Revert "Add more flexibility to MovingFunction window alignment (#44360)"

This reverts commit 1a58a487f0.

docs/reference/aggregations/pipeline/movfn-aggregation.asciidoc

@@ -24,15 +24,14 @@ A `moving_fn` aggregation looks like this in isolation:
 --------------------------------------------------
 // NOTCONSOLE
 
-[[moving-fn-params]]
+[[moving-avg-params]]
-.`moving_fn` Parameters
+.`moving_avg` Parameters
 [options="header"]
 |===
 |Parameter Name |Description |Required |Default Value
 |`buckets_path` |Path to the metric of interest (see <<buckets-path-syntax, `buckets_path` Syntax>> for more details |Required |
 |`window` |The size of window to "slide" across the histogram. |Required |
 |`script` |The script that should be executed on each window of data |Required |
-|`shift` |<<shift-parameter, Shift>> of window position. |Optional | 0
 |===
 
 `moving_fn` aggregations must be embedded inside of a `histogram` or `date_histogram` aggregation.  They can be
@@ -170,18 +169,6 @@ POST /_search
 // CONSOLE
 // TEST[setup:sales]
 
-[[shift-parameter]]
-==== shift parameter
-
-By default (with `shift = 0`), the window that is offered for calculation is the last `n` values excluding the current bucket.
-Increasing `shift` by 1 moves starting window position by `1` to the right.
-
-- To include current bucket to the window, use `shift = 1`.
-- For center alignment (`n / 2` values before and after the current bucket), use `shift = window / 2`.
-- For right alignment (`n` values after the current bucket), use `shift = window`.
-
-If either of window edges moves outside the borders of data series, the window shrinks to include available values only.
-
 ==== Pre-built Functions
 
 For convenience, a number of functions have been prebuilt and are available inside the `moving_fn` script context:

server/src/main/java/org/elasticsearch/search/aggregations/pipeline/MovFnPipelineAggregationBuilder.java

@@ -19,7 +19,6 @@
 
 package org.elasticsearch.search.aggregations.pipeline;
 
-import org.elasticsearch.Version;
 import org.elasticsearch.common.ParseField;
 import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.io.stream.StreamInput;
@@ -49,14 +48,12 @@ import static org.elasticsearch.search.aggregations.pipeline.PipelineAggregator.
 public class MovFnPipelineAggregationBuilder extends AbstractPipelineAggregationBuilder<MovFnPipelineAggregationBuilder> {
     public static final String NAME = "moving_fn";
     private static final ParseField WINDOW = new ParseField("window");
-    private static final ParseField SHIFT = new ParseField("shift");
 
     private final Script script;
     private final String bucketsPathString;
     private String format = null;
     private GapPolicy gapPolicy = GapPolicy.SKIP;
     private int window;
-    private int shift;
 
     private static final Function<String, ConstructingObjectParser<MovFnPipelineAggregationBuilder, Void>> PARSER
         = name -> {
@@ -71,7 +68,6 @@ public class MovFnPipelineAggregationBuilder extends AbstractPipelineAggregation
             (p, c) -> Script.parse(p), Script.SCRIPT_PARSE_FIELD, ObjectParser.ValueType.OBJECT_OR_STRING);
         parser.declareInt(ConstructingObjectParser.constructorArg(), WINDOW);
 
-        parser.declareInt(MovFnPipelineAggregationBuilder::setShift, SHIFT);
         parser.declareString(MovFnPipelineAggregationBuilder::format, FORMAT);
         parser.declareField(MovFnPipelineAggregationBuilder::gapPolicy, p -> {
             if (p.currentToken() == XContentParser.Token.VALUE_STRING) {
@@ -101,11 +97,6 @@ public class MovFnPipelineAggregationBuilder extends AbstractPipelineAggregation
         format = in.readOptionalString();
         gapPolicy = GapPolicy.readFrom(in);
         window = in.readInt();
-        if (in.getVersion().onOrAfter(Version.V_8_0_0)) { // TODO change this after backport
-            shift = in.readInt();
-        } else {
-            shift = 0;
-        }
     }
 
