1 files changed, 204 insertions, 0 deletions
diff --git a/services/settings/RemoteSettingsWorker.js b/services/settings/RemoteSettingsWorker.js
new file mode 100644
index 0000000000..662b3a8a20
--- /dev/null
+++ b/services/settings/RemoteSettingsWorker.js
@@ -0,0 +1,204 @@
+/* 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/. */
+
+/* eslint-env mozilla/chrome-worker */
+
+"use strict";
+
+/**
+ * A worker dedicated to Remote Settings.
+ */
+
+/* import-globals-from /toolkit/components/workerloader/require.js */
+/* import-globals-from /toolkit/modules/CanonicalJSON.jsm */
+/* import-globals-from IDBHelpers.jsm */
+/* import-globals-from SharedUtils.jsm */
+/* import-globals-from /toolkit/modules/third_party/jsesc/jsesc.js */
+importScripts(
+  "resource://gre/modules/workers/require.js",
+  "resource://gre/modules/CanonicalJSON.jsm",
+  "resource://services-settings/IDBHelpers.jsm",
+  "resource://services-settings/SharedUtils.jsm",
+  "resource://gre/modules/third_party/jsesc/jsesc.js"
+);
+
+const IDB_RECORDS_STORE = "records";
+const IDB_TIMESTAMPS_STORE = "timestamps";
+
+let gShutdown = false;
+
+const Agent = {
+  /**
+   * Return the canonical JSON serialization of the specified records.
+   * It has to match what is done on the server (See Kinto/kinto-signer).
+   *
+   * @param {Array<Object>} records
+   * @param {String} timestamp
+   * @returns {String}
+   */
+  async canonicalStringify(records, timestamp) {
+    // Sort list by record id.
+    let allRecords = records.sort((a, b) => {
+      if (a.id < b.id) {
+        return -1;
+      }
+      return a.id > b.id ? 1 : 0;
+    });
+    // All existing records are replaced by the version from the server
+    // and deleted records are removed.
+    for (let i = 0; i < allRecords.length /* no increment! */; ) {
+      const rec = allRecords[i];
+      const next = allRecords[i + 1];
+      if ((next && rec.id == next.id) || rec.deleted) {
+        allRecords.splice(i, 1); // remove local record
+      } else {
+        i++;
+      }
+    }
+    const toSerialize = {
+      last_modified: "" + timestamp,
+      data: allRecords,
+    };
+    return CanonicalJSON.stringify(toSerialize, jsesc);
+  },
+
+  /**
+   * If present, import the JSON file into the Remote Settings IndexedDB
+   * for the specified bucket and collection.
+   * (eg. blocklists/certificates, main/onboarding)
+   * @param {String} bucket
+   * @param {String} collection
+   * @returns {int} Number of records loaded from dump or -1 if no dump found.
+   */
+  async importJSONDump(bucket, collection) {
+    const { data: records, timestamp } = await SharedUtils.loadJSONDump(
+      bucket,
+      collection
+    );
+    if (records === null) {
+      // Return -1 if file is missing.
+      return -1;
+    }
+    if (gShutdown) {
+      throw new Error("Can't import when we've started shutting down.");
+    }
+    await importDumpIDB(bucket, collection, records, timestamp);
+    return records.length;
+  },
+
+  /**
+   * Check that the specified file matches the expected size and SHA-256 hash.
+   * @param {String} fileUrl file URL to read from
+   * @param {Number} size expected file size
+   * @param {String} size expected file SHA-256 as hex string
+   * @returns {boolean}
+   */
+  async checkFileHash(fileUrl, size, hash) {
+    let resp;
+    try {
+      resp = await fetch(fileUrl);
+    } catch (e) {
+      // File does not exist.
+      return false;
+    }
+    const buffer = await resp.arrayBuffer();
+    return SharedUtils.checkContentHash(buffer, size, hash);
+  },
+
+  async prepareShutdown() {
+    gShutdown = true;
+    // Ensure we can iterate and abort (which may delete items) by cloning
+    // the list.
+    let transactions = Array.from(gPendingTransactions);
+    for (let transaction of transactions) {
+      try {
+        transaction.abort();
+      } catch (ex) {
+        // We can hit this case if the transaction has finished but
+        // we haven't heard about it yet.
+      }
+    }
+  },
+
+  _test_only_import(bucket, collection, records, timestamp) {
+    return importDumpIDB(bucket, collection, records, timestamp);
+  },
+};
+
+/**
+ * Wrap worker invocations in order to return the `callbackId` along
+ * the result. This will allow to transform the worker invocations
+ * into promises in `RemoteSettingsWorker.jsm`.
+ */
+self.onmessage = event => {
+  const { callbackId, method, args = [] } = event.data;
+  Agent[method](...args)
+    .then(result => {
+      self.postMessage({ callbackId, result });
+    })
+    .catch(error => {
+      console.log(`RemoteSettingsWorker error: ${error}`);
+      self.postMessage({ callbackId, error: "" + error });
+    });
+};
+
+let gPendingTransactions = new Set();
+
+/**
+ * Import the records into the Remote Settings Chrome IndexedDB.
+ *
+ * Note: This duplicates some logics from `kinto-offline-client.js`.
+ *
+ * @param {String} bucket
+ * @param {String} collection
+ * @param {Array<Object>} records
+ * @param {Number} timestamp
+ */
+async function importDumpIDB(bucket, collection, records, timestamp) {
+  // Open the DB. It will exist since if we are running this, it means
+  // we already tried to read the timestamp in `remote-settings.js`
+  const db = await IDBHelpers.openIDB(false /* do not allow upgrades */);
+
+  // try...finally to ensure we always close the db.
+  try {
+    if (gShutdown) {
+      throw new Error("Can't import when we've started shutting down.");
+    }
+
+    // Each entry of the dump will be stored in the records store.
+    // They are indexed by `_cid`.
+    const cid = bucket + "/" + collection;
+    // We can just modify the items in-place, as we got them from SharedUtils.loadJSONDump().
+    records.forEach(item => {
+      item._cid = cid;
+    });
+    // Store the collection timestamp.
+    let { transaction, promise } = IDBHelpers.executeIDB(
+      db,
+      [IDB_RECORDS_STORE, IDB_TIMESTAMPS_STORE],
+      "readwrite",
+      ([recordsStore, timestampStore], rejectTransaction) => {
+        // Wipe before loading
+        recordsStore.delete(IDBKeyRange.bound([cid], [cid, []], false, true));
+        IDBHelpers.bulkOperationHelper(
+          recordsStore,
+          {
+            reject: rejectTransaction,
+            completion() {
+              timestampStore.put({ cid, value: timestamp });
+            },
+          },
+          "put",
+          records
+        );
+      }
+    );
+    gPendingTransactions.add(transaction);
+    promise = promise.finally(() => gPendingTransactions.delete(transaction));
+    await promise;
+  } finally {
+    // Close now that we're done.
+    db.close();
+  }
+}