Make "fromGeojsonVt" faster

index.ts

@@ -1,14 +1,14 @@
 import Pbf from 'pbf';
-import {type GeoJSONOptions, type Feature, GeoJSONWrapper} from './lib/geojson_wrapper';
+import {type Feature, GEOJSON_TILE_LAYER_NAME, type GeoJSONOptions, GeoJSONWrapper} from "./lib/geojson_wrapper";
 import geojsonvt from 'geojson-vt';
-import {type VectorTileLayer, type VectorTile, VectorTileFeature} from '@mapbox/vector-tile';
+import type {VectorTileFeatureLike, VectorTileLike, VectorTileLayerLike} from './lib/types';
 
 interface Context {
     keys: string[];
     values: (string | boolean | number)[];
     keycache: Record<string, number>;
     valuecache: Record<string, number>;
-    feature?: VectorTileFeature;
+    feature?: VectorTileFeatureLike;
 }
 
 /**
@@ -17,7 +17,7 @@ interface Context {
  * @param tile
  * @return uncompressed, pbf-serialized tile data
  */
-export function fromVectorTileJs(tile: VectorTile): Uint8Array {
+export function fromVectorTileJs(tile: VectorTileLike): Uint8Array {
     const out = new Pbf();
     writeTile(tile, out);
     return out.finish();
@@ -31,7 +31,7 @@ export function fromVectorTileJs(tile: VectorTile): Uint8Array {
  * @return uncompressed, pbf-serialized tile data
  */
 export function fromGeojsonVt(layers: geojsonvt.Tile[], options?: GeoJSONOptions): Uint8Array {
-    const l: Record<string, VectorTileLayer> = {};
+    const l: Record<string, VectorTileLayerLike> = {};
     // eslint-disable-next-line @typescript-eslint/no-for-in-array
     for (const k in layers) {
         l[k] = new GeoJSONWrapper(layers[k].features, options);
@@ -42,13 +42,13 @@ export function fromGeojsonVt(layers: geojsonvt.Tile[], options?: GeoJSONOptions
     return fromVectorTileJs({ layers: l });
 }
 
-function writeTile(tile: VectorTile, pbf: Pbf) {
+function writeTile(tile: VectorTileLike, pbf: Pbf) {
     for (const key in tile.layers) {
         pbf.writeMessage(3, writeLayer, tile.layers[key]);
     }
 }
 
-function writeLayer(layer: VectorTileLayer, pbf: Pbf) {
+function writeLayer(layer: VectorTileLayerLike, pbf: Pbf) {
     pbf.writeVarintField(15, layer.version || 1);
     pbf.writeStringField(1, layer.name || '');
     pbf.writeVarintField(5, layer.extent || 4096);
@@ -128,7 +128,7 @@ function zigzag(num: number) {
     return (num << 1) ^ (num >> 31);
 }
 
-function writeGeometry(feature: VectorTileFeature, pbf: Pbf) {
+function writeGeometry(feature: VectorTileFeatureLike, pbf: Pbf) {
     const geometry = feature.loadGeometry();
     const type = feature.type;
     let x = 0;
@@ -179,5 +179,9 @@ function writeValue(value: string | boolean | number, pbf: Pbf) {
 export {
     GeoJSONWrapper,
     GeoJSONOptions,
-    Feature
-}
+    Feature,
+    GEOJSON_TILE_LAYER_NAME,
+    VectorTileFeatureLike,
+    VectorTileLike,
+    VectorTileLayerLike,
+};

lib/geojson_wrapper.ts

@@ -1,8 +1,13 @@
 import Point from '@mapbox/point-geometry';
-import {VectorTileFeature, VectorTileLayer, type VectorTile} from '@mapbox/vector-tile';
 import type {TileFeature, AnyProps} from 'supercluster';
 import {type Feature as GeoJSONVTFeature, Geometry} from 'geojson-vt';
-import Pbf from 'pbf';
+import type {
+    VectorTileFeatureLike,
+    VectorTileLayerLike,
+    VectorTileLike,
+} from "./types";
+
+export { VectorTileFeatureLike, VectorTileLayerLike, VectorTileLike };
 
 export type Feature = TileFeature<AnyProps, AnyProps> | GeoJSONVTFeature;
 
