  public static synchronized void error(String tag, String message, Throwable error) {
+    Iterator<LogWriter> it = logWriters.iterator();
+    while (it.hasNext()) {
+      LogWriter writer = it.next();
+      try {
+        writer.error(tag, message, error);
+      } catch (Exception e) {
+        Log.e(LOGGER_TAG, "Got exception logging; removing LogWriter " + writer + ".", e);
+        it.remove();
+      }
+    }
+  }
+
+  public static synchronized void warn(String tag, String message, Throwable error) {
+    Iterator<LogWriter> it = logWriters.iterator();
+    while (it.hasNext()) {
+      LogWriter writer = it.next();
+      try {
+        writer.warn(tag, message, error);
+      } catch (Exception e) {
+        Log.e(LOGGER_TAG, "Got exception logging; removing LogWriter " + writer + ".", e);
+        it.remove();
+      }
+    }
+  }
+
+  public static synchronized void info(String tag, String message, Throwable error) {
+    Iterator<LogWriter> it = logWriters.iterator();
+    while (it.hasNext()) {
+      LogWriter writer = it.next();
+      try {
+        writer.info(tag, message, error);
+      } catch (Exception e) {
+        Log.e(LOGGER_TAG, "Got exception logging; removing LogWriter " + writer + ".", e);
+        it.remove();
+      }
+    }
+  }
+
+  public static synchronized void debug(String tag, String message, Throwable error) {
+    Iterator<LogWriter> it = logWriters.iterator();
+    while (it.hasNext()) {
+      LogWriter writer = it.next();
+      try {
+        writer.debug(tag, message, error);
+      } catch (Exception e) {
+        Log.e(LOGGER_TAG, "Got exception logging; removing LogWriter " + writer + ".", e);
+        it.remove();
+      }
+    }
+  }
+
+  public static synchronized void trace(String tag, String message, Throwable error) {
+    Iterator<LogWriter> it = logWriters.iterator();
+    while (it.hasNext()) {
+      LogWriter writer = it.next();
+      try {
+        writer.trace(tag, message, error);
+      } catch (Exception e) {
+        Log.e(LOGGER_TAG, "Got exception logging; removing LogWriter " + writer + ".", e);
+        it.remove();
+      }
+    }
+  }
+}
diff --git a/mobile/android/services/src/main/java/org/mozilla/gecko/background/common/log/writers/AndroidLevelCachingLogWriter.java b/mobile/android/services/src/main/java/org/mozilla/gecko/background/common/log/writers/AndroidLevelCachingLogWriter.java
new file mode 100644
index 000000000..ac4250a03
--- /dev/null
+++ b/mobile/android/services/src/main/java/org/mozilla/gecko/background/common/log/writers/AndroidLevelCachingLogWriter.java
@@ -0,0 +1,132 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.background.common.log.writers;
+
+import java.util.IdentityHashMap;
+import java.util.Map;
+
+import android.util.Log;
+
+/**
+ * Make a <code>LogWriter</code> only log when the Android log system says to.
+ */
+public class AndroidLevelCachingLogWriter extends LogWriter {
+  protected final LogWriter inner;
+
+  public AndroidLevelCachingLogWriter(LogWriter inner) {
+    this.inner = inner;
+  }
+
+  // I can't believe we have to implement this ourselves.
+  // These aren't synchronized (and neither are the setters) because
+  // the logging calls themselves are synchronized.
+  private Map<String, Boolean> isErrorLoggable   = new IdentityHashMap<String, Boolean>();
+  private Map<String, Boolean> isWarnLoggable    = new IdentityHashMap<String, Boolean>();
+  private Map<String, Boolean> isInfoLoggable    = new IdentityHashMap<String, Boolean>();
+  private Map<String, Boolean> isDebugLoggable   = new IdentityHashMap<String, Boolean>();
+  private Map<String, Boolean> isVerboseLoggable = new IdentityHashMap<String, Boolean>();
+
+  /**
+   * Empty the caches of log levels.
