feat: move pmtiles to it's own file

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

src/main.js

@@ -7,9 +7,8 @@ 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 { GetPMtilesInfo } from './pmtiles_adapter.js';
 
 const __filename = fileURLToPath(import.meta.url);
 const __dirname = path.dirname(__filename);
@@ -104,7 +103,7 @@ const startWithPMTiles = async (pmtilesFile) => {
   }
 
   const info = await GetPMtilesInfo(pmtilesFile);
-  const metadata = info.metadata
+  const metadata = info.metadata;
 
   console.log(info);
 
@@ -168,7 +167,6 @@ const startWithPMTiles = async (pmtilesFile) => {
   }
 
   return startServer(null, config);
-
 };
 
 const startWithMBTiles = (mbtilesFile) => {

src/pmtiles_adapter.js

@@ -0,0 +1,304 @@
+import fs from 'node:fs';
+import * as fflate from 'fflate';
+import PMTiles from 'pmtiles';
+
+export const GetPMtilesHeader = async (pmtilesFile) => {
+  var buffer = await ReadBytes(pmtilesFile, 0, 127);
+  const header = PMTiles.bytesToHeader(buffer, undefined);
+  return header;
+};
+
+export const GetPMtilesInfo = async (pmtilesFile) => {
+  //Get metadata from pmtiles file
+  var header = await GetPMtilesHeader(pmtilesFile);
+  const metadataBytes = await ReadBytes(
+    pmtilesFile,
+    header.jsonMetadataOffset,
+    header.jsonMetadataLength,
+  );
+  const metadataDecomp = await GetPMtilesDecompress(header, metadataBytes);
+  const dec = new TextDecoder('utf-8');
+  const metadata = JSON.parse(dec.decode(metadataDecomp));
+
+  //Add missing metadata from header
+  metadata['format'] = GetPmtilesTileType(header.tileType).type;
+
+  if (
+    header.minLat != 0 &&
+    header.minLon != 0 &&
+    header.maxLat != 0 &&
+    header.maxLon != 0
+  ) {
+    const bounds = [header.minLat, header.minLon, header.maxLat, header.maxLon];
+    metadata['bounds'] = bounds;
+  }
+  if (header.centerLon != 0 && header.centerLat != 0) {
+    const center = [header.centerLon, header.centerLat, header.centerLat];
+    metadata['center'] = center;
+  }
+  metadata['minzoom'] = header.minZoom;
+  metadata['maxzoom'] = header.maxZoom;
+
+  return { header: header, metadata: metadata };
+};
+
+export const GetPMtilesTile = async (pmtilesFile, z, x, y) => {
+  const tile_id = PMTiles.zxyToTileId(z, x, y);
+  const header = await GetPMtilesHeader(pmtilesFile);
+
+  if (z < header.minZoom || z > header.maxZoom) {
+    return undefined;
+  }
+
+  let rootDirectoryOffset = header.rootDirectoryOffset;
+  let rootDirectoryLength = header.rootDirectoryLength;
+  for (let depth = 0; depth <= 3; depth++) {
+    const RootDirectoryBytes = await ReadBytes(
+      pmtilesFile,
+      rootDirectoryOffset,
+      rootDirectoryLength,
+    );
+    const RootDirectoryBytesaDecomp = await GetPMtilesDecompress(
+      header,
+      RootDirectoryBytes,
+    );
