dbus-0.2.3/src/objpath.rs

use super::{Connection, Message, MessageItem, Error, TypeSig};
use std::collections::BTreeMap;
use std::rc::Rc;
use std::cell::{Cell, RefCell};
use std::borrow::Cow;

/// a Method has a list of Arguments.
pub struct Argument<'a> {
    name: &'a str,
    sig: TypeSig<'a>,
}

impl<'a> Argument<'a> {
    /// Create a new Argument.
    pub fn new<T: Into<Cow<'a, str>>>(name: &'a str, sig: T) -> Argument<'a> {
        Argument { name: name, sig: sig.into() }
    }
}

struct Annotation {
    name: String,
    value: String,
}

struct ISignal<'a> {
    args: Vec<Argument<'a>>,
    anns: Vec<Annotation>,
}

/// Declares that an Interface can send this signal
pub struct Signal<'a> {
    name: String,
    i: ISignal<'a>,
}

impl<'a> Signal<'a> {
    /// Create a new Signal.
    pub fn new<N: ToString>(name: N, args: Vec<Argument<'a>>) -> Signal<'a> {
        Signal { name: name.to_string(), i: ISignal { args: args, anns: vec![] } }
    }

    /// Add an Annotation to the Signal.
    pub fn annotate<N: ToString, V: ToString>(&mut self, name: N, value: V) {
        self.i.anns.push(Annotation { name: name.to_string(), value: value.to_string() });
    }
}

/// A method returns either a list of MessageItems, or an error - the tuple
/// represents the name and message of the Error.
pub type MethodResult = Result<Vec<MessageItem>, (&'static str, String)>;
/// Contains the retrieved MessageItem or an error tuple containing the
/// name and message of the error.
pub type PropertyGetResult = Result<MessageItem, (&'static str, String)>;
/// Contains () or an error tuple containing the name and message of
/// the error.
pub type PropertySetResult = Result<(), (&'static str, String)>;

/// A boxed closure for dynamic dispatch. It is called when the method is
/// called by a remote application.
pub type MethodHandler<'a> = Box<FnMut(&mut Message) -> MethodResult + 'a>;

struct IMethod<'a> {
    in_args: Vec<Argument<'a>>,
    out_args: Vec<Argument<'a>>,
    cb: Rc<RefCell<MethodHandler<'a>>>,
    anns: Vec<Annotation>,
}

/// a method that can be called from another application
pub struct Method<'a> {
    name: String,
    i: IMethod<'a>
}

impl<'a> Method<'a> {
    /// Create a new Method.
    pub fn new<N: ToString>(name: N, in_args: Vec<Argument<'a>>,
            out_args: Vec<Argument<'a>>, cb: MethodHandler<'a>) -> Method<'a> {
        Method { name: name.to_string(), i: IMethod {
            in_args: in_args, out_args: out_args, cb: Rc::new(RefCell::new(cb)), anns: vec![] }
        }
    }

    /// Add an Annotation to the Method.
    pub fn annotate<N: ToString, V: ToString>(&mut self, name: N, value: V) {
        self.i.anns.push(Annotation { name: name.to_string(), value: value.to_string() });
    }
}

/// A read/write property handler.
pub trait PropertyRWHandler {
    /// Get a property's value.
    fn get(&self) -> PropertyGetResult;
    /// Set a property's value.
    fn set(&self, &MessageItem) -> PropertySetResult;
}

/// A read-only property handler.
pub trait PropertyROHandler {
    /// Get a property's value.
    fn get(&self) -> PropertyGetResult;
}

/// A write-only property handler.
pub trait PropertyWOHandler {
    /// Set a property's value.
    fn set(&self, &MessageItem) -> PropertySetResult;
}

/// Types of access to a Property.
pub enum PropertyAccess<'a> {
    RO(Box<PropertyROHandler+'a>),
    RW(Box<PropertyRWHandler+'a>),
    WO(Box<PropertyWOHandler+'a>),
}

struct IProperty<'a> {
    sig: TypeSig<'a>,
    access: PropertyAccess<'a>,
    anns: Vec<Annotation>,
}