+   */
+  public void refreshLogLevels() {
+    isErrorLoggable   = new IdentityHashMap<String, Boolean>();
+    isWarnLoggable    = new IdentityHashMap<String, Boolean>();
+    isInfoLoggable    = new IdentityHashMap<String, Boolean>();
+    isDebugLoggable   = new IdentityHashMap<String, Boolean>();
+    isVerboseLoggable = new IdentityHashMap<String, Boolean>();
+  }
+
+  private boolean shouldLogError(String logTag) {
+    Boolean out = isErrorLoggable.get(logTag);
+    if (out != null) {
+      return out;
+    }
+    out = Log.isLoggable(logTag, Log.ERROR);
+    isErrorLoggable.put(logTag, out);
+    return out;
+  }
+
+  private boolean shouldLogWarn(String logTag) {
+    Boolean out = isWarnLoggable.get(logTag);
+    if (out != null) {
+      return out;
+    }
+    out = Log.isLoggable(logTag, Log.WARN);
+    isWarnLoggable.put(logTag, out);
+    return out;
+  }
+
+  private boolean shouldLogInfo(String logTag) {
+    Boolean out = isInfoLoggable.get(logTag);
+    if (out != null) {
+      return out;
+    }
+    out = Log.isLoggable(logTag, Log.INFO);
+    isInfoLoggable.put(logTag, out);
+    return out;
+  }
+
+  private boolean shouldLogDebug(String logTag) {
+    Boolean out = isDebugLoggable.get(logTag);
+    if (out != null) {
+      return out;
+    }
+    out = Log.isLoggable(logTag, Log.DEBUG);
+    isDebugLoggable.put(logTag, out);
+    return out;
+  }
+
+  @Override
+  public boolean shouldLogVerbose(String logTag) {
+    Boolean out = isVerboseLoggable.get(logTag);
+    if (out != null) {
+      return out;
+    }
+    out = Log.isLoggable(logTag, Log.VERBOSE);
+    isVerboseLoggable.put(logTag, out);
+    return out;
+  }
+
+  @Override
+  public void error(String tag, String message, Throwable error) {
+    if (shouldLogError(tag)) {
+      inner.error(tag, message, error);
+    }
+  }
+
+  @Override
+  public void warn(String tag, String message, Throwable error) {
+    if (shouldLogWarn(tag)) {
+      inner.warn(tag, message, error);
+    }
+  }
+
+  @Override
+  public void info(String tag, String message, Throwable error) {
+    if (shouldLogInfo(tag)) {
+      inner.info(tag, message, error);
+    }
+  }
+
+  @Override
+  public void debug(String tag, String message, Throwable error) {
+    if (shouldLogDebug(tag)) {
+      inner.debug(tag, message, error);
+    }
+  }
+
+  @Override
+  public void trace(String tag, String message, Throwable error) {
+    if (shouldLogVerbose(tag)) {
+      inner.trace(tag, message, error);
+    }
+  }
+
+  @Override
+  public void close() {
+    inner.close();
+  }
+}
diff --git a/mobile/android/services/src/main/java/org/mozilla/gecko/background/common/log/writers/AndroidLogWriter.java b/mobile/android/services/src/main/java/org/mozilla/gecko/background/common/log/writers/AndroidLogWriter.java
new file mode 100644
index 000000000..9d309844d
--- /dev/null
+++ b/mobile/android/services/src/main/java/org/mozilla/gecko/background/common/log/writers/AndroidLogWriter.java
@@ -0,0 +1,46 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.background.common.log.writers;
+
+import android.util.Log;
+
+/**
+ * Log to the Android log.
