Better runtime error filtering

src/main/java/ch/njol/skript/sections/SecCatchErrors.java

@@ -68,7 +68,6 @@ public boolean isSatisfiedBy(ExperimentSet experimentSet) {
 		TriggerItem.walk(first, event);
         ExprCaughtErrors.lastErrors = catcher.getCachedErrors().stream().map(RuntimeError::error).toArray(String[]::new);
 		catcher.clearCachedErrors()
-			.clearCachedFrames()
 			.stop();
 		return walk(event, false);
 	}

src/main/java/org/skriptlang/skript/log/runtime/RuntimeErrorCatcher.java

@@ -1,13 +1,14 @@
 package org.skriptlang.skript.log.runtime;
 
+import ch.njol.skript.Skript;
 import ch.njol.skript.log.SkriptLogger;
+import org.jetbrains.annotations.Nullable;
 import org.jetbrains.annotations.UnmodifiableView;
 import org.skriptlang.skript.log.runtime.Frame.FrameOutput;
 
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
-import java.util.Map.Entry;
 import java.util.logging.Level;
 
 /**
@@ -20,15 +21,21 @@ public class RuntimeErrorCatcher implements RuntimeErrorConsumer {
 
 	private final List<RuntimeError> cachedErrors = new ArrayList<>();
 
-	private final List<Entry<FrameOutput, Level>> cachedFrames = new ArrayList<>();
+	// hard limit on stored errors to prevent a runaway loop from filling up memory, for example.
+	private static final int ERROR_LIMIT = 1000;
 
 	public RuntimeErrorCatcher() {}
 
 	/**
 	 * Gets the {@link RuntimeErrorManager}.
 	 */
 	private RuntimeErrorManager getManager() {
-		return RuntimeErrorManager.getInstance();
+		return Skript.getRuntimeErrorManager();
+	}
+
+	@Override
+	public @Nullable RuntimeErrorFilter getFilter() {
+		return RuntimeErrorFilter.NO_FILTER; // no filter means everything gets printed.
 	}
 
 	/**
@@ -47,7 +54,7 @@ public RuntimeErrorCatcher start() {
 	/**
 	 * Stops this {@link RuntimeErrorCatcher}, removing from {@link RuntimeErrorManager} and restoring the previous
 	 * {@link RuntimeErrorConsumer}s from {@link #storedConsumers}.
-	 * Prints all cached {@link RuntimeError}s, {@link #cachedErrors}, and cached {@link FrameOutput}s, {@link #cachedFrames}.
+	 * Prints all cached {@link RuntimeError}s, {@link #cachedErrors}.
 	 */
 	public void stop() {
 		if (!getManager().removeConsumer(this)) {
@@ -57,8 +64,6 @@ public void stop() {
 		getManager().addConsumers(storedConsumers.toArray(RuntimeErrorConsumer[]::new));
 		for (RuntimeError runtimeError : cachedErrors)
 			storedConsumers.forEach(consumer -> consumer.printError(runtimeError));
-		for (Entry<FrameOutput, Level> entry : cachedFrames)
-			storedConsumers.forEach(consumer -> consumer.printFrameOutput(entry.getKey(), entry.getValue()));
 	}
 
 	/**
@@ -68,13 +73,6 @@ public void stop() {
 		return Collections.unmodifiableList(cachedErrors);
 	}
 
-	/**
-	 * Gets all cached {@link FrameOutput}s stored with its corresponding {@link Level} in an {@link Entry}
-	 */
-	public @UnmodifiableView List<Entry<FrameOutput, Level>> getCachedFrames() {
-		return Collections.unmodifiableList(cachedFrames);
-	}
-
 	/**
 	 * Clear all cached {@link RuntimeError}s.
 	 */
@@ -83,37 +81,15 @@ public RuntimeErrorCatcher clearCachedErrors() {
 		return this;
 	}
 
-	/**
-	 * Clears all cached {@link FrameOutput}s.
-	 */
-	public RuntimeErrorCatcher clearCachedFrames() {
-		cachedFrames.clear();
-		return this;
-	}
-
 	@Override
 	public void printError(RuntimeError error) {
-		cachedErrors.add(error);
+		if (cachedErrors.size() < ERROR_LIMIT)
+			cachedErrors.add(error);
 	}
 