+    const Directory = deserializeIndex(RootDirectoryBytesaDecomp);
+    const entry = PMTiles.findTile(Directory, tile_id);
+    if (entry) {
+      if (entry.runLength > 0) {
+        const EntryBytesArrayBuff = await ReadBytes(
+          pmtilesFile,
+          header.tileDataOffset + entry.offset,
+          entry.length,
+        );
+        const EntryBytes = ArrayBufferToBuffer(EntryBytesArrayBuff);
+        const EntryTileType = GetPmtilesTileType(header.tileType);
+        return { data: EntryBytes, header: EntryTileType.header };
+      } else {
+        rootDirectoryOffset = header.leafDirectoryOffset + entry.offset;
+        rootDirectoryLength = entry.length;
+      }
+    } else {
+      return undefined;
+    }
+  }
+};
+
+/**
+ *
+ * @param typenum
+ */
+function GetPmtilesTileType(typenum) {
+  let head = {};
+  let tileType;
+  switch (typenum) {
+    case 0:
+      tileType = 'Unknown';
+      break;
+    case 1:
+      tileType = 'pbf';
+      head['Content-Type'] = 'application/x-protobuf';
+      break;
+    case 2:
+      tileType = 'png';
+      head['Content-Type'] = 'image/png';
+      break;
+    case 3:
+      tileType = 'jpg';
+      head['Content-Type'] = 'image/jpeg';
+      break;
+    case 4:
+      tileType = 'webp';
+      head['Content-Type'] = 'image/webp';
+      break;
+    case 5:
+      tileType = 'avif';
+      head['Content-Type'] = 'image/avif';
+      break;
+  }
+  return { type: tileType, header: head };
+}
+/**
+ *
+ * @param buffer
+ */
+function BufferToArrayBuffer(buffer) {
+  const arrayBuffer = new ArrayBuffer(buffer.length);
+  const view = new Uint8Array(arrayBuffer);
+  for (let i = 0; i < buffer.length; ++i) {
+    view[i] = buffer[i];
+  }
+  return arrayBuffer;
+}
+
+/**
+ *
+ * @param ab
+ */
+function ArrayBufferToBuffer(ab) {
+  var buffer = Buffer.alloc(ab.byteLength);
+  var view = new Uint8Array(ab);
+  for (var i = 0; i < buffer.length; ++i) {
+    buffer[i] = view[i];
+  }
+  return buffer;
+}
+
+const ReadBytes = async (filePath, offset, size) => {
+  const sharedBuffer = Buffer.alloc(size);
+  const stats = fs.statSync(filePath); // file details
+  const fd = fs.openSync(filePath); // file descriptor
+  let bytesRead = 0; // how many bytes were read
+  let end = size;
+
+  for (let i = 0; i < size; i++) {
+    let postion = offset + i;
+    await ReadFileBytes(fd, sharedBuffer, postion);
+    bytesRead = (i + 1) * size;
+    if (bytesRead > stats.size) {
+      // When we reach the end of file,
+      // we have to calculate how many bytes were actually read
+      end = size - (bytesRead - stats.size);
+    }
+    if (bytesRead === size) {
+      break;
+    }
+  }
+
+  return BufferToArrayBuffer(sharedBuffer);
+};
+
+/**
+ *
+ * @param fd
+ * @param sharedBuffer
+ * @param offset
+ */
+function ReadFileBytes(fd, sharedBuffer, offset) {