+ */
+public class AndroidLogWriter extends LogWriter {
+  @Override
+  public boolean shouldLogVerbose(String logTag) {
+    return true;
+  }
+
+  @Override
+  public void error(String tag, String message, Throwable error) {
+    Log.e(tag, message, error);
+  }
+
+  @Override
+  public void warn(String tag, String message, Throwable error) {
+    Log.w(tag, message, error);
+  }
+
+  @Override
+  public void info(String tag, String message, Throwable error) {
+    Log.i(tag, message, error);
+  }
+
+  @Override
+  public void debug(String tag, String message, Throwable error) {
+    Log.d(tag, message, error);
+  }
+
+  @Override
+  public void trace(String tag, String message, Throwable error) {
+    Log.v(tag, message, error);
+  }
+
+  @Override
+  public void close() {
+  }
+}
diff --git a/mobile/android/services/src/main/java/org/mozilla/gecko/background/common/log/writers/LevelFilteringLogWriter.java b/mobile/android/services/src/main/java/org/mozilla/gecko/background/common/log/writers/LevelFilteringLogWriter.java
new file mode 100644
index 000000000..74c3608c4
--- /dev/null
+++ b/mobile/android/services/src/main/java/org/mozilla/gecko/background/common/log/writers/LevelFilteringLogWriter.java
@@ -0,0 +1,67 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.background.common.log.writers;
+
+import android.util.Log;
+
+/**
+ * A LogWriter that logs only if the message is as important as the specified
+ * level. For example, if the specified level is <code>Log.WARN</code>, only
+ * <code>warn</code> and <code>error</code> will log.
+ */
+public class LevelFilteringLogWriter extends LogWriter {
+  protected final LogWriter inner;
+  protected final int logLevel;
+
+  public LevelFilteringLogWriter(int logLevel, LogWriter inner) {
+    this.inner = inner;
+    this.logLevel = logLevel;
+  }
+
+  @Override
+  public void close() {
+    inner.close();
+  }
+
+  @Override
+  public void error(String tag, String message, Throwable error) {
+    if (logLevel <= Log.ERROR) {
+      inner.error(tag, message, error);
+    }
+  }
+
+  @Override
+  public void warn(String tag, String message, Throwable error) {
+    if (logLevel <= Log.WARN) {
+      inner.warn(tag, message, error);
+    }
+  }
+
+  @Override
+  public void info(String tag, String message, Throwable error) {
+    if (logLevel <= Log.INFO) {
+      inner.info(tag, message, error);
+    }
+  }
+
+  @Override
+  public void debug(String tag, String message, Throwable error) {
+    if (logLevel <= Log.DEBUG) {
+      inner.debug(tag, message, error);
+    }
+  }
+
+  @Override
+  public void trace(String tag, String message, Throwable error) {
+    if (logLevel <= Log.VERBOSE) {
+      inner.trace(tag, message, error);
+    }
+  }
+
+  @Override
+  public boolean shouldLogVerbose(String tag) {
+    return logLevel <= Log.VERBOSE;
+  }
+}
diff --git a/mobile/android/services/src/main/java/org/mozilla/gecko/background/common/log/writers/LogWriter.java b/mobile/android/services/src/main/java/org/mozilla/gecko/background/common/log/writers/LogWriter.java
new file mode 100644
index 000000000..acfb09969
--- /dev/null
+++ b/mobile/android/services/src/main/java/org/mozilla/gecko/background/common/log/writers/LogWriter.java
@@ -0,0 +1,29 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.background.common.log.writers;
+
+/**
+ * An abstract object that logs information in some way.
+ * <p>
+ * Intended to be composed with other log writers, for example a log
+ * writer could make all log entries have the same single log tag, or
+ * could ignore certain log levels, before delegating to an inner log
+ * writer.
+ */
+public abstract class LogWriter {
+  public abstract void error(String tag, String message, Throwable error);
+  public abstract void warn(String tag, String message, Throwable error);
+  public abstract void info(String tag, String message, Throwable error);
+  public abstract void debug(String tag, String message, Throwable error);
+  public abstract void trace(String tag, String message, Throwable error);
+
+  /**
+   * We expect <code>close</code> to be called only by static
+   * synchronized methods in class <code>Logger</code>.
