Bug 842377 - Rename "constant only" to "pull only"; r=rnewman

The new name better reflects the lazy-init behavior of providers.

services/healthreport/healthreporter.jsm

@@ -88,8 +88,8 @@ function AbstractHealthReporter(branch, policy, sessionRecorder) {
   this._shutdownComplete = false;
   this._shutdownCompleteCallback = null;
 
-  this._constantOnlyProviders = {};
-  this._constantOnlyProvidersRegistered = false;
+  this._pullOnlyProviders = {};
+  this._pullOnlyProvidersRegistered = false;
   this._lastDailyDate = null;
 
   // Yes, this will probably run concurrently with remaining constructor work.
@@ -387,7 +387,7 @@ AbstractHealthReporter.prototype = Object.freeze({
    * Obtain a provider from its name.
    *
    * This will only return providers that are currently initialized. If
-   * a provider is lazy initialized (like constant-only providers) this
+   * a provider is lazy initialized (like pull-only providers) this
    * will likely not return anything.
    */
   getProvider: function (name) {
@@ -410,19 +410,19 @@ AbstractHealthReporter.prototype = Object.freeze({
   /**
    * Registers a provider from its constructor function.
    *
-   * If the provider is constant-only, it will be stashed away and
+   * If the provider is pull-only, it will be stashed away and
    * initialized later. Null will be returned.
    *
-   * If it is not constant-only, it will be initialized immediately and a
+   * If it is not pull-only, it will be initialized immediately and a
    * promise will be returned. The promise will be resolved when the
    * provider has finished initializing.
    */
   registerProviderFromType: function (type) {
     let proto = type.prototype;
-    if (proto.constantOnly) {
-      this._log.info("Provider is constant-only. Deferring initialization: " +
+    if (proto.pullOnly) {
+      this._log.info("Provider is pull-only. Deferring initialization: " +
                      proto.name);
-      this._constantOnlyProviders[proto.name] = type;
+      this._pullOnlyProviders[proto.name] = type;
 
       return null;
     }
@@ -506,50 +506,50 @@ AbstractHealthReporter.prototype = Object.freeze({
   },
 
   /**
-   * Ensure that constant-only providers are registered.
+   * Ensure that pull-only providers are registered.
    */
-  ensureConstantOnlyProvidersRegistered: function () {
-    if (this._constantOnlyProvidersRegistered) {
+  ensurePullOnlyProvidersRegistered: function () {
+    if (this._pullOnlyProvidersRegistered) {
       return Promise.resolve();
     }
 
     let onFinished = function () {
-      this._constantOnlyProvidersRegistered = true;
+      this._pullOnlyProvidersRegistered = true;
 
       return Promise.resolve();
     }.bind(this);
 
-    return Task.spawn(function registerConstantProviders() {
-      for each (let providerType in this._constantOnlyProviders) {
+    return Task.spawn(function registerPullProviders() {
+      for each (let providerType in this._pullOnlyProviders) {
         try {
           let provider = this.initProviderFromType(providerType);
           yield this.registerProvider(provider);
         } catch (ex) {
-          this._log.warn("Error registering constant-only provider: " +
+          this._log.warn("Error registering pull-only provider: " +
                          CommonUtils.exceptionStr(ex));
         }
       }
     }.bind(this)).then(onFinished, onFinished);
   },
 
-  ensureConstantOnlyProvidersUnregistered: function () {
-    if (!this._constantOnlyProvidersRegistered) {
+  ensurePullOnlyProvidersUnregistered: function () {
+    if (!this._pullOnlyProvidersRegistered) {
       return Promise.resolve();
     }
 
     let onFinished = function () {
-      this._constantOnlyProvidersRegistered = false;
+      this._pullOnlyProvidersRegistered = false;
 
       return Promise.resolve();
     }.bind(this);
 
-    return Task.spawn(function unregisterConstantProviders() {
+    return Task.spawn(function unregisterPullProviders() {
       for (let provider of this._collector.providers) {
-        if (!provider.constantOnly) {
+        if (!provider.pullOnly) {
           continue;
         }
 
-        this._log.info("Shutting down constant-only provider: " +
+        this._log.info("Shutting down pull-only provider: " +
                        provider.name);
 
         try {
@@ -618,7 +618,7 @@ AbstractHealthReporter.prototype = Object.freeze({
    */
   collectAndObtainJSONPayload: function (asObject=false) {
     return Task.spawn(function collectAndObtain() {
-      yield this.ensureConstantOnlyProvidersRegistered();
+      yield this.ensurePullOnlyProvidersRegistered();
 
       let payload;
       let error;
@@ -631,7 +631,7 @@ AbstractHealthReporter.prototype = Object.freeze({
         this._log.warn("Error collecting and/or retrieving JSON payload: " +
                        CommonUtils.exceptionStr(ex));
       } finally {
-        yield this.ensureConstantOnlyProvidersUnregistered();
+        yield this.ensurePullOnlyProvidersUnregistered();
 
