improved logger serialization by removing cruft

Author: ceki

logback-classic/src/main/java/ch/qos/logback/classic/Logger.java

@@ -20,6 +20,7 @@
 import java.util.Iterator;
 import java.util.List;
 
+import ch.qos.logback.classic.spi.LoggerContextVO;
 import ch.qos.logback.classic.util.LoggerNameUtil;
 import org.slf4j.LoggerFactory;
 import org.slf4j.Marker;
@@ -55,22 +56,22 @@ public final class Logger implements org.slf4j.Logger, LocationAwareLogger,
   private String name;
 
   // The assigned levelInt of this logger. Can be null.
-  private Level level;
+  transient private Level level;
 
   // The effective levelInt is the assigned levelInt and if null, a levelInt is
   // inherited form a parent.
-  private int effectiveLevelInt;
+  transient private int effectiveLevelInt;
 
   /**
    * The parent of this category. All categories have at least one ancestor
    * which is the root category.
    */
-  private Logger parent;
+  transient private Logger parent;
 
   /**
    * The children of this logger. A logger may have zero or more children.
    */
-  private List<Logger> childrenList;
+  transient private List<Logger> childrenList;
 
   /**
    * It is assumed that once the 'aai' variable is set to a non-null value, it
@@ -92,7 +93,7 @@ public final class Logger implements org.slf4j.Logger, LocationAwareLogger,
    * <p>
    * 4) AppenderAttachableImpl is thread safe
    */
-  private transient AppenderAttachableImpl<ILoggingEvent> aai;
+  transient private AppenderAttachableImpl<ILoggingEvent> aai;
   /**
    * Additivity is set to true by default, that is children inherit the
    * appenders of their ancestors by default. If this variable is set to
@@ -101,18 +102,14 @@ public final class Logger implements org.slf4j.Logger, LocationAwareLogger,
    * its appenders, unless the children have their additivity flag set to
    * <code>false</code> too. See the user manual for more details.
    */
-  private boolean additive = true;
+  transient private boolean additive = true;
 
   final transient LoggerContext loggerContext;
-  // loggerRemoteView cannot be final because it may change as a consequence
-  // of changes in LoggerContext
-  LoggerRemoteView loggerRemoteView;
 
   Logger(String name, Logger parent, LoggerContext loggerContext) {
     this.name = name;
     this.parent = parent;
     this.loggerContext = loggerContext;
-    buildRemoteView();
   }
 
   public Level getEffectiveLevel() {
@@ -789,14 +786,6 @@ public LoggerContext getLoggerContext() {
     return loggerContext;
   }
 
-  public LoggerRemoteView getLoggerRemoteView() {
-    return loggerRemoteView;
-  }
-
-  void buildRemoteView() {
-    this.loggerRemoteView = new LoggerRemoteView(name, loggerContext);
-  }
-
   public void log(Marker marker, String fqcn, int levelInt, String message,
       Object[] argArray, Throwable t) {
     Level level = Level.fromLocationAwareLoggerInteger(levelInt);

logback-classic/src/main/java/ch/qos/logback/classic/LoggerContext.java

@@ -84,23 +84,20 @@ void initEvaluatorMap() {
    * A new instance of LoggerContextRemoteView needs to be created each time the
    * name or propertyMap (including keys or values) changes.
    */
-  private void syncRemoteView() {
+  private void updateLoggerContextVO() {
     loggerContextRemoteView = new LoggerContextVO(this);
-    for (Logger logger : loggerCache.values()) {
-      logger.buildRemoteView();
-    }
   }
 
   @Override
   public void putProperty(String key, String val) {
     super.putProperty(key, val);
-    syncRemoteView();
+    updateLoggerContextVO();
   }
 