+  return new Promise((resolve, reject) => {
+    fs.read(fd, sharedBuffer, 0, sharedBuffer.length, offset, (err) => {
+      if (err) {
+        return reject(err);
+      }
+      resolve();
+    });
+  });
+}
+
+export const GetPMtilesDecompress = async (header, buffer) => {
+  const compression = header.internalCompression;
+  var decompressed;
+  if (
+    compression === PMTiles.Compression.None ||
+    compression === PMTiles.Compression.Unknown
+  ) {
+    decompressed = buffer;
+  } else if (compression === PMTiles.Compression.Gzip) {
+    decompressed = fflate.decompressSync(new Uint8Array(buffer));
+  } else {
+    throw Error('Compression method not supported');
+  }
+
+  return decompressed;
+};
+
+/**
+ *
+ * @param low
+ * @param high
+ */
+function toNum(low, high) {
+  return (high >>> 0) * 0x100000000 + (low >>> 0);
+}
+
+/**
+ *
+ * @param l
+ * @param p
+ */
+function readVarintRemainder(l, p) {
+  const buf = p.buf;
+  let h, b;
+  b = buf[p.pos++];
+  h = (b & 0x70) >> 4;
+  if (b < 0x80) return toNum(l, h);
+  b = buf[p.pos++];
+  h |= (b & 0x7f) << 3;
+  if (b < 0x80) return toNum(l, h);
+  b = buf[p.pos++];
+  h |= (b & 0x7f) << 10;
+  if (b < 0x80) return toNum(l, h);
+  b = buf[p.pos++];
+  h |= (b & 0x7f) << 17;
+  if (b < 0x80) return toNum(l, h);
+  b = buf[p.pos++];
+  h |= (b & 0x7f) << 24;
+  if (b < 0x80) return toNum(l, h);
+  b = buf[p.pos++];
+  h |= (b & 0x01) << 31;
+  if (b < 0x80) return toNum(l, h);
+  throw new Error('Expected varint not more than 10 bytes');
+}
+
+/**
+ *
+ * @param p
+ */
+export function readVarint(p) {
+  const buf = p.buf;
+  let val, b;
+
+  b = buf[p.pos++];
+  val = b & 0x7f;
+  if (b < 0x80) return val;
+  b = buf[p.pos++];
+  val |= (b & 0x7f) << 7;
+  if (b < 0x80) return val;
+  b = buf[p.pos++];
+  val |= (b & 0x7f) << 14;
+  if (b < 0x80) return val;
+  b = buf[p.pos++];
+  val |= (b & 0x7f) << 21;
+  if (b < 0x80) return val;
+  b = buf[p.pos];
+  val |= (b & 0x0f) << 28;
+
+  return readVarintRemainder(val, p);
+}
+
+/**
+ *
+ * @param buffer
+ */
+function deserializeIndex(buffer) {
+  const p = { buf: new Uint8Array(buffer), pos: 0 };
+  const numEntries = readVarint(p);
+
+  var entries = [];
+
+  let lastId = 0;
+  for (let i = 0; i < numEntries; i++) {
+    const v = readVarint(p);
+    entries.push({ tileId: lastId + v, offset: 0, length: 0, runLength: 1 });
+    lastId += v;
+  }
+
+  for (let i = 0; i < numEntries; i++) {
+    entries[i].runLength = readVarint(p);
+  }
+
+  for (let i = 0; i < numEntries; i++) {
+    entries[i].length = readVarint(p);
+  }
+
+  for (let i = 0; i < numEntries; i++) {
+    const v = readVarint(p);
+    if (v === 0 && i > 0) {
+      entries[i].offset = entries[i - 1].offset + entries[i - 1].length;
+    } else {
+      entries[i].offset = v - 1;
+    }
+  }
+
+  return entries;
+}

