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//! IPC handling thread/task. Handles communication between [`Mpv`](crate::Mpv) instances and mpv's unix socket
use futures::{SinkExt, StreamExt};
use serde_json::{json, Value};
use tokio::{
net::UnixStream,
sync::{broadcast, mpsc, oneshot},
};
use tokio_util::codec::{Framed, LinesCodec};
use crate::MpvError;
/// Container for all state that regards communication with the mpv IPC socket
/// and message passing with [`Mpv`](crate::Mpv) controllers.
pub(crate) struct MpvIpc {
socket: Framed<UnixStream, LinesCodec>,
command_channel: mpsc::Receiver<(MpvIpcCommand, oneshot::Sender<MpvIpcResponse>)>,
event_channel: broadcast::Sender<MpvIpcEvent>,
}
/// Commands that can be sent to [`MpvIpc`]
#[derive(Debug, Clone, PartialEq, Eq)]
pub(crate) enum MpvIpcCommand {
Command(Vec<String>),
GetProperty(String),
SetProperty(String, Value),
ObserveProperty(usize, String),
UnobserveProperty(usize),
Exit,
/// [`MpvIpc`]'s response to a [`MpvIpcCommand`].
#[derive(Debug)]
pub(crate) struct MpvIpcResponse(pub(crate) Result<Option<Value>, MpvError>);
/// A deserialized and partially parsed event from mpv.
#[derive(Debug, Clone)]
pub(crate) struct MpvIpcEvent(pub(crate) Value);
impl MpvIpc {
pub(crate) fn new(
socket: UnixStream,
) -> Self {
MpvIpc {
socket: Framed::new(socket, LinesCodec::new()),
command_channel,
event_channel,
pub(crate) async fn send_command(
&mut self,
command: &[Value],
) -> Result<Option<Value>, MpvError> {
let ipc_command = json!({ "command": command });
let ipc_command_str =
serde_json::to_string(&ipc_command).map_err(MpvError::JsonParseError)?;
log::trace!("Sending command: {}", ipc_command_str);
self.socket
.send(ipc_command_str)
.await
.map_err(|why| MpvError::MpvSocketConnectionError(why.to_string()))?;
let response = loop {
let response = self
.socket
.next()
.ok_or(MpvError::MpvSocketConnectionError(
"Could not receive response from mpv".to_owned(),
))?
let parsed_response =
serde_json::from_str::<Value>(&response).map_err(MpvError::JsonParseError);
if parsed_response
.as_ref()
.ok()
.and_then(|v| v.as_object().map(|o| o.contains_key("event")))
.unwrap_or(false)
{
self.handle_event(parsed_response).await;
} else {
break parsed_response;
log::trace!("Received response: {:?}", response);
parse_mpv_response_data(response?)
pub(crate) async fn get_mpv_property(
property: &str,
self.send_command(&[json!("get_property"), json!(property)])
pub(crate) async fn set_mpv_property(
value: Value,
self.send_command(&[json!("set_property"), json!(property), value])
pub(crate) async fn observe_property(
id: usize,
self.send_command(&[json!("observe_property"), json!(id), json!(property)])
pub(crate) async fn unobserve_property(
self.send_command(&[json!("unobserve_property"), json!(id)])
async fn handle_event(&mut self, event: Result<Value, MpvError>) {
match &event {
Ok(event) => {
log::trace!("Parsed event: {:?}", event);
if let Err(broadcast::error::SendError(_)) =
self.event_channel.send(MpvIpcEvent(event.to_owned()))
log::trace!("Failed to send event to channel, ignoring");
Err(e) => {
log::trace!("Error parsing event, ignoring:\n {:?}\n {:?}", &event, e);
pub(crate) async fn run(mut self) -> Result<(), MpvError> {
loop {
tokio::select! {
Some(event) = self.socket.next() => {
log::trace!("Got event: {:?}", event);
let parsed_event = event
.map_err(|why| MpvError::MpvSocketConnectionError(why.to_string()))
.and_then(|event|
serde_json::from_str::<Value>(&event)
.map_err(MpvError::JsonParseError));
self.handle_event(parsed_event).await;
Some((cmd, tx)) = self.command_channel.recv() => {
log::trace!("Handling command: {:?}", cmd);
match cmd {
MpvIpcCommand::Command(command) => {
let refs = command.iter().map(|s| json!(s)).collect::<Vec<Value>>();
let response = self.send_command(refs.as_slice()).await;
tx.send(MpvIpcResponse(response)).unwrap()
MpvIpcCommand::GetProperty(property) => {
let response = self.get_mpv_property(&property).await;
MpvIpcCommand::SetProperty(property, value) => {
let response = self.set_mpv_property(&property, value).await;
MpvIpcCommand::ObserveProperty(id, property) => {
let response = self.observe_property(id, &property).await;
MpvIpcCommand::UnobserveProperty(id) => {
let response = self.unobserve_property(id).await;
MpvIpcCommand::Exit => {
tx.send(MpvIpcResponse(Ok(None))).unwrap();
return Ok(());
/// This function does the most basic JSON parsing and error handling
/// for status codes and errors that all responses from mpv are
/// expected to contain.
fn parse_mpv_response_data(value: Value) -> Result<Option<Value>, MpvError> {
log::trace!("Parsing mpv response data: {:?}", value);
let result = value
.as_object()
.ok_or(MpvError::ValueContainsUnexpectedType {
expected_type: "object".to_string(),
received: value.clone(),
})
.and_then(|o| {
let error = o
.get("error")
.ok_or(MpvError::MissingKeyInObject {
key: "error".to_string(),
map: o.clone(),
})?
.as_str()
expected_type: "string".to_string(),
received: o.get("error").unwrap().clone(),
})?;
let data = o.get("data");
Ok((error, data))
.and_then(|(error, data)| match error {
"success" => Ok(data),
"property unavailable" => Ok(None),
err => Err(MpvError::MpvError(err.to_string())),
});
match &result {
Ok(v) => log::trace!("Successfully parsed mpv response data: {:?}", v),
Err(e) => log::trace!("Error parsing mpv response data: {:?}", e),
result.map(|opt| opt.cloned())