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center mode POLYFILL TABLE working
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@DeanSherwin
DeanSherwin committed Apr 4, 2024
1 parent 3bf2bf1 commit 23f93ce
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6 changes: 3 additions & 3 deletions clouds/snowflake/modules/sql/h3/H3_POLYFILL.sql
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@@ -1,6 +1,6 @@
----------------------------
-- Copyright (C) 2021 CARTO
----------------------------
--------------------------------
-- Copyright (C) 2021-2024 CARTO
--------------------------------

CREATE OR REPLACE FUNCTION @@SF_SCHEMA@@._HAS_POLYGON_JS
(geojson STRING)
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191 changes: 23 additions & 168 deletions clouds/snowflake/modules/sql/h3/H3_POLYFILL_TABLE.sql
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@@ -1,161 +1,12 @@
----------------------------
-- Copyright (C) 2023 CARTO
----------------------------
--------------------------------
-- Copyright (C) 2023-2024 CARTO
--------------------------------

CREATE OR REPLACE FUNCTION @@SF_SCHEMA@@._H3_POLYFILL_GEOJSON
(geojson STRING, input_resolution DOUBLE)
RETURNS ARRAY
LANGUAGE JAVASCRIPT
IMMUTABLE
AS $$
if (!GEOJSON || INPUT_RESOLUTION == null) {
return [];
}

@@SF_LIBRARY_H3_POLYFILL@@

const resolution = Number(INPUT_RESOLUTION);
if (resolution < 0 || resolution > 15) {
return [];
}

const bboxA = [-180, -90, 0, 90]
const bboxB = [0, -90, 180, 90]
const featureGeometry = JSON.parse(GEOJSON)
let polygonCoordinatesA = [];
let polygonCoordinatesB = [];
switch(featureGeometry.type) {
case 'GeometryCollection':
featureGeometry.geometries.forEach(function (geom) {
if (geom.type === 'MultiPolygon') {
var clippedGeometryA = h3PolyfillLib.bboxClip(geom, bboxA).geometry;
polygonCoordinatesA = polygonCoordinatesA.concat(clippedGeometryA.coordinates);
var clippedGeometryB = h3PolyfillLib.bboxClip(geom, bboxB).geometry;
polygonCoordinatesB = polygonCoordinatesB.concat(clippedGeometryB.coordinates);
} else if (geom.type === 'Polygon') {
var clippedGeometryA = h3PolyfillLib.bboxClip(geom, bboxA).geometry;
polygonCoordinatesA = polygonCoordinatesA.concat([clippedGeometryA.coordinates]);
var clippedGeometryB = h3PolyfillLib.bboxClip(geom, bboxB).geometry;
polygonCoordinatesB = polygonCoordinatesB.concat([clippedGeometryB.coordinates]);
}
});
break;
case 'MultiPolygon':
var clippedGeometryA = h3PolyfillLib.bboxClip(featureGeometry, bboxA).geometry;
polygonCoordinatesA = clippedGeometryA.coordinates;
var clippedGeometryB = h3PolyfillLib.bboxClip(featureGeometry, bboxB).geometry;
polygonCoordinatesB = clippedGeometryB.coordinates;
break;
case 'Polygon':
var clippedGeometryA = h3PolyfillLib.bboxClip(featureGeometry, bboxA).geometry;
polygonCoordinatesA = [clippedGeometryA.coordinates];
var clippedGeometryB = h3PolyfillLib.bboxClip(featureGeometry, bboxB).geometry;
polygonCoordinatesB = [clippedGeometryB.coordinates];
break;
default:
return [];
}

if (polygonCoordinatesA.length + polygonCoordinatesB.length === 0) {
return [];
}

let hexesA = polygonCoordinatesA.reduce(
(acc, coordinates) => acc.concat(h3PolyfillLib.polyfill(coordinates, resolution, true)),
[]
).filter(h => h != null);
let hexesB = polygonCoordinatesB.reduce(
(acc, coordinates) => acc.concat(h3PolyfillLib.polyfill(coordinates, resolution, true)),
[]
).filter(h => h != null);
hexes = [...hexesA, ...hexesB];
hexes = [...new Set(hexes)];

return hexes;
$$;

CREATE OR REPLACE FUNCTION @@SF_SCHEMA@@._H3_AVG_EDGE_LENGTH
(resolution INTEGER)
RETURNS DOUBLE
IMMUTABLE
AS $$
SELECT CASE resolution
WHEN 0 THEN CAST(1281256.011 AS DOUBLE)
WHEN 1 THEN CAST(483056.8391 AS DOUBLE)
WHEN 2 THEN CAST(182512.9565 AS DOUBLE)
WHEN 3 THEN CAST(68979.22179 AS DOUBLE)
WHEN 4 THEN CAST(26071.75968 AS DOUBLE)
WHEN 5 THEN CAST(9854.090990 AS DOUBLE)
WHEN 6 THEN CAST(3724.532667 AS DOUBLE)
WHEN 7 THEN CAST(1406.475763 AS DOUBLE)
WHEN 8 THEN CAST(531.414010 AS DOUBLE)
WHEN 9 THEN CAST(200.786148 AS DOUBLE)
WHEN 10 THEN CAST(75.863783 AS DOUBLE)
WHEN 11 THEN CAST(28.663897 AS DOUBLE)
WHEN 12 THEN CAST(10.830188 AS DOUBLE)
WHEN 13 THEN CAST(4.092010 AS DOUBLE)
WHEN 14 THEN CAST(1.546100 AS DOUBLE)
WHEN 15 THEN CAST(0.584169 AS DOUBLE)
ELSE
NULL
END
$$;