src/serve_data.js

@@ -7,11 +7,11 @@ import zlib from 'zlib';
 import clone from 'clone';
 import express from 'express';
 import MBTiles from '@mapbox/mbtiles';
-import PMTiles from 'pmtiles';
 import Pbf from 'pbf';
 import { VectorTile } from '@mapbox/vector-tile';
 
-import { getTileUrls, fixTileJSONCenter, GetPMtilesInfo, GetPMtilesTile } from './utils.js';
+import { getTileUrls, fixTileJSONCenter } from './utils.js';
+import { GetPMtilesInfo, GetPMtilesTile } from './pmtiles_adapter.js';
 
 export const serve_data = {
   init: (options, repo) => {
@@ -54,10 +54,10 @@ export const serve_data = {
         if (tileJSONExtension === 'pmtiles') {
           let isGzipped;
           let tileinfo = await GetPMtilesTile(item.source, z, x, y);
-          let data = tileinfo.data
-          let headers = tileinfo.header
-          console.log(data)
-          console.log(headers)
+          let data = tileinfo.data;
+          let headers = tileinfo.header;
+          console.log(data);
+          console.log(headers);
           if (data == undefined) {
             return res.status(404).send('Not found');
           } else {
@@ -109,75 +109,73 @@ export const serve_data = {
 