         if (error) {
           throw error;
@@ -1044,7 +1044,7 @@ HealthReporter.prototype = Object.freeze({
    */
   requestDataUpload: function (request) {
     return Task.spawn(function doUpload() {
-      yield this.ensureConstantOnlyProvidersRegistered();
+      yield this.ensurePullOnlyProvidersRegistered();
       try {
         yield this.collectMeasurements();
         try {
@@ -1053,7 +1053,7 @@ HealthReporter.prototype = Object.freeze({
           this._onSubmitDataRequestFailure(ex);
         }
       } finally {
-        yield this.ensureConstantOnlyProvidersUnregistered();
+        yield this.ensurePullOnlyProvidersUnregistered();
       }
     }.bind(this));
   },

services/healthreport/profile.jsm

@@ -214,7 +214,7 @@ ProfileMetadataProvider.prototype = {
 
   measurementTypes: [ProfileMetadataMeasurement],
 
-  constantOnly: true,
+  pullOnly: true,
 
   getProfileCreationDays: function () {
     let accessor = new ProfileCreationTimeAccessor(null, this._log);

services/healthreport/providers.jsm

@@ -126,7 +126,7 @@ AppInfoProvider.prototype = Object.freeze({
 
   measurementTypes: [AppInfoMeasurement, AppVersionMeasurement],
 
-  constantOnly: true,
+  pullOnly: true,
 
   appInfoFields: {
     // From nsIXULAppInfo.
@@ -303,7 +303,7 @@ SysInfoProvider.prototype = Object.freeze({
 
   measurementTypes: [SysInfoMeasurement],
 
-  constantOnly: true,
+  pullOnly: true,
 
   sysInfoFields: {
     cpucount: "cpuCount",
@@ -486,7 +486,7 @@ SessionsProvider.prototype = Object.freeze({
 
   measurementTypes: [CurrentSessionMeasurement, PreviousSessionsMeasurement],
 
-  constantOnly: true,
+  pullOnly: true,
 
   collectConstantData: function () {
     let previous = this.getMeasurement("previous", 3);
@@ -757,7 +757,7 @@ CrashesProvider.prototype = Object.freeze({
 
   measurementTypes: [DailyCrashesMeasurement],
 
-  constantOnly: true,
+  pullOnly: true,
 
   collectConstantData: function () {
     return Task.spawn(this._populateCrashCounts.bind(this));

services/healthreport/tests/xpcshell/test_healthreporter.js

@@ -171,9 +171,8 @@ add_task(function test_register_providers_from_category_manager() {
   reporter._shutdown();
 });
 
-// Constant only providers are only initialized at constant collect
-// time.
-add_task(function test_constant_only_providers() {
+// Pull-only providers are only initialized at collect time.
+add_task(function test_pull_only_providers() {
   const category = "healthreporter-constant-only";
 
   let cm = Cc["@mozilla.org/categorymanager;1"]
@@ -194,9 +193,9 @@ add_task(function test_constant_only_providers() {
   do_check_neq(reporter.getProvider("DummyProvider"), null);
   do_check_null(reporter.getProvider("DummyConstantProvider"));
 
-  yield reporter.ensureConstantOnlyProvidersRegistered();
+  yield reporter.ensurePullOnlyProvidersRegistered();
   yield reporter.collectMeasurements();
-  yield reporter.ensureConstantOnlyProvidersUnregistered();
+  yield reporter.ensurePullOnlyProvidersUnregistered();
 
   do_check_eq(reporter._collector._providers.size, 1);
   do_check_true(reporter._storage.hasProvider("DummyConstantProvider"));

services/metrics/dataprovider.jsm

@@ -392,18 +392,20 @@ this.Provider = function () {
 
 Provider.prototype = Object.freeze({
   /**
-   * Whether the provider provides only constant data.
+   * Whether the provider only pulls data from other sources.
    *
-   * If this is true, the provider likely isn't instantiated until
-   * `collectConstantData` is called and the provider may be torn down after
-   * this function has finished.
+   * If this is true, the provider pulls data from other sources. By contrast,
+   * "push-based" providers subscribe to foreign sources and record/react to
+   * external events as they happen.
    *
-   * This is an optimization so provider instances aren't dead weight while the
-   * application is running.
+   * Pull-only providers likely aren't instantiated until a data collection
+   * is performed. Thus, implementations cannot rely on a provider instance
+   * always being alive. This is an optimization so provider instances aren't
+   * dead weight while the application is running.
    *
-   * This must be set on the prototype for the optimization to be realized.
+   * This must be set on the prototype to have an effect.
    */
-  constantOnly: false,
+  pullOnly: false,
 
   /**
    * Obtain a `Measurement` from its name and version.

services/metrics/modules-testing/mocks.jsm

@@ -103,6 +103,6 @@ this.DummyConstantProvider = function () {
 DummyConstantProvider.prototype = {
   __proto__: DummyProvider.prototype,
 
-  constantOnly: true,
+  pullOnly: true,
 };