Add InitLogger and startup logging

base/src/main/java/de/staropensource/sosengine/base/Engine.java

@@ -92,7 +92,7 @@ public final class Engine extends SubsystemClass {
      * @see LoggerInstance
      * @since v1-alpha0
      */
-    private static LoggerInstance logger;
+    private static final LoggerInstance logger = new LoggerInstance.Builder().setClazz(Engine.class).setOrigin("ENGINE").setMetadata(EngineInformation.getVersioningCodename()).build();
 
     /**
      * Contains the engine state.
@@ -162,19 +162,18 @@ public final class Engine extends SubsystemClass {
             return;
 
         long initTime = Miscellaneous.measureExecutionTime(() -> {
-            state = EngineState.STARTUP;
+            state = EngineState.EARLY_STARTUP;
 
-            // Initialize engine configuration
             new EngineConfiguration();
             EngineConfiguration.getInstance().loadConfiguration();
 
+            logger.info("Initializing engine");
             initializeClasses();         // Initialize classes
             populateCrashContent();      // Populate crash content
             cacheEvents();               // Cache event listeners
             startThreads();              // Start threads
 
-            // Set the logger instance
+            state = EngineState.STARTUP;
-            logger = new LoggerInstance.Builder().setClazz(getClass()).setOrigin("ENGINE").setMetadata(EngineInformation.getVersioningCodename()).build();
 
             // Perform automatic subsystem initialization
             if (EngineConfiguration.getInstance().isOptimizeSubsystemInitialization()) {
@@ -199,9 +198,10 @@ public final class Engine extends SubsystemClass {
      * @since v1-alpha0
      */
     private void initializeClasses() {
+        logger.verb("Initializing engine classes");
         new PlaceholderEngine();
 
-        EngineInformation.updateVariables();
+        EngineInformation.update();
     }
 
     /**
@@ -212,6 +212,8 @@ public final class Engine extends SubsystemClass {
      */
     @SuppressWarnings({ "ExtractMethodRecommender" })
     private void populateCrashContent() {
+        logger.diag("Populating crash content");
+
         // Issuer
         Map<@NotNull String, @NotNull String> crashContentIssuer = new LinkedHashMap<>();
         crashContentIssuer.put("Code part", "%issuer_origin%");
@@ -261,6 +263,8 @@ public final class Engine extends SubsystemClass {
      * @since v1-alpha0
      */
     private void cacheEvents() {
+        logger.diag("Caching events");
+
         // Internal events
         EventHelper.cacheEvent(InternalEngineShutdownEvent.class);
 
@@ -278,6 +282,8 @@ public final class Engine extends SubsystemClass {
      * @since v1-alpha1
      */
     public void startThreads() {
+        logger.diag("Starting threads");
+
         Logger.startLoggingThread();
     }
 

base/src/main/java/de/staropensource/sosengine/base/data/information/EngineInformation.java

@@ -314,19 +314,20 @@ public final class EngineInformation {
     /**
      * Updates all variables.
      * <p>
-     * This method does not need to be invoked, as the information provided by this
+     * This method does not need to be invoked manually, as the information provided by
-     * class is static (does not change) and is already populated at engine startup.
+     * this class is static (does not change) and is already populated at engine startup.
      *
      * @since v1-alpha1
      */
-    public static synchronized void updateVariables() {
+    public static synchronized void update() {
+        logger.diag("Updating engine information");
+
         // Load properties from bundled gradle.properties
         Properties gradleProperties = new Properties();
         InputStream gradleStream = EngineInformation.class.getClassLoader().getResourceAsStream("sosengine-gradle.properties");
 
         if (gradleStream == null) {
-            System.out.println("Unable to load build information: The bundled gradle.properties file could not be found.");
+            logger.crash("Unable to load build information: The bundled gradle.properties file could not be found.");
-            Engine.getInstance().shutdown(69);
             return;
         }
 
