Add bing_tile_children and bing_tile_parent functions

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

@@ -497,6 +497,28 @@ represent a valid tile will raise an exception.
 
     Creates a Bing tile object from a quadkey.
 
+.. function:: bing_tile_parent(tile) -> BingTile
+
+    Returns the parent of the Bing tile at one lower zoom level.
+    Throws an exception if tile is at zoom level 0.
+
+.. function:: bing_tile_parent(tile, newZoom) -> BingTile
+
+    Returns the parent of the Bing tile at the specified lower zoom level.
+    Throws an exception if newZoom is less than 0, or newZoom is greater than
+    the tile's zoom.
+
+.. function:: bing_tile_children(tile) -> array(BingTile)
+
+    Returns the children of the Bing tile at one higher zoom level.
+    Throws an exception if tile is at max zoom level.
+
+.. function:: bing_tile_children(tile, newZoom) -> array(BingTile)
+
+    Returns the children of the Bing tile at the specified higher zoom level.
+    Throws an exception if newZoom is greater than the max zoom level, or
+    newZoom is less than the tile's zoom.
+
 .. function:: bing_tile_at(latitude, longitude, zoom_level) -> BingTile
 
     Returns a Bing tile at a given zoom level containing a point at a given latitude

presto-geospatial/pom.xml

@@ -160,6 +160,11 @@
             <scope>test</scope>
         </dependency>
 
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+        </dependency>
+
         <dependency>
             <groupId>com.facebook.presto</groupId>
             <artifactId>presto-tests</artifactId>

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

@@ -17,7 +17,9 @@
 import com.fasterxml.jackson.annotation.JsonCreator;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.google.common.annotations.VisibleForTesting;
+import com.google.common.collect.ImmutableList;
 
+import java.util.List;
 import java.util.Objects;
 
 import static com.facebook.presto.spi.StandardErrorCode.INVALID_FUNCTION_ARGUMENT;
@@ -155,11 +157,55 @@ public String toQuadKey()
         return String.valueOf(quadKey);
     }
 
+    public List<BingTile> findChildren()
+    {
+        return findChildren(zoomLevel + 1);
+    }
+
+    public List<BingTile> findChildren(int newZoom)
+    {
+        if (newZoom == zoomLevel) {
+            return ImmutableList.of(this);
+        }
+
+        checkArgument(newZoom <= MAX_ZOOM_LEVEL, "newZoom must be less than or equal to %s: %s", MAX_ZOOM_LEVEL, newZoom);
+        checkArgument(newZoom >= zoomLevel, "newZoom must be greater than or equal to current zoom %s: %s", zoomLevel, newZoom);
+
+        int zoomDelta = newZoom - zoomLevel;
+        int xNew = x << zoomDelta;
+        int yNew = y << zoomDelta;
+        ImmutableList.Builder<BingTile> builder = ImmutableList.builderWithExpectedSize(1 << (2 * zoomDelta));
+        for (int yDelta = 0; yDelta < 1 << zoomDelta; ++yDelta) {
+            for (int xDelta = 0; xDelta < 1 << zoomDelta; ++xDelta) {
+                builder.add(BingTile.fromCoordinates(xNew + xDelta, yNew + yDelta, newZoom));
+            }
+        }
+        return builder.build();
+    }
+
+    public BingTile findParent()
+    {
+        return findParent(zoomLevel - 1);
+    }
+
+    public BingTile findParent(int newZoom)
+    {
+        if (newZoom == zoomLevel) {
+            return this;
+        }
+
+        checkArgument(newZoom >= 0, "newZoom must be greater than or equal to 0: %s", newZoom);
+        checkArgument(newZoom <= zoomLevel, "newZoom must be less than or equal to current zoom %s: %s", zoomLevel, newZoom);
+
+        int zoomDelta = zoomLevel - newZoom;
+        return BingTile.fromCoordinates(x >> zoomDelta, y >> zoomDelta, newZoom);
+    }
+
     /**
      * Encodes Bing tile as a 64-bit long:
      * Version (5 bits), 0 (4 bits), x (23 bits), Zoom (5 bits), 0 (4 bits), y (23 bits)
      * (high bits left, low bits right).
-     *
+     * <p>
      * This arrangement maximizes low-bit entropy for the Java long hash function.
      */
     public long encode()

