Improved logging support

We now use a logger factory, which means loggers can be created
per class.

This allows use of 'wrapped' Apache log4j2 loggers with the added
benefit of more accurate class/line-number reporting.

Java/src/main/java/org/ciyam/at/AtLogger.java

@@ -0,0 +1,11 @@
+package org.ciyam.at;
+
+public interface AtLogger {
+
+	void error(final String message);
+
+	void debug(final String message);
+
+	void echo(final String message);
+
+}

Java/src/main/java/org/ciyam/at/AtLoggerFactory.java

@@ -0,0 +1,7 @@
+package org.ciyam.at;
+
+public interface AtLoggerFactory {
+
+	AtLogger create(final Class<?> loggerName);
+
+}

Java/src/main/java/org/ciyam/at/LoggerInterface.java

@@ -1,11 +0,0 @@
-package org.ciyam.at;
-
-public interface LoggerInterface {
-
-	public void error(String message);
-
-	public void debug(String message);
-
-	public void echo(String message);
-
-}

Java/src/main/java/org/ciyam/at/MachineState.java

@@ -126,7 +126,8 @@ public class MachineState {
 	private boolean isFirstOpCodeAfterSleeping;
 
 	private API api;
-	private LoggerInterface logger;
+	private AtLoggerFactory loggerFactory;
+	private AtLogger logger;
 
 	// NOTE: These are package-scope to allow easy access/operations in Opcode/FunctionCode.
 	/* package */ ByteBuffer codeByteBuffer;
@@ -137,7 +138,7 @@ public class MachineState {
 	// Constructors
 
 	/** For internal use when recreating a machine state */
-	private MachineState(API api, LoggerInterface logger, byte[] headerBytes) {
+	private MachineState(byte[] headerBytes, API api, AtLoggerFactory loggerFactory) {
 		if (headerBytes.length != HEADER_LENGTH)
 			throw new IllegalArgumentException("headerBytes length " + headerBytes.length + " incorrect, expected " + HEADER_LENGTH);
 
@@ -190,12 +191,13 @@ public class MachineState {
 		this.currentBalance = 0;
 		this.previousBalance = 0;
 		this.steps = 0;
-		this.logger = logger;
+		this.loggerFactory = loggerFactory;
+		this.logger = loggerFactory.create(MachineState.class);
 	}
 
 	/** For creating a new machine state */
-	public MachineState(API api, byte[] creationBytes) {
-		this(api, null, Arrays.copyOfRange(creationBytes, 0, HEADER_LENGTH));
+	public MachineState(API api, AtLoggerFactory loggerFactory, byte[] creationBytes) {
+		this(Arrays.copyOfRange(creationBytes, 0, HEADER_LENGTH), api, loggerFactory);
 
 		int expectedLength = HEADER_LENGTH + this.numCodePages * this.constants.CODE_PAGE_SIZE + this.numDataPages * this.constants.DATA_PAGE_SIZE;
 		if (creationBytes.length != expectedLength)
@@ -210,8 +212,8 @@ public class MachineState {
 	}
 
 	/** For creating a new machine state - used in tests */
-	public MachineState(API api, LoggerInterface logger, byte[] headerBytes, byte[] codeBytes, byte[] dataBytes) {
-		this(api, logger, headerBytes);
+	public MachineState(API api, AtLoggerFactory loggerFactory, byte[] headerBytes, byte[] codeBytes, byte[] dataBytes) {
+		this(headerBytes, api, loggerFactory);
 
 		if (codeBytes.length > this.numCodePages * this.constants.CODE_PAGE_SIZE)
 			throw new IllegalArgumentException("Number of code pages too small to hold code bytes");
@@ -342,7 +344,11 @@ public class MachineState {
 		return this.api;
 	}
 
-	public LoggerInterface getLogger() {
+	public AtLoggerFactory getLoggerFactory() {
+		return this.loggerFactory;
+	}
+
+	/* package */ AtLogger getLogger() {
 		return this.logger;
 	}
 
@@ -516,13 +522,13 @@ public class MachineState {
 	}
 
 	/** For restoring a previously serialized machine state */
-	public static MachineState fromBytes(API api, LoggerInterface logger, byte[] bytes, byte[] codeBytes) {
+	public static MachineState fromBytes(API api, AtLoggerFactory loggerFactory, byte[] bytes, byte[] codeBytes) {
 		ByteBuffer byteBuffer = ByteBuffer.wrap(bytes);
 
 		byte[] headerBytes = new byte[HEADER_LENGTH];
 		byteBuffer.get(headerBytes);
 
-		MachineState state = new MachineState(api, logger, headerBytes);
+		MachineState state = new MachineState(headerBytes, api, loggerFactory);
 
 		if (codeBytes.length != state.codeByteBuffer.capacity())
 			throw new IllegalStateException("Passed codeBytes does not match length in header");

Java/src/test/java/org/ciyam/at/MiscTests.java

@@ -62,7 +62,7 @@ public class MiscTests extends ExecutableTest {
 		byte[] codeBytes = codeByteBuffer.array();
 		byte[] dataBytes = new byte[0];
 
-		state = new MachineState(api, logger, headerBytes, codeBytes, dataBytes);
+		state = new MachineState(api, loggerFactory, headerBytes, codeBytes, dataBytes);
 
 		assertTrue(state.isFrozen());
 		assertEquals((Long) (minActivationAmount - 1L), state.getFrozenBalance());