@@ -335,9 +336,7 @@ public final class EngineInformation {
             gradleStream.close();
         } catch (IOException exception) {
             StackTraceParser parser = new StackTraceParser(exception);
-            System.out.println("Unable to load build information: InputStream 'gradleStream' failed");
+            logger.crash("Unable to load build information: InputStream 'gradleStream' failed", exception);
-            System.out.println(parser.getHeader() + "\n" + parser.getStackTrace());
-            Engine.getInstance().shutdown(69);
             return;
         }
 
@@ -365,9 +364,7 @@ public final class EngineInformation {
                 gitStream.close();
             } catch (IOException exception) {
                 StackTraceParser parser = new StackTraceParser(exception);
-                System.out.println("Unable to load build information: InputStream 'gitStream' failed");
+                logger.crash("Unable to load build information: InputStream 'gitStream' failed", exception);
-                System.out.println(parser.getHeader() + "\n" + parser.getStackTrace());
-                Engine.getInstance().shutdown(69);
                 return;
             }
         }

base/src/main/java/de/staropensource/sosengine/base/logging/InitLogger.java

@@ -0,0 +1,201 @@
+/*
+ * STAROPENSOURCE ENGINE SOURCE FILE
+ * Copyright (c) 2024 The StarOpenSource Engine Contributors
+ * Licensed under the GNU Affero General Public License v3
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package de.staropensource.sosengine.base.logging;
+
+import de.staropensource.sosengine.base.EngineConfiguration;
+import de.staropensource.sosengine.base.internal.placeholders.logger.LogMessage;
+import de.staropensource.sosengine.base.internal.placeholders.logger.LogPath;
+import de.staropensource.sosengine.base.types.logging.LogLevel;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+/**
+ * Provides logging capabilities during engine startup.
+ *
+ * @since v1-alpha4
+ */
+public final class InitLogger {
+    /**
+     * Contains the logging template used during startup.
+     *
+     * @since v1-alpha4
+     */
+    private static final @NotNull String template = "%log_level% %log_path%  %log_message%";
+
+    /**
+     * Constructs this class.
+     *
+     * @since v1-alpha4
+     */
+    public InitLogger() {}
+
+    /**
+     * {@link Logger#log(LogLevel, Class, String, String, String)} and {@link Logger#processLogMessage(LogLevel, Class, String, String, String)} combined into one method.
+     *
+     * @param level          level
+     * @param issuerClass    class of the issuer
+     * @param issuerOrigin   origin of the issuer
+     * @param issuerMetadata metadata about the issuer
+     * @param message        message
+     * @since v1-alpha4
+     */
+    private static synchronized void log(@NotNull LogLevel level, @NotNull Class<?> issuerClass, @NotNull String issuerOrigin, @Nullable String issuerMetadata, @NotNull String message) {
+        // Dismiss if level is not allowed
+        if (level.compareTo(EngineConfiguration.getInstance().getLoggerLevel()) < 0)
+            return;
+
+        // Invoke LoggerImpl#prePlaceholder
+        String base = Logger.getLoggerImplementation().prePlaceholder(level, issuerClass, issuerOrigin, issuerMetadata, message, template);
+        if (base == null)
+            base = template;
+
+        // Replace placeholders
+        // This is done manually to avoid depending on PlaceholderEngine
+        base = new de.staropensource.sosengine.base.internal.placeholders.logger.LogLevel(level).replace(base);
+        base = new LogPath(issuerClass).replace(base);
+        base = new LogMessage(message).replace(base);
+
+        // Invoke LoggerImpl#postPlaceholder
+        base = Logger.getLoggerImplementation().postPlaceholder(level, issuerClass, issuerOrigin, issuerMetadata, message, base);
+
+        // Print log message by invoking LoggerImpl#print
+        Logger.getLoggerImplementation().print(level, issuerClass, issuerOrigin, issuerMetadata, message, base);
+    }
+
+    /**
+     * Prints a diagnostic message.
+     *
+     * @param issuerClass    class of the issuer
+     * @param issuerOrigin   origin of the issuer
+     * @param issuerMetadata metadata about the issuer
+     * @param message        message
+     * @since v1-alpha4
+     */
+    public static void diag(@NotNull Class<?> issuerClass, @NotNull String issuerOrigin, @Nullable String issuerMetadata, @NotNull String message) {
+        log(LogLevel.DIAGNOSTIC, issuerClass, issuerOrigin, issuerMetadata, message);