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

@@ -29,6 +29,8 @@
 import com.google.common.collect.ImmutableList;
 import io.airlift.slice.Slice;
 
+import java.util.List;
+
 import static com.facebook.presto.common.function.OperatorType.CAST;
 import static com.facebook.presto.common.type.BigintType.BIGINT;
 import static com.facebook.presto.common.type.IntegerType.INTEGER;
@@ -64,6 +66,7 @@
 import static com.facebook.presto.plugin.geospatial.BingTileUtils.tileXYToLatitudeLongitude;
 import static com.facebook.presto.plugin.geospatial.GeometryType.GEOMETRY_TYPE_NAME;
 import static com.facebook.presto.spi.StandardErrorCode.INVALID_CAST_ARGUMENT;
+import static com.facebook.presto.spi.StandardErrorCode.INVALID_FUNCTION_ARGUMENT;
 import static com.google.common.base.Preconditions.checkArgument;
 import static com.google.common.base.Verify.verify;
 import static io.airlift.slice.Slices.utf8Slice;
@@ -375,6 +378,68 @@ public static Slice bingTilePolygon(@SqlType(BingTileType.NAME) long input)
         return serialize(tileToEnvelope(tile));
     }
 
+    @Description("Return the parent for a Bing tile")
+    @ScalarFunction("bing_tile_parent")
+    @SqlType(BingTileType.NAME)
+    public static long bingTileParent(@SqlType(BingTileType.NAME) long input)
+    {
+        BingTile tile = BingTile.decode(input);
+        try {
+            return tile.findParent().encode();
+        }
+        catch (IllegalArgumentException e) {
+            throw new PrestoException(INVALID_FUNCTION_ARGUMENT, e.getMessage(), e);
+        }
+    }
+
+    @Description("Return the parent for the given zoom level for a Bing tile")
+    @ScalarFunction("bing_tile_parent")
+    @SqlType(BingTileType.NAME)
+    public static long bingTileParent(@SqlType(BingTileType.NAME) long input, @SqlType(StandardTypes.INTEGER) long newZoom)
+    {
+        BingTile tile = BingTile.decode(input);
+        try {
+            return tile.findParent(toIntExact(newZoom)).encode();
+        }
+        catch (IllegalArgumentException e) {
+            throw new PrestoException(INVALID_FUNCTION_ARGUMENT, e.getMessage(), e);
+        }
+    }
+
+    @Description("Return the children for a Bing tile")
+    @ScalarFunction("bing_tile_children")
+    @SqlType("array(" + BingTileType.NAME + ")")
+    public static Block bingTileChildren(@SqlType(BingTileType.NAME) long input)
+    {
+        BingTile tile = BingTile.decode(input);
+        try {
+            List<BingTile> children = tile.findChildren();
+            BlockBuilder blockBuilder = BIGINT.createBlockBuilder(null, children.size());
+            children.stream().forEach(child -> BIGINT.writeLong(blockBuilder, child.encode()));
+            return blockBuilder.build();
+        }
+        catch (IllegalArgumentException e) {
+            throw new PrestoException(INVALID_FUNCTION_ARGUMENT, e.getMessage(), e);
+        }
+    }
+
+    @Description("Return the children for the given zoom level for a Bing tile")
+    @ScalarFunction("bing_tile_children")
+    @SqlType("array(" + BingTileType.NAME + ")")
+    public static Block bingTileChildren(@SqlType(BingTileType.NAME) long input, @SqlType(StandardTypes.INTEGER) long newZoom)
+    {
+        BingTile tile = BingTile.decode(input);
+        try {
+            List<BingTile> children = tile.findChildren(toIntExact(newZoom));
+            BlockBuilder blockBuilder = BIGINT.createBlockBuilder(null, children.size());
+            children.stream().forEach(child -> BIGINT.writeLong(blockBuilder, child.encode()));
+            return blockBuilder.build();
+        }
+        catch (IllegalArgumentException e) {
+            throw new PrestoException(INVALID_FUNCTION_ARGUMENT, e.getMessage(), e);
+        }
+    }
+
     @Description("Given a geometry and a zoom level, returns the minimum set of Bing tiles that fully covers that geometry")
     @ScalarFunction("geometry_to_bing_tiles")
     @SqlType("array(" + BingTileType.NAME + ")")

