Bug 1650099 - Unify UrlbarProviders logger boilerplate. r=adw

Differential Revision: https://phabricator.services.mozilla.com/D82939

browser/app/profile/firefox.js

@@ -289,6 +289,9 @@ pref("browser.urlbar.speculativeConnect.enabled", true);
 // search for bookmarklets typing "javascript: " followed by the actual query.
 pref("browser.urlbar.filter.javascript", true);
 
+// Enable a certain level of urlbar logging to the Browser Console. See Log.jsm.
+pref("browser.urlbar.loglevel", "Error");
+
 // the maximum number of results to show in autocomplete when doing richResults
 pref("browser.urlbar.maxRichResults", 10);
 

browser/components/urlbar/UrlbarEventBufferer.jsm

@@ -14,11 +14,11 @@ XPCOMUtils.defineLazyModuleGetters(this, {
   clearTimeout: "resource://gre/modules/Timer.jsm",
   Services: "resource://gre/modules/Services.jsm",
   setTimeout: "resource://gre/modules/Timer.jsm",
-  Log: "resource://gre/modules/Log.jsm",
+  UrlbarUtils: "resource:///modules/UrlbarUtils.jsm",
 });
 
 XPCOMUtils.defineLazyGetter(this, "logger", () =>
-  Log.repository.getLogger("Urlbar.EventBufferer")
+  UrlbarUtils.getLogger({ prefix: "EventBufferer" })
 );
 
 // Maximum time events can be deferred for.

browser/components/urlbar/UrlbarMuxerUnifiedComplete.jsm

@@ -14,7 +14,6 @@ const { XPCOMUtils } = ChromeUtils.import(
   "resource://gre/modules/XPCOMUtils.jsm"
 );
 XPCOMUtils.defineLazyModuleGetters(this, {
-  Log: "resource://gre/modules/Log.jsm",
   Services: "resource://gre/modules/Services.jsm",
   UrlbarPrefs: "resource:///modules/UrlbarPrefs.jsm",
   UrlbarMuxer: "resource:///modules/UrlbarUtils.jsm",
@@ -22,7 +21,7 @@ XPCOMUtils.defineLazyModuleGetters(this, {
 });
 
 XPCOMUtils.defineLazyGetter(this, "logger", () =>
-  Log.repository.getLogger("Urlbar.Muxer.UnifiedComplete")
+  UrlbarUtils.getLogger({ prefix: "MuxerUnifiedComplete" })
 );
 
 function groupFromResult(result) {

browser/components/urlbar/UrlbarProviderExtension.jsm

@@ -286,6 +286,7 @@ class UrlbarProviderExtension extends UrlbarProvider {
         name: "UrlbarProviderExtension notification timer",
         time: UrlbarProviderExtension.notificationTimeout,
         reportErrorOnTimeout: true,
+        logger: this.logger,
       });
       result = await Promise.race([
         timer.promise,

browser/components/urlbar/UrlbarProviderHeuristicFallback.jsm

@@ -16,7 +16,6 @@ const { XPCOMUtils } = ChromeUtils.import(
   "resource://gre/modules/XPCOMUtils.jsm"
 );
 XPCOMUtils.defineLazyModuleGetters(this, {
-  Log: "resource://gre/modules/Log.jsm",
   Services: "resource://gre/modules/Services.jsm",
   UrlbarPrefs: "resource:///modules/UrlbarPrefs.jsm",
   UrlbarProvider: "resource:///modules/UrlbarUtils.jsm",
@@ -25,10 +24,6 @@ XPCOMUtils.defineLazyModuleGetters(this, {
   UrlbarUtils: "resource:///modules/UrlbarUtils.jsm",
 });
 
-XPCOMUtils.defineLazyGetter(this, "logger", () =>
-  Log.repository.getLogger("Urlbar.Provider.HeuristicFallback")
-);
-
 /**
  * Class used to create the provider.
  */
@@ -83,7 +78,6 @@ class ProviderHeuristicFallback extends UrlbarProvider {
    * @returns {Promise} resolved when the query stops.
    */
   async startQuery(queryContext, addCallback) {
-    logger.info(`Starting query for ${queryContext.searchString}`);
     let instance = {};
     this.queries.set(queryContext, instance);
 
