fixup - comments

Author: pabloem

x-pack/plugin/esql/qa/testFixtures/src/main/resources/k8s-timeseries-clamp.csv-spec

@@ -75,3 +75,26 @@ bytes_in:long | clamped_network_bytes_in:long | time_bucket:datetime
 3850          | 1468                          | 2024-05-10T00:09:00.000Z
 
 ;
+
+clamp_without_stats_command
+required_capability: clamp_functions
+// tag::clamp[]
+TS k8s
+| EVAL full_clamped_cost = clamp(network.cost, 1, 20)
+| KEEP full_clamped_cost, @timestamp
+// end::clamp-max[]
+| SORT full_clamped_cost DESC, @timestamp | LIMIT 10;
+
+// tag::clamp-max-result[]
+full_clamped_cost:double | @timestamp:datetime
+12.5                     | 2024-05-10T00:09:52.000Z
+12.375                   | 2024-05-10T00:01:29.000Z
+12.375                   | 2024-05-10T00:06:42.000Z
+12.375                   | 2024-05-10T00:17:12.000Z
+12.25                    | 2024-05-10T00:19:48.000Z
+12.125                   | 2024-05-10T00:00:57.000Z
+12.125                   | 2024-05-10T00:03:26.000Z
+12.125                   | 2024-05-10T00:07:19.000Z
+12.125                   | 2024-05-10T00:17:39.000Z
+12.0                     | 2024-05-10T00:08:08.000Z
+;

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/scalar/Clamp.java

@@ -7,8 +7,6 @@
 
 package org.elasticsearch.xpack.esql.expression.function.scalar;
 
-import org.elasticsearch.common.io.stream.NamedWriteableRegistry;
-import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.compute.operator.EvalOperator.ExpressionEvaluator;
 import org.elasticsearch.xpack.esql.core.expression.Expression;
@@ -22,7 +20,6 @@
 import org.elasticsearch.xpack.esql.expression.function.Param;
 import org.elasticsearch.xpack.esql.expression.function.scalar.conditional.ClampMax;
 import org.elasticsearch.xpack.esql.expression.function.scalar.conditional.ClampMin;
-import org.elasticsearch.xpack.esql.io.stream.PlanStreamInput;
 
 import java.io.IOException;
 import java.util.List;
@@ -33,7 +30,6 @@
  * Clamps the values of all samples to have a lower limit of min and an upper limit of max.
  */
 public class Clamp extends EsqlScalarFunction implements SurrogateExpression {
-    public static final NamedWriteableRegistry.Entry ENTRY = new NamedWriteableRegistry.Entry(Expression.class, "Clamp", Clamp::new);
 
     private final Expression field;
     private final Expression min;
@@ -68,18 +64,9 @@ public Clamp(
         this.max = max;
     }
 
-    private Clamp(StreamInput in) throws IOException {
-        this(
-            Source.readFrom((PlanStreamInput) in),
-            in.readNamedWriteable(Expression.class),
-            in.readNamedWriteable(Expression.class),
-            in.readNamedWriteable(Expression.class)
-        );
-    }
-
     @Override
     public String getWriteableName() {
-        return ENTRY.name;
+        throw new UnsupportedOperationException("Clamp does not support serialization (as it should be replaced by ClampMin and ClampMax)");
     }
 
     @Override
@@ -135,15 +122,14 @@ protected NodeInfo<? extends Expression> info() {
 
     @Override
     public void writeTo(StreamOutput out) throws IOException {
-        source().writeTo(out);
-        out.writeNamedWriteable(field);
-        out.writeNamedWriteable(min);
-        out.writeNamedWriteable(max);
+        throw new UnsupportedOperationException("Clamp does not support serialization (as it should be replaced by ClampMin and ClampMax)");
     }
 
     @Override
     public ExpressionEvaluator.Factory toEvaluator(ToEvaluator toEvaluator) {
-        return null;
+        throw new UnsupportedOperationException(
+            "Clamp should have been replaced by ClampMin and ClampMax. Something went wrong in the ESQL engine."
+        );
     }
 
     @Override

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/scalar/ScalarFunctionWritables.java

@@ -92,7 +92,6 @@ public static List<NamedWriteableRegistry.Entry> getNamedWriteables() {
         entries.add(MonthName.ENTRY);
         entries.add(IpPrefix.ENTRY);
         entries.add(Least.ENTRY);
-        entries.add(Clamp.ENTRY);
         entries.add(ClampMax.ENTRY);
         entries.add(ClampMin.ENTRY);
         entries.add(Left.ENTRY);

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/scalar/conditional/ClampMax.java

@@ -34,7 +34,7 @@
 import static org.elasticsearch.xpack.esql.core.type.DataType.NULL;
 
 /**
- * Returns the input values clamped to have an upper limit of max.
+ * Clamps the input values to have an upper limit of max.
  */
 public class ClampMax extends EsqlScalarFunction {
     public static final NamedWriteableRegistry.Entry ENTRY = new NamedWriteableRegistry.Entry(Expression.class, "ClampMax", ClampMax::new);

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/scalar/conditional/ClampMin.java

@@ -34,13 +34,11 @@
 import static org.elasticsearch.xpack.esql.core.type.DataType.NULL;
 
 /**
- * Returns the input values clamped to have a lower limit of min.
+ * Clamps input values to have a lower limit of min.
  */
 public class ClampMin extends EsqlScalarFunction {
     public static final NamedWriteableRegistry.Entry ENTRY = new NamedWriteableRegistry.Entry(Expression.class, "ClampMin", ClampMin::new);
 
-    private DataType dataType;
-
     @FunctionInfo(
         returnType = { "double", "integer", "long", "double", "unsigned_long", "keyword", "ip", "boolean", "date", "version" },
         description = "Returns clamps the values of all input samples clamped to have a lower limit of min.",
@@ -80,10 +78,7 @@ public String getWriteableName() {
 
     @Override
     public DataType dataType() {
-        if (dataType == null) {
-            resolveType();
-        }
-        return dataType;
+        return children().getFirst().dataType();
     }
 
     @Override
@@ -103,11 +98,9 @@ protected TypeResolution resolveType() {
             fieldDataType.typeName()
         );
         if (resolution.unresolved()) {
-            dataType = NULL;
             return resolution;
         }
         if (fieldDataType == NULL) {
-            dataType = NULL;
             return new TypeResolution("'field' must not be null in clamp()");
         }
         resolution = TypeResolutions.isType(
@@ -118,10 +111,8 @@ protected TypeResolution resolveType() {
             fieldDataType.typeName()
         );
         if (resolution.unresolved()) {
-            dataType = NULL;
             return resolution;
         }
-        dataType = fieldDataType;
         return TypeResolution.TYPE_RESOLVED;
     }