     @Override
@@ -115,9 +106,6 @@ public class MovFnPipelineAggregationBuilder extends AbstractPipelineAggregation
         out.writeOptionalString(format);
         gapPolicy.writeTo(out);
         out.writeInt(window);
-        if (out.getVersion().onOrAfter(Version.V_8_0_0)) { // TODO change this after backport
-            out.writeInt(shift);
-        }
     }
 
     /**
@@ -180,13 +168,9 @@ public class MovFnPipelineAggregationBuilder extends AbstractPipelineAggregation
         this.window = window;
     }
 
-    public void setShift(int shift) {
-        this.shift = shift;
-    }
-
     @Override
     public void doValidate(AggregatorFactory parent, Collection<AggregationBuilder> aggFactories,
-                           Collection<PipelineAggregationBuilder> pipelineAggregatorFactories) {
+                           Collection<PipelineAggregationBuilder> pipelineAggregatoractories) {
         if (window <= 0) {
             throw new IllegalArgumentException("[" + WINDOW.getPreferredName() + "] must be a positive, non-zero integer.");
         }
@@ -196,7 +180,7 @@ public class MovFnPipelineAggregationBuilder extends AbstractPipelineAggregation
 
     @Override
     protected PipelineAggregator createInternal(Map<String, Object> metaData) {
-        return new MovFnPipelineAggregator(name, bucketsPathString, script, window, shift, formatter(), gapPolicy, metaData);
+        return new MovFnPipelineAggregator(name, bucketsPathString, script, window, formatter(), gapPolicy, metaData);
     }
 
     @Override
@@ -208,7 +192,6 @@ public class MovFnPipelineAggregationBuilder extends AbstractPipelineAggregation
         }
         builder.field(GAP_POLICY.getPreferredName(), gapPolicy.getName());
         builder.field(WINDOW.getPreferredName(), window);
-        builder.field(SHIFT.getPreferredName(), shift);
         return builder;
     }
 
@@ -242,7 +225,7 @@ public class MovFnPipelineAggregationBuilder extends AbstractPipelineAggregation
 
     @Override
     public int hashCode() {
-        return Objects.hash(super.hashCode(), bucketsPathString, script, format, gapPolicy, window, shift);
+        return Objects.hash(super.hashCode(), bucketsPathString, script, format, gapPolicy, window);
     }
 
     @Override
@@ -255,8 +238,7 @@ public class MovFnPipelineAggregationBuilder extends AbstractPipelineAggregation
             && Objects.equals(script, other.script)
             && Objects.equals(format, other.format)
             && Objects.equals(gapPolicy, other.gapPolicy)
-            && Objects.equals(window, other.window)
+            && Objects.equals(window, other.window);
-            && Objects.equals(shift, other.shift);
     }
 
     @Override

server/src/main/java/org/elasticsearch/search/aggregations/pipeline/MovFnPipelineAggregator.java

@@ -19,7 +19,7 @@
 
 package org.elasticsearch.search.aggregations.pipeline;
 
-import org.elasticsearch.Version;
+import org.elasticsearch.common.collect.EvictingQueue;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.script.Script;
@@ -63,9 +63,8 @@ public class MovFnPipelineAggregator extends PipelineAggregator {
     private final Script script;
     private final String bucketsPath;
     private final int window;
-    private final int shift;
 
-    MovFnPipelineAggregator(String name, String bucketsPath, Script script, int window, int shift, DocValueFormat formatter,
+    MovFnPipelineAggregator(String name, String bucketsPath, Script script, int window, DocValueFormat formatter,
                             BucketHelpers.GapPolicy gapPolicy, Map<String, Object> metadata) {
         super(name, new String[]{bucketsPath}, metadata);
         this.bucketsPath = bucketsPath;
@@ -73,7 +72,6 @@ public class MovFnPipelineAggregator extends PipelineAggregator {
         this.formatter = formatter;
         this.gapPolicy = gapPolicy;
         this.window = window;
-        this.shift = shift;
     }
 
     public MovFnPipelineAggregator(StreamInput in) throws IOException {
@@ -83,11 +81,6 @@ public class MovFnPipelineAggregator extends PipelineAggregator {
         gapPolicy = BucketHelpers.GapPolicy.readFrom(in);
         bucketsPath = in.readString();
         window = in.readInt();
-        if (in.getVersion().onOrAfter(Version.V_8_0_0)) { // TODO change this after backport
-            shift = in.readInt();
-        } else {
-            shift = 0;
-        }
     }
 