@@ -131,7 +125,6 @@ class ProviderHeuristicFallback extends UrlbarProvider {
    * @param {object} queryContext The query context object
    */
   cancelQuery(queryContext) {
-    logger.info(`Canceling query for ${queryContext.searchString}`);
     this.queries.delete(queryContext);
   }
 

browser/components/urlbar/UrlbarProviderInterventions.jsm

@@ -14,7 +14,6 @@ const { XPCOMUtils } = ChromeUtils.import(
 XPCOMUtils.defineLazyModuleGetters(this, {
   AppUpdater: "resource:///modules/AppUpdater.jsm",
   BrowserWindowTracker: "resource:///modules/BrowserWindowTracker.jsm",
-  Log: "resource://gre/modules/Log.jsm",
   NLP: "resource://gre/modules/NLP.jsm",
   PrivateBrowsingUtils: "resource://gre/modules/PrivateBrowsingUtils.jsm",
   ResetProfile: "resource://gre/modules/ResetProfile.jsm",
@@ -25,10 +24,6 @@ XPCOMUtils.defineLazyModuleGetters(this, {
   UrlbarUtils: "resource:///modules/UrlbarUtils.jsm",
 });
 
-XPCOMUtils.defineLazyGetter(this, "logger", () =>
-  Log.repository.getLogger("Urlbar.Provider.Interventions")
-);
-
 XPCOMUtils.defineLazyGetter(this, "appUpdater", () => new AppUpdater());
 
 // The possible tips to show.  These names (except NONE) are used in the names
@@ -666,7 +661,6 @@ class ProviderInterventions extends UrlbarProvider {
    *        query for.
    */
   cancelQuery(queryContext) {
-    logger.info(`Canceling query for ${queryContext.searchString}`);
     this.queries.delete(queryContext);
 
     // If we're waiting for appUpdater to finish its update check,

browser/components/urlbar/UrlbarProviderOmnibox.jsm

@@ -15,7 +15,6 @@ const { XPCOMUtils } = ChromeUtils.import(
   "resource://gre/modules/XPCOMUtils.jsm"
 );
 XPCOMUtils.defineLazyModuleGetters(this, {
-  Log: "resource://gre/modules/Log.jsm",
   ExtensionSearchHandler: "resource://gre/modules/ExtensionSearchHandler.jsm",
   SkippableTimer: "resource:///modules/UrlbarUtils.jsm",
   UrlbarProvider: "resource:///modules/UrlbarUtils.jsm",
@@ -23,10 +22,6 @@ XPCOMUtils.defineLazyModuleGetters(this, {
   UrlbarUtils: "resource:///modules/UrlbarUtils.jsm",
 });
 
-XPCOMUtils.defineLazyGetter(this, "logger", () =>
-  Log.repository.getLogger("Urlbar.Provider.Omnibox")
-);
-
 // After this time, we'll give up waiting for the extension to return matches.
 const MAXIMUM_ALLOWED_EXTENSION_TIME_MS = 3000;
 
@@ -116,7 +111,6 @@ class ProviderOmnibox extends UrlbarProvider {
    *   The callback invoked by this method to add each result.
    */
   async startQuery(queryContext, addCallback) {
-    logger.info(`Starting query for ${queryContext.searchString}`);
     let instance = {};
     this.queries.set(queryContext, instance);
 