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

@@ -15,8 +15,11 @@
 
 import com.facebook.presto.operator.scalar.AbstractTestFunctions;
 import com.fasterxml.jackson.databind.ObjectMapper;
+import com.google.common.collect.ImmutableList;
 import org.testng.annotations.Test;
 
+import java.util.List;
+
 import static com.facebook.presto.plugin.geospatial.BingTile.MAX_ZOOM_LEVEL;
 import static com.facebook.presto.plugin.geospatial.BingTile.fromCoordinates;
 import static com.facebook.presto.plugin.geospatial.BingTileUtils.MAX_LATITUDE;
@@ -25,6 +28,9 @@
 import static com.facebook.presto.plugin.geospatial.BingTileUtils.MIN_LONGITUDE;
 import static com.facebook.presto.plugin.geospatial.BingTileUtils.tileXToLongitude;
 import static com.facebook.presto.plugin.geospatial.BingTileUtils.tileYToLatitude;
+import static com.google.common.collect.ImmutableList.toImmutableList;
+import static java.lang.String.format;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
 import static org.testng.Assert.assertEquals;
 
 public class TestBingTile
@@ -90,4 +96,55 @@ public void testTileYToLatitude()
             assertEquals(tileYToLatitude(1 << zoom, zoom), MIN_LATITUDE, delta);
         }
     }
+
+    @Test
+    public void testFindChildren()
+    {
+        assertEquals(
+                toSortedQuadkeys(BingTile.fromQuadKey("").findChildren()),
+                ImmutableList.of("0", "1", "2", "3"));
+
+        assertEquals(
+                toSortedQuadkeys(BingTile.fromQuadKey("0123").findChildren()),
+                ImmutableList.of("01230", "01231", "01232", "01233"));
+
+        assertEquals(
+                toSortedQuadkeys(BingTile.fromQuadKey("").findChildren(2)),
+                ImmutableList.of("00", "01", "02", "03", "10", "11", "12", "13", "20", "21", "22", "23", "30", "31", "32", "33"));
+
+        assertThatThrownBy(() -> BingTile.fromCoordinates(0, 0, MAX_ZOOM_LEVEL).findChildren())
+                .hasMessage(format("newZoom must be less than or equal to %s: %s", MAX_ZOOM_LEVEL, MAX_ZOOM_LEVEL + 1));
+
+        assertThatThrownBy(() -> BingTile.fromCoordinates(0, 0, 13).findChildren(MAX_ZOOM_LEVEL + 1))
+                .hasMessage(format("newZoom must be less than or equal to %s: %s", MAX_ZOOM_LEVEL, MAX_ZOOM_LEVEL + 1));
+
+        assertThatThrownBy(() -> BingTile.fromCoordinates(0, 0, 13).findChildren(12))
+                .hasMessage(format("newZoom must be greater than or equal to current zoom %s: %s", 13, 12));
+    }
+
+    private List<String> toSortedQuadkeys(List<BingTile> tiles)
+    {
+        return tiles.stream()
+                .map(BingTile::toQuadKey)
+                .sorted()
+                .collect(toImmutableList());
+    }
+
+    @Test
+    public void testFindParent()
+    {
+        assertEquals(BingTile.fromQuadKey("0123").findParent().toQuadKey(), "012");
+        assertEquals(BingTile.fromQuadKey("1").findParent().toQuadKey(), "");
+        assertEquals(BingTile.fromQuadKey("0123").findParent(1).toQuadKey(), "0");
+        assertEquals(BingTile.fromQuadKey("0123").findParent(4).toQuadKey(), "0123");
+
+        assertThatThrownBy(() -> BingTile.fromQuadKey("0123").findParent(5))
+                .hasMessage(format("newZoom must be less than or equal to current zoom %s: %s", 4, 5));
+
+        assertThatThrownBy(() -> BingTile.fromQuadKey("").findParent())
+                .hasMessage(format("newZoom must be greater than or equal to 0: %s", -1));
+
+        assertThatThrownBy(() -> BingTile.fromQuadKey("12").findParent(-1))
+                .hasMessage(format("newZoom must be greater than or equal to 0: %s", -1));
+    }
 }