CREATE OR REPLACE FUNCTION @@SF_SCHEMA@@._H3_POLYFILL_INIT
(geog GEOGRAPHY, resolution INTEGER)
RETURNS ARRAY
IMMUTABLE
AS $$
SELECT @@SF_SCHEMA@@._H3_POLYFILL_GEOJSON(
CAST(
ST_ASGEOJSON(
@@SF_SCHEMA@@.ST_BUFFER(
geog,
@@SF_SCHEMA@@._H3_AVG_EDGE_LENGTH(resolution)
)
) AS STRING),
CAST(resolution AS DOUBLE)
)
$$;

CREATE OR REPLACE FUNCTION @@SF_SCHEMA@@._H3_POLYFILL_QUERY
(
input_query STRING,
resolution DOUBLE,
mode STRING,
output_table STRING
)
RETURNS STRING
LANGUAGE JAVASCRIPT
IMMUTABLE
AS $$
if (!['center', 'intersects', 'contains'].includes(MODE)) {
throw Error('Invalid mode, should be center, intersects, or contains.');
}

if (RESOLUTION < 0 || RESOLUTION > 15) {
throw Error('Invalid resolution, should be between 0 and 15.');
}

const containmentFunction = (MODE === 'contains') ? 'ST_CONTAINS' : 'ST_INTERSECTS';
const cellFunction = (MODE === 'center') ? '@@SF_SCHEMA@@.H3_CENTER' : '@@SF_SCHEMA@@.H3_BOUNDARY';

const parentResolution = Math.max(0, RESOLUTION - 4)

return `
CREATE OR REPLACE TABLE ${OUTPUT_TABLE} CLUSTER BY (h3) AS
WITH __input AS (${INPUT_QUERY}),
__cells AS (
SELECT CAST(children.value AS STRING) AS h3, i.*
FROM __input AS i,
TABLE(FLATTEN(@@SF_SCHEMA@@._H3_POLYFILL_INIT(geom, ${parentResolution}))) AS parent,
TABLE(FLATTEN(@@SF_SCHEMA@@.H3_TOCHILDREN(CAST(parent.value AS STRING), ${RESOLUTION}))) AS children
)
SELECT * EXCLUDE(geom)
FROM __cells
WHERE ${containmentFunction}(geom, ${cellFunction}(h3))
`;
$$;
-- TODO: mode
-- TODO: CLUSTER
-- TODO: disallow query column names which conflict with FLATTEN columns
-- TODO: SCHEMA
-- TODO: TESTS

CREATE OR REPLACE PROCEDURE @@SF_SCHEMA@@.H3_POLYFILL_TABLE
(
Expand All @@ -168,15 +19,19 @@ RETURNS STRING
LANGUAGE SQL
EXECUTE AS CALLER
AS $$
DECLARE polyfill_query STRING;
BEGIN
polyfill_query := (SELECT @@SF_SCHEMA@@._H3_POLYFILL_QUERY(
:input_query,
CAST(:resolution AS DOUBLE),
:mode,
:output_table
));
EXECUTE IMMEDIATE polyfill_query;
RETURN 'Polyfill completed.';
END;
DECLARE
column_names_csv STRING;
BEGIN
-- Validate
EXECUTE IMMEDIATE 'SELECT * FROM (' || :input_query || ') WHERE FALSE';

-- New table with correct columns
EXECUTE IMMEDIATE 'CREATE TABLE ' || :output_table || ' AS SELECT * EXCLUDE geom, NULL as H3 FROM (' || :input_query || ') WHERE FALSE';

column_names_csv := (SELECT LISTAGG(COLUMN_NAME, ',') FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME ILIKE :output_table AND TABLE_SCHEMA=CURRENT_SCHEMA());

EXECUTE IMMEDIATE 'INSERT INTO ' || :output_table || ' (' || :column_names_csv || ') SELECT ' || :column_names_csv || ' FROM (WITH virtual_table AS (' || :input_query || ') SELECT *, value as H3 FROM virtual_table, LATERAL FLATTEN(input => H3_POLYFILL(virtual_table.geom, ' || :resolution || ')))';

RETURN 'Finished!';
END;
$$;
26 changes: 0 additions & 26 deletions clouds/snowflake/modules/test/h3/H3_POLYFILL_TABLE.test.js
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const { runQuery } = require('../../../common/test-utils');

const SF_SCHEMA = process.env.SF_SCHEMA;

test('H3_POLYFILL_TABLE should generate the correct query', async () => {
const query = `SELECT @@SF_SCHEMA@@._H3_POLYFILL_QUERY(
'SELECT geom, name, value FROM <project>.<dataset>.<table>',
12, 'center',
'<project>.<dataset>.<output_table>'
) AS output`;
const rows = await runQuery(query);
expect(rows.length).toEqual(1);
expect(rows[0].OUTPUT).toEqual(`
CREATE OR REPLACE TABLE <project>.<dataset>.<output_table> CLUSTER BY (h3) AS
WITH __input AS (SELECT geom, name, value FROM <project>.<dataset>.<table>),
__cells AS (
SELECT CAST(children.value AS STRING) AS h3, i.*
FROM __input AS i,
TABLE(FLATTEN(@@SF_SCHEMA@@._H3_POLYFILL_INIT(geom, 8))) AS parent,
TABLE(FLATTEN(@@SF_SCHEMA@@.H3_TOCHILDREN(CAST(parent.value AS STRING), 12))) AS children
)
SELECT * EXCLUDE(geom)
FROM __cells
WHERE ST_INTERSECTS(geom, @@SF_SCHEMA@@.H3_CENTER(h3))
`.replace(/@@SF_SCHEMA@@/g, SF_SCHEMA));
});

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