servo/components/devtools/actors/root.rs
atbrakhi 71d97bd935
Devtools: send error replies instead of ignoring messages (#37686)
Client messages, which are always requests, are dispatched to Actor
instances one at a time via Actor::handle_message. Each request must be
paired with exactly one reply from the same actor the request was sent
to, where a reply is a message with no type (if a message from the
server has a type, it’s a notification, not a reply).

Failing to reply to a request will almost always permanently break that
actor, because either the client gets stuck waiting for a reply, or the
client receives the reply for a subsequent request as if it was the
reply for the current request. If an actor fails to reply to a request,
we want the dispatcher (ActorRegistry::handle_message) to send an error
of type `unrecognizedPacketType`, to keep the conversation for that
actor in sync. Since replies come in all shapes and sizes, we want to
allow Actor types to send replies without having to return them to the
dispatcher.

This patch adds a wrapper type around a client stream that guarantees
request/reply invariants. It allows the dispatcher to check if a valid
reply was sent, and guarantees that if the actor tries to send a reply,
it’s actually a valid reply (see ClientRequest::is_valid_reply). It does
not currently guarantee anything about messages sent via the TcpStream
released via ClientRequest::try_clone_stream or the return value of
ClientRequest::reply. We also send `unrecognizedPacketType`,
`missingParameter`, `badParameterType`, and `noSuchActor` messages per
the
[protocol](https://firefox-source-docs.mozilla.org/devtools/backend/protocol.html#error-packets)
[docs](https://firefox-source-docs.mozilla.org/devtools/backend/protocol.html#packets).

Testing: automated tests all pass, and manual testing looks ok
Fixes: #37683 and at least six bugs, plus one with a different root
cause, plus three with zero impact

---------

Signed-off-by: atbrakhi <atbrakhi@igalia.com>
Signed-off-by: Delan Azabani <dazabani@igalia.com>
Co-authored-by: delan azabani <dazabani@igalia.com>
Co-authored-by: Simon Wülker <simon.wuelker@arcor.de>
Co-authored-by: the6p4c <me@doggirl.gay>
2025-07-07 12:40:44 +00:00