@@ -173,7 +167,7 @@ class ProviderOmnibox extends UrlbarProvider {
     let timeoutPromise = new SkippableTimer({
       name: "ProviderOmnibox",
       time: MAXIMUM_ALLOWED_EXTENSION_TIME_MS,
-      logger,
+      logger: this.logger,
     }).promise;
     await Promise.race([timeoutPromise, this._resultsPromise]).catch(
       Cu.reportError

browser/components/urlbar/UrlbarProviderOpenTabs.jsm

@@ -15,7 +15,6 @@ const { XPCOMUtils } = ChromeUtils.import(
   "resource://gre/modules/XPCOMUtils.jsm"
 );
 XPCOMUtils.defineLazyModuleGetters(this, {
-  Log: "resource://gre/modules/Log.jsm",
   PlacesUtils: "resource://gre/modules/PlacesUtils.jsm",
   UrlbarProvider: "resource:///modules/UrlbarUtils.jsm",
   UrlbarProvidersManager: "resource:///modules/UrlbarProvidersManager.jsm",
@@ -23,10 +22,6 @@ XPCOMUtils.defineLazyModuleGetters(this, {
   UrlbarUtils: "resource:///modules/UrlbarUtils.jsm",
 });
 
-XPCOMUtils.defineLazyGetter(this, "logger", () =>
-  Log.repository.getLogger("Urlbar.Provider.OpenTabs")
-);
-
 /**
  * Class used to create the provider.
  */
@@ -156,7 +151,6 @@ class ProviderOpenTabs extends UrlbarProvider {
     // temp table to return proper frecency.
     // TODO:
     //  * properly search and handle tokens, this is just a mock for now.
-    logger.info(`Starting query for ${queryContext.searchString}`);
     let instance = {};
     this.queries.set(queryContext, instance);
     let conn = await this.promiseDb();
@@ -193,7 +187,6 @@ class ProviderOpenTabs extends UrlbarProvider {
    * @param {object} queryContext The query context object
    */
   cancelQuery(queryContext) {
-    logger.info(`Canceling query for ${queryContext.searchString}`);
     this.queries.delete(queryContext);
   }
 }

browser/components/urlbar/UrlbarProviderPrivateSearch.jsm

@@ -14,7 +14,6 @@ const { XPCOMUtils } = ChromeUtils.import(
   "resource://gre/modules/XPCOMUtils.jsm"
 );
 XPCOMUtils.defineLazyModuleGetters(this, {
-  Log: "resource://gre/modules/Log.jsm",
   Services: "resource://gre/modules/Services.jsm",
   SkippableTimer: "resource:///modules/UrlbarUtils.jsm",
   UrlbarProvider: "resource:///modules/UrlbarUtils.jsm",
@@ -23,10 +22,6 @@ XPCOMUtils.defineLazyModuleGetters(this, {
   UrlbarUtils: "resource:///modules/UrlbarUtils.jsm",
 });
 
-XPCOMUtils.defineLazyGetter(this, "logger", () =>
-  Log.repository.getLogger("Urlbar.Provider.PrivateSearch")
-);
-
 XPCOMUtils.defineLazyPreferenceGetter(
   this,
   "separatePrivateDefaultUIEnabled",
@@ -92,8 +87,6 @@ class ProviderPrivateSearch extends UrlbarProvider {
    * @returns {Promise} resolved when the query stops.
    */
   async startQuery(queryContext, addCallback) {
-    logger.info(`Starting query for ${queryContext.searchString}`);
-
     let searchString = queryContext.searchString.trim();
     if (
       queryContext.tokens.some(
@@ -119,7 +112,7 @@ class ProviderPrivateSearch extends UrlbarProvider {
       : await Services.search.getDefaultPrivate();
     let isPrivateEngine =
       separatePrivateDefault && engine != (await Services.search.getDefault());
-    logger.info(`isPrivateEngine: ${isPrivateEngine}`);
+    this.logger.info(`isPrivateEngine: ${isPrivateEngine}`);
 