Java/src/test/java/org/ciyam/at/SerializationTests.java

@@ -102,12 +102,12 @@ public class SerializationTests extends ExecutableTest {
 		byte[] codeBytes = codeByteBuffer.array();
 		byte[] dataBytes = dataByteBuffer.array();
 
-		state = new MachineState(api, logger, headerBytes, codeBytes, dataBytes);
+		state = new MachineState(api, loggerFactory, headerBytes, codeBytes, dataBytes);
 		packedState = state.toBytes();
 
 		byte[] creationBytes = MachineState.toCreationBytes(TestUtils.VERSION, codeBytes, dataBytes, TestUtils.NUM_CALL_STACK_PAGES, TestUtils.NUM_USER_STACK_PAGES, TestUtils.MIN_ACTIVATION_AMOUNT);
 
-		MachineState restoredState = new MachineState(api, creationBytes);
+		MachineState restoredState = new MachineState(api, loggerFactory, creationBytes);
 		byte[] packedRestoredSate = restoredState.toBytes();
 
 		assertTrue(Arrays.equals(packedState, packedRestoredSate));
@@ -118,14 +118,14 @@ public class SerializationTests extends ExecutableTest {
 		byte[] codeBytes = codeByteBuffer.array();
 		byte[] dataBytes = new byte[0];
 
-		state = new MachineState(api, logger, headerBytes, codeBytes, dataBytes);
+		state = new MachineState(api, loggerFactory, headerBytes, codeBytes, dataBytes);
 
 		return executeAndCheck(state);
 	}
 
 	private byte[] continueSimulation(byte[] savedState) {
 		byte[] codeBytes = codeByteBuffer.array();
-		state = MachineState.fromBytes(api, logger, savedState, codeBytes);
+		state = MachineState.fromBytes(api, loggerFactory, savedState, codeBytes);
 
 		// Pretend we're on next block
 		api.bumpCurrentBlockHeight();
@@ -141,7 +141,7 @@ public class SerializationTests extends ExecutableTest {
 		byte[] codeBytes = state.getCodeBytes();
 
 		// Rebuild new MachineState using fetched state & bytes
-		MachineState restoredState = MachineState.fromBytes(api, logger, stateBytes, codeBytes);
+		MachineState restoredState = MachineState.fromBytes(api, loggerFactory, stateBytes, codeBytes);
 		// Extract rebuilt state and code bytes
 		byte[] restoredStateBytes = restoredState.toBytes();
 		byte[] restoredCodeBytes = state.getCodeBytes();

Java/src/test/java/org/ciyam/at/test/ExecutableTest.java

@@ -14,7 +14,7 @@ public abstract class ExecutableTest {
 	private static final int DATA_OFFSET = MachineState.HEADER_LENGTH; // code bytes are not present
 	private static final int CALL_STACK_OFFSET = DATA_OFFSET + TestUtils.NUM_DATA_PAGES * MachineState.VALUE_SIZE;
 
-	public TestLogger logger;
+	public TestLoggerFactory loggerFactory;
 	public TestAPI api;
 	public MachineState state;
 	public ByteBuffer codeByteBuffer;
@@ -32,7 +32,7 @@ public abstract class ExecutableTest {
 
 	@Before
 	public void beforeTest() {
-		logger = new TestLogger();
+		loggerFactory = new TestLoggerFactory();
 		api = new TestAPI();
 		codeByteBuffer = ByteBuffer.allocate(TestUtils.NUM_CODE_PAGES * MachineState.OPCODE_SIZE);
 		dataByteBuffer = ByteBuffer.allocate(TestUtils.NUM_DATA_PAGES * MachineState.VALUE_SIZE);
@@ -47,7 +47,7 @@ public abstract class ExecutableTest {
 		codeByteBuffer = null;
 		dataByteBuffer = null;
 		api = null;
-		logger = null;
+		loggerFactory = null;
 	}
 
 	protected void execute(boolean onceOnly) {
@@ -58,12 +58,12 @@ public abstract class ExecutableTest {
 		if (packedState == null) {
 			// First time
 			System.out.println("First execution - deploying...");
-			state = new MachineState(api, logger, headerBytes, codeBytes, dataBytes);
+			state = new MachineState(api, loggerFactory, headerBytes, codeBytes, dataBytes);
 			packedState = state.toBytes();
 		}
 
 		do {
-			state = MachineState.fromBytes(api, logger, packedState, codeBytes);
+			state = MachineState.fromBytes(api, loggerFactory, packedState, codeBytes);
 
 			System.out.println("Starting execution round!");
 			System.out.println("Current block height: " + api.getCurrentBlockHeight());

Java/src/test/java/org/ciyam/at/test/TestLogger.java

@@ -1,8 +1,9 @@
 package org.ciyam.at.test;
 
-import org.ciyam.at.LoggerInterface;
+import org.ciyam.at.AtLogger;
+
+public class TestLogger implements AtLogger {
 
-public class TestLogger implements LoggerInterface {
 	@Override
 	public void error(String message) {
 		System.err.println("ERROR: " + message);

Java/src/test/java/org/ciyam/at/test/TestLoggerFactory.java

@@ -0,0 +1,13 @@
+package org.ciyam.at.test;
+
+import org.ciyam.at.AtLogger;
+import org.ciyam.at.AtLoggerFactory;
+
+public class TestLoggerFactory implements AtLoggerFactory {
+
+	@Override
+	public AtLogger create(Class<?> loggerName) {
+		return new TestLogger();
+	}
+
+}