     @Override
@@ -97,9 +90,6 @@ public class MovFnPipelineAggregator extends PipelineAggregator {
         gapPolicy.writeTo(out);
         out.writeString(bucketsPath);
         out.writeInt(window);
-        if (out.getVersion().onOrAfter(Version.V_8_0_0)) { // TODO change this after backport
-            out.writeInt(shift);
-        }
     }
 
     @Override
@@ -116,6 +106,7 @@ public class MovFnPipelineAggregator extends PipelineAggregator {
         HistogramFactory factory = (HistogramFactory) histo;
 
         List<MultiBucketsAggregation.Bucket> newBuckets = new ArrayList<>();
+        EvictingQueue<Double> values = new EvictingQueue<>(this.window);
 
         // Initialize the script
         MovingFunctionScript.Factory scriptFactory = reduceContext.scriptService().compile(script, MovingFunctionScript.CONTEXT);
@@ -126,12 +117,6 @@ public class MovFnPipelineAggregator extends PipelineAggregator {
 
         MovingFunctionScript executableScript = scriptFactory.newInstance();
 
-        List<Double> values = buckets.stream()
-            .map(b -> resolveBucketValue(histo, b, bucketsPaths()[0], gapPolicy))
-            .filter(v -> v != null && v.isNaN() == false)
-            .collect(Collectors.toList());
-
-        int index = 0;
         for (InternalMultiBucketAggregation.InternalBucket bucket : buckets) {
             Double thisBucketValue = resolveBucketValue(histo, bucket, bucketsPaths()[0], gapPolicy);
 
@@ -139,18 +124,11 @@ public class MovFnPipelineAggregator extends PipelineAggregator {
             // since we only change newBucket if we can add to it
             MultiBucketsAggregation.Bucket newBucket = bucket;
 
-            if (thisBucketValue != null && thisBucketValue.isNaN() == false) {
+            if (thisBucketValue != null && thisBucketValue.equals(Double.NaN) == false) {
 
                 // The custom context mandates that the script returns a double (not Double) so we
                 // don't need null checks, etc.
-                int fromIndex = clamp(index - window + shift, values);
+                double movavg = executableScript.execute(vars, values.stream().mapToDouble(Double::doubleValue).toArray());
-                int toIndex = clamp(index + shift, values);
-                double movavg = executableScript.execute(
-                    vars,
-                    values.subList(fromIndex, toIndex).stream()
-                        .mapToDouble(Double::doubleValue)
-                        .toArray()
-                );
 
                 List<InternalAggregation> aggs = StreamSupport
                     .stream(bucket.getAggregations().spliterator(), false)
@@ -158,21 +136,11 @@ public class MovFnPipelineAggregator extends PipelineAggregator {
                     .collect(Collectors.toList());
                 aggs.add(new InternalSimpleValue(name(), movavg, formatter, new ArrayList<>(), metaData()));
                 newBucket = factory.createBucket(factory.getKey(bucket), bucket.getDocCount(), new InternalAggregations(aggs));
-                index++;
+                values.offer(thisBucketValue);
             }
             newBuckets.add(newBucket);
         }
 
         return factory.createAggregation(newBuckets);
     }
-
-    private int clamp(int index, List<Double> list) {
-        if (index < 0) {
-            return 0;
-        }
-        if (index > list.size()) {
-            return list.size();
-        }
-        return index;
-    }
 }

server/src/test/java/org/elasticsearch/search/aggregations/pipeline/MovFnPipelineAggregationBuilderSerializationTests.java

@@ -22,6 +22,7 @@ package org.elasticsearch.search.aggregations.pipeline;
 import org.elasticsearch.common.io.stream.Writeable;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.script.Script;
+import org.elasticsearch.search.aggregations.pipeline.MovFnPipelineAggregationBuilder;
 import org.elasticsearch.test.AbstractSerializingTestCase;
 
 import java.io.IOException;
@@ -30,14 +31,7 @@ public class MovFnPipelineAggregationBuilderSerializationTests extends AbstractS
 