     // This is a delay added before returning results, to avoid flicker.
     // Our result must appear only when all results are searches, but if search
@@ -128,7 +121,7 @@ class ProviderPrivateSearch extends UrlbarProvider {
     await new SkippableTimer({
       name: "ProviderPrivateSearch",
       time: 100,
-      logger,
+      logger: this.logger,
     }).promise;
 
     let result = new UrlbarResult(
@@ -152,7 +145,6 @@ class ProviderPrivateSearch extends UrlbarProvider {
    * @param {object} queryContext The query context object
    */
   cancelQuery(queryContext) {
-    logger.info(`Canceling query for ${queryContext.searchString}`);
     this.queries.delete(queryContext);
   }
 }

browser/components/urlbar/UrlbarProviderSearchSuggestions.jsm

@@ -14,7 +14,6 @@ const { XPCOMUtils } = ChromeUtils.import(
   "resource://gre/modules/XPCOMUtils.jsm"
 );
 XPCOMUtils.defineLazyModuleGetters(this, {
-  Log: "resource://gre/modules/Log.jsm",
   SearchSuggestionController:
     "resource://gre/modules/SearchSuggestionController.jsm",
   Services: "resource://gre/modules/Services.jsm",
@@ -27,10 +26,6 @@ XPCOMUtils.defineLazyModuleGetters(this, {
   UrlbarUtils: "resource:///modules/UrlbarUtils.jsm",
 });
 
-XPCOMUtils.defineLazyGetter(this, "logger", () =>
-  Log.repository.getLogger("Urlbar.Provider.SearchSuggestions")
-);
-
 /**
  * Returns whether the passed in string looks like a url.
  * @param {string} str
@@ -215,7 +210,6 @@ class ProviderSearchSuggestions extends UrlbarProvider {
    * @returns {Promise} resolved when the query stops.
    */
   async startQuery(queryContext, addCallback) {
-    logger.info(`Starting query for ${queryContext.searchString}`);
     let instance = {};
     this.queries.set(queryContext, instance);
 
@@ -327,8 +321,6 @@ class ProviderSearchSuggestions extends UrlbarProvider {
    * @param {object} queryContext The query context object
    */
   cancelQuery(queryContext) {
-    logger.info(`Canceling query for ${queryContext.searchString}`);
-
     if (this._suggestionsController) {
       this._suggestionsController.stop();
       this._suggestionsController = null;
@@ -434,7 +426,7 @@ class ProviderSearchSuggestions extends UrlbarProvider {
     let tailTimer = new SkippableTimer({
       name: "ProviderSearchSuggestions",
       time: 100,
-      logger,
+      logger: this.logger,
     });
 
     for (let entry of fetchData.remote) {

browser/components/urlbar/UrlbarProviderSearchTips.jsm

@@ -19,7 +19,6 @@ XPCOMUtils.defineLazyModuleGetters(this, {
   AppMenuNotifications: "resource://gre/modules/AppMenuNotifications.jsm",
   DefaultBrowserCheck: "resource:///modules/BrowserGlue.jsm",
   BrowserWindowTracker: "resource:///modules/BrowserWindowTracker.jsm",
-  Log: "resource://gre/modules/Log.jsm",
   ProfileAge: "resource://gre/modules/ProfileAge.jsm",
   Services: "resource://gre/modules/Services.jsm",
   setTimeout: "resource://gre/modules/Timer.jsm",
@@ -30,10 +29,6 @@ XPCOMUtils.defineLazyModuleGetters(this, {
   UrlbarUtils: "resource:///modules/UrlbarUtils.jsm",
 });
 
-XPCOMUtils.defineLazyGetter(this, "logger", () =>
-  Log.repository.getLogger("Urlbar.Provider.SearchTips")
-);
-
 XPCOMUtils.defineLazyServiceGetter(
   this,
   "updateManager",
@@ -230,7 +225,6 @@ class ProviderSearchTips extends UrlbarProvider {
    *        query for.
    */
   cancelQuery(queryContext) {
-    logger.info(`Canceling query for ${queryContext.searchString}`);
     this.queries.delete(queryContext);
   }
 

browser/components/urlbar/UrlbarProviderTokenAliasEngines.jsm

@@ -14,17 +14,12 @@ const { XPCOMUtils } = ChromeUtils.import(
   "resource://gre/modules/XPCOMUtils.jsm"
 );
 XPCOMUtils.defineLazyModuleGetters(this, {
-  Log: "resource://gre/modules/Log.jsm",
   UrlbarProvider: "resource:///modules/UrlbarUtils.jsm",
   UrlbarResult: "resource:///modules/UrlbarResult.jsm",
   UrlbarSearchUtils: "resource:///modules/UrlbarSearchUtils.jsm",
   UrlbarUtils: "resource:///modules/UrlbarUtils.jsm",
 });
 
