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/* 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
const lazy = {};
ChromeUtils.defineESModuleGetters(lazy, {
});
const IS_MAIN_PROCESS =
Services.appinfo.processType === Services.appinfo.PROCESS_TYPE_DEFAULT;
// This branch is used to store experiment data
const SYNC_DATA_PREF_BRANCH = "nimbus.syncdatastore.";
// This branch is used to store remote rollouts
const SYNC_DEFAULTS_PREF_BRANCH = "nimbus.syncdefaultsstore.";
let tryJSONParse = data => {
try {
return JSON.parse(data);
} catch (e) {}
return null;
};
ChromeUtils.defineLazyGetter(lazy, "syncDataStore", () => {
let experimentsPrefBranch = Services.prefs.getBranch(SYNC_DATA_PREF_BRANCH);
let defaultsPrefBranch = Services.prefs.getBranch(SYNC_DEFAULTS_PREF_BRANCH);
return {
_tryParsePrefValue(branch, pref) {
try {
return tryJSONParse(branch.getStringPref(pref, ""));
} catch (e) {
/* This is expected if we don't have anything stored */
}
return null;
},
_trySetPrefValue(branch, pref, value) {
try {
branch.setStringPref(pref, JSON.stringify(value));
} catch (e) {
console.error(e);
}
},
_trySetTypedPrefValue(pref, value) {
let variableType = typeof value;
switch (variableType) {
case "boolean":
Services.prefs.setBoolPref(pref, value);
break;
case "number":
Services.prefs.setIntPref(pref, value);
break;
case "string":
Services.prefs.setStringPref(pref, value);
break;
case "object":
Services.prefs.setStringPref(pref, JSON.stringify(value));
break;
}
},
_clearBranchChildValues(prefBranch) {
const variablesBranch = Services.prefs.getBranch(prefBranch);
const prefChildList = variablesBranch.getChildList("");
for (let variable of prefChildList) {
variablesBranch.clearUserPref(variable);
}
},
/**
* Given a branch pref returns all child prefs and values
* { childPref: value }
* where value is parsed to the appropriate type
*
* @returns {Object[]}
*/
_getBranchChildValues(prefBranch, featureId) {
const branch = Services.prefs.getBranch(prefBranch);
const prefChildList = branch.getChildList("");
let values = {};
if (!prefChildList.length) {
return null;
}
for (const childPref of prefChildList) {
let prefName = `${prefBranch}${childPref}`;
let value = lazy.PrefUtils.getPref(prefName);
// Try to parse string values that could be stringified objects
if (
lazy.FeatureManifest[featureId]?.variables[childPref]?.type === "json"
) {
let parsedValue = tryJSONParse(value);
if (parsedValue) {
value = parsedValue;
}
}
values[childPref] = value;
}
return values;
},
get(featureId) {
let metadata = this._tryParsePrefValue(experimentsPrefBranch, featureId);
if (!metadata) {
return null;
}
let prefBranch = `${SYNC_DATA_PREF_BRANCH}${featureId}.`;
metadata.branch.feature.value = this._getBranchChildValues(
prefBranch,
featureId
);
return metadata;
},
getDefault(featureId) {
let metadata = this._tryParsePrefValue(defaultsPrefBranch, featureId);
if (!metadata) {
return null;
}
let prefBranch = `${SYNC_DEFAULTS_PREF_BRANCH}${featureId}.`;
metadata.branch.feature.value = this._getBranchChildValues(
prefBranch,
featureId
);
return metadata;
},
set(featureId, value) {
/* If the enrollment branch has variables we store those separately
* in pref branches of appropriate type:
* { featureId: "foo", value: { enabled: true } }
* gets stored as `${SYNC_DATA_PREF_BRANCH}foo.enabled=true`
*/
if (value.branch?.feature?.value) {
for (let variable of Object.keys(value.branch.feature.value)) {
let prefName = `${SYNC_DATA_PREF_BRANCH}${featureId}.${variable}`;
this._trySetTypedPrefValue(
prefName,
value.branch.feature.value[variable]
);
}
this._trySetPrefValue(experimentsPrefBranch, featureId, {
...value,
branch: {
...value.branch,
feature: {
...value.branch.feature,
value: null,
},
},
});
} else {
this._trySetPrefValue(experimentsPrefBranch, featureId, value);
}
},
setDefault(featureId, enrollment) {
/* We store configuration variables separately in pref branches of
* appropriate type:
* (feature: "foo") { variables: { enabled: true } }
* gets stored as `${SYNC_DEFAULTS_PREF_BRANCH}foo.enabled=true`
*/
let { feature } = enrollment.branch;
for (let variable of Object.keys(feature.value)) {
let prefName = `${SYNC_DEFAULTS_PREF_BRANCH}${featureId}.${variable}`;
this._trySetTypedPrefValue(prefName, feature.value[variable]);
}
this._trySetPrefValue(defaultsPrefBranch, featureId, {
...enrollment,
branch: {
...enrollment.branch,
feature: {
...enrollment.branch.feature,
value: null,
},
},
});
},
getAllDefaultBranches() {
return defaultsPrefBranch.getChildList("").filter(
// Filter out remote defaults variable prefs
pref => !pref.includes(".")
