1 files changed, 187 insertions, 0 deletions
diff --git a/browser/components/urlbar/private/BlockedSuggestions.sys.mjs b/browser/components/urlbar/private/BlockedSuggestions.sys.mjs
new file mode 100644
index 0000000000..d74a0979d1
--- /dev/null
+++ b/browser/components/urlbar/private/BlockedSuggestions.sys.mjs
@@ -0,0 +1,187 @@
+/* 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/. */
+
+import { BaseFeature } from "resource:///modules/urlbar/private/BaseFeature.sys.mjs";
+
+const lazy = {};
+
+ChromeUtils.defineESModuleGetters(lazy, {
+  TaskQueue: "resource:///modules/UrlbarUtils.sys.mjs",
+  UrlbarPrefs: "resource:///modules/UrlbarPrefs.sys.mjs",
+});
+
+/**
+ * A set of blocked suggestions for quick suggest.
+ */
+export class BlockedSuggestions extends BaseFeature {
+  constructor() {
+    super();
+    this.#taskQueue = new lazy.TaskQueue();
+    lazy.UrlbarPrefs.addObserver(this);
+  }
+
+  get shouldEnable() {
+    // Return true so that we'll always load blocked digests when quick suggest
+    // is enabled, even if blocking new suggestions is currently disabled.
+    // Blocking may have been enabled previously, and blocked suggestions should
+    // remain blocked as long as quick suggest as a whole remains enabled.
+    return true;
+  }
+
+  enable(enabled) {
+    if (enabled) {
+      this.#loadDigests();
+    }
+  }
+
+  /**
+   * Blocks a suggestion.
+   *
+   * @param {string} originalUrl
+   *   The suggestion's original URL with its unreplaced timestamp template.
+   */
+  async add(originalUrl) {
+    this.logger.debug(`Queueing add: ${originalUrl}`);
+    await this.#taskQueue.queue(async () => {
+      this.logger.info(`Blocking suggestion: ${originalUrl}`);
+      let digest = await this.#getDigest(originalUrl);
+      this.logger.debug(`Got digest for '${originalUrl}': ${digest}`);
+      this.#digests.add(digest);
+      let json = JSON.stringify([...this.#digests]);
+      this.#updatingDigests = true;
+      try {
+        lazy.UrlbarPrefs.set("quicksuggest.blockedDigests", json);
+      } finally {
+        this.#updatingDigests = false;
+      }
+      this.logger.debug(`All blocked suggestions: ${json}`);
+    });
+  }
+
+  /**
+   * Gets whether a suggestion is blocked.
+   *
+   * @param {string} originalUrl
+   *   The suggestion's original URL with its unreplaced timestamp template.
+   * @returns {boolean}
+   *   Whether the suggestion is blocked.
+   */
+  async has(originalUrl) {
+    this.logger.debug(`Queueing has: ${originalUrl}`);
+    return this.#taskQueue.queue(async () => {
+      this.logger.info(`Getting blocked status: ${originalUrl}`);
+      let digest = await this.#getDigest(originalUrl);
+      this.logger.debug(`Got digest for '${originalUrl}': ${digest}`);
+      let isBlocked = this.#digests.has(digest);
+      this.logger.info(`Blocked status for '${originalUrl}': ${isBlocked}`);
+      return isBlocked;
+    });
+  }
+
+  /**
+   * Unblocks all suggestions.
+   */
+  async clear() {
+    this.logger.debug(`Queueing clearBlockedSuggestions`);
+    await this.#taskQueue.queue(() => {
+      this.logger.info(`Clearing all blocked suggestions`);
+      this.#digests.clear();
+      lazy.UrlbarPrefs.clear("quicksuggest.blockedDigests");
+    });
+  }
+
+  /**
+   * Called when a urlbar pref changes.
+   *
+   * @param {string} pref
+   *   The name of the pref relative to `browser.urlbar`.
+   */
+  onPrefChanged(pref) {
+    switch (pref) {
+      case "quicksuggest.blockedDigests":
+        if (!this.#updatingDigests) {
+          this.logger.info(
+            "browser.urlbar.quicksuggest.blockedDigests changed"
+          );
+          this.#loadDigests();
+        }
+        break;
+    }
+  }
+
+  /**
+   * Loads blocked suggestion digests from the pref into `#digests`.
+   */
+  async #loadDigests() {
+    this.logger.debug(`Queueing #loadDigests`);
+    await this.#taskQueue.queue(() => {
+      this.logger.info(`Loading blocked suggestion digests`);
+      let json = lazy.UrlbarPrefs.get("quicksuggest.blockedDigests");
+      this.logger.debug(
+        `browser.urlbar.quicksuggest.blockedDigests value: ${json}`
+      );
+      if (!json) {
+        this.logger.info(`There are no blocked suggestion digests`);
+        this.#digests.clear();
+      } else {
+        try {
+          this.#digests = new Set(JSON.parse(json));
+          this.logger.info(`Successfully loaded blocked suggestion digests`);
+        } catch (error) {
+          this.logger.error(
+            `Error loading blocked suggestion digests: ${error}`
+          );
+        }
+      }
+    });
+  }
+
+  /**
+   * Returns the SHA-1 digest of a string as a 40-character hex-encoded string.
+   *
+   * @param {string} string
+   *   The string to convert to SHA-1
+   * @returns {string}
+   *   The hex-encoded digest of the given string.
+   */
+  async #getDigest(string) {
+    let stringArray = new TextEncoder().encode(string);
+    let hashBuffer = await crypto.subtle.digest("SHA-1", stringArray);
+    let hashArray = new Uint8Array(hashBuffer);
+    return Array.from(hashArray, b => b.toString(16).padStart(2, "0")).join("");
+  }
+
+  get _test_readyPromise() {
+    return this.#taskQueue.emptyPromise;
+  }
+
+  get _test_digests() {
+    return this.#digests;
+  }
+
+  _test_getDigest(string) {
+    return this.#getDigest(string);
+  }
+
+  // Set of digests of the original URLs of blocked suggestions. A suggestion's
+  // "original URL" is its URL straight from the source with an unreplaced
+  // timestamp template. For details on the digests, see `#getDigest()`.
+  //
+  // The only reason we use URL digests is that suggestions currently do not
+  // have persistent IDs. We could use the URLs themselves but SHA-1 digests are
+  // only 40 chars long, so they save a little space. This is also consistent
+  // with how blocked tiles on the newtab page are stored, but they use MD5. We
+  // do *not* store digests for any security or obfuscation reason.
+  //
+  // This value is serialized as a JSON'ed array to the
+  // `browser.urlbar.quicksuggest.blockedDigests` pref.
+  #digests = new Set();
+
+  // Used to serialize access to blocked suggestions. This is only necessary
+  // because getting a suggestion's URL digest is async.
+  #taskQueue = null;
+
+  // Whether blocked digests are currently being updated.
+  #updatingDigests = false;
+}