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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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
#include "mozilla/browser/NimbusFeatures.h"
#include "mozilla/browser/NimbusFeatureManifest.h"
#include "mozilla/Telemetry.h"
#include "mozilla/Try.h"
#include "mozilla/dom/ScriptSettings.h"
#include "jsapi.h"
#include "js/JSON.h"
#include "nsJSUtils.h"
namespace mozilla {
static nsTHashSet<nsCString> sExposureFeatureSet;
void NimbusFeatures::GetPrefName(const nsACString& branchPrefix,
const nsACString& aFeatureId,
const nsACString& aVariable,
nsACString& aPref) {
nsAutoCString featureAndVariable;
featureAndVariable.Append(aFeatureId);
if (!aVariable.IsEmpty()) {
featureAndVariable.Append(".");
featureAndVariable.Append(aVariable);
}
aPref.Truncate();
aPref.Append(branchPrefix);
aPref.Append(featureAndVariable);
}
/**
* Returns the variable value configured via experiment or rollout.
* If a fallback pref is defined in the FeatureManifest and it
* has a user value set this takes precedence over remote configurations.
*/
bool NimbusFeatures::GetBool(const nsACString& aFeatureId,
const nsACString& aVariable, bool aDefault) {
nsAutoCString experimentPref;
GetPrefName(kSyncDataPrefBranch, aFeatureId, aVariable, experimentPref);
if (Preferences::HasUserValue(experimentPref.get())) {
return Preferences::GetBool(experimentPref.get(), aDefault);
}
nsAutoCString rolloutPref;
GetPrefName(kSyncRolloutsPrefBranch, aFeatureId, aVariable, rolloutPref);
if (Preferences::HasUserValue(rolloutPref.get())) {
return Preferences::GetBool(rolloutPref.get(), aDefault);
}
auto prefName = GetNimbusFallbackPrefName(aFeatureId, aVariable);
if (prefName.isSome()) {
return Preferences::GetBool(prefName->get(), aDefault);
}
return aDefault;
}
/**
* Returns the variable value configured via experiment or rollout.
* If a fallback pref is defined in the FeatureManifest and it
* has a user value set this takes precedence over remote configurations.
*/
int NimbusFeatures::GetInt(const nsACString& aFeatureId,
const nsACString& aVariable, int aDefault) {
nsAutoCString experimentPref;
GetPrefName(kSyncDataPrefBranch, aFeatureId, aVariable, experimentPref);
if (Preferences::HasUserValue(experimentPref.get())) {
return Preferences::GetInt(experimentPref.get(), aDefault);
}
nsAutoCString rolloutPref;
GetPrefName(kSyncRolloutsPrefBranch, aFeatureId, aVariable, rolloutPref);
if (Preferences::HasUserValue(rolloutPref.get())) {
return Preferences::GetInt(rolloutPref.get(), aDefault);
}
auto prefName = GetNimbusFallbackPrefName(aFeatureId, aVariable);
if (prefName.isSome()) {
return Preferences::GetInt(prefName->get(), aDefault);
}
return aDefault;
}
nsresult NimbusFeatures::OnUpdate(const nsACString& aFeatureId,
const nsACString& aVariable,
PrefChangedFunc aUserCallback,
void* aUserData) {
nsAutoCString experimentPref;
nsAutoCString rolloutPref;
GetPrefName(kSyncDataPrefBranch, aFeatureId, aVariable, experimentPref);
GetPrefName(kSyncRolloutsPrefBranch, aFeatureId, aVariable, rolloutPref);
nsresult rv =
Preferences::RegisterCallback(aUserCallback, experimentPref, aUserData);
NS_ENSURE_SUCCESS(rv, rv);
rv = Preferences::RegisterCallback(aUserCallback, rolloutPref, aUserData);
NS_ENSURE_SUCCESS(rv, rv);
return NS_OK;
}
nsresult NimbusFeatures::OffUpdate(const nsACString& aFeatureId,
const nsACString& aVariable,
PrefChangedFunc aUserCallback,
void* aUserData) {
nsAutoCString experimentPref;
nsAutoCString rolloutPref;
GetPrefName(kSyncDataPrefBranch, aFeatureId, aVariable, experimentPref);
GetPrefName(kSyncRolloutsPrefBranch, aFeatureId, aVariable, rolloutPref);
nsresult rv =
Preferences::UnregisterCallback(aUserCallback, experimentPref, aUserData);
NS_ENSURE_SUCCESS(rv, rv);
rv = Preferences::UnregisterCallback(aUserCallback, rolloutPref, aUserData);
NS_ENSURE_SUCCESS(rv, rv);
return NS_OK;
}
/**
* Attempt to read Nimbus preference to determine experiment and branch slug.
