1 files changed, 131 insertions, 0 deletions
diff --git a/remote/shared/NetworkResponse.sys.mjs b/remote/shared/NetworkResponse.sys.mjs
new file mode 100644
index 0000000000..45a03fb445
--- /dev/null
+++ b/remote/shared/NetworkResponse.sys.mjs
@@ -0,0 +1,131 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+const lazy = {};
+ChromeUtils.defineESModuleGetters(lazy, {
+  NetworkUtils:
+    "resource://devtools/shared/network-observer/NetworkUtils.sys.mjs",
+});
+
+/**
+ * The NetworkResponse class is a wrapper around the internal channel which
+ * provides getters and methods closer to fetch's response concept
+ * (https://fetch.spec.whatwg.org/#concept-response).
+ */
+export class NetworkResponse {
+  #channel;
+  #decodedBodySize;
+  #encodedBodySize;
+  #fromCache;
+  #headersTransmittedSize;
+  #status;
+  #statusMessage;
+  #totalTransmittedSize;
+  #wrappedChannel;
+
+  /**
+   *
+   * @param {nsIChannel} channel
+   *     The channel for the response.
+   * @param {object} params
+   * @param {boolean} params.fromCache
+   *     Whether the response was read from the cache or not.
+   * @param {string=} params.rawHeaders
+   *     The response's raw (ie potentially compressed) headers
+   */
+  constructor(channel, params) {
+    this.#channel = channel;
+    const { fromCache, rawHeaders = "" } = params;
+    this.#fromCache = fromCache;
+    this.#wrappedChannel = ChannelWrapper.get(channel);
+
+    this.#decodedBodySize = 0;
+    this.#encodedBodySize = 0;
+    this.#headersTransmittedSize = rawHeaders.length;
+    this.#totalTransmittedSize = rawHeaders.length;
+
+    // TODO: responseStatus and responseStatusText are sometimes inconsistent.
+    // For instance, they might be (304, Not Modified) when retrieved during the
+    // responseStarted event, and then (200, OK) during the responseCompleted
+    // event.
+    // For now consider them as immutable and store them on startup.
+    this.#status = this.#channel.responseStatus;
+    this.#statusMessage = this.#channel.responseStatusText;
+  }
+
+  get decodedBodySize() {
+    return this.#decodedBodySize;
+  }
+
+  get encodedBodySize() {
+    return this.#encodedBodySize;
+  }
+
+  get headersTransmittedSize() {
+    return this.#headersTransmittedSize;
+  }
+
+  get fromCache() {
+    return this.#fromCache;
+  }
+
+  get protocol() {
+    return lazy.NetworkUtils.getProtocol(this.#channel);
+  }
+
+  get serializedURL() {
+    return this.#channel.URI.spec;
+  }
+
+  get status() {
+    return this.#status;
+  }
+
+  get statusMessage() {
+    return this.#statusMessage;
+  }
+
+  get totalTransmittedSize() {
+    return this.#totalTransmittedSize;
+  }
+
+  addResponseContent(responseContent) {
+    this.#decodedBodySize = responseContent.decodedBodySize;
+    this.#encodedBodySize = responseContent.bodySize;
+    this.#totalTransmittedSize = responseContent.transferredSize;
+  }
+
+  getComputedMimeType() {
+    // TODO: DevTools NetworkObserver is computing a similar value in
+    // addResponseContent, but uses an inconsistent implementation in
+    // addResponseStart. This approach can only be used as early as in
+    // addResponseHeaders. We should move this logic to the NetworkObserver and
+    // expose mimeType in addResponseStart. Bug 1809670.
+    let mimeType = "";
+
+    try {
+      mimeType = this.#wrappedChannel.contentType;
+      const contentCharset = this.#channel.contentCharset;
+      if (contentCharset) {
+        mimeType += `;charset=${contentCharset}`;
+      }
+    } catch (e) {
+      // Ignore exceptions when reading contentType/contentCharset
+    }
+
+    return mimeType;
+  }
+
+  getHeadersList() {
+    const headers = [];
+
+    this.#channel.visitOriginalResponseHeaders({
+      visitHeader(name, value) {
+        headers.push([name, value]);
+      },
+    });
+
+    return headers;
+  }
+}