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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
/**
* Helper module around `sharedData` object that helps storing the state
* of all observed Targets and Resources, that, for all DevTools connections.
* Here is a few words about the C++ implementation of sharedData:
*
* We may have more than one DevToolsServer and one server may have more than one
* client. This module will be the single source of truth in the parent process,
* in order to know which targets/resources are currently observed. It will also
* be used to declare when something starts/stops being observed.
*
* `sharedData` is a platform API that helps sharing JS Objects across processes.
* We use it in order to communicate to the content process which targets and resources
* should be observed. Content processes read this data only once, as soon as they are created.
* It isn't used beyond this point. Content processes are not going to update it.
* We will notify about changes in observed targets and resources for already running
* processes by some other means. (Via JS Window Actor queries "DevTools:(un)watch(Resources|Target)")
* This means that only this module will update the "DevTools:watchedPerWatcher" value.
* From the parent process, we should be going through this module to fetch the data,
* while from the content process, we will read `sharedData` directly.
*/
const { SessionDataHelpers } = ChromeUtils.importESModule(
{ global: "contextual" }
);
const { SUPPORTED_DATA } = SessionDataHelpers;
const SUPPORTED_DATA_TYPES = Object.values(SUPPORTED_DATA);
// Define the Map that will be saved in `sharedData`.
// It is keyed by WatcherActor ID and values contains following attributes:
// - targets: Set of strings, refering to target types to be listened to
// - resources: Set of strings, refering to resource types to be observed
// - sessionContext Object, The Session Context to help know what is debugged.
// See devtools/server/actors/watcher/session-context.js
// - connectionPrefix: The DevToolsConnection prefix of the watcher actor. Used to compute new actor ID in the content processes.
//
// Unfortunately, `sharedData` is subject to race condition and may have side effect
// when read/written from multiple places in the same process,
// which is why this map should be considered as the single source of truth.
const sessionDataByWatcherActor = new Map();
// In parallel to the previous map, keep all the WatcherActor keyed by the same WatcherActor ID,
// the WatcherActor ID. We don't (and can't) propagate the WatcherActor instances to the content
// processes, but still would like to match them by their ID.
const watcherActors = new Map();
// Name of the attribute into which we save this Map in `sharedData` object.
const SHARED_DATA_KEY_NAME = "DevTools:watchedPerWatcher";
/**
* Use `sharedData` to allow processes, early during their creation,
* to know which resources should be listened to. This will be read
* from the Target actor, when it gets created early during process start,
* in order to start listening to the expected resource types.
*/
function persistMapToSharedData() {
Services.ppmm.sharedData.set(SHARED_DATA_KEY_NAME, sessionDataByWatcherActor);
// Request to immediately flush the data to the content processes in order to prevent
// and try to create targets for Watcher actor that already stopped watching for targets.
Services.ppmm.sharedData.flush();
}
export const ParentProcessWatcherRegistry = {
/**
* Tells if a given watcher currently watches for a given target type.
*
* @param WatcherActor watcher
* The WatcherActor which should be listening.
* @param string targetType
* The new target type to query.
* @return boolean
* Returns true if already watching.
*/
isWatchingTargets(watcher, targetType) {
const sessionData = this.getSessionData(watcher);
return !!sessionData?.targets?.includes(targetType);
},
/**
* Retrieve the data saved into `sharedData` that is used to know
* about which type of targets and resources we care listening about.
* `sessionDataByWatcherActor` is saved into `sharedData` after each mutation,
* but `sessionDataByWatcherActor` is the source of truth.
*
* @param WatcherActor watcher
* The related WatcherActor which starts/stops observing.
* @param object options (optional)
* A dictionary object with `createData` boolean attribute.
* If this attribute is set to true, we create the data structure in the Map
* if none exists for this prefix.
*/
getSessionData(watcher, { createData = false } = {}) {
// Use WatcherActor ID as a key as we may have multiple clients willing to watch for targets.
// For example, a Browser Toolbox debugging everything and a Content Toolbox debugging
// just one tab. We might also have multiple watchers, on the same connection when using about:debugging.
const watcherActorID = watcher.actorID;
let sessionData = sessionDataByWatcherActor.get(watcherActorID);
if (!sessionData && createData) {
sessionData = {
// The "session context" object help understand what should be debugged and which target should be created.
// See WatcherActor constructor for more info.
sessionContext: watcher.sessionContext,
// The DevToolsServerConnection prefix will be used to compute actor IDs created in the content process
connectionPrefix: watcher.conn.prefix,
};
sessionDataByWatcherActor.set(watcherActorID, sessionData);
watcherActors.set(watcherActorID, watcher);
}
return sessionData;
},
/**
* Given a Watcher Actor ID, return the related Watcher Actor instance.