/// Properties that a remote application can get/set.
pub struct Property<'a> {
    name: String,
    i: IProperty<'a>
}

impl<'a> Property<'a> {
    fn new<N: ToString>(name: N, sig: TypeSig<'a>, a: PropertyAccess<'a>) -> Property<'a> {
        Property { name: name.to_string(), i: IProperty { sig: sig, access: a, anns: vec![] } }
    }
    /// Creates a new read-only Property
    pub fn new_ro<N: ToString>(name: N, sig: TypeSig<'a>, h: Box<PropertyROHandler+'a>) -> Property<'a> {
        Property::new(name, sig, PropertyAccess::RO(h))
    }
    /// Creates a new read-write Property
    pub fn new_rw<N: ToString>(name: N, sig: TypeSig<'a>, h: Box<PropertyRWHandler+'a>) -> Property<'a> {
        Property::new(name, sig, PropertyAccess::RW(h))
    }
    /// Creates a new write-only Property
    pub fn new_wo<N: ToString>(name: N, sig: TypeSig<'a>, h: Box<PropertyWOHandler+'a>) -> Property<'a> {
        Property::new(name, sig, PropertyAccess::WO(h))
    }
    /// Add an annotation to the Property
    pub fn annotate<N: ToString, V: ToString>(&mut self, name: N, value: V) {
        self.i.anns.push(Annotation { name: name.to_string(), value: value.to_string() })
    }
}

/// Interfaces can contain Methods, Properties, and Signals.
pub struct Interface<'a> {
    methods: BTreeMap<String, IMethod<'a>>,
    properties: BTreeMap<String, IProperty<'a>>,
    signals: BTreeMap<String, ISignal<'a>>,
}

impl<'a> Interface<'a> {
    /// Create a new Interface.
    pub fn new(m: Vec<Method<'a>>, p: Vec<Property<'a>>, s: Vec<Signal<'a>>) -> Interface<'a> {
        Interface {
           methods: m.into_iter().map(|m| (m.name, m.i)).collect(),
           properties: p.into_iter().map(|p| (p.name, p.i)).collect(),
           signals: s.into_iter().map(|s| (s.name, s.i)).collect(),
        }
    }
}

struct IObjectPath<'a> {
    conn: &'a Connection,
    path: String,
    registered: Cell<bool>,
    interfaces: RefCell<BTreeMap<String, Interface<'a>>>,
}

/// Represents a D-Bus object path, which can in turn contain Interfaces.
pub struct ObjectPath<'a> {
    // We need extra references for the introspector and property handlers, hence this extra boxing
    i: Rc<IObjectPath<'a>>,
}

impl<'a> Drop for ObjectPath<'a> {
    fn drop(&mut self) {
        let _ = self.i.set_registered(false);
        self.i.interfaces.borrow_mut().clear(); // This should remove all the other references to i
    }
}

fn introspect_args(args: &Vec<Argument>, indent: &str, dir: &str) -> String {
    args.iter().fold("".to_string(), |aa, az| {
        format!("{}{}<arg name=\"{}\" type=\"{}\"{}/>\n", aa, indent, az.name, az.sig, dir)
    })
}

fn introspect_anns(anns: &Vec<Annotation>, indent: &str) -> String {
    anns.iter().fold("".to_string(), |aa, az| {
        format!("{}{}<annotation name=\"{}\" value=\"{}\"/>\n", aa, indent, az.name, az.value)
    })
}

fn introspect_map<T, C: Fn(&T) -> (String, String)>
    (h: &BTreeMap<String, T>, name: &str, indent: &str, func: C) -> String {

    h.iter().fold("".to_string(), |a, (k, v)| {
        let (params, contents) = func(v);
        format!("{}{}<{} name=\"{}\"{}{}>\n",
            a, indent, name, k, params, if contents.len() > 0 {
                format!(">\n{}{}</{}", contents, indent, name)
            }
            else { format!("/") }
        )
    })
}

impl<'a> IObjectPath<'a> {

    fn set_registered(&self, register: bool) -> Result<(), Error> {
        if register == self.registered.get() { return Ok(()) };
        if register {
            try!(self.conn.register_object_path(&self.path));
        } else {
            self.conn.unregister_object_path(&self.path);
        }
        self.registered.set(register);
        Ok(())
    }