   @Override
   public void setName(String name) {
     super.setName(name);
-    syncRemoteView();
+    updateLoggerContextVO();
   }
 
   public final Logger getLogger(final Class clazz) {

logback-classic/src/main/java/ch/qos/logback/classic/spi/LoggerContextVO.java

@@ -45,7 +45,6 @@ public LoggerContextVO(LoggerContext lc) {
     this.name = lc.getName();
     this.propertyMap = lc.getCopyOfPropertyMap();
     this.birthTime = lc.getBirthTime();
-
   }
 
   public LoggerContextVO(String name, Map<String,String> propertyMap, long birthTime) {
@@ -94,6 +93,9 @@ public int hashCode() {
     int result = name != null ? name.hashCode() : 0;
     result = 31 * result + (propertyMap != null ? propertyMap.hashCode() : 0);
     result = 31 * result + (int) (birthTime ^ (birthTime >>> 32));
+
+    System.out.println("LoggerContextVO"+System.identityHashCode(this)+" hashcode:"+result);
+
     return result;
   }
 }

logback-classic/src/test/java/ch/qos/logback/classic/LoggerSerializationTest.java

@@ -13,17 +13,15 @@
  */
 package ch.qos.logback.classic;
 
-import java.io.ByteArrayInputStream;
-import java.io.ByteArrayOutputStream;
-import java.io.IOException;
-import java.io.ObjectInputStream;
-import java.io.ObjectOutputStream;
+import java.io.*;
 
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
 import org.slf4j.LoggerFactory;
 
+import static org.junit.Assert.assertTrue;
+
 public class LoggerSerializationTest {
 
   // force SLF4J initialization for subsequent Logger readResolce ooperaiton
@@ -50,25 +48,103 @@ public void tearDown() throws Exception {
     lc = null;
     logger = null;
   }
-  
+
   @Test
-  public void serialization() throws IOException, ClassNotFoundException {
+  public void basicSerialization() throws IOException, ClassNotFoundException {
     Foo foo = new Foo(logger);
     foo.doFoo();
     Foo fooBack = writeAndRead(foo);
     fooBack.doFoo();
   }
 
-  private Foo writeAndRead(Foo foo) throws IOException,
-      ClassNotFoundException {
-    oos.writeObject(foo);
+  @Test
+  public void deepTreeSerialization() throws IOException {
+    // crate a tree of loggers under "aaaaaaaa"
+    Logger a = lc.getLogger("aaaaaaaa");
+    lc.getLogger("aaaaaaaa.a");
+    lc.getLogger("aaaaaaaa.a.a");
+    lc.getLogger("aaaaaaaa.a.b");
+    lc.getLogger("aaaaaaaa.a.c");
+    lc.getLogger("aaaaaaaa.a.d");
+
+    lc.getLogger("aaaaaaaa.b");
+    lc.getLogger("aaaaaaaa.b.a");
+    lc.getLogger("aaaaaaaa.b.b");
+    lc.getLogger("aaaaaaaa.b.c");
+    lc.getLogger("aaaaaaaa.b.d");
+
+    lc.getLogger("aaaaaaaa.c");
+    lc.getLogger("aaaaaaaa.c.a");
+    lc.getLogger("aaaaaaaa.c.b");
+    lc.getLogger("aaaaaaaa.c.c");
+    lc.getLogger("aaaaaaaa.c.d");
+
+    lc.getLogger("aaaaaaaa.d");
+    lc.getLogger("aaaaaaaa.d.a");
+    lc.getLogger("aaaaaaaa.d.b");
+    lc.getLogger("aaaaaaaa.d.c");
+    lc.getLogger("aaaaaaaa.d.d");
+
+    Logger b = lc.getLogger("b");
+
+    writeObject(oos, a);
+    oos.close();
+    int sizeA = bos.size();
+
+    bos = new ByteArrayOutputStream();
+    oos = new ObjectOutputStream(bos);
+
+    writeObject(oos, b);
+    oos.close();
+    int sizeB = bos.size();
+
+    assertTrue("serialized logger should be less than 100 bytes", sizeA < 100);
+    // logger tree should not influnce serialization
+    assertTrue("serialized loggers should be nearly the same size a:" + sizeA + ", sizeB:" + sizeB, (sizeA - sizeB) < 10);
+  }
+
+  @Test
+  public void secondObjectShouldAddLittleToLength() throws IOException {
+    Logger a = lc.getLogger("a");
+    Logger b = lc.getLogger("b");
+
+    writeObject(oos, a);
+    int sizeA = bos.size();
     oos.flush();
+    writeObject(oos,b);
+    int sizeAB = bos.size();
     oos.close();
+
+    System.out.println("sizeA:"+sizeA);
+    System.out.println("sizeAB:"+sizeAB);
+    System.out.println("diff:"+(sizeAB-sizeA));
+
+    FileOutputStream fos = new FileOutputStream("/tmp/a.ser");
+    fos.write(bos.toByteArray());
+    fos.close();
+
+  }
+
+  private Foo writeAndRead(Foo foo) throws IOException,
+          ClassNotFoundException {
+    writeObject(oos, foo);
     ByteArrayInputStream bis = new ByteArrayInputStream(bos.toByteArray());
     inputStream = new ObjectInputStream(bis);
-
-    Foo fooBack =  (Foo) inputStream.readObject();
+    Foo fooBack = readFooObject(inputStream);
     inputStream.close();
     return fooBack;
   }
+
+  Foo readFooObject(ObjectInputStream inputStream) throws IOException, ClassNotFoundException {
+    return (Foo) readObject(inputStream);
+  }
+  private Object readObject(ObjectInputStream inputStream) throws IOException, ClassNotFoundException {
+    return inputStream.readObject();
+  }
+
+  private void writeObject(ObjectOutputStream oos, Object o) throws IOException {
+    oos.writeObject(o);
+    oos.flush();
+    oos.close();
+  }
 }

