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to improve performance: do not use BigDecimal for rounding #938

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Merged
osana merged 1 commit into from
Dec 13, 2018
Merged

to improve performance: do not use BigDecimal for rounding #938

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9 changes: 5 additions & 4 deletions services-geojson/src/main/java/com/mapbox/geojson/gson/BoundingBoxSerializer.java
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Original file line number Diff line number Diff line change
Expand Up @@ -8,6 +8,7 @@
import com.mapbox.geojson.BoundingBox;
import com.mapbox.geojson.Point;
import com.mapbox.geojson.shifter.CoordinateShifterManager;
import com.mapbox.geojson.utils.GeoJsonUtils;

import java.lang.reflect.Type;
import java.util.List;
Expand Down Expand Up @@ -48,8 +49,8 @@ public JsonElement serialize(BoundingBox src, Type typeOfSrc, JsonSerializationC
List<Double> unshiftedCoordinates =
CoordinateShifterManager.getCoordinateShifter().unshiftPoint(point);

bbox.add(new JsonPrimitive(unshiftedCoordinates.get(0)));
bbox.add(new JsonPrimitive(unshiftedCoordinates.get(1)));
bbox.add(new JsonPrimitive(GeoJsonUtils.trim(unshiftedCoordinates.get(0))));
bbox.add(new JsonPrimitive(GeoJsonUtils.trim(unshiftedCoordinates.get(1))));
if (point.hasAltitude()) {
bbox.add(new JsonPrimitive(unshiftedCoordinates.get(2)));
}
Expand All @@ -58,8 +59,8 @@ public JsonElement serialize(BoundingBox src, Type typeOfSrc, JsonSerializationC
point = src.northeast();
unshiftedCoordinates =
CoordinateShifterManager.getCoordinateShifter().unshiftPoint(point);
bbox.add(new JsonPrimitive(unshiftedCoordinates.get(0)));
bbox.add(new JsonPrimitive(unshiftedCoordinates.get(1)));
bbox.add(new JsonPrimitive(GeoJsonUtils.trim(unshiftedCoordinates.get(0))));
bbox.add(new JsonPrimitive(GeoJsonUtils.trim(unshiftedCoordinates.get(1))));
if (point.hasAltitude()) {
bbox.add(new JsonPrimitive(unshiftedCoordinates.get(2)));
}
Expand Down
15 changes: 3 additions & 12 deletions services-geojson/src/main/java/com/mapbox/geojson/gson/CoordinateTypeAdapter.java
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Original file line number Diff line number Diff line change
Expand Up @@ -5,10 +5,9 @@
import com.google.gson.stream.JsonWriter;

import com.mapbox.geojson.shifter.CoordinateShifterManager;
import com.mapbox.geojson.utils.GeoJsonUtils;

import java.io.IOException;
import java.math.BigDecimal;
import java.math.RoundingMode;
import java.util.ArrayList;
import java.util.List;

Expand All @@ -27,16 +26,8 @@ public void write(JsonWriter out, List<Double> value) throws IOException {
List<Double> unshiftedCoordinates =
CoordinateShifterManager.getCoordinateShifter().unshiftPoint(value);

BigDecimal lon = BigDecimal.valueOf(unshiftedCoordinates.get(0));
String lonString = lon.setScale(7, RoundingMode.HALF_UP)
.stripTrailingZeros().toPlainString();

BigDecimal lat = BigDecimal.valueOf(unshiftedCoordinates.get(1));
String latString = lat.setScale(7, RoundingMode.HALF_UP)
.stripTrailingZeros().toPlainString();

out.value(Double.valueOf(lonString));
out.value(Double.valueOf(latString));
out.value(GeoJsonUtils.trim(unshiftedCoordinates.get(0)));
out.value(GeoJsonUtils.trim(unshiftedCoordinates.get(1)));

// Includes altitude
if (value.size() > 2) {
Expand Down
15 changes: 3 additions & 12 deletions services-geojson/src/main/java/com/mapbox/geojson/gson/PointSerializer.java
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Original file line number Diff line number Diff line change
Expand Up @@ -7,10 +7,9 @@
import com.google.gson.JsonSerializer;
import com.mapbox.geojson.Point;
import com.mapbox.geojson.shifter.CoordinateShifterManager;
import com.mapbox.geojson.utils.GeoJsonUtils;

import java.lang.reflect.Type;
import java.math.BigDecimal;
import java.math.RoundingMode;
import java.util.List;