    fn introspect(&self, _: &mut Message) -> MethodResult {
        let ifacestr = introspect_map(&self.interfaces.borrow(), "interface", "  ", |iv|
            (format!(""), format!("{}{}{}",
                introspect_map(&iv.methods, "method", "    ", |m| (format!(""), format!("{}{}{}",
                    introspect_args(&m.in_args, "      ", " direction=\"in\""),
                    introspect_args(&m.out_args, "      ", " direction=\"out\""),
                    introspect_anns(&m.anns, "      ")
                ))),
                introspect_map(&iv.properties, "property", "    ", |p| (
                    format!(" type=\"{}\" access=\"{}\"", p.sig, match p.access {
                        PropertyAccess::RO(_) => "read",
                        PropertyAccess::RW(_) => "readwrite",
                        PropertyAccess::WO(_) => "write",
                    }),
                    introspect_anns(&p.anns, "      ")
                )),
                introspect_map(&iv.signals, "signal", "    ", |s| (format!(""), format!("{}{}",
                    introspect_args(&s.args, "      ", ""),
                    introspect_anns(&s.anns, "      ")
                )))
            ))
        );
        let childstr = self.conn.list_registered_object_paths(&self.path).iter().fold("".to_string(), |na, n|
            format!(r##"{}  <node name="{}"/>
"##, na, n)
        );
        let nodestr = format!(r##"<!DOCTYPE node PUBLIC "-//freedesktop//DTD D-BUS Object Introspection 1.0//EN" "http://www.freedesktop.org/standards/dbus/1.0/introspect.dtd">
<node name="{}">
{}{}</node>"##, self.path, ifacestr, childstr);

        Ok(vec!(MessageItem::Str(nodestr)))
    }

    fn property_get(&self, msg: &mut Message) -> MethodResult {
        let items = msg.get_items();
        let iface_name = try!(parse_msg_str(items.get(0)));
        let prop_name = try!(parse_msg_str(items.get(1)));

        let is = self.interfaces.borrow();
        let i = try!(is.get(iface_name).ok_or_else(||
            ("org.freedesktop.DBus.Error.UnknownInterface", format!("Unknown interface {}", iface_name))));
        let p = try!(i.properties.get(prop_name).ok_or_else(||
            ("org.freedesktop.DBus.Error.UnknownProperty", format!("Unknown property {}", prop_name))));
        let v = try!(match p.access {
            PropertyAccess::RO(ref cb) => cb.get(),
            PropertyAccess::RW(ref cb) => cb.get(),
            PropertyAccess::WO(_) => {
                return Err(("org.freedesktop.DBus.Error.Failed", format!("Property {} is write only", prop_name)))
            }
        });
        Ok(vec!(MessageItem::Variant(Box::new(v))))
    }

    fn property_getall(&self, msg: &mut Message) -> MethodResult {
        let items = msg.get_items();
        let iface_name = try!(parse_msg_str(items.get(0)));

        let is = self.interfaces.borrow();
        let i = try!(is.get(iface_name).ok_or_else(||
            ("org.freedesktop.DBus.Error.UnknownInterface", format!("Unknown interface {}", iface_name))));
        let mut result = Vec::new();
        result.push(try!(MessageItem::from_dict(i.properties.iter().filter_map(|(pname, pv)| {
            let v = match pv.access {
                PropertyAccess::RO(ref cb) => cb.get(),
                PropertyAccess::RW(ref cb) => cb.get(),
                PropertyAccess::WO(_) => { return None }
            };
            Some(v.map(|vv| (pname.clone(),vv)))
        }))));
        Ok(result)
    }

    fn property_set(&self, msg: &mut Message) -> MethodResult {
        let items = msg.get_items();
        let iface_name = try!(parse_msg_str(items.get(0)));
        let prop_name = try!(parse_msg_str(items.get(1)));
        let value = try!(parse_msg_variant(items.get(2)));

        let is = self.interfaces.borrow();
        let i = try!(is.get(iface_name).ok_or_else(||
            ("org.freedesktop.DBus.Error.UnknownInterface", format!("Unknown interface {}", iface_name))));
        let p = try!(i.properties.get(prop_name).ok_or_else(||
            ("org.freedesktop.DBus.Error.UnknownProperty", format!("Unknown property {}", prop_name))));
        try!(match p.access {
            PropertyAccess::WO(ref cb) => cb.set(value),
            PropertyAccess::RW(ref cb) => cb.set(value),
            PropertyAccess::RO(_) => {
                return Err(("org.freedesktop.DBus.Error.PropertyReadOnly", format!("Property {} is read only", prop_name)))
            }
        });
        Ok(vec!())
    }
}

fn parse_msg_str(a: Option<&MessageItem>) -> Result<&str,(&'static str, String)> {
    let name = try!(a.ok_or_else(|| ("org.freedesktop.DBus.Error.InvalidArgs", format!("Invalid argument {:?}", a))));
    name.inner().map_err(|_| ("org.freedesktop.DBus.Error.InvalidArgs", format!("Invalid argument {:?}", a)))
}

