1 files changed, 245 insertions, 0 deletions
diff --git a/dom/manifest/Manifest.sys.mjs b/dom/manifest/Manifest.sys.mjs
new file mode 100644
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+++ b/dom/manifest/Manifest.sys.mjs
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+/* 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/. */
+
+/*
+ * Manifest.jsm is the top level api for managing installed web applications
+ * https://www.w3.org/TR/appmanifest/
+ *
+ * It is used to trigger the installation of a web application via .install()
+ * and to access the manifest data (including icons).
+ *
+ * TODO:
+ *  - Trigger appropriate app installed events
+ */
+
+import { ManifestObtainer } from "resource://gre/modules/ManifestObtainer.sys.mjs";
+
+import { ManifestIcons } from "resource://gre/modules/ManifestIcons.sys.mjs";
+
+const lazy = {};
+
+ChromeUtils.defineESModuleGetters(lazy, {
+  JSONFile: "resource://gre/modules/JSONFile.sys.mjs",
+});
+
+/**
+ * Generates an hash for the given string.
+ *
+ * @note The generated hash is returned in base64 form.  Mind the fact base64
+ * is case-sensitive if you are going to reuse this code.
+ */
+function generateHash(aString) {
+  const cryptoHash = Cc["@mozilla.org/security/hash;1"].createInstance(
+    Ci.nsICryptoHash
+  );
+  cryptoHash.init(Ci.nsICryptoHash.MD5);
+  const stringStream = Cc[
+    "@mozilla.org/io/string-input-stream;1"
+  ].createInstance(Ci.nsIStringInputStream);
+  stringStream.data = aString;
+  cryptoHash.updateFromStream(stringStream, -1);
+  // base64 allows the '/' char, but we can't use it for filenames.
+  return cryptoHash.finish(true).replace(/\//g, "-");
+}
+
+/**
+ * Trims the query parameters from a url
+ */
+function stripQuery(url) {
+  return url.split("?")[0];
+}
+
+// Folder in which we store the manifest files
+const MANIFESTS_DIR = PathUtils.join(PathUtils.profileDir, "manifests");
+
+// We maintain a list of scopes for installed webmanifests so we can determine
+// whether a given url is within the scope of a previously installed manifest
+const MANIFESTS_FILE = "manifest-scopes.json";
+
+/**
+ * Manifest object
+ */
+
+class Manifest {
+  constructor(browser, manifestUrl) {
+    this._manifestUrl = manifestUrl;
+    // The key for this is the manifests URL that is required to be unique.
+    // However arbitrary urls are not safe file paths so lets hash it.
+    const fileName = generateHash(manifestUrl) + ".json";
+    this._path = PathUtils.join(MANIFESTS_DIR, fileName);
+    this.browser = browser;
+  }
+
+  get browser() {
+    return this._browser;
+  }
+
+  set browser(aBrowser) {
+    this._browser = aBrowser;
+  }
+
+  async initialize() {
+    this._store = new lazy.JSONFile({ path: this._path, saveDelayMs: 100 });
+    await this._store.load();
+  }
+
+  async prefetch(browser) {
+    const manifestData = await ManifestObtainer.browserObtainManifest(browser);
+    const icon = await ManifestIcons.browserFetchIcon(
+      browser,
+      manifestData,
+      192
+    );
+    const data = {
+      installed: false,
+      manifest: manifestData,
+      cached_icon: icon,
+    };
+    return data;
+  }
+
+  async install() {
+    const manifestData = await ManifestObtainer.browserObtainManifest(
+      this._browser
+    );
+    this._store.data = {
+      installed: true,
+      manifest: manifestData,
+    };
+    Manifests.manifestInstalled(this);
+    this._store.saveSoon();
+  }
+
+  async icon(expectedSize) {
+    if ("cached_icon" in this._store.data) {
+      return this._store.data.cached_icon;
+    }
+    const icon = await ManifestIcons.browserFetchIcon(
+      this._browser,
+      this._store.data.manifest,
+      expectedSize
+    );
+    // Cache the icon so future requests do not go over the network
+    this._store.data.cached_icon = icon;
+    this._store.saveSoon();
+    return icon;
+  }
+
+  get scope() {
+    const scope =
+      this._store.data.manifest.scope || this._store.data.manifest.start_url;
+    return stripQuery(scope);
+  }
+
+  get name() {
+    return (
+      this._store.data.manifest.short_name ||
+      this._store.data.manifest.name ||
+      this._store.data.manifest.short_url
+    );
+  }
+
+  get url() {
+    return this._manifestUrl;
+  }
+
+  get installed() {
+    return (this._store.data && this._store.data.installed) || false;
+  }
+
+  get start_url() {
+    return this._store.data.manifest.start_url;
+  }
+
+  get path() {
+    return this._path;
+  }
+}
+
+/*
+ * Manifests maintains the list of installed manifests
+ */
+export var Manifests = {
+  async _initialize() {
+    if (this._readyPromise) {
+      return this._readyPromise;
+    }
+
+    // Prevent multiple initializations
+    this._readyPromise = (async () => {
+      // Make sure the manifests have the folder needed to save into
+      await IOUtils.makeDirectory(MANIFESTS_DIR, { ignoreExisting: true });
+
+      // Ensure any existing scope data we have about manifests is loaded
+      this._path = PathUtils.join(PathUtils.profileDir, MANIFESTS_FILE);
+      this._store = new lazy.JSONFile({ path: this._path });
+      await this._store.load();
+
+      // If we don't have any existing data, initialize empty
+      if (!this._store.data.hasOwnProperty("scopes")) {
+        this._store.data.scopes = new Map();
+      }
+    })();
+
+    // Cache the Manifest objects creates as they are references to files
+    // and we do not want multiple file handles
+    this.manifestObjs = new Map();
+    return this._readyPromise;
+  },
+
+  // When a manifest is installed, we save its scope so we can determine if
+  // future visits fall within this manifests scope
+  manifestInstalled(manifest) {
+    this._store.data.scopes[manifest.scope] = manifest.url;
+    this._store.saveSoon();
+  },
+
+  // Given a url, find if it is within an installed manifests scope and if so
+  // return that manifests url
+  findManifestUrl(url) {
+    for (let scope in this._store.data.scopes) {
+      if (url.startsWith(scope)) {
+        return this._store.data.scopes[scope];
+      }
+    }
+    return null;
+  },
+
+  // Get the manifest given a url, or if not look for a manifest that is
+  // tied to the current page
+  async getManifest(browser, manifestUrl) {
+    // Ensure we have all started up
+    if (!this._readyPromise) {
+      await this._initialize();
+    }
+
+    // If the client does not already know its manifestUrl, we take the
+    // url of the client and see if it matches the scope of any installed
+    // manifests
+    if (!manifestUrl) {
+      const url = stripQuery(browser.currentURI.spec);
+      manifestUrl = this.findManifestUrl(url);
+    }
+
+    // No matches so no manifest
+    if (manifestUrl === null) {
+      return null;
+    }
+
+    // If we have already created this manifest return cached
+    if (this.manifestObjs.has(manifestUrl)) {
+      const manifest = this.manifestObjs.get(manifestUrl);
+      if (manifest.browser !== browser) {
+        manifest.browser = browser;
+      }
+      return manifest;
+    }
+
+    // Otherwise create a new manifest object
+    const manifest = new Manifest(browser, manifestUrl);
+    this.manifestObjs.set(manifestUrl, manifest);
+    await manifest.initialize();
+    return manifest;
+  },
+};