feat: move pmtiles reading to utils

Signed-off-by: Andrew Calcutt <acalcutt@techidiots.net>

src/main.js

@@ -7,9 +7,9 @@ import path from 'path';
 import { fileURLToPath } from 'url';
 import request from 'request';
 import { server } from './server.js';
+import { GetPMtilesInfo } from './utils.js';
 
 import MBTiles from '@mapbox/mbtiles';
-import PMTiles from 'pmtiles';
 
 const __filename = fileURLToPath(import.meta.url);
 const __dirname = path.dirname(__filename);
@@ -102,22 +102,11 @@ const startWithPMTiles = async (pmtilesFile) => {
     console.log(`ERROR: Not valid pmtiles file: ${pmtilesFile}`);
     process.exit(1);
   }
-  const buffer = fs.readFileSync(pmtilesFile)
-  const arrayBuffer = new ArrayBuffer(buffer.length);
-  const view = new Uint8Array(arrayBuffer);
-  for (let i = 0; i < buffer.length; ++i) {
-    view[i] = buffer[i];
-  }
 
-  let source = new PMTilesLocalSource(arrayBuffer);
+  const info = await GetPMtilesInfo(pmtilesFile);
-  let pmtiles = new PMTiles.PMTiles(source);
+  const metadata = info.metadata
 
-  const header = await pmtiles.getHeader();
-  const info = await pmtiles.getMetadata();
-  const bounds = [header.minLat, header.minLon, header.maxLat, header.maxLon]
-  console.log(header);
   console.log(info);
-  console.log(bounds);
 
   const styleDir = path.resolve(
     __dirname,
@@ -138,8 +127,8 @@ const startWithPMTiles = async (pmtilesFile) => {
   };
 
   if (
-    info.format === 'pbf' &&
+    metadata.format === 'pbf' &&
-    info.name.toLowerCase().indexOf('openmaptiles') > -1
+    metadata.name.toLowerCase().indexOf('openmaptiles') > -1
   ) {
     config['data'][`v3`] = {
       mbtiles: path.basename(pmtilesFile),
@@ -153,7 +142,7 @@ const startWithPMTiles = async (pmtilesFile) => {
         config['styles'][styleName] = {
           style: styleFileRel,
           tilejson: {
-            bounds: bounds,
+            bounds: info.bounds,
           },
         };
       }
@@ -163,7 +152,7 @@ const startWithPMTiles = async (pmtilesFile) => {
       `WARN: MBTiles not in "openmaptiles" format. Serving raw data only...`,
     );
     config['data'][
-      (info.id || 'mbtiles')
+      (metadata.id || 'mbtiles')
         .replace(/\//g, '_')
         .replace(/:/g, '_')
         .replace(/\?/g, '_')

src/utils.js

@@ -5,6 +5,7 @@ import fs from 'node:fs';
 
 import clone from 'clone';
 import glyphCompose from '@mapbox/glyph-pbf-composite';
+import PMTiles from 'pmtiles';
 
 /**
  * Generate new URL object
@@ -163,3 +164,32 @@ export const getFontsPbf = (
 
   return Promise.all(queue).then((values) => glyphCompose.combine(values));
 };
+
+const PMTilesLocalSource = class {
+  constructor(file) {
+    this.file = file;
+  }
+  getKey() {
+    return this.file.name;
+  }
+  async getBytes(offset, length) {
+    const blob = this.file.slice(offset, offset + length);
+    return { data: blob };
+  }
+};
+
+export const GetPMtilesInfo = async (pmtilesFile) => {
+  const buffer = fs.readFileSync(pmtilesFile)
+  const arrayBuffer = new ArrayBuffer(buffer.length);
+  const view = new Uint8Array(arrayBuffer);
+  for (let i = 0; i < buffer.length; ++i) {
+    view[i] = buffer[i];
+  }
+  let source = new PMTilesLocalSource(arrayBuffer);
+  let pmtiles = new PMTiles.PMTiles(source);
+
+  const header = await pmtiles.getHeader();
+  const metadata = await pmtiles.getMetadata();
+  const bounds = [header.minLat, header.minLon, header.maxLat, header.maxLon]
+  return { header: header, metadata: metadata, bounds: bounds };
+}