             return res.status(200).send(data);
           }
-
         } else {
-        item.source.getTile(z, x, y, (err, data, headers) => {
-          let isGzipped;
-          if (err) {
-            if (/does not exist/.test(err.message)) {
-              return res.status(204).send();
+          item.source.getTile(z, x, y, (err, data, headers) => {
+            let isGzipped;
+            if (err) {
+              if (/does not exist/.test(err.message)) {
+                return res.status(204).send();
+              } else {
+                return res
+                  .status(500)
+                  .header('Content-Type', 'text/plain')
+                  .send(err.message);
+              }
             } else {
-              return res
-                .status(500)
-                .header('Content-Type', 'text/plain')
-                .send(err.message);
-            }
-          } else {
-            if (data == null) {
-              return res.status(404).send('Not found');
-            } else {
-              if (tileJSONFormat === 'pbf') {
-                isGzipped =
-                  data.slice(0, 2).indexOf(Buffer.from([0x1f, 0x8b])) === 0;
-                if (options.dataDecoratorFunc) {
+              if (data == null) {
+                return res.status(404).send('Not found');
+              } else {
+                if (tileJSONFormat === 'pbf') {
+                  isGzipped =
+                    data.slice(0, 2).indexOf(Buffer.from([0x1f, 0x8b])) === 0;
+                  if (options.dataDecoratorFunc) {
+                    if (isGzipped) {
+                      data = zlib.unzipSync(data);
+                      isGzipped = false;
+                    }
+                    data = options.dataDecoratorFunc(id, 'data', data, z, x, y);
+                  }
+                }
+                if (format === 'pbf') {
+                  headers['Content-Type'] = 'application/x-protobuf';
+                } else if (format === 'geojson') {
+                  headers['Content-Type'] = 'application/json';
+
                   if (isGzipped) {
                     data = zlib.unzipSync(data);
                     isGzipped = false;
                   }
-                  data = options.dataDecoratorFunc(id, 'data', data, z, x, y);
-                }
-              }
-              if (format === 'pbf') {
-                headers['Content-Type'] = 'application/x-protobuf';
-              } else if (format === 'geojson') {
-                headers['Content-Type'] = 'application/json';
 
-                if (isGzipped) {
-                  data = zlib.unzipSync(data);
-                  isGzipped = false;
-                }
-
-                const tile = new VectorTile(new Pbf(data));
-                const geojson = {
-                  type: 'FeatureCollection',
-                  features: [],
-                };
-                for (const layerName in tile.layers) {
-                  const layer = tile.layers[layerName];
-                  for (let i = 0; i < layer.length; i++) {
-                    const feature = layer.feature(i);
-                    const featureGeoJSON = feature.toGeoJSON(x, y, z);
-                    featureGeoJSON.properties.layer = layerName;
-                    geojson.features.push(featureGeoJSON);
+                  const tile = new VectorTile(new Pbf(data));
+                  const geojson = {
+                    type: 'FeatureCollection',
+                    features: [],
+                  };
+                  for (const layerName in tile.layers) {
+                    const layer = tile.layers[layerName];
+                    for (let i = 0; i < layer.length; i++) {
+                      const feature = layer.feature(i);
+                      const featureGeoJSON = feature.toGeoJSON(x, y, z);
+                      featureGeoJSON.properties.layer = layerName;
+                      geojson.features.push(featureGeoJSON);
+                    }
                   }
+                  data = JSON.stringify(geojson);
                 }
-                data = JSON.stringify(geojson);
-              }
-              delete headers['ETag']; // do not trust the tile ETag -- regenerate
-              headers['Content-Encoding'] = 'gzip';
-              res.set(headers);
+                delete headers['ETag']; // do not trust the tile ETag -- regenerate
+                headers['Content-Encoding'] = 'gzip';
+                res.set(headers);
 
