Merge pull request #20 from DurstDog87/pass-client

Pass client

README.md

@@ -1,14 +1,10 @@
-🚧 **work in progress** 🚧 
-#### This project is in active development and not stable
-#### Things might change at any time
-
  # Drop In Tileservice
 
 A drop in vector tile service using pg for turning any postres backend into a tileserver.
 
 ### Pre Requisites:
 
-- [PostgreSQL](https://www.postgresql.org/) with [PostGIS](http://postgis.net/) installed.
+- [PostgreSQL](https://www.postgresql.org/) with the [PostGIS](http://postgis.net/) extension added.
 - This Package requires the [node-postgres](https://node-postgres.com/) package
 
 ### Installation 
@@ -39,19 +35,22 @@ const connection_params = {
 
 const pool = new Pool(connection_params)
 
-const tileService = new Tileserver(pool)
+const tileService = new Tileserver()
 //SQL to be run against the pool db
 tileservice.setQuery("SELECT id, geom FROM schema.table WHERE prop = 44") 
 tileservice.setSrid(2252) //Michigan Central
 
 app.get("/tiles/:z/:x/:y", async (req, res) => {
     try {
-        const tiles = await ts.query(req.params.z, req.params.x, req.params.y, {
+        const conn = await pool.connect()
+        const tiles = await ts.query(req.params.z, req.params.x, req.params.y, conn, {
             layername: "default"
         })
         res.status(200).send(tiles) //protobuf sent as result 
     } catch (e) {
         console.log(e)
+    } finally {
+        await conn.release()
     }
 