);
},
delete(featureId) {
const prefBranch = `${SYNC_DATA_PREF_BRANCH}${featureId}.`;
this._clearBranchChildValues(prefBranch);
try {
experimentsPrefBranch.clearUserPref(featureId);
} catch (e) {}
},
deleteDefault(featureId) {
let prefBranch = `${SYNC_DEFAULTS_PREF_BRANCH}${featureId}.`;
this._clearBranchChildValues(prefBranch);
try {
defaultsPrefBranch.clearUserPref(featureId);
} catch (e) {}
},
};
});
const DEFAULT_STORE_ID = "ExperimentStoreData";
/**
* Returns all feature ids associated with the branch provided.
* Fallback for when `featureIds` was not persisted to disk. Can be removed
*
* @param {Branch} branch
* @returns {string[]}
*/
function getAllBranchFeatureIds(branch) {
return featuresCompat(branch).map(f => f.featureId);
}
function featuresCompat(branch) {
if (!branch || (!branch.feature && !branch.features)) {
return [];
}
let { features } = branch;
// In <=v1.5.0 of the Nimbus API, experiments had single feature
if (!features) {
features = [branch.feature];
}
return features;
}
export class ExperimentStore extends SharedDataMap {
static SYNC_DATA_PREF_BRANCH = SYNC_DATA_PREF_BRANCH;
static SYNC_DEFAULTS_PREF_BRANCH = SYNC_DEFAULTS_PREF_BRANCH;
constructor(sharedDataKey, options = { isParent: IS_MAIN_PROCESS }) {
super(sharedDataKey || DEFAULT_STORE_ID, options);
}
async init() {
await super.init();
this.getAllActiveExperiments().forEach(({ branch, featureIds }) => {
(featureIds || getAllBranchFeatureIds(branch)).forEach(featureId =>
this._emitFeatureUpdate(featureId, "feature-experiment-loaded")
);
});
this.getAllActiveRollouts().forEach(({ featureIds }) => {
featureIds.forEach(featureId =>
this._emitFeatureUpdate(featureId, "feature-rollout-loaded")
);
});
Services.tm.idleDispatchToMainThread(() => this._cleanupOldRecipes());
}
/**
* Given a feature identifier, find an active experiment that matches that feature identifier.
* This assumes, for now, that there is only one active experiment per feature per browser.
* Does not activate the experiment (send an exposure event)
*
* @param {string} featureId
* @returns {Enrollment|undefined} An active experiment if it exists
* @memberof ExperimentStore
*/
getExperimentForFeature(featureId) {
return (
this.getAllActiveExperiments().find(
experiment =>
experiment.featureIds?.includes(featureId) ||
// Supports <v1.3.0, which was when .featureIds was added
getAllBranchFeatureIds(experiment.branch).includes(featureId)
// Default to the pref store if data is not yet ready
) || lazy.syncDataStore.get(featureId)
);
}
/**
* Check if an active experiment already exists for a feature.
* Does not activate the experiment (send an exposure event)
*
* @param {string} featureId
* @returns {boolean} Does an active experiment exist for that feature?
* @memberof ExperimentStore
*/
hasExperimentForFeature(featureId) {
if (!featureId) {
return false;
}
return !!this.getExperimentForFeature(featureId);
}
/**
* @returns {Enrollment[]}
*/
getAll() {
let data = [];
try {
data = Object.values(this._data || {});
} catch (e) {
console.error(e);
}
return data;
}
/**
* Returns all active experiments
* @returns {Enrollment[]}
*/
getAllActiveExperiments() {
return this.getAll().filter(
enrollment => enrollment.active && !enrollment.isRollout
);
}
/**
* Returns all active rollouts
* @returns {Enrollment[]}
*/
getAllActiveRollouts() {
return this.getAll().filter(
enrollment => enrollment.active && enrollment.isRollout
);
}
/**
* Query the store for the remote configuration of a feature
* @param {string} featureId The feature we want to query for
* @returns {{Rollout}|undefined} Remote defaults if available
*/
getRolloutForFeature(featureId) {
return (
this.getAllActiveRollouts().find(r => r.featureIds.includes(featureId)) ||
lazy.syncDataStore.getDefault(featureId)
);
}
/**
* Check if an active rollout already exists for a feature.