+    }
+
+    /**
+     * Prints a verbose message.
+     *
+     * @param issuerClass    class of the issuer
+     * @param issuerOrigin   origin of the issuer
+     * @param issuerMetadata metadata about the issuer
+     * @param message        message
+     * @since v1-alpha4
+     */
+    public static void verb(@NotNull Class<?> issuerClass, @NotNull String issuerOrigin, @Nullable String issuerMetadata, @NotNull String message) {
+        log(LogLevel.VERBOSE, issuerClass, issuerOrigin, issuerMetadata, message);
+    }
+
+    /**
+     * Prints a silent warning message.
+     *
+     * @param issuerClass    class of the issuer
+     * @param issuerOrigin   origin of the issuer
+     * @param issuerMetadata metadata about the issuer
+     * @param message        message
+     * @since v1-alpha4
+     */
+    public static void sarn(@NotNull Class<?> issuerClass, @NotNull String issuerOrigin, @Nullable String issuerMetadata, @NotNull String message) {
+        log(LogLevel.SILENT_WARNING, issuerClass, issuerOrigin, issuerMetadata, message);
+    }
+
+    /**
+     * Prints an informational message.
+     *
+     * @param issuerClass    class of the issuer
+     * @param issuerOrigin   origin of the issuer
+     * @param issuerMetadata metadata about the issuer
+     * @param message        message
+     * @since v1-alpha4
+     */
+    public static void info(@NotNull Class<?> issuerClass, @NotNull String issuerOrigin, @Nullable String issuerMetadata, @NotNull String message) {
+        log(LogLevel.INFORMATIONAL, issuerClass, issuerOrigin, issuerMetadata, message);
+    }
+
+    /**
+     * Prints a warning message.
+     *
+     * @param issuerClass    class of the issuer
+     * @param issuerOrigin   origin of the issuer
+     * @param issuerMetadata metadata about the issuer
+     * @param message        message
+     * @since v1-alpha4
+     */
+    public static void warn(@NotNull Class<?> issuerClass, @NotNull String issuerOrigin, @Nullable String issuerMetadata, @NotNull String message) {
+        log(LogLevel.WARNING, issuerClass, issuerOrigin, issuerMetadata, message);
+    }
+
+    /**
+     * Prints an error message.
+     *
+     * @param issuerClass    class of the issuer
+     * @param issuerOrigin   origin of the issuer
+     * @param issuerMetadata metadata about the issuer
+     * @param message        message
+     * @since v1-alpha4
+     */
+    public static void error(@NotNull Class<?> issuerClass, @NotNull String issuerOrigin, @Nullable String issuerMetadata, @NotNull String message) {
+        log(LogLevel.ERROR, issuerClass, issuerOrigin, issuerMetadata, message);
+    }
+
+    /**
+     * Crashes the entire engine.
+     *
+     * @param issuerClass    class of the issuer
+     * @param issuerOrigin   origin of the issuer
+     * @param issuerMetadata metadata about the issuer
+     * @param message        message
+     * @param throwable      the throwable that caused this crash
+     * @param handled        declares the throwable has handled, not causing the engine to shutdown
+     * @since v1-alpha4
+     */
+    public static void crash(@NotNull Class<?> issuerClass, @NotNull String issuerOrigin, @Nullable String issuerMetadata, @NotNull String message, @NotNull Throwable throwable, boolean handled) {
+        Logger.crash(issuerClass, issuerOrigin, issuerMetadata, message, throwable, handled);
+    }
+
+    /**
+     * Crashes the entire engine.
+     *
+     * @param issuerClass    class of the issuer
+     * @param issuerOrigin   origin of the issuer
+     * @param issuerMetadata metadata about the issuer
+     * @param message        message
+     * @param throwable      the throwable that caused this crash
+     * @since v1-alpha4
+     */
+    public static void crash(@NotNull Class<?> issuerClass, @NotNull String issuerOrigin, @Nullable String issuerMetadata, @NotNull String message, @NotNull Throwable throwable) {
+        Logger.crash(issuerClass, issuerOrigin, issuerMetadata, message, throwable);
+    }
+
+    /**
+     * Crashes the entire engine.
+     *
+     * @param issuerClass    class of the issuer
+     * @param issuerOrigin   origin of the issuer
+     * @param issuerMetadata metadata about the issuer
+     * @param message        message
+     * @since v1-alpha4
+     */
+    public static void crash(@NotNull Class<?> issuerClass, @NotNull String issuerOrigin, @Nullable String issuerMetadata, @NotNull String message) {
+        Logger.crash(issuerClass, issuerOrigin, issuerMetadata, message);
+    }
+}

