support local mbtiles

mapbox · Jul 25, 2015 · f945449 · f945449
1 parent f0d2b20
commit f945449
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Showing 2 changed files with 83 additions and 31 deletions.
diff --git a/index.js b/index.js
@@ -9,11 +9,14 @@ var queue = require('queue-async');
 var request = require('request');
 var VectorTile = require('vector-tile').VectorTile;
 var Pbf = require('pbf');
+var MBTiles = require('mbtiles');
+var zlib = require('zlib');
 
 module.exports = function (coverArea, opts){
   var workers = [];
   var tilesCompleted = 0;
   var ee = new EventEmitter();
+  var dbs = {};
 
   // compute cover
   var tiles = computeCover(coverArea, opts.zoom);
@@ -51,52 +54,80 @@ module.exports = function (coverArea, opts){
   return ee;
 };
 
-function getVectorTile(tile, tileLayer, done){
-  var layers = {
-    name:tileLayer.name,
-    layers:tileLayer.layers
-  };
-
+function getRemoteVectorTile(tile, tileLayer, done){
   var url = tileLayer.url.split('{x}').join(tile[0]);
   url = url.split('{y}').join(tile[1]);
-  url = url.split('{z}').join(tile[2]);
+  url = url.split('{z}').join(tile[2])
 
   var requestOpts = {
     url: url,
     gzip: true,
     encoding: null
   };
   request(requestOpts, function(err, res, body) {
-    var vt;
-    try {
-      vt = new VectorTile(new Pbf(new Uint8Array(body)));
-    } catch(e){
-      done(e, null);
-    }
-    tileLayer.layers.forEach(function(layer){
-      layers[layer] = turf.featurecollection([]);
-      if(vt && vt.layers[layer]){
-        for(var i = 0; i < vt.layers[layer].length; i++){
-          try {
-            layers[layer].features.push(vt.layers[layer].feature(i).toGeoJSON(tile[0],tile[1],tile[2]));
-          } catch(e){
-            done(e, null);
-          }
+    getTileFeatures(tile, body, tileLayer, done);
+  });
+}
+
+function getLocalVectorTile(tile, tileLayer, dbs, done){
+  var tilename = tileLayer.mbtiles.split('.')[0];
+
+  dbs[tilename].getTile(tile[2],tile[0],tile[1],function(err, data) {
+    if (err) throw err;
+    zlib.unzip(data, function(err, body) {
+      getTileFeatures(tile, body, tileLayer, done);
+    });
+  });
+}
+
+function getTileFeatures(tile, data, tileLayer, cb){
+  var layers = {
+    name:tileLayer.name,
+    layers:tileLayer.layers
+  };
+
+  var vt;
+  try {
+    vt = new VectorTile(new Pbf(new Uint8Array(data)));
+  } catch(e) {
+    cb(e, null);
+  }
+
+  tileLayer.layers.forEach(function(layer){
+    layers[layer] = turf.featurecollection([]);
+    if (vt && vt.layers[layer]) {
+      for (var i = 0; i < vt.layers[layer].length; i++) {
+        try {
+          layers[layer].features.push(vt.layers[layer].feature(i).toGeoJSON(tile[0],tile[1],tile[2]));
+        } catch(e) {
+          cb(e, null);
         }
       }
-    });
+    }
+  });
+
+  cb(null, layers);
+}
 
-    done(null, layers);
+function loadTiles(mbtile, dbs, done){
+  new MBTiles(mbtile, function(err, src) {
+    if (err) throw err;
+    dbs[mbtile.split('.')[0]] = src;
+    done(err, null);
   });
 }
 
-function sendData (tiles, workers, opts) {
-  if(!opts.maxrate || opts.maxrate > 200) opts.maxrate = 200;
-  var getData = rateLimit(opts.maxrate / opts.tileLayers.length, 1000, function(tile){
+function sendData (tiles, workers, opts){
+  var dbs = {};
+  var rl = false;
+  var q = queue(4);
+
+  var getData = function(tile){
     var layerCollection = {};
     var q = queue(4);
     opts.tileLayers.forEach(function(tileLayer){
-      q.defer(getVectorTile, tile, tileLayer);
+      if (tileLayer.url) q.defer(getRemoteVectorTile, tile, tileLayer);
+      if (tileLayer.mbtiles) q.defer(getLocalVectorTile, tile, tileLayer, dbs);
     });
     q.awaitAll(function(err, res){
       if(res){
@@ -113,9 +144,26 @@ function sendData (tiles, workers, opts) {
         });
       }
     });
+  }
+
+  opts.tileLayers.forEach(function(tl){
+    if (tl.url || opts.maxrate) rl = true;
+    if (tl.mbtiles) {
+      q.defer(loadTiles, tl.mbtiles, dbs);
+    }
   });
-  tiles.forEach(function(tile){
-    getData(tile);
+
+  q.awaitAll(function(err, res){
+    if (rl) {
+      if(!opts.maxrate || opts.maxrate > 200) opts.maxrate = 200;
+      tiles.forEach(function(tile){
+        rateLimit(opts.maxrate / opts.tileLayers.length, 1000, getData(tile));
+      });
+    } else {
+      tiles.forEach(function(tile){
+        getData(tile);
+      });
+    }
   });
 }
 
@@ -200,4 +248,7 @@ module.exports.isValidTile = isValidTile;
 module.exports.tilesToZoom = tilesToZoom;
 module.exports.sendData = sendData;
 module.exports.sendTiles = sendTiles;
-module.exports.getVectorTile = getVectorTile;
+module.exports.loadTiles = loadTiles;
+module.exports.getRemoteVectorTile = getRemoteVectorTile;
+module.exports.getLocalVectorTile = getLocalVectorTile;
+module.exports.getTileFeatures = getTileFeatures;
diff --git a/package.json b/package.json
@@ -27,6 +27,7 @@
     "function-rate-limit": "^1.0.1",
     "geojson-flatten": "^0.1.0",
     "geojson-normalize": "0.0.0",
+    "mbtiles": "^0.8.0",
     "pbf": "^1.3.2",
     "queue-async": "^1.0.7",
     "request": "^2.54.0",