* Does not active the experiment (send an exposure event).
*
* @param {string} featureId
* @returns {boolean} Does an active rollout exist for that feature?
*/
hasRolloutForFeature(featureId) {
if (!featureId) {
return false;
}
return !!this.getRolloutForFeature(featureId);
}
/**
* Remove inactive enrollments older than 6 months
*/
_cleanupOldRecipes() {
// Roughly six months
const threshold = 15552000000;
const nowTimestamp = new Date().getTime();
const recipesToRemove = this.getAll().filter(
experiment =>
!experiment.active &&
// Flip the comparison here to catch scenarios in which lastSeen is
// invalid or undefined. The result with be a comparison with NaN
// which is always false
!(nowTimestamp - new Date(experiment.lastSeen).getTime() < threshold)
);
this._removeEntriesByKeys(recipesToRemove.map(r => r.slug));
}
_emitUpdates(enrollment) {
this.emit(`update:${enrollment.slug}`, enrollment);
const featureIds =
enrollment.featureIds || getAllBranchFeatureIds(enrollment.branch);
const reason = enrollment.isRollout
? "rollout-updated"
: "experiment-updated";
for (const featureId of featureIds) {
this._emitFeatureUpdate(featureId, reason);
}
}
_emitFeatureUpdate(featureId, reason) {
this.emit(`featureUpdate:${featureId}`, reason);
}
_onFeatureUpdate(featureId, callback) {
if (this._isReady) {
const hasExperiment = this.hasExperimentForFeature(featureId);
if (hasExperiment || this.hasRolloutForFeature(featureId)) {
callback(
`featureUpdate:${featureId}`,
hasExperiment ? "experiment-updated" : "rollout-updated"
);
}
}
this.on(`featureUpdate:${featureId}`, callback);
}
_offFeatureUpdate(featureId, callback) {
this.off(`featureUpdate:${featureId}`, callback);
}
/**
* Persists early startup experiments or rollouts
* @param {Enrollment} enrollment Experiment or rollout
*/
_updateSyncStore(enrollment) {
let features = featuresCompat(enrollment.branch);
for (let feature of features) {
if (
lazy.FeatureManifest[feature.featureId]?.isEarlyStartup ||
feature.isEarlyStartup
) {
if (!enrollment.active) {
// Remove experiments on un-enroll, no need to check if it exists
if (enrollment.isRollout) {
lazy.syncDataStore.deleteDefault(feature.featureId);
} else {
lazy.syncDataStore.delete(feature.featureId);
}
} else {
let updateEnrollmentSyncStore = enrollment.isRollout
? lazy.syncDataStore.setDefault.bind(lazy.syncDataStore)
: lazy.syncDataStore.set.bind(lazy.syncDataStore);
updateEnrollmentSyncStore(feature.featureId, {
...enrollment,
branch: {
...enrollment.branch,
feature,
// Only store the early startup feature
features: null,
},
});
}
}
}
}
/**
* Add an enrollment and notify listeners
* @param {Enrollment} enrollment
*/
addEnrollment(enrollment) {
if (!enrollment || !enrollment.slug) {
throw new Error(
`Tried to add an experiment but it didn't have a .slug property.`
);
}
this.set(enrollment.slug, enrollment);
this._updateSyncStore(enrollment);
this._emitUpdates(enrollment);
}
/**
* Merge new properties into the properties of an existing experiment
* @param {string} slug
* @param {Partial<Enrollment>} newProperties
*/
updateExperiment(slug, newProperties) {
const oldProperties = this.get(slug);
if (!oldProperties) {
throw new Error(
`Tried to update experiment ${slug} but it doesn't exist`
);
}
const updatedExperiment = { ...oldProperties, ...newProperties };
this.set(slug, updatedExperiment);
this._updateSyncStore(updatedExperiment);
this._emitUpdates(updatedExperiment);
}
/**
* Test only helper for cleanup
*
* @param slugOrFeatureId Can be called with slug (which removes the SharedDataMap entry) or
* with featureId which removes the SyncDataStore entry for the feature
*/
_deleteForTests(slugOrFeatureId) {
super._deleteForTests(slugOrFeatureId);
lazy.syncDataStore.deleteDefault(slugOrFeatureId);
lazy.syncDataStore.delete(slugOrFeatureId);
}
}