base/src/main/java/de/staropensource/sosengine/base/logging/LoggerInstance.java

@@ -19,6 +19,8 @@
 
 package de.staropensource.sosengine.base.logging;
 
+import de.staropensource.sosengine.base.Engine;
+import de.staropensource.sosengine.base.types.EngineState;
 import lombok.Getter;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
@@ -88,7 +90,10 @@ public final class LoggerInstance {
      * @since v1-alpha0
      */
     public void diag(@NotNull String message) {
-        Logger.diag(clazz, origin, metadata, message);
+        if (Engine.getInstance().getState() == EngineState.EARLY_STARTUP)
+            InitLogger.diag(clazz, origin, metadata, message);
+        else
+            Logger.diag(clazz, origin, metadata, message);
     }
 
     /**
@@ -98,7 +103,10 @@ public final class LoggerInstance {
      * @since v1-alpha0
      */
     public void verb(@NotNull String message) {
-        Logger.verb(clazz, origin, metadata, message);
+        if (Engine.getInstance().getState() == EngineState.EARLY_STARTUP)
+            InitLogger.verb(clazz, origin, metadata, message);
+        else
+            Logger.verb(clazz, origin, metadata, message);
     }
 
     /**
@@ -108,7 +116,10 @@ public final class LoggerInstance {
      * @since v1-alpha0
      */
     public void sarn(@NotNull String message) {
-        Logger.sarn(clazz, origin, metadata, message);
+        if (Engine.getInstance().getState() == EngineState.EARLY_STARTUP)
+            InitLogger.sarn(clazz, origin, metadata, message);
+        else
+            Logger.sarn(clazz, origin, metadata, message);
     }
 
     /**
@@ -118,7 +129,10 @@ public final class LoggerInstance {
      * @since v1-alpha0
      */
     public void info(@NotNull String message) {
-        Logger.info(clazz, origin, metadata, message);
+        if (Engine.getInstance().getState() == EngineState.EARLY_STARTUP)
+            InitLogger.info(clazz, origin, metadata, message);
+        else
+            Logger.info(clazz, origin, metadata, message);
     }
 
     /**
@@ -128,7 +142,10 @@ public final class LoggerInstance {
      * @since v1-alpha0
      */
     public void warn(@NotNull String message) {
-        Logger.warn(clazz, origin, metadata, message);
+        if (Engine.getInstance().getState() == EngineState.EARLY_STARTUP)
+            InitLogger.warn(clazz, origin, metadata, message);
+        else
+            Logger.warn(clazz, origin, metadata, message);
     }
 