-XPCOMUtils.defineLazyGetter(this, "logger", () =>
-  Log.repository.getLogger("Urlbar.Provider.TokenAliasEngines")
-);
-
 /**
  * Class used to create the provider.
  */
@@ -80,7 +75,6 @@ class ProviderTokenAliasEngines extends UrlbarProvider {
    *        result.
    */
   async startQuery(queryContext, addCallback) {
-    logger.info(`Starting query for ${queryContext.searchString}`);
     let instance = {};
     this.queries.set(queryContext, instance);
 
@@ -127,7 +121,6 @@ class ProviderTokenAliasEngines extends UrlbarProvider {
    * @param {object} queryContext The query context object
    */
   cancelQuery(queryContext) {
-    logger.info(`Canceling query for ${queryContext.searchString}`);
     this.queries.delete(queryContext);
   }
 }

browser/components/urlbar/UrlbarProviderTopSites.jsm

@@ -12,7 +12,6 @@ const { XPCOMUtils } = ChromeUtils.import(
 
 XPCOMUtils.defineLazyModuleGetters(this, {
   AboutNewTab: "resource:///modules/AboutNewTab.jsm",
-  Log: "resource://gre/modules/Log.jsm",
   PlacesUtils: "resource://gre/modules/PlacesUtils.jsm",
   Services: "resource://gre/modules/Services.jsm",
   UrlbarPrefs: "resource:///modules/UrlbarPrefs.jsm",
@@ -25,10 +24,6 @@ XPCOMUtils.defineLazyModuleGetters(this, {
   TOP_SITES_DEFAULT_ROWS: "resource://activity-stream/common/Reducers.jsm",
 });
 
-XPCOMUtils.defineLazyGetter(this, "logger", () =>
-  Log.repository.getLogger("Urlbar.Provider.TopSites")
-);
-
 /**
  * This module exports a provider returning the user's newtab Top Sites.
  */
@@ -247,7 +242,6 @@ class ProviderTopSites extends UrlbarProvider {
    *        query for.
    */
   cancelQuery(queryContext) {
-    logger.info(`Canceling query for ${queryContext.searchString}`);
     this.queries.delete(queryContext);
   }
 }

browser/components/urlbar/UrlbarProviderUnifiedComplete.jsm

@@ -16,7 +16,6 @@ const { XPCOMUtils } = ChromeUtils.import(
   "resource://gre/modules/XPCOMUtils.jsm"
 );
 XPCOMUtils.defineLazyModuleGetters(this, {
-  Log: "resource://gre/modules/Log.jsm",
   PlacesUtils: "resource://gre/modules/PlacesUtils.jsm",
   Services: "resource://gre/modules/Services.jsm",
   UrlbarProvider: "resource:///modules/UrlbarUtils.jsm",
@@ -31,10 +30,6 @@ XPCOMUtils.defineLazyServiceGetter(
   "nsIAutoCompleteSearch"
 );
 
-XPCOMUtils.defineLazyGetter(this, "logger", () =>
-  Log.repository.getLogger("Urlbar.Provider.UnifiedComplete")
-);
-
 /**
  * Class used to create the provider.
  */
@@ -80,7 +75,6 @@ class ProviderUnifiedComplete extends UrlbarProvider {
    * @returns {Promise} resolved when the query stops.
    */
   async startQuery(queryContext, addCallback) {
-    logger.info(`Starting query for ${queryContext.searchString}`);
     let instance = {};
     this.queries.set(queryContext, instance);
     let urls = new Set();
@@ -111,7 +105,6 @@ class ProviderUnifiedComplete extends UrlbarProvider {
    * @param {object} queryContext The query context object
    */
   cancelQuery(queryContext) {
-    logger.info(`Canceling query for ${queryContext.searchString}`);
     // This doesn't properly support being used concurrently by multiple fields.
     this.queries.delete(queryContext);
     unifiedComplete.stopSearch();