-              if (!isGzipped) {
-                data = zlib.gzipSync(data);
-                isGzipped = true;
-              }
+                if (!isGzipped) {
+                  data = zlib.gzipSync(data);
+                  isGzipped = true;
+                }
 
-              return res.status(200).send(data);
+                return res.status(200).send(data);
+              }
             }
-          }
-          
-        });
-      }
+          });
+        }
       },
     );
 

src/serve_rendered.js

@@ -18,7 +18,8 @@ import MBTiles from '@mapbox/mbtiles';
 import polyline from '@mapbox/polyline';
 import proj4 from 'proj4';
 import request from 'request';
-import { getFontsPbf, getTileUrls, fixTileJSONCenter, GetPMtilesInfo } from './utils.js';
+import { getFontsPbf, getTileUrls, fixTileJSONCenter } from './utils.js';
+import { GetPMtilesInfo } from './pmtiles_adapter.js';
 
 const FLOAT_PATTERN = '[+-]?(?:\\d+|\\d+.?\\d+)';
 const PATH_PATTERN =
@@ -1451,7 +1452,8 @@ export const serve_rendered = {
             // how to do this for multiple sources with different proj4 defs?
             const to3857 = proj4('EPSG:3857');
             const toDataProj = proj4(metadata.proj4);
-            repoobj.dataProjWGStoInternalWGS = (xy) => to3857.inverse(toDataProj.forward(xy));
+            repoobj.dataProjWGStoInternalWGS = (xy) =>
+              to3857.inverse(toDataProj.forward(xy));
           }
 
           const type = source.type;
@@ -1465,9 +1467,11 @@ export const serve_rendered = {
           delete source.scheme;
           console.log(source);
 
-          if (!attributionOverride &&
+          if (
+            !attributionOverride &&
             source.attribution &&
-            source.attribution.length > 0) {
+            source.attribution.length > 0
+          ) {
             if (!tileJSON.attribution.includes(source.attribution)) {
               if (tileJSON.attribution.length > 0) {
                 tileJSON.attribution += ' | ';
@@ -1483,52 +1487,59 @@ export const serve_rendered = {
               if (!mbtilesFileStats.isFile() || mbtilesFileStats.size === 0) {
                 throw Error(`Not valid MBTiles file: ${mbtilesFile}`);
               }
-              map.sources[name] = new MBTiles(mbtilesFile + '?mode=ro', (err) => {
-                map.sources[name].getInfo((err, info) => {
-                  if (err) {
-                    console.error(err);
-                    return;
-                  }
-  
-                  if (!repoobj.dataProjWGStoInternalWGS && info.proj4) {
-                    // how to do this for multiple sources with different proj4 defs?
-                    const to3857 = proj4('EPSG:3857');
-                    const toDataProj = proj4(info.proj4);
-                    repoobj.dataProjWGStoInternalWGS = (xy) =>
-                      to3857.inverse(toDataProj.forward(xy));
-                  }
-  
-                  const type = source.type;
-                  info['extension'] = 'mbtiles';
-                  Object.assign(source, info);
-                  source.type = type;
-                  source.tiles = [
-                    // meta url which will be detected when requested
-                    `mbtiles://${name}/{z}/{x}/{y}.${info.format || 'pbf'}`,
-                  ];
-                  delete source.scheme;
-  
-                  if (options.dataDecoratorFunc) {
-                    source = options.dataDecoratorFunc(name, 'tilejson', source);
-                  }
-  
-                  if (
-                    !attributionOverride &&
-                    source.attribution &&
-                    source.attribution.length > 0
-                  ) {
-                    if (!tileJSON.attribution.includes(source.attribution)) {
-                      if (tileJSON.attribution.length > 0) {
-                        tileJSON.attribution += ' | ';
-                      }
-                      tileJSON.attribution += source.attribution;
+              map.sources[name] = new MBTiles(
+                mbtilesFile + '?mode=ro',
+                (err) => {
+                  map.sources[name].getInfo((err, info) => {
+                    if (err) {
+                      console.error(err);
+                      return;
                     }
-                  }
-                  resolve();
-                });
-              });
+
+                    if (!repoobj.dataProjWGStoInternalWGS && info.proj4) {
+                      // how to do this for multiple sources with different proj4 defs?
+                      const to3857 = proj4('EPSG:3857');
+                      const toDataProj = proj4(info.proj4);
+                      repoobj.dataProjWGStoInternalWGS = (xy) =>
+                        to3857.inverse(toDataProj.forward(xy));
+                    }
+
+                    const type = source.type;
+                    info['extension'] = 'mbtiles';
+                    Object.assign(source, info);
+                    source.type = type;
+                    source.tiles = [
+                      // meta url which will be detected when requested
+                      `mbtiles://${name}/{z}/{x}/{y}.${info.format || 'pbf'}`,
+                    ];
+                    delete source.scheme;
+
+                    if (options.dataDecoratorFunc) {
+                      source = options.dataDecoratorFunc(
+                        name,
+                        'tilejson',
+                        source,
+                      );
+                    }
+
+                    if (
+                      !attributionOverride &&
+                      source.attribution &&
+                      source.attribution.length > 0
+                    ) {
+                      if (!tileJSON.attribution.includes(source.attribution)) {
+                        if (tileJSON.attribution.length > 0) {
+                          tileJSON.attribution += ' | ';
+                        }
+                        tileJSON.attribution += source.attribution;
+                      }
+                    }
+                    resolve();
+                  });
+                },
+              );
             }),
-          )
+          );
         }
       }
     }

