LayerServer: first version which can use a local MVT-server

scripts/osm2pgsql/tilecountServer.ts

@@ -0,0 +1,44 @@
+import { BBox } from "../../src/Logic/BBox"
+import { Client } from "pg"
+
+/**
+ * Connects with a Postgis database, gives back how much items there are within the given BBOX
+ */
+export default class TilecountServer {
+    private readonly _client: Client
+    private isConnected = false
+
+    constructor(connectionString: string) {
+        this._client = new Client(connectionString)
+    }
+
+    async getCount(layer: string, bbox: BBox = undefined): Promise<number> {
+        if (!this.isConnected) {
+            await this._client.connect()
+            this.isConnected = true
+        }
+
+        let query = "SELECT COUNT(*) FROM " + layer
+
+        if(bbox){
+            query += ` WHERE ST_MakeEnvelope (${bbox.minLon}, ${bbox.minLat}, ${bbox.maxLon}, ${bbox.maxLat}, 4326) ~ geom`
+        }
+console.log(query)
+        const result = await this._client.query(query)
+        return result.rows[0].count
+    }
+
+    disconnect() {
+        this._client.end()
+    }
+}
+
+const tcs = new TilecountServer("postgresql://user:none@localhost:5444/osm-poi")
+console.log(">>>", await tcs.getCount("drinking_water", new BBox([
+    [1.5052013991654007,
+        42.57480750272123,
+    ], [
+        1.6663677350703097,
+        42.499856652770745,
+    ]])))
+tcs.disconnect()