fn parse_msg_variant(a: Option<&MessageItem>) -> Result<&MessageItem,(&'static str, String)> {
    let name = try!(a.ok_or_else(|| ("org.freedesktop.DBus.Error.InvalidArgs", format!("Invalid argument {:?}", a))));
    name.inner().map_err(|_| ("org.freedesktop.DBus.Error.InvalidArgs", format!("Invalid argument {:?}", a)))
}

impl PropertyROHandler for MessageItem {
    fn get(&self) -> PropertyGetResult {
        Ok(self.clone())
    }
}

impl<'a> ObjectPath<'a> {
    /// Create a new ObjectPath.
    pub fn new(conn: &'a Connection, path: &str, introspectable: bool) -> ObjectPath<'a> {
        let i = IObjectPath {
            conn: conn,
            path: path.to_string(),
            registered: Cell::new(false),
            interfaces: RefCell::new(BTreeMap::new()),
        };
        let mut o = ObjectPath { i: Rc::new(i) };

        if introspectable {
            let o_cl = o.i.clone();
            let i = Interface::new(vec!(
                Method::new("Introspect", vec!(), vec!(Argument::new("xml_data", "s")),
                    Box::new(move |m| { o_cl.introspect(m) }))), vec!(), vec!());
            o.insert_interface("org.freedesktop.DBus.Introspectable", i);
        }
        o
    }

    fn add_property_handler(&mut self) {
        if self.i.interfaces.borrow().contains_key("org.freedesktop.DBus.Properties") { return };
        let (cl1, cl2, cl3) = (self.i.clone(), self.i.clone(), self.i.clone());
        let i = Interface::new(vec!(
            Method::new("Get",
                vec!(Argument::new("interface_name", "s"), Argument::new("property_name", "s")),
                vec!(Argument::new("value", "v")),
                Box::new(move |m| cl1.property_get(m))),
            Method::new("GetAll",
                vec!(Argument::new("interface_name", "s")),
                vec!(Argument::new("props", "a{sv}")),
                Box::new(move |m| cl2.property_getall(m))),
            Method::new("Set",
                vec!(Argument::new("interface_name", "s"), Argument::new("property_name", "s"),
                    Argument::new("value", "v")),
                vec!(),
                Box::new(move |m| cl3.property_set(m)))),
            vec!(), vec!());
        self.insert_interface("org.freedesktop.DBus.Properties", i);
    }

    /// Add an Interface to this ObjectPath.
    pub fn insert_interface<N: ToString>(&mut self, name: N, i: Interface<'a>) {
        if !i.properties.is_empty() {
            self.add_property_handler();
        }
        self.i.interfaces.borrow_mut().insert(name.to_string(), i);
    }

    /// Returns if the ObjectPath is registered.
    pub fn is_registered(&self) -> bool {
        self.i.registered.get()
    }

    /// Changes the registration status of the ObjectPath.
    pub fn set_registered(&mut self, register: bool) -> Result<(), Error> {
        self.i.set_registered(register)
    }

    /// Handles a method call if the object path matches.
    /// Return value: None => not handled (no match),
    /// Some(Err(())) => message reply send failed,
    /// Some(Ok()) => message reply send ok */
    pub fn handle_message(&mut self, msg: &mut Message) -> Option<Result<(), ()>> {
        let (_, path, iface, method) = msg.headers();
        if path.is_none() || path.unwrap() != self.i.path { return None; }
        if iface.is_none() { return None; }

        let method = {
            // This is because we don't want to hold the refcell lock when we call the
            // callback - maximum flexibility for clients.
            if let Some(i) = self.i.interfaces.borrow().get(&iface.unwrap()) {
                if let Some(Some(m)) = method.map(|m| i.methods.get(&m)) {
                    m.cb.clone()
                } else {
                    return Some(self.i.conn.send(Message::new_error(
                        msg, "org.freedesktop.DBus.Error.UnknownMethod", "Unknown method").unwrap()).map(|_| ()));
                }
            } else {
                return Some(self.i.conn.send(Message::new_error(msg,
                    "org.freedesktop.DBus.Error.UnknownInterface", "Unknown interface").unwrap()).map(|_| ()));
            }
        };

        let r = {
            // Now call it
            let mut m = method.borrow_mut();
            (&mut **m)(msg)
        };

        let reply = match r {
            Ok(r) => {
                let mut z = Message::new_method_return(msg).unwrap();
                z.append_items(&r);
                z
            },
            Err((aa,bb)) => Message::new_error(msg, aa, &bb).unwrap(),
        };