     /**
@@ -138,7 +155,10 @@ public final class LoggerInstance {
      * @since v1-alpha0
      */
     public void error(@NotNull String message) {
-        Logger.error(clazz, origin, metadata, message);
+        if (Engine.getInstance().getState() == EngineState.EARLY_STARTUP)
+            InitLogger.error(clazz, origin, metadata, message);
+        else
+            Logger.error(clazz, origin, metadata, message);
     }
 
     /**

base/src/main/java/de/staropensource/sosengine/base/logging/implementation/PlainLoggerImplementation.java

@@ -45,16 +45,14 @@ public class PlainLoggerImplementation implements LoggerImplementation {
 
     /** {@inheritDoc} */
     @Override
-    public @NotNull String prePlaceholder(@NotNull LogLevel level, @NotNull Class<?> issuerClass, @NotNull String issuerOrigin, @Nullable String issuerMetadata, @NotNull String message, @NotNull String format) {
+    public @Nullable String prePlaceholder(@NotNull LogLevel level, @NotNull Class<?> issuerClass, @NotNull String issuerOrigin, @Nullable String issuerMetadata, @NotNull String message, @NotNull String format) {
-        // No modifications necessary
+        return null;  // No modifications necessary
-        return format;
     }
 
     /** {@inheritDoc} */
     @Override
     public @NotNull String postPlaceholder(@NotNull LogLevel level, @NotNull Class<?> issuerClass, @NotNull String issuerOrigin, @Nullable String issuerMetadata, @NotNull String message, @NotNull String format) {
-        // No modifications necessary
+        return format;  // No modifications necessary
-        return format;
     }
 
     /** {@inheritDoc} */

base/src/main/java/de/staropensource/sosengine/base/logging/implementation/RawLoggerImplementation.java

@@ -45,16 +45,14 @@ public class RawLoggerImplementation implements LoggerImplementation {
 
     /** {@inheritDoc} */
     @Override
-    public @NotNull String prePlaceholder(@NotNull LogLevel level, @NotNull Class<?> issuerClass, @NotNull String issuerOrigin, @Nullable String issuerMetadata, @NotNull String message, @NotNull String format) {
+    public @Nullable String prePlaceholder(@NotNull LogLevel level, @NotNull Class<?> issuerClass, @NotNull String issuerOrigin, @Nullable String issuerMetadata, @NotNull String message, @NotNull String format) {
-        // No modifications necessary
+        return null;  // No modifications necessary
-        return format;
     }
 
     /** {@inheritDoc} */
     @Override
     public @NotNull String postPlaceholder(@NotNull LogLevel level, @NotNull Class<?> issuerClass, @NotNull String issuerOrigin, @Nullable String issuerMetadata, @NotNull String message, @NotNull String format) {
-        // No modifications necessary
+        return format;  // No modifications necessary
-        return format;
     }
 
     /** {@inheritDoc} */

base/src/main/java/de/staropensource/sosengine/base/types/EngineState.java

@@ -19,6 +19,9 @@
 
 package de.staropensource.sosengine.base.types;
 
+import de.staropensource.sosengine.base.logging.InitLogger;
+import de.staropensource.sosengine.base.logging.Logger;
+
 /**
  * Determines in which state the engine is currently in.
  *
@@ -35,9 +38,25 @@ public enum EngineState {
     UNKNOWN,
 
     /**
-     * The engine is currently starting up.
+     * The engine is in early startup.
+     * The engine is largely uninitialized and
+     * the logging infrastructure is not yet ready
+     * to be used.
+     * <p>
+     * This state is used to indicate that the
+     * {@link InitLogger} shall be used instead
+     * of {@link Logger}.
+     *
+     * @since v1-alpha4
+     */
+    EARLY_STARTUP,
+
+    /**
+     * The engine is starting up.
      * Some parts of the engine may not be initialized
-     * yet and may be unsafe to access.
+     * yet and may be unsafe to access. The logging
+     * infrastructure is ready to be used though and is
+     * safe to access.
      *
      * @since v1-alpha2
      */