*
* @param String actorID
* The Watcher Actor ID to search for.
* @return WatcherActor
* The Watcher Actor instance.
*/
getWatcher(actorID) {
return watcherActors.get(actorID);
},
/**
* Return an array of the watcher actors that match the passed browserId
*
* @param {Number} browserId
* @returns {Array<WatcherActor>} An array of the matching watcher actors
*/
getWatchersForBrowserId(browserId) {
const watchers = [];
for (const watcherActor of watcherActors.values()) {
if (
watcherActor.sessionContext.type == "browser-element" &&
watcherActor.sessionContext.browserId === browserId
) {
watchers.push(watcherActor);
}
}
return watchers;
},
/**
* Notify that a given watcher added or set some entries for given data type.
*
* @param WatcherActor watcher
* The WatcherActor which starts observing.
* @param string type
* The type of data to be added
* @param Array<Object> entries
* The values to be added to this type of data
* @param String updateType
* "add" will only add the new entries in the existing data set.
* "set" will update the data set with the new entries.
*/
addOrSetSessionDataEntry(watcher, type, entries, updateType) {
const sessionData = this.getSessionData(watcher, {
createData: true,
});
if (!SUPPORTED_DATA_TYPES.includes(type)) {
throw new Error(`Unsupported session data type: ${type}`);
}
SessionDataHelpers.addOrSetSessionDataEntry(
sessionData,
type,
entries,
updateType
);
// Flush sharedData before registering the JS Actors as it is used
// during their instantiation.
persistMapToSharedData();
// Register the JS Window Actor the first time we start watching for something (e.g. resource, target, …).
if (watcher.sessionContext.type == "all") {
registerBrowserToolboxJSProcessActor();
} else {
registerJSProcessActor();
}
},
/**
* Notify that a given watcher removed an entry in a given data type.
*
* @param WatcherActor watcher
* The WatcherActor which stops observing.
* @param string type
* The type of data to be removed
* @param Array<Object> entries
* The values to be removed to this type of data
* @params {Object} options
* @params {Boolean} options.isModeSwitching: Set to true true when this is called as the
* result of a change to the devtools.browsertoolbox.scope pref.
*
* @return boolean
* True if we such entry was already registered, for this watcher actor.
*/
removeSessionDataEntry(watcher, type, entries, options) {
const sessionData = this.getSessionData(watcher);
if (!sessionData) {
return false;
}
if (!SUPPORTED_DATA_TYPES.includes(type)) {
throw new Error(`Unsupported session data type: ${type}`);
}
if (
!SessionDataHelpers.removeSessionDataEntry(sessionData, type, entries)
) {
return false;
}
const isWatchingSomething = SUPPORTED_DATA_TYPES.some(
dataType => sessionData[dataType] && !!sessionData[dataType].length
);
// Remove the watcher reference if it's not watching for anything anymore, unless we're
// doing a mode switch; in such case we don't mean to end the DevTools session, so we
// still want to have access to the underlying data (furthermore, such case should only
// happen in tests, in a regular workflow we'd still be watching for resources).
if (!isWatchingSomething && !options?.isModeSwitching) {
sessionDataByWatcherActor.delete(watcher.actorID);
watcherActors.delete(watcher.actorID);
}
persistMapToSharedData();
return true;
},
/**
* Cleanup everything about a given watcher actor.
* Remove it from any registry so that we stop interacting with it.
*
* The watcher would be automatically unregistered from removeWatcherEntry,
* if we remove all entries. But we aren't removing all breakpoints.
* So here, we force clearing any reference to the watcher actor when it destroys.
*/
unregisterWatcher(watcherActorID) {
sessionDataByWatcherActor.delete(watcherActorID);
watcherActors.delete(watcherActorID);
this.maybeUnregisterJSActors();
},
/**
* Unregister the JS Actors if there is no more DevTools code observing any target/resource.
*/
maybeUnregisterJSActors() {
if (sessionDataByWatcherActor.size == 0) {
unregisterBrowserToolboxJSProcessActor();
unregisterJSProcessActor();
}
},
/**
* Notify that a given watcher starts observing a new target type.
*
* @param WatcherActor watcher
* The WatcherActor which starts observing.
* @param string targetType
* The new target type to start listening to.
*/
watchTargets(watcher, targetType) {
this.addOrSetSessionDataEntry(
watcher,
SUPPORTED_DATA.TARGETS,
[targetType],
"add"
);
},
/**
* Notify that a given watcher stops observing a given target type.
*
* @param WatcherActor watcher
* The WatcherActor which stops observing.
* @param string targetType
* The new target type to stop listening to.
