add comments/todos

Author: jan-elastic

x-pack/plugin/esql/compute/src/main/java/org/elasticsearch/compute/operator/ChangePointOperator.java

@@ -22,6 +22,13 @@
 import java.util.Deque;
 import java.util.LinkedList;
 
+/**
+ * Find spikes, dips and change point in a list of values.
+ * <p>
+ * Warning: this operator cannot handle large amounts of data! It buffers all
+ * data that is passed to it, runs the change point detector on the data (which
+ * is a compute-heavy process), and then outputs all data with the change points.
+ */
 public class ChangePointOperator implements Operator {
 
     public static final int INPUT_VALUE_COUNT_LIMIT = 1000;
@@ -49,6 +56,8 @@ public String describe() {
     private boolean finished;
     private Warnings warnings;
 
+    // TODO: make org.elasticsearch.xpack.esql.core.tree.Source available here
+    // (by modularizing esql-core) and use that instead of the individual fields.
     public ChangePointOperator(DriverContext driverContext, int channel, String sourceText, int sourceLine, int sourceColumn) {
         this.driverContext = driverContext;
         this.channel = channel;

x-pack/plugin/esql/compute/src/main/java/org/elasticsearch/compute/operator/Warnings.java

@@ -31,6 +31,7 @@ public void registerException(Exception exception) {
      * @param sourceText The source text that caused the warning. Same as `source.text()`
      * @return A warnings collector object
      */
+    // TODO: rename to createWarningsTreatedAsNull
     public static Warnings createWarnings(DriverContext.WarningsMode warningsMode, int lineNumber, int columnNumber, String sourceText) {
         return createWarnings(warningsMode, lineNumber, columnNumber, sourceText, "evaluation of [{}] failed, treating result as null");
     }
@@ -62,6 +63,7 @@ public static Warnings createWarningsTreatedAsFalse(
      * @param sourceText The source text that caused the warning. Same as `source.text()`
      * @return A warnings collector object
      */
+    // TODO: rename to createWarnings
     public static Warnings createOnlyWarnings(
         DriverContext.WarningsMode warningsMode,
         int lineNumber,