299 lines
8.5 KiB
Rust

/* 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
* file, You can obtain one at https://mozilla.org/MPL/2.0/. */
//! Connection point for all new remote devtools interactions, providing lists of know actors
//! that perform more specific actions (targets, addons, browser chrome, etc.)
//!
//! Liberally derived from the [Firefox JS implementation].
//!
//! [Firefox JS implementation]: https://searchfox.org/mozilla-central/source/devtools/server/actors/root.js
use std::cell::RefCell;
use serde::Serialize;
use serde_json::{Map, Value, json};
use crate::StreamId;
use crate::actor::{Actor, ActorError, ActorRegistry};
use crate::actors::device::DeviceActor;
use crate::actors::performance::PerformanceActor;
use crate::actors::process::{ProcessActor, ProcessActorMsg};
use crate::actors::tab::{TabDescriptorActor, TabDescriptorActorMsg};
use crate::actors::worker::{WorkerActor, WorkerMsg};
use crate::protocol::{ActorDescription, ClientRequest};
#[derive(Serialize)]
#[serde(rename_all = "camelCase")]
struct ActorTraits {
sources: bool,
highlightable: bool,
custom_highlighters: bool,
network_monitor: bool,
}
#[derive(Serialize)]
struct ListAddonsReply {
from: String,
addons: Vec<AddonMsg>,
}
#[derive(Serialize)]
enum AddonMsg {}
#[derive(Serialize)]
#[serde(rename_all = "camelCase")]
struct GetRootReply {
from: String,
selected: u32,
performance_actor: String,
device_actor: String,
preference_actor: String,
}
#[derive(Serialize)]
struct ListTabsReply {
from: String,
tabs: Vec<TabDescriptorActorMsg>,
}
#[derive(Serialize)]
struct GetTabReply {
from: String,
tab: TabDescriptorActorMsg,
}
#[derive(Serialize)]
#[serde(rename_all = "camelCase")]
pub struct RootActorMsg {
from: String,
application_type: String,
traits: ActorTraits,
}
#[derive(Serialize)]
pub struct ProtocolDescriptionReply {
from: String,
types: Types,
}
#[derive(Serialize)]
struct ListWorkersReply {
from: String,
workers: Vec<WorkerMsg>,
}
#[derive(Serialize)]
struct ListServiceWorkerRegistrationsReply {
from: String,
registrations: Vec<u32>, // TODO: follow actual JSON structure.
}
#[derive(Serialize)]
pub struct Types {
performance: ActorDescription,
device: ActorDescription,
}
#[derive(Serialize)]
struct ListProcessesResponse {
from: String,
processes: Vec<ProcessActorMsg>,
}
#[derive(Default, Serialize)]
#[serde(rename_all = "camelCase")]
pub struct DescriptorTraits {
pub(crate) watcher: bool,
pub(crate) supports_reload_descriptor: bool,
}
#[derive(Serialize)]
#[serde(rename_all = "camelCase")]
struct GetProcessResponse {
from: String,
process_descriptor: ProcessActorMsg,
}
pub struct RootActor {
pub tabs: Vec<String>,
pub workers: Vec<String>,
pub performance: String,
pub device: String,
pub preference: String,
pub process: String,
pub active_tab: RefCell<Option<String>>,
}
impl Actor for RootActor {
fn name(&self) -> String {
"root".to_owned()
}
fn handle_message(
&self,
request: ClientRequest,
registry: &ActorRegistry,
msg_type: &str,
msg: &Map<String, Value>,
_id: StreamId,
) -> Result<(), ActorError> {
match msg_type {
"connect" => {
let message = json!({
"from": "root",
});
request.reply_final(&message)?
},
"listAddons" => {
let actor = ListAddonsReply {
from: "root".to_owned(),
addons: vec![],
};
request.reply_final(&actor)?
},
"listProcesses" => {
let process = registry.find::<ProcessActor>(&self.process).encodable();
let reply = ListProcessesResponse {
from: self.name(),
processes: vec![process],
};
request.reply_final(&reply)?
},
// TODO: Unexpected message getTarget for process (when inspecting)
"getProcess" => {
let process = registry.find::<ProcessActor>(&self.process).encodable();
let reply = GetProcessResponse {
from: self.name(),
process_descriptor: process,
};
request.reply_final(&reply)?
},
"getRoot" => {
let actor = GetRootReply {
from: "root".to_owned(),
selected: 0,
performance_actor: self.performance.clone(),
device_actor: self.device.clone(),
preference_actor: self.preference.clone(),
};
request.reply_final(&actor)?
},
"listTabs" => {
let actor = ListTabsReply {
from: "root".to_owned(),
tabs: self
.tabs
.iter()
.filter_map(|target| {
let tab_actor = registry.find::<TabDescriptorActor>(target);
// Filter out iframes and workers
if tab_actor.is_top_level_global() {
Some(tab_actor.encodable(registry, false))
} else {
None
}
})
.collect(),
};
request.reply_final(&actor)?
},
"listServiceWorkerRegistrations" => {
let reply = ListServiceWorkerRegistrationsReply {
from: self.name(),
registrations: vec![],
};
request.reply_final(&reply)?
},
"listWorkers" => {
let reply = ListWorkersReply {
from: self.name(),
workers: self
.workers
.iter()
.map(|name| registry.find::<WorkerActor>(name).encodable())
.collect(),
};
request.reply_final(&reply)?
},
"getTab" => {
let browser_id = msg
.get("browserId")
.ok_or(ActorError::MissingParameter)?
.as_u64()
.ok_or(ActorError::BadParameterType)?;
let Some(tab) = self.get_tab_msg_by_browser_id(registry, browser_id as u32) else {
return Err(ActorError::Internal);
};
let reply = GetTabReply {
from: self.name(),
tab,
};
request.reply_final(&reply)?
},
"protocolDescription" => {
let msg = ProtocolDescriptionReply {
from: self.name(),
types: Types {
performance: PerformanceActor::description(),
device: DeviceActor::description(),
},
};
request.reply_final(&msg)?
},
_ => return Err(ActorError::UnrecognizedPacketType),
};
Ok(())
}
}
impl RootActor {
pub fn encodable(&self) -> RootActorMsg {
RootActorMsg {
from: "root".to_owned(),
application_type: "browser".to_owned(),
traits: ActorTraits {
sources: false,
highlightable: true,
custom_highlighters: true,
network_monitor: true,
},
}
}
fn get_tab_msg_by_browser_id(
&self,
registry: &ActorRegistry,
browser_id: u32,
) -> Option<TabDescriptorActorMsg> {
let tab_msg = self
.tabs
.iter()
.map(|target| {
registry
.find::<TabDescriptorActor>(target)
.encodable(registry, true)
})
.find(|tab| tab.browser_id() == browser_id);
if let Some(ref msg) = tab_msg {
*self.active_tab.borrow_mut() = Some(msg.actor());
}
tab_msg
}
#[allow(dead_code)]
pub fn active_tab(&self) -> Option<String> {
self.active_tab.borrow().clone()
}
}