browser/components/urlbar/UrlbarProvidersManager.jsm

@@ -15,7 +15,6 @@ const { XPCOMUtils } = ChromeUtils.import(
   "resource://gre/modules/XPCOMUtils.jsm"
 );
 XPCOMUtils.defineLazyModuleGetters(this, {
-  Log: "resource://gre/modules/Log.jsm",
   PlacesUtils: "resource://gre/modules/PlacesUtils.jsm",
   SkippableTimer: "resource:///modules/UrlbarUtils.jsm",
   UrlbarMuxer: "resource:///modules/UrlbarUtils.jsm",
@@ -27,7 +26,7 @@ XPCOMUtils.defineLazyModuleGetters(this, {
 });
 
 XPCOMUtils.defineLazyGetter(this, "logger", () =>
-  Log.repository.getLogger("Urlbar.ProvidersManager")
+  UrlbarUtils.getLogger({ prefix: "ProvidersManager" })
 );
 
 // List of available local providers, each is implemented in its own jsm module
@@ -234,7 +233,7 @@ class ProvidersManager {
    * @param {object} queryContext
    */
   cancelQuery(queryContext) {
-    logger.info(`Query cancel ${queryContext.searchString}`);
+    logger.info(`Query cancel "${queryContext.searchString}"`);
     let query = this.queries.get(queryContext);
     if (!query) {
       throw new Error("Couldn't find a matching query for the given context");
@@ -363,13 +362,21 @@ class Query {
     }
 
     // Start querying active providers.
+
     let queryPromises = [];
+    let startQuery = provider => {
+      provider.logger.info(`Starting query for "${this.context.searchString}"`);
+      return provider.tryMethod(
+        "startQuery",
+        this.context,
+        this.add.bind(this)
+      );
+    };
+
     for (let provider of activeProviders) {
       if (provider.type == UrlbarUtils.PROVIDER_TYPE.HEURISTIC) {
         this.context.pendingHeuristicProviders.add(provider.name);
-        queryPromises.push(
+        queryPromises.push(startQuery(provider));
-          provider.tryMethod("startQuery", this.context, this.add.bind(this))
-        );
         continue;
       }
       if (!this._sleepTimer) {
@@ -379,20 +386,13 @@ class Query {
         this._sleepTimer = new SkippableTimer({
           name: "Query provider timer",
           time: UrlbarPrefs.get("delay"),
-          logger,
+          logger: provider.logger,
         });
       }
       queryPromises.push(
-        this._sleepTimer.promise.then(() => {
+        this._sleepTimer.promise.then(() =>
-          if (this.canceled) {
+          this.canceled ? undefined : startQuery(provider)
-            return undefined;
+        )
-          }
-          return provider.tryMethod(
-            "startQuery",
-            this.context,
-            this.add.bind(this)
-          );
-        })
       );
     }
 
@@ -418,6 +418,9 @@ class Query {
     }
     this.canceled = true;
     for (let provider of this.providers) {
+      provider.logger.info(
+        `Canceling query for "${this.context.searchString}"`
+      );
       provider.tryMethod("cancelQuery", this.context);
     }
     if (this._chunkTimer) {
@@ -518,7 +521,7 @@ class Query {
           name: "Heuristic provider timer",
           callback: () => this._notifyResults(),
           time: CHUNK_RESULTS_DELAY_MS,
-          logger,
+          logger: provider.logger,
         });
       }
     } else if (!this._chunkTimer) {
@@ -526,7 +529,7 @@ class Query {
         name: "Query chunk timer",
         callback: () => this._notifyResults(),
         time: CHUNK_RESULTS_DELAY_MS,
-        logger,
+        logger: provider.logger,
       });
     }
     // If all active heuristic providers have returned results, we can skip the
@@ -570,13 +573,13 @@ class Query {
 