        Some(self.i.conn.send(reply).map(|_| ()))
    }
}

#[cfg(test)]
fn make_objpath<'a>(c: &'a Connection) -> ObjectPath<'a> {
    let mut o = ObjectPath::new(c, "/echo", true);
    o.insert_interface("com.example.echo", Interface::new(
        vec!(Method::new("Echo",
            vec!(Argument::new("request", "s")),
            vec!(Argument::new("reply", "s")), Box::new(|_| { Err(("dummy", "dummy".to_string())) } ))),
        vec!(Property::new_ro("EchoCount", MessageItem::Int32(7).type_sig(), Box::new(MessageItem::Int32(7)))),
        vec!(Signal::new("Echoed", vec!(Argument::new("data", "s"))))));
    o
}

#[test]
fn test_objpath() {
    let c = Connection::get_private(super::BusType::Session).unwrap();
    let mut o = make_objpath(&c);
    o.set_registered(true).unwrap();
    let busname = format!("com.example.objpath.test.test_objpath");
    assert_eq!(c.register_name(&busname, super::NameFlag::ReplaceExisting as u32).unwrap(), super::RequestNameReply::PrimaryOwner);

    let thread = ::std::thread::spawn(move || {
        let c = Connection::get_private(super::BusType::Session).unwrap();
        let pr = super::Props::new(&c, &*busname, "/echo", "com.example.echo", 5000);
        assert_eq!(pr.get("EchoCount").unwrap(), 7i32.into());
        let m = pr.get_all().unwrap();
        assert_eq!(m.get("EchoCount").unwrap(), &7i32.into());
    });

    let mut i = 0;
    for n in c.iter(1000) {
        println!("objpath msg {:?}", n);
        if let super::ConnectionItem::MethodCall(mut m) = n {
            if let Some(msg) = o.handle_message(&mut m) {
                msg.unwrap();
                i += 1;
                if i >= 2 { break };
            }
        }
    }

    thread.join().unwrap();
}


/// Currently commented out because it requires feature(alloc)
/*
#[test]
fn test_refcount() {
    let c = Connection::get_private(super::BusType::Session).unwrap();
    let i = {
        let o = make_objpath(&c);
        o.i.clone()
    };
    assert!(::std::rc::is_unique(&i));
}
*/

#[test]
fn test_introspect() {
    let c = Connection::get_private(super::BusType::Session).unwrap();
    let mut o = make_objpath(&c);
    o.set_registered(true).unwrap();
    let mut o2 = ObjectPath::new(&c, "/echo/subpath", true);
    o2.set_registered(true).unwrap();
    let mut msg = Message::new_method_call("com.example.echoserver", "/echo", "org.freedesktop.DBus.Introspectable", "Introspect").unwrap();
    println!("Introspect result: {}", parse_msg_str(o.i.introspect(&mut msg).unwrap().get(0)).unwrap());

    let result = r##"<!DOCTYPE node PUBLIC "-//freedesktop//DTD D-BUS Object Introspection 1.0//EN" "http://www.freedesktop.org/standards/dbus/1.0/introspect.dtd">
<node name="/echo">
  <interface name="com.example.echo">
    <method name="Echo">
      <arg name="request" type="s" direction="in"/>
      <arg name="reply" type="s" direction="out"/>
    </method>
    <property name="EchoCount" type="i" access="read"/>
    <signal name="Echoed">
      <arg name="data" type="s"/>
    </signal>
  </interface>
  <interface name="org.freedesktop.DBus.Introspectable">
    <method name="Introspect">
      <arg name="xml_data" type="s" direction="out"/>
    </method>
  </interface>
  <interface name="org.freedesktop.DBus.Properties">
    <method name="Get">
      <arg name="interface_name" type="s" direction="in"/>
      <arg name="property_name" type="s" direction="in"/>
      <arg name="value" type="v" direction="out"/>
    </method>
    <method name="GetAll">
      <arg name="interface_name" type="s" direction="in"/>
      <arg name="props" type="a{sv}" direction="out"/>
    </method>
    <method name="Set">
      <arg name="interface_name" type="s" direction="in"/>
      <arg name="property_name" type="s" direction="in"/>
      <arg name="value" type="v" direction="in"/>
    </method>
  </interface>
  <node name="subpath"/>
</node>"##;

    assert_eq!(result, parse_msg_str(o.i.introspect(&mut msg).unwrap().get(0)).unwrap());

}