src/utils.js

@@ -2,11 +2,8 @@
 
 import path from 'path';
 import fs from 'node:fs';
-import * as fflate from 'fflate';
-
 import clone from 'clone';
 import glyphCompose from '@mapbox/glyph-pbf-composite';
-import PMTiles from 'pmtiles';
 
 /**
  * Generate new URL object
@@ -165,286 +162,3 @@ export const getFontsPbf = (
 
   return Promise.all(queue).then((values) => glyphCompose.combine(values));
 };
-
-function ReadFileBytes(fd, sharedBuffer, offset) {
-  return new Promise((resolve, reject) => {
-      fs.read(
-          fd, 
-          sharedBuffer,
-          0,
-          sharedBuffer.length,
-          offset,
-          (err) => {
-              if(err) { return reject(err); }
-              resolve();
-          }
-      );
-  });
-}
-
-const ReadBytes = async (filePath, offset, size) => {
-  const sharedBuffer = Buffer.alloc(size);
-  const stats = fs.statSync(filePath); // file details
-  const fd = fs.openSync(filePath); // file descriptor
-  let bytesRead = 0; // how many bytes were read
-  let end = size; 
-  
-  for(let i = 0; i < size; i++) {
-      let postion = offset + i
-      await ReadFileBytes(fd, sharedBuffer, postion);
-      bytesRead = (i + 1) * size;
-      if(bytesRead > stats.size) {
-         // When we reach the end of file, 
-         // we have to calculate how many bytes were actually read
-         end = size - (bytesRead - stats.size);
-      }
-      if(bytesRead === size) {break;}
-  }
-
-  return BufferToArrayBuffer(sharedBuffer);
-}
-
-function BufferToArrayBuffer(buffer) {
-  const arrayBuffer = new ArrayBuffer(buffer.length);
-  const view = new Uint8Array(arrayBuffer);
-  for (let i = 0; i < buffer.length; ++i) {
-    view[i] = buffer[i];
-  }
-  return arrayBuffer;
-}
-
-function ArrayBufferToBuffer(ab) {
-  var buffer = Buffer.alloc(ab.byteLength);
-  var view = new Uint8Array(ab);
-  for (var i = 0; i < buffer.length; ++i) {
-      buffer[i] = view[i];
-  }
-  return buffer;
-}
-
-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 GetPMtilesHeader = async (pmtilesFile) => {
-  var buffer = await ReadBytes(pmtilesFile, 0, 127)
-  const header = PMTiles.bytesToHeader(buffer, undefined)
-  return header
-}
-
-export const GetPMtilesDecompress = async (header, buffer) => {
-  const compression = header.internalCompression;
-  var decompressed;
-  if (compression === PMTiles.Compression.None || compression === PMTiles.Compression.Unknown) {
-    decompressed = buffer;
-  } else if (compression === PMTiles.Compression.Gzip) {
-    decompressed = fflate.decompressSync(new Uint8Array(buffer));
-  } else {
-    throw Error("Compression method not supported");
-  }
-
-  return decompressed
-}
-
-export const GetPMtilesInfo = async (pmtilesFile) => {
-  var header = await GetPMtilesHeader(pmtilesFile)
-  const jsonMetadataOffset = header.jsonMetadataOffset;
-  const jsonMetadataLength = header.jsonMetadataLength;
-  const compression = header.internalCompression;
-  const metadataBytes = await ReadBytes(pmtilesFile, jsonMetadataOffset, jsonMetadataLength)
-  const metadataDecomp = await GetPMtilesDecompress(header, metadataBytes)
-  const dec = new TextDecoder("utf-8");
-  const metadata = JSON.parse(dec.decode(metadataDecomp));
-
-  var tileType
-  switch (header.tileType) {
-    case 0:
-      tileType = "Unknown"
-      break;
-    case 1:
-      tileType = "pbf"
-      break;
-    case 2:
-      tileType = "png"
-      break;
-    case 3:
-      tileType = "jpg"
-      break;
-    case 4:
-      tileType = "webp"
-      break;
-    case 5:
-      tileType = "avif"
-      break;
-  }
-  metadata['format'] = tileType;
-
-  if(header.minLat != 0 && header.minLon != 0 && header.maxLat != 0 && header.maxLon != 0) {
-    const bounds = [header.minLat, header.minLon, header.maxLat, header.maxLon]
-    metadata['bounds'] = bounds;
-  }
-  if(header.centerLon != 0 && header.centerLat != 0) {
-    const center = [header.centerLon, header.centerLat, header.centerLat]
-    metadata['center'] = center;
-  }
-  metadata['minzoom'] = header.minZoom;
-  metadata['maxzoom'] = header.maxZoom;
-