@@ -11,14 +16,18 @@ export interface GeoJSONOptions {
     extent: number;
 }
 
-class FeatureWrapper extends VectorTileFeature {
+class FeatureWrapper implements VectorTileFeatureLike {
     feature: Feature;
+    type: VectorTileFeatureLike['type'];
+    properties: VectorTileFeatureLike['properties'];
+    id: VectorTileFeatureLike['id'];
+    extent: VectorTileFeatureLike['extent'];
 
     constructor(feature: Feature, extent: number) {
-        super(new Pbf(), 0, extent, [], []);
         this.feature = feature;
         this.type = feature.type;
         this.properties = feature.tags ? feature.tags : {};
+        this.extent = extent;
 
         // If the feature has a top-level `id` property, copy it over, but only
         // if it can be coerced to an integer, because this wrapper is used for
@@ -50,25 +59,26 @@ class FeatureWrapper extends VectorTileFeature {
     }
 }
 
-export class GeoJSONWrapper extends VectorTileLayer implements VectorTile {
-    layers: Record<string, VectorTileLayer>;
-    name: string;
-    extent: number;
-    length: number;
-    version: number;
+export const GEOJSON_TILE_LAYER_NAME = "_geojsonTileLayer";
+
+export class GeoJSONWrapper implements VectorTileLayerLike {
+    layers: Record<string, VectorTileLayerLike>;
     features: Feature[];
+    version: VectorTileLayerLike['version'];
+    name: VectorTileLayerLike['name'];
+    extent: VectorTileLayerLike['extent'];
+    length: VectorTileLayerLike['length'];
 
     constructor(features: Feature[], options?: GeoJSONOptions) {
-        super(new Pbf());
-        this.layers = {'_geojsonTileLayer': this};
-        this.name = '_geojsonTileLayer';
+        this.layers = { [GEOJSON_TILE_LAYER_NAME]: this };
+        this.name = GEOJSON_TILE_LAYER_NAME;
         this.version = options ? options.version : 1;
         this.extent = options ? options.extent : 4096;
         this.length = features.length;
         this.features = features;
     }
 
-    feature(i: number): VectorTileFeature {
+    feature(i: number): VectorTileFeatureLike {
         return new FeatureWrapper(this.features[i], this.extent);
     }
 }

lib/types.ts

@@ -0,0 +1,21 @@
+import type Point from '@mapbox/point-geometry';
+
+export interface VectorTileFeatureLike {
+    type: 0 | 1 | 2 | 3;
+    properties: Record<string, number | string | boolean>;
+    id: number | undefined;
+    extent: number;
+    loadGeometry(): Point[][];
+}
+
+export interface VectorTileLayerLike {
+    version: number;
+    name: string;
+    extent: number;
+    length: number;
+    feature(i: number): VectorTileFeatureLike;
+}
+
+export interface VectorTileLike {
+    layers: Record<string, VectorTileLayerLike>;
+}

test/geojson_wrapper-test.ts

@@ -1,5 +1,5 @@
 import {describe, test, expect} from 'vitest';
-import {GeoJSONWrapper} from '../index.ts';
+import {GeoJSONWrapper} from '../index';
 
 describe('geojsonwrapper', () => {
     test('linestring', () => {

tsconfig.json

@@ -12,9 +12,5 @@
         "moduleResolution": "bundler",
         "declarationDir": "dist/"
     },
-    "files": [
-        "index.ts",
-        "lib/geojson_wrapper.ts",
-        "rollup.config.ts"
-    ]
-}
+    "include": ["**/*.ts"]
+}