Add geospatial expand_envelope function.

presto-docs/src/main/sphinx/functions/geospatial.rst

@@ -205,6 +205,13 @@ Operations
     the bounding rectangular polygon of a geometry. Returns ``null`` if input
     geometry is empty.
 
+.. function:: expand_envelope(Geometry, double) -> Geometry
+
+    Returns the bounding rectangular polygon of a geometry, expanded by a
+    distance. Empty geometries will return an empty polygon.  Negative or NaN
+    distances will return an error.  Positive infinity distances may lead to
+    undefined results.
+
 .. function:: ST_ExteriorRing(Geometry) -> Geometry
 
     Returns a line string representing the exterior ring of the input polygon.

presto-geospatial-toolkit/src/main/java/com/facebook/presto/geospatial/serde/GeometrySerde.java

@@ -31,6 +31,7 @@
 import com.esri.core.geometry.ogc.OGCPoint;
 import com.esri.core.geometry.ogc.OGCPolygon;
 import com.facebook.presto.geospatial.GeometryType;
+import com.google.common.annotations.VisibleForTesting;
 import io.airlift.slice.BasicSliceInput;
 import io.airlift.slice.DynamicSliceOutput;
 import io.airlift.slice.Slice;
@@ -66,7 +67,6 @@ public static Slice serialize(OGCGeometry input)
     public static Slice serialize(Envelope envelope)
     {
         requireNonNull(envelope, "envelope is null");
-        verify(!envelope.isEmpty());
         DynamicSliceOutput output = new DynamicSliceOutput(100);
         output.appendByte(GeometrySerializationType.ENVELOPE.code());
         writeEnvelopeCoordinates(output, envelope);
@@ -215,7 +215,8 @@ private static OGCGeometry readSimpleGeometry(BasicSliceInput input, Slice input
         return createFromEsriGeometry(esriGeometry, type.geometryType().isMultitype());
     }
 
-    private static OGCGeometry createFromEsriGeometry(Geometry geometry, boolean multiType)
+    @VisibleForTesting
+    static OGCGeometry createFromEsriGeometry(Geometry geometry, boolean multiType)
     {
         Geometry.Type type = geometry.getType();
         switch (type) {

presto-geospatial-toolkit/src/main/java/com/facebook/presto/geospatial/serde/JtsGeometrySerde.java

@@ -31,6 +31,7 @@
 import java.util.ArrayList;
 import java.util.List;
 
+import static com.facebook.presto.geospatial.GeometryUtils.isEsriNaN;
 import static com.facebook.presto.geospatial.GeometryUtils.translateToAVNaN;
 import static com.google.common.base.Verify.verify;
 import static com.google.common.collect.Iterables.getOnlyElement;
@@ -216,6 +217,10 @@ private static Geometry readEnvelope(SliceInput input)
         double xMax = input.readDouble();
         double yMax = input.readDouble();
 
+        if (isEsriNaN(xMin) || isEsriNaN(yMin) || isEsriNaN(xMax) || isEsriNaN(yMax)) {
+            return GEOMETRY_FACTORY.createPolygon();
+        }
+
         Coordinate[] coordinates = new Coordinate[5];
         coordinates[0] = new Coordinate(xMin, yMin);
         coordinates[1] = new Coordinate(xMin, yMax);

presto-geospatial-toolkit/src/test/java/com/facebook/presto/geospatial/serde/TestGeometrySerialization.java

@@ -21,7 +21,7 @@
 import org.locationtech.jts.io.WKTReader;
 import org.testng.annotations.Test;
 
-import static com.esri.core.geometry.ogc.OGCGeometry.createFromEsriGeometry;
+import static com.facebook.presto.geospatial.serde.GeometrySerde.createFromEsriGeometry;
 import static com.facebook.presto.geospatial.serde.GeometrySerde.deserialize;
 import static com.facebook.presto.geospatial.serde.GeometrySerde.deserializeEnvelope;
 import static com.facebook.presto.geospatial.serde.GeometrySerde.deserializeType;
@@ -133,16 +133,17 @@ public void testGeometryCollection()
     @Test
     public void testEnvelope()
     {
+        testEnvelopeSerialization(new Envelope());
         testEnvelopeSerialization(new Envelope(0, 0, 1, 1));
         testEnvelopeSerialization(new Envelope(1, 2, 3, 4));
         testEnvelopeSerialization(new Envelope(10101, -2.05, -3e5, 0));
     }
 
     private void testEnvelopeSerialization(Envelope envelope)
     {
-        assertEquals(deserialize(serialize(envelope)), createFromEsriGeometry(envelope, null));
+        assertEquals(deserialize(serialize(envelope)), createFromEsriGeometry(envelope, false));
         assertEquals(deserializeEnvelope(serialize(envelope)), envelope);
-        assertEquals(JtsGeometrySerde.serialize(JtsGeometrySerde.deserialize(serialize(envelope))), serialize(createFromEsriGeometry(envelope, null)));
+        assertEquals(JtsGeometrySerde.serialize(JtsGeometrySerde.deserialize(serialize(envelope))), serialize(createFromEsriGeometry(envelope, false)));
     }
 