logback-classic/src/test/java/ch/qos/logback/classic/net/testObjectBuilders/LoggingEventWithParametersBuilder.java

@@ -22,8 +22,8 @@ public class LoggingEventWithParametersBuilder implements Builder<LoggingEvent>
 
   final String MSG = "aaaaabbbbbcccc {} cdddddaaaaabbbbbcccccdddddaaaa {}";
 
-  private Logger logger = new LoggerContext()
-      .getLogger(Logger.ROOT_LOGGER_NAME);
+  LoggerContext loggerContext = new LoggerContext();
+  private Logger logger = loggerContext.getLogger(Logger.ROOT_LOGGER_NAME);
 
   public LoggingEvent build(int i) {
 
@@ -42,7 +42,7 @@ public LoggingEvent build(int i) {
     le.getFormattedMessage();
     le.setLevel(Level.DEBUG);
     le.setLoggerName(logger.getName());
-    le.setLoggerContextRemoteView(logger.getLoggerRemoteView().getLoggerContextView());
+    le.setLoggerContextRemoteView(loggerContext.getLoggerContextRemoteView());
     le.setThreadName("threadName");
     return le;
   }

logback-classic/src/test/java/ch/qos/logback/classic/net/testObjectBuilders/TrivialLoggingEventBuilder.java

@@ -20,15 +20,16 @@
 
 public class TrivialLoggingEventBuilder implements Builder {
 
-  private Logger logger = new LoggerContext()
-      .getLogger(Logger.ROOT_LOGGER_NAME);
+  LoggerContext loggerContext = new LoggerContext();
+
+  private Logger logger = loggerContext.getLogger(Logger.ROOT_LOGGER_NAME);
 
   public Object build(int i) {
     LoggingEvent le = new LoggingEvent();
     le.setTimeStamp(System.currentTimeMillis());
     le.setLevel(Level.DEBUG);
     le.setLoggerName(logger.getName());
-    le.setLoggerContextRemoteView(logger.getLoggerRemoteView().getLoggerContextView());
+    le.setLoggerContextRemoteView(loggerContext.getLoggerContextRemoteView());
     le.setMessage(MSG_PREFIX);
     le.setThreadName("threadName");
     return le;