     // Crop results to the requested number, taking their result spans into
     // account.
-    logger.debug(
-      `Cropping ${this.context.results.length} results to ${this.context.maxResults}`
-    );
     let resultCount = this.context.maxResults;
     for (let i = 0; i < this.context.results.length; i++) {
       resultCount -= UrlbarUtils.getSpanForResult(this.context.results[i]);
       if (resultCount < 0) {
+        logger.debug(
+          `Splicing results from ${i} to crop results to ${this.context.maxResults}`
+        );
         this.context.results.splice(i, this.context.results.length - i);
         break;
       }

browser/components/urlbar/UrlbarTokenizer.jsm

@@ -15,11 +15,13 @@ var EXPORTED_SYMBOLS = ["UrlbarTokenizer"];
 const { XPCOMUtils } = ChromeUtils.import(
   "resource://gre/modules/XPCOMUtils.jsm"
 );
-const { Services } = ChromeUtils.import("resource://gre/modules/Services.jsm");
+XPCOMUtils.defineLazyModuleGetters(this, {
+  Services: "resource://gre/modules/Services.jsm",
+  UrlbarUtils: "resource:///modules/UrlbarUtils.jsm",
+});
 
-ChromeUtils.defineModuleGetter(this, "Log", "resource://gre/modules/Log.jsm");
 XPCOMUtils.defineLazyGetter(this, "logger", () =>
-  Log.repository.getLogger("Urlbar.Tokenizer")
+  UrlbarUtils.getLogger({ prefix: "Tokenizer" })
 );
 
 var UrlbarTokenizer = {

browser/components/urlbar/UrlbarUtils.jsm

@@ -23,6 +23,7 @@ const { XPCOMUtils } = ChromeUtils.import(
 XPCOMUtils.defineLazyModuleGetters(this, {
   BrowserUtils: "resource://gre/modules/BrowserUtils.jsm",
   BrowserWindowTracker: "resource:///modules/BrowserWindowTracker.jsm",
+  Log: "resource://gre/modules/Log.jsm",
   PrivateBrowsingUtils: "resource://gre/modules/PrivateBrowsingUtils.jsm",
   PlacesUIUtils: "resource:///modules/PlacesUIUtils.jsm",
   PlacesUtils: "resource://gre/modules/PlacesUtils.jsm",
@@ -659,6 +660,30 @@ var UrlbarUtils = {
     }
     return context.heuristicResult;
   },
+
+  /**
+   * Creates a logger.
+   * Logging level can be controlled through browser.urlbar.loglevel.
+   * @param {string} [prefix] Prefix to use for the logged messages, "::" will
+   *                 be appended automatically to the prefix.
+   * @returns {object} The logger.
+   */
+  getLogger({ prefix = "" } = {}) {
+    if (!this._logger) {
+      this._logger = Log.repository.getLogger("urlbar");
+      this._logger.manageLevelFromPref("browser.urlbar.loglevel");
+      this._logger.addAppender(
+        new Log.ConsoleAppender(new Log.BasicFormatter())
+      );
+    }
+    if (prefix) {
+      // This is not an early return because it is necessary to invoke getLogger
+      // at least once before getLoggerWithMessagePrefix; it replaces a
+      // method of the original logger, rather than using an actual Proxy.
+      return Log.repository.getLoggerWithMessagePrefix("urlbar", prefix + "::");
+    }
+    return this._logger;
+  },
 };
 
 XPCOMUtils.defineLazyGetter(UrlbarUtils.ICON, "DEFAULT", () => {
@@ -1100,6 +1125,12 @@ class UrlbarMuxer {
  * The provider scope is to query a datasource and return results from it.
  */
 class UrlbarProvider {
+  constructor() {
+    XPCOMUtils.defineLazyGetter(this, "logger", () =>
+      UrlbarUtils.getLogger({ prefix: `Provider.${this.name}` })
+    );
+  }
+
   /**
    * Unique name for the provider, used by the context to filter on providers.
    * Not using a unique name will cause the newest registration to win.