WIP - add extractor, generate snippet_data

node_modules/workbox-range-requests/createPartialResponse.mjs

@@ -0,0 +1,105 @@
+/*
+  Copyright 2017 Google Inc.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+      https://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+*/
+
+import {WorkboxError} from 'workbox-core/_private/WorkboxError.mjs';
+import {assert} from 'workbox-core/_private/assert.mjs';
+import {logger} from 'workbox-core/_private/logger.mjs';
+
+import {calculateEffectiveBoundaries} from
+  './utils/calculateEffectiveBoundaries.mjs';
+import {parseRangeHeader} from './utils/parseRangeHeader.mjs';
+
+import './_version.mjs';
+
+/**
+ * Given a `Request` and `Response` objects as input, this will return a
+ * promise for a new `Response`.
+ *
+ * @param {Request} request A request, which should contain a Range:
+ * header.
+ * @param {Response} originalResponse An original response containing the full
+ * content.
+ * @return {Promise<Response>} Either a `206 Partial Content` response, with
+ * the response body set to the slice of content specified by the request's
+ * `Range:` header, or a `416 Range Not Satisfiable` response if the
+ * conditions of the `Range:` header can't be met.
+ *
+ * @memberof workbox.rangeRequests
+ */
+async function createPartialResponse(request, originalResponse) {
+  try {
+    if (process.env.NODE_ENV !== 'production') {
+      assert.isInstance(request, Request, {
+        moduleName: 'workbox-range-requests',
+        funcName: 'createPartialResponse',
+        paramName: 'request',
+      });
+
+      assert.isInstance(originalResponse, Response, {
+        moduleName: 'workbox-range-requests',
+        funcName: 'createPartialResponse',
+        paramName: 'originalResponse',
+      });
+    }
+
+    const rangeHeader = request.headers.get('range');
+    if (!rangeHeader) {
+      throw new WorkboxError('no-range-header');
+    }
+
+    const boundaries = parseRangeHeader(rangeHeader);
+    const originalBlob = await originalResponse.blob();
+
+    const effectiveBoundaries = calculateEffectiveBoundaries(
+      originalBlob, boundaries.start, boundaries.end);
+
+    const slicedBlob = originalBlob.slice(effectiveBoundaries.start,
+      effectiveBoundaries.end);
+    const slicedBlobSize = slicedBlob.size;
+
+    const slicedResponse = new Response(slicedBlob, {
+      // Status code 206 is for a Partial Content response.
+      // See https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/206
+      status: 206,
+      statusText: 'Partial Content',
+      headers: originalResponse.headers,
+    });
+
+    slicedResponse.headers.set('Content-Length', slicedBlobSize);
+    slicedResponse.headers.set('Content-Range',
+      `bytes ${effectiveBoundaries.start}-${effectiveBoundaries.end - 1}/` +
+      originalBlob.size);
+
+    return slicedResponse;
+  } catch (error) {
+    if (process.env.NODE_ENV !== 'production') {
+      logger.warn(`Unable to construct a partial response; returning a ` +
+        `416 Range Not Satisfiable response instead.`);
+      logger.groupCollapsed(`View details here.`);
+      logger.unprefixed.log(error);
+      logger.unprefixed.log(request);
+      logger.unprefixed.log(originalResponse);
+      logger.groupEnd();
+    }
+
+    return new Response('', {
+      status: 416,
+      statusText: 'Range Not Satisfiable',
+    });
+  }
+}
+
+export {createPartialResponse};