-  return { header: header, metadata: metadata };
-}
-
-function toNum(low, high) {
-  return (high >>> 0) * 0x100000000 + (low >>> 0);
-}
-
-function readVarintRemainder(l, p) {
-  const buf = p.buf;
-  let h, b;
-  b = buf[p.pos++];
-  h = (b & 0x70) >> 4;
-  if (b < 0x80) return toNum(l, h);
-  b = buf[p.pos++];
-  h |= (b & 0x7f) << 3;
-  if (b < 0x80) return toNum(l, h);
-  b = buf[p.pos++];
-  h |= (b & 0x7f) << 10;
-  if (b < 0x80) return toNum(l, h);
-  b = buf[p.pos++];
-  h |= (b & 0x7f) << 17;
-  if (b < 0x80) return toNum(l, h);
-  b = buf[p.pos++];
-  h |= (b & 0x7f) << 24;
-  if (b < 0x80) return toNum(l, h);
-  b = buf[p.pos++];
-  h |= (b & 0x01) << 31;
-  if (b < 0x80) return toNum(l, h);
-  throw new Error("Expected varint not more than 10 bytes");
-}
-
-export function readVarint(p) {
-  const buf = p.buf;
-  let val, b;
-
-  b = buf[p.pos++];
-  val = b & 0x7f;
-  if (b < 0x80) return val;
-  b = buf[p.pos++];
-  val |= (b & 0x7f) << 7;
-  if (b < 0x80) return val;
-  b = buf[p.pos++];
-  val |= (b & 0x7f) << 14;
-  if (b < 0x80) return val;
-  b = buf[p.pos++];
-  val |= (b & 0x7f) << 21;
-  if (b < 0x80) return val;
-  b = buf[p.pos];
-  val |= (b & 0x0f) << 28;
-
-  return readVarintRemainder(val, p);
-}
-
-function deserializeIndex(buffer) {
-  const p = { buf: new Uint8Array(buffer), pos: 0 };
-  const numEntries = readVarint(p);
-
-  var entries = [];
-
-  let lastId = 0;
-  for (let i = 0; i < numEntries; i++) {
-    const v = readVarint(p);
-    entries.push({ tileId: lastId + v, offset: 0, length: 0, runLength: 1 });
-    lastId += v;
-  }
-
-  for (let i = 0; i < numEntries; i++) {
-    entries[i].runLength = readVarint(p);
-  }
-
-  for (let i = 0; i < numEntries; i++) {
-    entries[i].length = readVarint(p);
-  }
-
-  for (let i = 0; i < numEntries; i++) {
-    const v = readVarint(p);
-    if (v === 0 && i > 0) {
-      entries[i].offset = entries[i - 1].offset + entries[i - 1].length;
-    } else {
-      entries[i].offset = v - 1;
-    }
-  }
-
-  return entries;
-}
-
-export const GetPMtilesTile = async (pmtilesFile, z, x, y) => {
-  const tile_id = PMTiles.zxyToTileId(z, x, y);
-  const header = await GetPMtilesHeader(pmtilesFile)
-
-  if (z < header.minZoom || z > header.maxZoom) {
-    return undefined;
-  }
-
-  let rootDirectoryOffset = header.rootDirectoryOffset;
-  let rootDirectoryLength = header.rootDirectoryLength;
-  for (let depth = 0; depth <= 3; depth++) {
-    const RootDirectoryBytes = await ReadBytes(pmtilesFile, rootDirectoryOffset, rootDirectoryLength)
-    const RootDirectoryBytesaDecomp = await GetPMtilesDecompress(header, RootDirectoryBytes)
-    const Directory = deserializeIndex(RootDirectoryBytesaDecomp)
-    const entry = PMTiles.findTile(Directory, tile_id);
-    if (entry) {
-      if (entry.runLength > 0) {
-        const EntryBytesArrayBuff = await ReadBytes(pmtilesFile, header.tileDataOffset + entry.offset, entry.length)
-        const EntryBytes = ArrayBufferToBuffer(EntryBytesArrayBuff)
-        //const EntryDecomp = await GetPMtilesDecompress(header, EntryBytes)
-        const EntryTileType = GetPmtilesTileType(header.tileType)
-        return {data: EntryBytes, header: EntryTileType.header}
-
-      } else {
-        rootDirectoryOffset = header.leafDirectoryOffset + entry.offset;
-        rootDirectoryLength = entry.length;
-      }
-    } else {
-      return undefined;
-    }
-  }
-}
-
-function GetPmtilesTileType(typenum) {
-  let head = {};
-  let tileType
-  switch (typenum) {
-    case 0:
-      tileType = "Unknown"
-      break;
-    case 1:
-      tileType = "pbf"
-      head['Content-Type'] = 'application/x-protobuf';
-      break;
-    case 2:
-      tileType = "png"
-      head['Content-Type'] = 'image/png';
-      break;
-    case 3:
-      tileType = "jpg"
-      head['Content-Type'] = 'image/jpeg';
-      break;
-    case 4:
-      tileType = "webp"
-      head['Content-Type'] = 'image/webp';
-      break;
-    case 5:
-      tileType = "avif"
-      head['Content-Type'] = 'image/avif';
-      break;
-  }
-  return {type: tileType, header: head}
-}