+   */
+  public abstract void close();
+
+  public abstract boolean shouldLogVerbose(String tag);
+}
diff --git a/mobile/android/services/src/main/java/org/mozilla/gecko/background/common/log/writers/PrintLogWriter.java b/mobile/android/services/src/main/java/org/mozilla/gecko/background/common/log/writers/PrintLogWriter.java
new file mode 100644
index 000000000..6e1f63de3
--- /dev/null
+++ b/mobile/android/services/src/main/java/org/mozilla/gecko/background/common/log/writers/PrintLogWriter.java
@@ -0,0 +1,77 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.background.common.log.writers;
+
+import java.io.PrintWriter;
+
+/**
+ * Log to a <code>PrintWriter</code>.
+ */
+public class PrintLogWriter extends LogWriter {
+  protected final PrintWriter pw;
+  protected boolean closed = false;
+
+  public static final String ERROR   = " :: E :: ";
+  public static final String WARN    = " :: W :: ";
+  public static final String INFO    = " :: I :: ";
+  public static final String DEBUG   = " :: D :: ";
+  public static final String VERBOSE = " :: V :: ";
+
+  public PrintLogWriter(PrintWriter pw) {
+    this.pw = pw;
+  }
+
+  protected void log(String tag, String message, Throwable error) {
+    if (closed) {
+      return;
+    }
+
+    pw.println(tag + message);
+    if (error != null) {
+      error.printStackTrace(pw);
+    }
+  }
+
+  @Override
+  public void error(String tag, String message, Throwable error) {
+    log(tag, ERROR + message, error);
+  }
+
+  @Override
+  public void warn(String tag, String message, Throwable error) {
+    log(tag, WARN + message, error);
+  }
+
+  @Override
+  public void info(String tag, String message, Throwable error) {
+    log(tag, INFO + message, error);
+  }
+
+  @Override
+  public void debug(String tag, String message, Throwable error) {
+    log(tag, DEBUG + message, error);
+  }
+
+  @Override
+  public void trace(String tag, String message, Throwable error) {
+    log(tag, VERBOSE + message, error);
+  }
+
+  @Override
+  public boolean shouldLogVerbose(String tag) {
+    return true;
+  }
+
+  @Override
+  public void close() {
+    if (closed) {
+      return;
+    }
+    if (pw != null) {
+      pw.close();
+    }
+    closed = true;
+  }
+}
diff --git a/mobile/android/services/src/main/java/org/mozilla/gecko/background/common/log/writers/SimpleTagLogWriter.java b/mobile/android/services/src/main/java/org/mozilla/gecko/background/common/log/writers/SimpleTagLogWriter.java
new file mode 100644
index 000000000..a17654371
--- /dev/null
+++ b/mobile/android/services/src/main/java/org/mozilla/gecko/background/common/log/writers/SimpleTagLogWriter.java
@@ -0,0 +1,21 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.background.common.log.writers;
+
+/**
+ * Make a <code>LogWriter</code> only log with a single string tag.