* Nimbus will store a pref with experiment metadata in the following format:
* {
* slug: "experiment slug",
* branch: { slug: "branch slug" },
* ...
* }
* The naming convention for preference names is:
* `nimbus.syncdatastore.<feature_id>`
* These values are used to send `exposure` telemetry pings.
*/
nsresult NimbusFeatures::GetExperimentSlug(const nsACString& aFeatureId,
nsACString& aExperimentSlug,
nsACString& aBranchSlug) {
nsAutoCString prefName;
nsAutoString prefValue;
aExperimentSlug.Truncate();
aBranchSlug.Truncate();
GetPrefName(kSyncDataPrefBranch, aFeatureId, EmptyCString(), prefName);
MOZ_TRY(Preferences::GetString(prefName.get(), prefValue));
if (prefValue.IsEmpty()) {
return NS_ERROR_UNEXPECTED;
}
dom::AutoJSAPI jsapi;
if (!jsapi.Init(xpc::PrivilegedJunkScope())) {
return NS_ERROR_UNEXPECTED;
}
JSContext* cx = jsapi.cx();
JS::Rooted<JS::Value> json(cx, JS::NullValue());
if (JS_ParseJSON(cx, prefValue.BeginReading(), prefValue.Length(), &json) &&
json.isObject()) {
JS::Rooted<JSObject*> experimentJSON(cx, json.toObjectOrNull());
JS::Rooted<JS::Value> expSlugValue(cx);
if (!JS_GetProperty(cx, experimentJSON, "slug", &expSlugValue)) {
return NS_ERROR_UNEXPECTED;
}
AssignJSString(cx, aExperimentSlug, expSlugValue.toString());
JS::Rooted<JS::Value> branchJSON(cx);
if (!JS_GetProperty(cx, experimentJSON, "branch", &branchJSON) &&
!branchJSON.isObject()) {
return NS_ERROR_UNEXPECTED;
}
JS::Rooted<JSObject*> branchObj(cx, branchJSON.toObjectOrNull());
JS::Rooted<JS::Value> branchSlugValue(cx);
if (!JS_GetProperty(cx, branchObj, "slug", &branchSlugValue)) {
return NS_ERROR_UNEXPECTED;
}
AssignJSString(cx, aBranchSlug, branchSlugValue.toString());
}
return NS_OK;
}
/**
* Sends an exposure event for aFeatureId when enrolled in an experiment.
* By default attempt to send once per function call. For some usecases it might
* be useful to send only once, in which case set the optional aOnce to `true`.
*/
nsresult NimbusFeatures::RecordExposureEvent(const nsACString& aFeatureId,
const bool aOnce) {
nsAutoCString featureName(aFeatureId);
if (!sExposureFeatureSet.EnsureInserted(featureName) && aOnce) {
// We already sent (or tried to send) an exposure ping for this featureId
return NS_ERROR_ABORT;
}
nsAutoCString slugName;
nsAutoCString branchName;
MOZ_TRY(GetExperimentSlug(aFeatureId, slugName, branchName));
if (slugName.IsEmpty() || branchName.IsEmpty()) {
// Failed getting experiment metadata or not enrolled in an experiment for
// this featureId
return NS_ERROR_UNEXPECTED;
}
Telemetry::SetEventRecordingEnabled("normandy"_ns, true);
nsTArray<Telemetry::EventExtraEntry> extra(2);
extra.AppendElement(Telemetry::EventExtraEntry{"branchSlug"_ns, branchName});
extra.AppendElement(Telemetry::EventExtraEntry{"featureId"_ns, featureName});
Telemetry::RecordEvent(Telemetry::EventID::Normandy_Expose_NimbusExperiment,
Some(slugName), Some(std::move(extra)));
return NS_OK;
}
} // namespace mozilla