     @Test

presto-geospatial/src/main/java/com/facebook/presto/plugin/geospatial/GeoFunctions.java

@@ -979,6 +979,30 @@ public static Block stEnvelopeAsPts(@SqlType(GEOMETRY_TYPE_NAME) Slice input)
         return blockBuilder.build();
     }
 
+    @Description("Returns the bounding rectangle of a Geometry expanded by distance.")
+    @ScalarFunction("expand_envelope")
+    @SqlType(GEOMETRY_TYPE_NAME)
+    public static Slice expandEnvelope(@SqlType(GEOMETRY_TYPE_NAME) Slice input, @SqlType(DOUBLE) double distance)
+    {
+        if (isNaN(distance)) {
+            throw new PrestoException(INVALID_FUNCTION_ARGUMENT, "expand_envelope: distance is NaN");
+        }
+
+        if (distance < 0) {
+            throw new PrestoException(INVALID_FUNCTION_ARGUMENT, format("expand_envelope: distance %s is negative", distance));
+        }
+
+        Envelope envelope = deserializeEnvelope(input);
+        if (envelope.isEmpty()) {
+            return EMPTY_POLYGON;
+        }
+        return serialize(new Envelope(
+                envelope.getXMin() - distance,
+                envelope.getYMin() - distance,
+                envelope.getXMax() + distance,
+                envelope.getYMax() + distance));
+    }
+
     @Description("Returns the Geometry value that represents the point set difference of two geometries")
     @ScalarFunction("ST_Difference")
     @SqlType(GEOMETRY_TYPE_NAME)

presto-geospatial/src/test/java/com/facebook/presto/plugin/geospatial/TestGeoFunctions.java

@@ -660,6 +660,24 @@ private void assertEnvelopeAsPts(String wkt, Point lowerLeftCorner, Point upperR
         assertFunction(format("transform(ST_EnvelopeAsPts(ST_GeometryFromText('%s')), x -> ST_AsText(x))", wkt), new ArrayType(VARCHAR), ImmutableList.of(new OGCPoint(lowerLeftCorner, null).asText(), new OGCPoint(upperRightCorner, null).asText()));
     }
 
+    @Test
+    public void testExpandEnvelope()
+    {
+        assertFunction("ST_IsEmpty(expand_envelope(ST_GeometryFromText('POINT EMPTY'), 1))", BOOLEAN, true);
+        assertFunction("ST_IsEmpty(expand_envelope(ST_GeometryFromText('POLYGON EMPTY'), 1))", BOOLEAN, true);
+        assertFunction("ST_AsText(expand_envelope(ST_Envelope(ST_Point(1, 10)), 3))", VARCHAR, "POLYGON ((-2 7, 4 7, 4 13, -2 13, -2 7))");
+        assertFunction("ST_AsText(expand_envelope(ST_Point(1, 10), 3))", VARCHAR, "POLYGON ((-2 7, 4 7, 4 13, -2 13, -2 7))");
+        assertFunction("ST_AsText(expand_envelope(ST_GeometryFromText('LINESTRING (1 10, 3 15)'), 2))", VARCHAR, "POLYGON ((-1 8, 5 8, 5 17, -1 17, -1 8))");
+        assertFunction("ST_AsText(expand_envelope(ST_GeometryFromText('GEOMETRYCOLLECTION (POINT (5 1), LINESTRING (3 4, 4 4))'), 1))", VARCHAR, "POLYGON ((2 0, 6 0, 6 5, 2 5, 2 0))");
+        // JTS has an envelope expanded by infinity to be empty, which is weird.
+        // PostGIS returns an infinite envelope, which is a tricky concept.
+        // We'll leave it like this until it becomes a problem.
+        assertFunction("ST_AsText(expand_envelope(ST_Point(0, 0), infinity()))", VARCHAR, "POLYGON EMPTY");
+        assertInvalidFunction("ST_AsText(expand_envelope(ST_Point(0, 0), nan()))", "expand_envelope: distance is NaN");
+        assertInvalidFunction("ST_AsText(expand_envelope(ST_Point(0, 0), -1))", "expand_envelope: distance -1.0 is negative");
+        assertInvalidFunction("ST_AsText(expand_envelope(ST_Point(0, 0), -infinity()))", "expand_envelope: distance -Infinity is negative");
+    }
+
     @Test
     public void testSTDifference()
     {