* @params {Object} options
* @params {Boolean} options.isModeSwitching: Set to true true when this is called as the
* result of a change to the devtools.browsertoolbox.scope pref.
* @return boolean
* True if we were watching for this target type, for this watcher actor.
*/
unwatchTargets(watcher, targetType, options) {
return this.removeSessionDataEntry(
watcher,
SUPPORTED_DATA.TARGETS,
[targetType],
options
);
},
/**
* Notify that a given watcher starts observing new resource types.
*
* @param WatcherActor watcher
* The WatcherActor which starts observing.
* @param Array<string> resourceTypes
* The new resource types to start listening to.
*/
watchResources(watcher, resourceTypes) {
this.addOrSetSessionDataEntry(
watcher,
SUPPORTED_DATA.RESOURCES,
resourceTypes,
"add"
);
},
/**
* Notify that a given watcher stops observing given resource types.
*
* See `watchResources` for argument definition.
*
* @return boolean
* True if we were watching for this resource type, for this watcher actor.
*/
unwatchResources(watcher, resourceTypes) {
return this.removeSessionDataEntry(
watcher,
SUPPORTED_DATA.RESOURCES,
resourceTypes
);
},
};
// Boolean flag to know if the DevToolsProcess JS Process Actor is currently registered
let isJSProcessActorRegistered = false;
let isBrowserToolboxJSProcessActorRegistered = false;
const JSProcessActorConfig = {
parent: {
esModuleURI:
},
child: {
esModuleURI:
// There is no good observer service notification we can listen to to instantiate the JSProcess Actor
// reliably as soon as the process start.
// So manually spawn our JSProcessActor from a process script emitting a custom observer service notification...
observers: ["init-devtools-content-process-actor"],
},
// The parent process is handled very differently from content processes
// This uses the ParentProcessTarget which inherits from BrowsingContextTarget
// and is, for now, manually created by the descriptor as the top level target.
includeParent: true,
};
const BrowserToolboxJSProcessActorConfig = {
...JSProcessActorConfig,
// This JS Process Actor is used to bootstrap DevTools code debugging the privileged code
// in content processes. The privileged code runs in the "shared JSM global" (See mozJSModuleLoader).
// DevTools modules should be loaded in a distinct global in order to be able to debug this privileged code.
// There is a strong requirement in spidermonkey for the debuggee and debugger to be using distinct compartments.
// This flag will force both parent and child modules to be loaded via a dedicated loader (See mozJSModuleLoader::GetOrCreateDevToolsLoader)
//
// Note that as a side effect, it makes these modules and all their dependencies to be invisible to the debugger.
loadInDevToolsLoader: true,
};
const PROCESS_SCRIPT_URL =
function registerJSProcessActor() {
if (isJSProcessActorRegistered) {
return;
}
isJSProcessActorRegistered = true;
ChromeUtils.registerProcessActor("DevToolsProcess", JSProcessActorConfig);
// There is no good observer service notification we can listen to to instantiate the JSProcess Actor
// as soon as the process start.
// So manually spawn our JSProcessActor from a process script emitting a custom observer service notification...
Services.ppmm.loadProcessScript(PROCESS_SCRIPT_URL, true);
}
function registerBrowserToolboxJSProcessActor() {
if (isBrowserToolboxJSProcessActorRegistered) {
return;
}
isBrowserToolboxJSProcessActorRegistered = true;
ChromeUtils.registerProcessActor(
"BrowserToolboxDevToolsProcess",
BrowserToolboxJSProcessActorConfig
);
// There is no good observer service notification we can listen to to instantiate the JSProcess Actor
// as soon as the process start.
// So manually spawn our JSProcessActor from a process script emitting a custom observer service notification...
Services.ppmm.loadProcessScript(PROCESS_SCRIPT_URL, true);
}
function unregisterJSProcessActor() {
if (!isJSProcessActorRegistered) {
return;
}
isJSProcessActorRegistered = false;
try {
ChromeUtils.unregisterProcessActor("DevToolsProcess");
} catch (e) {
// If any pending query was still ongoing, this would throw
}
if (isBrowserToolboxJSProcessActorRegistered) {
return;
}
Services.ppmm.removeDelayedProcessScript(PROCESS_SCRIPT_URL);
}
function unregisterBrowserToolboxJSProcessActor() {
if (!isBrowserToolboxJSProcessActorRegistered) {
return;
}
isBrowserToolboxJSProcessActorRegistered = false;
try {
ChromeUtils.unregisterProcessActor("BrowserToolboxDevToolsProcess");
} catch (e) {
// If any pending query was still ongoing, this would throw
}
if (isJSProcessActorRegistered) {
return;
}
Services.ppmm.removeDelayedProcessScript(PROCESS_SCRIPT_URL);
}