support for wx mini program

src/environment.ts

@@ -456,7 +456,7 @@ function getGlobalNamespace(): {ENV: Environment} {
   } else if (typeof (process) !== 'undefined') {
     ns = process;
   } else {
-    throw new Error('Could not find a global object');
+    ns = global;
   }
   return ns;
 }

src/io/browser_http.ts

@@ -26,6 +26,7 @@ import {concatenateArrayBuffers, getModelArtifactsInfoForJSON} from './io_utils'
 import {IORouter, IORouterRegistry} from './router_registry';
 import {IOHandler, ModelArtifacts, SaveResult, WeightsManifestConfig, WeightsManifestEntry} from './types';
 import {loadWeightsAsArrayBuffer} from './weights_loader';
+import {fetch} from '../mp_util';
 
 export class BrowserHTTPRequest implements IOHandler {
   protected readonly path: string|string[];

src/io/weights_loader.ts

@@ -17,6 +17,7 @@
 
 import {NamedTensorMap} from '../tensor_types';
 import * as util from '../util';
+import {fetch} from '../mp_util';
 
 import {decodeWeights} from './io_utils';
 import {DTYPE_VALUE_SIZE_MAP, WeightsManifestConfig, WeightsManifestEntry} from './types';

src/mp_util.ts

@@ -0,0 +1,63 @@
+/// <reference path="./wx.d.ts">
+function generateResponse(res:any) {
+  let header = res.header || {};
+  return {
+    ok: ((res.statusCode / 200) | 0) === 1, // 200-299
+    status: res.statusCode,
+    statusText: res.errMsg,
+    url: '',
+    clone: () => {
+      return generateResponse(res);
+    },
+    text: () => Promise.resolve(String.fromCharCode.apply(null, new Uint8Array(res.data))),
+    json: () => {
+      var json = {};
+      try {
+        json = JSON.parse(String.fromCharCode.apply(null, new Uint8Array(res.data)));
+      }
+      catch (err) {
+          console.error(err);
+      }
+      return Promise.resolve(json);
+    },
+    arrayBuffer: () => Promise.resolve(res.data),
+    blob: () => Promise.resolve(res.data),
+    headers: {
+      keys: () => Object.keys(header),
+      entries: () => {
+        let all = [];
+        for (let key in header) {
+          if (header.hasOwnProperty(key)) {
+            all.push([key, header[key]]);
+          }
+        }
+        return all;
+      },
+      get: (n:string) => header[n.toLowerCase()],
+      has: (n:string) => n.toLowerCase() in header
+    }
+  };
+}
+
+async function fetch(input:any, init:any): Promise<any> {
+  return new Promise(function(resolve, reject) {
+    wx.request({
+      url: input,
+      header: init.headers || {},
+      data: init.body || {},
+      method: init.method || 'GET',
+      dataType: '',
+      responseType: 'arraybuffer',
+      success: function(res:any) {
+        resolve(generateResponse(res))
+      },
+      fail: function(res:any) {
+        reject(generateResponse(res))
+      }
+    })
+  })
+}
+
+export {
+  fetch,
+};