 })
@@ -65,13 +64,16 @@ tileservice.setSrid(2252) //Michigan Central
 
 app.get("/tiles/:z/:x/:y", async (req, res) => {
     try {
-        const tiles = await ts.query(req.params.z, req.params.x, req.params.y, {
+        const conn = await pool.connect()
+        const tiles = await ts.query(req.params.z, req.params.x, req.params.y, conn, {
             params: [44],
             layername: "default"
         })
         res.status(200).send(tiles) //protobuf sent as result 
     } catch (e) {
         console.log(e)
+    } finally {
+        await conn.release()
     }
 })
 ```
@@ -81,7 +83,8 @@ app.get("/tiles/:z/:x/:y", async (req, res) => {
 ```javascript
 app.get("/tiles/:z/:x/:y", async (req, res) => {
     try {
-        const tiles = await ts.query(req.params.z, req.params.x, req.params.y, {
+        const conn = await pool.connect()
+        const tiles = await ts.query(req.params.z, req.params.x, req.params.y, conn, {
             queryString: "SELECT id, geom FROM schema.table WHERE prop = $1",
             srid: 2252,
             params: [44],
@@ -90,6 +93,8 @@ app.get("/tiles/:z/:x/:y", async (req, res) => {
         res.status(200).send(tiles) //protobuf sent as result 
     } catch (e) {
         console.log(e)
+    } finally {
+        await conn.release()
     }
 })
 ```

src/__tests__/tile.ts

@@ -1,5 +1,5 @@
 import { describe, expect, test } from '@jest/globals';
-import { tileExt, nTiles, makeEnvelopeFromTileCoord, validateTileCoords } from '../util/tile';
+import { tileExt, nTiles, makeBboxFromTileCoord, validateTileCoords } from '../util/tile';
 
 describe('tile utilities', () => {
   test('find tile extent at given zoom', () => {
@@ -13,7 +13,7 @@ describe('tile utilities', () => {
   });
 
   test('find the envelope for and zxy set', () => {
-    const res = makeEnvelopeFromTileCoord(3, 3, 4);
+    const res = makeBboxFromTileCoord(3, 3, 4);
     expect(res).toStrictEqual({
       xMin: -5009377.085697301,
       xMax: 0.0,

src/index.ts

@@ -1,32 +1,27 @@
-import { Pool, QueryResult } from 'pg';
+import { Client, QueryResult } from 'pg';
 import { IQueryOptions } from './types';
+import { makeBboxFromTileCoord } from './util/tile';
 
 export const DEFAULT_SRID = 4269;
 export const DEFAULT_EXTENT = 4096;
 export const DEFAULT_BUFFER = 256;
 export const DEFAULT_CLIP_GEOM = true;
 
 export class Tileserver {
-  pool: Pool;
   srid: number;
   extent: number;
   buffer: number;
   clip_geom: boolean;
   queryString: string;
 
-  constructor(pool: Pool) {
-    this.pool = pool;
+  constructor() {
     this.srid = DEFAULT_SRID;
     this.extent = DEFAULT_EXTENT;
     this.buffer = DEFAULT_BUFFER;
     this.clip_geom = DEFAULT_CLIP_GEOM;
     this.queryString = '';
   }
 
-  setPool(pool: Pool) {
-    this.pool = pool;
-  }
-
   setQuery(query: string) {
     this.queryString = query;
   }
@@ -35,7 +30,7 @@ export class Tileserver {
     this.srid = srid;
   }
 
-  async query(z: number, x: number, y: number, options: IQueryOptions = {}): Promise<ArrayBuffer> {
+  async query(z: number, x: number, y: number, client: Client, options: IQueryOptions = {}): Promise<ArrayBuffer> {
     if (z === undefined || x === undefined || y === undefined) {
       throw EvalError('tile coordinates not defined');
     }
@@ -44,32 +39,30 @@ export class Tileserver {
       throw EvalError('no query string set');
     }
 
-    const query = `
+    const query = `--sql
         WITH mvtgeom AS (
             SELECT ST_AsMVTGeom(
                 ST_Transform(geom, 3857), 
-                ST_TileEnvelope($1,$2,$3), 
+                ST_MakeEnvelope($1,$2,$3,$4, 4326), 
                 ${options.extent ?? this.extent},
                 ${options.buffer ?? this.buffer},
                 ${options.clip_geom ?? this.clip_geom}
                 ) AS mvtgeom, dat.*
             FROM (${(options.queryString ?? this.queryString).replace(/;$/g, '')}) AS dat
             WHERE ST_Intersects(
                 geom, 
-                ST_Transform(ST_TileEnvelope($1,$2,$3), ${options.srid ?? this.srid}))
-        )
+                ST_Transform(ST_MakeEnvelope($1,$2,$3,$4, ${options.srid ?? this.srid}), ${options.srid ?? this.srid})
+        ))
         SELECT ST_AsMVT(mvtgeom.*, '${options.layerName ?? 'default'}') AS mvt FROM mvtgeom;
         `;
 
-    const conn = await this.pool.connect();
-
-    try {
-      const result: QueryResult<{ mvt: ArrayBuffer }> = await conn.query(query, [z, x, y]);
-      return result.rows[0].mvt;
-    } catch (e) {
-      throw e;
-    } finally {
-      conn.release();
-    }
+    const bbox = makeBboxFromTileCoord(z, x, y);
+    const result: QueryResult<{ mvt: ArrayBuffer }> = await client.query(query, [
+      bbox.xMin,
+      bbox.yMin,
+      bbox.xMax,
+      bbox.yMax,
+    ]);
+    return result.rows[0].mvt;
   }
 }

src/types.ts

@@ -1,4 +1,4 @@
-export interface ITileEnvelope {
+export interface ITileBbox {
   xMin: number;
   xMax: number;
   yMin: number;

src/util/tile.ts

@@ -1,4 +1,4 @@
-import { ITileEnvelope } from '../types';
+import { ITileBbox } from '../types';
 
 export function tileExt(zoom: number): number {
   //tile width at zoom level `zoom`
@@ -10,7 +10,7 @@ export function nTiles(zoom: number): number {
   return 2 ** (2 * zoom);
 }
 
-export function makeEnvelopeFromTileCoord(z: number, x: number, y: number): ITileEnvelope {
+export function makeBboxFromTileCoord(z: number, x: number, y: number): ITileBbox {
   const webMercMax = 20037508.3427892;
   const webMercMin = -1 * webMercMax;
   const worldSize = webMercMax - webMercMin;