 	@Override
 	public void printFrameOutput(FrameOutput output, Level level) {
-		cachedFrames.add(new Entry<FrameOutput, Level>() {
-			@Override
-			public FrameOutput getKey() {
-				return output;
-			}
-
-			@Override
-			public Level getValue() {
-				return level;
-			}
-
-			@Override
-			public Level setValue(Level value) {
-				return null;
-			}
-		});
+		// do nothing, this won't be called since we have no filter.
 	}
 
 }

src/main/java/org/skriptlang/skript/log/runtime/RuntimeErrorConsumer.java

@@ -1,5 +1,7 @@
 package org.skriptlang.skript.log.runtime;
 
+import org.jetbrains.annotations.Nullable;
+
 import java.util.logging.Level;
 
 /**
@@ -15,6 +17,15 @@ public interface RuntimeErrorConsumer {
 	 */
 	void printError(RuntimeError error);
 
+	/**
+	 * @return The filter to use when checking if this consumer should print an error. Defaults to the standard
+	 * 			config-driven filter. If no filter should be used, return {@link RuntimeErrorFilter#NO_FILTER}. This value
+	 * 			MUST be effectively final.
+	 */
+	default @Nullable RuntimeErrorFilter getFilter() {
+		return RuntimeErrorManager.standardFilter;
+	}
+
 	/**
 	 * Prints the output of a frame, including skipped errors, timeouts, and whatever other information required.
 	 * @param output An output object containing unmodifiable views of the frame data.

src/main/java/org/skriptlang/skript/log/runtime/RuntimeErrorFilter.java

@@ -0,0 +1,68 @@
+package org.skriptlang.skript.log.runtime;
+
+import org.jetbrains.annotations.NotNull;
+
+import java.util.logging.Level;
+
+/**
+ * Handles filtering of runtime errors based on their level and predefined limits.
+ * Uses the concept of 'frames' to track the number of errors and warnings that are allowed in a given period.
+ * Use {@link #test(RuntimeError)} to determine if a runtime error should be printed or not.
+ * Printing the frame outputs can be done via {@link #getErrorFrame()} and {@link #getWarningFrame()}.
+ */
+public class RuntimeErrorFilter {
+
+	/**
+	 * A filter that does not filter anything, allowing all errors and warnings to be printed.
+	 * Modifications to its limits will do nothing, and the returned frames will hold no relevant data.
+	 */
+	public static final RuntimeErrorFilter NO_FILTER = new RuntimeErrorFilter(
+			new Frame.FrameLimit(Integer.MAX_VALUE, Integer.MAX_VALUE, Integer.MAX_VALUE, Integer.MAX_VALUE),
+			new Frame.FrameLimit(Integer.MAX_VALUE, Integer.MAX_VALUE, Integer.MAX_VALUE, Integer.MAX_VALUE)
+		) {
+			@Override
+			public boolean test(@NotNull RuntimeError error) {
+				return true;
+			}
+		};
+
+	private Frame errorFrame, warningFrame;
+
+	public RuntimeErrorFilter(Frame.FrameLimit errorFrameLimits, Frame.FrameLimit warningFrameLimits) {
+		this.errorFrame = new Frame(errorFrameLimits);
+		this.warningFrame = new Frame(warningFrameLimits);
+	}
+
+	/**
+	 * Tests whether a runtime error should be printed or not.
+	 * @param error True if it should be printed, false if not.
+	 */
+	public boolean test(@NotNull RuntimeError error) {
+		// print if < limit
+		return (error.level() == Level.SEVERE && errorFrame.add(error))
+			|| (error.level() == Level.WARNING && warningFrame.add(error));
+	}
+
+	public void setErrorFrameLimits(Frame.FrameLimit limits) {
+		this.errorFrame = new Frame(limits);
+	}
+
+	public void setWarningFrameLimits(Frame.FrameLimit limits) {
+		this.warningFrame = new Frame(limits);
+	}
+
+	/**
+	 * @return The frame containing emitted errors.
+	 */
+	public Frame getErrorFrame() {
+		return errorFrame;
+	}
+
+	/**
+	 * @return The frame containing emitted warnings.
+	 */
+	public Frame getWarningFrame() {
+		return warningFrame;
+	}
+
+}