/**
Expand Down Expand Up @@ -50,16 +49,8 @@ public JsonElement serialize(Point src, Type typeOfSrc, JsonSerializationContext
List<Double> unshiftedCoordinates =
CoordinateShifterManager.getCoordinateShifter().unshiftPoint(src);

BigDecimal lon = BigDecimal.valueOf(unshiftedCoordinates.get(0));
String lonString = lon.setScale(7, RoundingMode.HALF_UP)
.stripTrailingZeros().toPlainString();

BigDecimal lat = BigDecimal.valueOf(unshiftedCoordinates.get(1));
String latString = lat.setScale(7, RoundingMode.HALF_UP)
.stripTrailingZeros().toPlainString();

rawCoordinates.add(new JsonPrimitive(Double.valueOf(lonString)));
rawCoordinates.add(new JsonPrimitive(Double.valueOf(latString)));
rawCoordinates.add(new JsonPrimitive(GeoJsonUtils.trim(unshiftedCoordinates.get(0))));
rawCoordinates.add(new JsonPrimitive(GeoJsonUtils.trim(unshiftedCoordinates.get(1))));

// Includes altitude
if (src.hasAltitude()) {
Expand Down
25 changes: 25 additions & 0 deletions services-geojson/src/main/java/com/mapbox/geojson/utils/GeoJsonUtils.java
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Original file line number Diff line number Diff line change
@@ -0,0 +1,25 @@
package com.mapbox.geojson.utils;

/**
* GeoJson utils class contains method that can be used throughout geojson package.
*
* @since 4.3.0
*/
public class GeoJsonUtils {

private static double ROUND_PRECISION = 10000000.0;
private static long MAX_DOUBLE_TO_ROUND = (long) (Long.MAX_VALUE / ROUND_PRECISION);

/**
* Trims a double value to have only 7 digits after period.
*
* @param value to be trimed
* @return trimmed value
*/
public static double trim(double value) {
if (value > MAX_DOUBLE_TO_ROUND || value < -MAX_DOUBLE_TO_ROUND) {
return value;
}
return Math.round(value * ROUND_PRECISION) / ROUND_PRECISION;
}
}
53 changes: 53 additions & 0 deletions services-geojson/src/test/java/com/mapbox/geojson/utils/GeoJsonUtilsTest.java
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Original file line number Diff line number Diff line change
@@ -0,0 +1,53 @@
package com.mapbox.geojson.utils;

import static org.junit.Assert.assertEquals;

import com.mapbox.core.TestUtils;
import org.junit.Test;


public class GeoJsonUtilsTest extends TestUtils {


@Test
public void trimPositiveRoundUp() {
double trimmedValue = GeoJsonUtils.trim(3.123456789);
double expected = 3.1234568;
assertEquals("trim to 7 digits after period", expected, trimmedValue, 1e-8);
}

@Test
public void trimPositiveRoundDown() {
double trimmedValue = GeoJsonUtils.trim(3.123456712);
double expected = 3.1234567;
assertEquals("trim to 7 digits after period", expected, trimmedValue, 1e-8);
}

@Test
public void trimNegative() {
double trimmedValue = GeoJsonUtils.trim(-3.123456789);
double expected = -3.1234568;
assertEquals("trim to 7 digits after period", expected, trimmedValue, 1e-8);
}

@Test
public void trimZero() {
double trimmedValue = GeoJsonUtils.trim(0);
double expected = 0;
assertEquals("trim to 7 digits after period", expected, trimmedValue, 1e-8);
}

@Test
public void trimInt() {
double trimmedValue = GeoJsonUtils.trim(8);
double expected = 8;
assertEquals("trim to 7 digits after period", expected, trimmedValue, 1e-8);
}

@Test
public void trimMaxLong() {
double trimmedValue = GeoJsonUtils.trim(Long.MAX_VALUE + 0.1);
double expected = Long.MAX_VALUE;
assertEquals("trim to 7 digits after period", expected, trimmedValue, 1e-8);
}
}