     @Override
     protected MovFnPipelineAggregationBuilder createTestInstance() {
-        MovFnPipelineAggregationBuilder builder = new MovFnPipelineAggregationBuilder(
+        return new MovFnPipelineAggregationBuilder(randomAlphaOfLength(10), "foo", new Script("foo"), randomIntBetween(1, 10));
-            randomAlphaOfLength(10),
-            "foo",
-            new Script("foo"),
-            randomIntBetween(1, 10)
-        );
-        builder.setShift(randomIntBetween(1, 10));
-        return builder;
     }
 
     @Override

server/src/test/java/org/elasticsearch/search/aggregations/pipeline/MovFnUnitTests.java

@@ -53,7 +53,6 @@ import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.function.Consumer;
-import java.util.stream.Collectors;
 
 import static org.hamcrest.Matchers.equalTo;
 import static org.mockito.Mockito.mock;
@@ -80,42 +79,25 @@ public class MovFnUnitTests extends AggregatorTestCase {
     private static final List<Integer> datasetValues = Arrays.asList(1,2,3,4,5,6,7,8,9,10);
 
     public void testMatchAllDocs() throws IOException {
-        check(0, List.of(Double.NaN, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0));
-    }
-
-    public void testShift() throws IOException {
-        check(1, List.of(1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0));
-        check(5, List.of(5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 10.0, 10.0, Double.NaN, Double.NaN));
-        check(-5, List.of(Double.NaN, Double.NaN, Double.NaN, Double.NaN, Double.NaN, Double.NaN, 1.0, 2.0, 3.0, 4.0));
-    }
-
-    public void testWideWindow() throws IOException {
-        Script script = new Script(Script.DEFAULT_SCRIPT_TYPE, "painless", "test", Collections.emptyMap());
-        MovFnPipelineAggregationBuilder builder = new MovFnPipelineAggregationBuilder("mov_fn", "avg", script, 100);
-        builder.setShift(50);
-        check(builder, script, List.of(10.0, 10.0, 10.0, 10.0, 10.0, 10.0, 10.0, 10.0, 10.0, 10.0));
-    }
-
-    private void check(int shift, List<Double> expected) throws IOException {
-        Script script = new Script(Script.DEFAULT_SCRIPT_TYPE, "painless", "test", Collections.emptyMap());
-        MovFnPipelineAggregationBuilder builder = new MovFnPipelineAggregationBuilder("mov_fn", "avg", script, 3);
-        builder.setShift(shift);
-        check(builder, script, expected);
-    }
-
-    private void check(MovFnPipelineAggregationBuilder builder, Script script, List<Double> expected) throws IOException {
         Query query = new MatchAllDocsQuery();
+        Script script = new Script(Script.DEFAULT_SCRIPT_TYPE, "painless", "test", Collections.emptyMap());
+
         DateHistogramAggregationBuilder aggBuilder = new DateHistogramAggregationBuilder("histo");
         aggBuilder.calendarInterval(DateHistogramInterval.DAY).field(DATE_FIELD);
         aggBuilder.subAggregation(new AvgAggregationBuilder("avg").field(VALUE_FIELD));
-        aggBuilder.subAggregation(builder);
+        aggBuilder.subAggregation(new MovFnPipelineAggregationBuilder("mov_fn", "avg", script, 3));
 
         executeTestCase(query, aggBuilder, histogram -> {
+                assertEquals(10, histogram.getBuckets().size());
                 List<? extends Histogram.Bucket> buckets = histogram.getBuckets();
-                List<Double> actual = buckets.stream()
+                for (int i = 0; i < buckets.size(); i++) {
-                    .map(bucket -> ((InternalSimpleValue) (bucket.getAggregations().get("mov_fn"))).value())
+                    if (i == 0) {
-                    .collect(Collectors.toList());
+                        assertThat(((InternalSimpleValue)(buckets.get(i).getAggregations().get("mov_fn"))).value(), equalTo(Double.NaN));
-                assertThat(actual, equalTo(expected));
+                    } else {
+                        assertThat(((InternalSimpleValue)(buckets.get(i).getAggregations().get("mov_fn"))).value(), equalTo(((double) i)));
+                    }
+
+                }
             }, 1000, script);
     }