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

@@ -29,6 +29,7 @@
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
+import java.util.OptionalInt;
 
 import static com.facebook.presto.block.BlockAssertions.createTypedLongsBlock;
 import static com.facebook.presto.common.type.BigintType.BIGINT;
@@ -39,6 +40,7 @@
 import static com.facebook.presto.metadata.FunctionExtractor.extractFunctions;
 import static com.facebook.presto.operator.aggregation.AggregationTestUtils.assertAggregation;
 import static com.facebook.presto.operator.scalar.ApplyFunction.APPLY_FUNCTION;
+import static com.facebook.presto.plugin.geospatial.BingTile.MAX_ZOOM_LEVEL;
 import static com.facebook.presto.plugin.geospatial.BingTile.fromCoordinates;
 import static com.facebook.presto.plugin.geospatial.BingTileType.BING_TILE;
 import static com.facebook.presto.plugin.geospatial.BingTileUtils.MAX_LATITUDE;
@@ -130,6 +132,57 @@ public void testBingTile()
         assertInvalidFunction("bing_tile(2, 7, 37)", "Zoom level must be <= 23");
     }
 
+    @Test
+    public void testBingTileChildren()
+    {
+        assertBingTileChildren("0", OptionalInt.empty(), ImmutableList.of("00", "01", "02", "03"));
+        assertBingTileChildren("0", OptionalInt.of(3), ImmutableList.of(
+                "000", "001", "002", "003",
+                "010", "011", "012", "013",
+                "020", "021", "022", "023",
+                "030", "031", "032", "033"));
+        assertInvalidFunction("bing_tile_children(bing_tile('0'), 0)", "newZoom must be greater than or equal to current zoom 1: 0");
+        assertInvalidFunction(format("bing_tile_children(bing_tile('0'), %s)", MAX_ZOOM_LEVEL + 1), format("newZoom must be less than or equal to %s: %s", MAX_ZOOM_LEVEL, MAX_ZOOM_LEVEL + 1));
+    }
+
+    private void assertBingTileChildren(String quadkey, OptionalInt newZoom, List<String> childQuadkeys)
+    {
+        String children;
+        if (newZoom.isPresent()) {
+            children = format("bing_tile_children(bing_tile('%s'), %s)", quadkey, newZoom.getAsInt());
+        }
+        else {
+            children = format("bing_tile_children(bing_tile('%s'))", quadkey);
+        }
+
+        assertFunction(
+                format("array_sort(transform(%s, x -> bing_tile_quadkey(x)))", children),
+                new ArrayType(VARCHAR),
+                ImmutableList.sortedCopyOf(childQuadkeys));
+    }
+
+    @Test
+    public void testBingTileParent()
+    {
+        assertBingTileParent("03", OptionalInt.empty(), "0");
+        assertBingTileParent("0123", OptionalInt.of(2), "01");
+        assertInvalidFunction("bing_tile_parent(bing_tile('0'), 2)", "newZoom must be less than or equal to current zoom 1: 2");
+        assertInvalidFunction(format("bing_tile_parent(bing_tile('0'), %s)", -1), "newZoom must be greater than or equal to 0: -1");
+    }
+
+    private void assertBingTileParent(String quadkey, OptionalInt newZoom, String parentQuadkey)
+    {
+        String parent;
+        if (newZoom.isPresent()) {
+            parent = format("bing_tile_parent(bing_tile('%s'), %s)", quadkey, newZoom.getAsInt());
+        }
+        else {
+            parent = format("bing_tile_parent(bing_tile('%s'))", quadkey);
+        }
+
+        assertFunction(format("bing_tile_quadkey(%s)", parent), VARCHAR, parentQuadkey);
+    }
+
     @Test
     public void testPointToBingTile()
     {