+ */
+public class SimpleTagLogWriter extends TagLogWriter {
+  final String tag;
+  public SimpleTagLogWriter(String tag, LogWriter inner) {
+    super(inner);
+    this.tag = tag;
+  }
+
+  @Override
+  protected String getMainTag() {
+    return tag;
+  }
+}
diff --git a/mobile/android/services/src/main/java/org/mozilla/gecko/background/common/log/writers/StringLogWriter.java b/mobile/android/services/src/main/java/org/mozilla/gecko/background/common/log/writers/StringLogWriter.java
new file mode 100644
index 000000000..d6a9f5eb8
--- /dev/null
+++ b/mobile/android/services/src/main/java/org/mozilla/gecko/background/common/log/writers/StringLogWriter.java
@@ -0,0 +1,57 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.background.common.log.writers;
+
+import java.io.PrintWriter;
+import java.io.StringWriter;
+
+public class StringLogWriter extends LogWriter {
+  protected final StringWriter sw;
+  protected final PrintLogWriter inner;
+
+  public StringLogWriter() {
+    sw = new StringWriter();
+    inner = new PrintLogWriter(new PrintWriter(sw));
+  }
+
+  public String toString() {
+    return sw.toString();
+  }
+
+  @Override
+  public boolean shouldLogVerbose(String tag) {
+    return true;
+  }
+
+  @Override
+  public void error(String tag, String message, Throwable error) {
+    inner.error(tag, message, error);
+  }
+
+  @Override
+  public void warn(String tag, String message, Throwable error) {
+    inner.warn(tag, message, error);
+  }
+
+  @Override
+  public void info(String tag, String message, Throwable error) {
+    inner.info(tag, message, error);
+  }
+
+  @Override
+  public void debug(String tag, String message, Throwable error) {
+    inner.debug(tag, message, error);
+  }
+
+  @Override
+  public void trace(String tag, String message, Throwable error) {
+    inner.trace(tag, message, error);
+  }
+
+  @Override
+  public void close() {
+    inner.close();
+  }
+}
diff --git a/mobile/android/services/src/main/java/org/mozilla/gecko/background/common/log/writers/TagLogWriter.java b/mobile/android/services/src/main/java/org/mozilla/gecko/background/common/log/writers/TagLogWriter.java
new file mode 100644
index 000000000..fbcd94a91
--- /dev/null
+++ b/mobile/android/services/src/main/java/org/mozilla/gecko/background/common/log/writers/TagLogWriter.java
@@ -0,0 +1,55 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.background.common.log.writers;
+
+/**
+ * A @link{LogWriter} that logs each message under a parent tag.
+ */
+public abstract class TagLogWriter extends LogWriter {
+
+  protected final LogWriter inner;
+
+  public TagLogWriter(final LogWriter inner) {
+    super();
+    this.inner = inner;
+  }
+
+  protected abstract String getMainTag();
+
+  @Override
+  public void error(String tag, String message, Throwable error) {
+    inner.error(this.getMainTag(), tag + " :: " + message, error);
+  }
+
+  @Override
+  public void warn(String tag, String message, Throwable error) {
+    inner.warn(this.getMainTag(), tag + " :: " + message, error);
+  }
+
+  @Override
+  public void info(String tag, String message, Throwable error) {
+    inner.info(this.getMainTag(), tag + " :: " + message, error);
+  }
+
+  @Override
+  public void debug(String tag, String message, Throwable error) {
+    inner.debug(this.getMainTag(), tag + " :: " + message, error);
+  }
+
+  @Override
+  public void trace(String tag, String message, Throwable error) {
+    inner.trace(this.getMainTag(), tag + " :: " + message, error);
+  }
+
+  @Override
+  public boolean shouldLogVerbose(String tag) {
+    return inner.shouldLogVerbose(this.getMainTag());
+  }
+
+  @Override
+  public void close() {
+    inner.close();
+  }
+}
\ No newline at end of file
diff --git a/mobile/android/services/src/main/java/org/mozilla/gecko/background/common/log/writers/ThreadLocalTagLogWriter.java b/mobile/android/services/src/main/java/org/mozilla/gecko/background/common/log/writers/ThreadLocalTagLogWriter.java
new file mode 100644
index 000000000..0c83504a0
--- /dev/null
+++ b/mobile/android/services/src/main/java/org/mozilla/gecko/background/common/log/writers/ThreadLocalTagLogWriter.java
@@ -0,0 +1,25 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.background.common.log.writers;
+
+/**
+ * Log with a single global tag… but that tag can be different for each thread.
+ *
+ * Takes a @link{ThreadLocal} as a constructor parameter.
+ */
+public class ThreadLocalTagLogWriter extends TagLogWriter {
+
+  private final ThreadLocal<String> tag;
+
+  public ThreadLocalTagLogWriter(ThreadLocal<String> tag, LogWriter inner) {
+    super(inner);
+    this.tag = tag;
+  }
+
+  @Override
+  protected String getMainTag() {
+    return this.tag.get();
+  }
+}