From e370a57a422eeecb40a963d7a6a4594a8787c6de Mon Sep 17 00:00:00 2001
From: Tristan Hume <tris.hume@gmail.com>
Date: Thu, 30 Apr 2015 19:22:08 -0400
Subject: [PATCH] Add routing infrastructure.

---
 source/ddbus/router.d | 80 +++++++++++++++++++++++++++++++++++++++++++
 source/ddbus/thin.d   | 59 ++++++++++++++++++++++++++++---
 source/ddbus/util.d   |  2 ++
 3 files changed, 137 insertions(+), 4 deletions(-)
 create mode 100644 source/ddbus/router.d

diff --git a/source/ddbus/router.d b/source/ddbus/router.d
new file mode 100644
index 0000000..63d6637
--- /dev/null
+++ b/source/ddbus/router.d
@@ -0,0 +1,80 @@
+module ddbus.router;
+
+import ddbus.thin;
+import std.string;
+import std.typecons;
+
+struct MessagePattern {
+  string sender;
+  string path;
+  string iface;
+  string method;
+
+  this(Message msg) {
+    path = msg.path();
+    iface = msg.iface();
+    method = msg.member();
+    if(msg.type()==MessageType.Signal) {
+      sender = msg.sender();
+    } else {
+      sender = null;
+    }
+  }
+
+  size_t toHash() const @safe nothrow {
+    size_t hash = 0;
+    auto stringHash = &(typeid(path).getHash);
+    hash += stringHash(&sender);
+    hash += stringHash(&path);
+    hash += stringHash(&iface);
+    hash += stringHash(&method);
+    return hash;
+  }
+
+  bool opEquals(ref const this s) const @safe pure nothrow {
+    return (path == s.path) && (iface == s.iface) && (method == s.method) && (sender == s.sender);
+  }
+}
+
+class MessageRouter {
+  alias HandlerFunc = void delegate(Message call, Connection conn);
+  Connection conn;
+  HandlerFunc[MessagePattern] callTable;
+
+  this(Connection conn) {
+    this.conn = conn;
+  }
+
+  bool handle(Message msg) {
+    MessageType type = msg.type();
+    if(type != MessageType.Call && type != MessageType.Signal)
+      return false;
+    auto pattern = MessagePattern(msg);
+    HandlerFunc* handler = (pattern in callTable);
+    if(handler is null) return false;
+    (*handler)(msg,conn);
+    return true;
+  }
+
+  void setHandler(Ret, Args...)(MessagePattern patt, Connection conn, Ret delegate(Args) handler) {
+    void handlerWrapper(Message call, Connection conn) {
+      Tuple!Args args = call.readTuple!(Tuple!Args)();
+      Ret ret = handler(args.expand);
+      auto retMsg = call.createReturn();
+      static if(!is(Ret == void)) {
+        retMsg.build(ret);
+      }
+      conn.send(retMsg);
+    }
+    callTable[patt] = &handlerWrapper;
+  }
+}
+
+unittest {
+  import dunit.toolkit;
+  auto msg = new Message("org.example.test", "/test","org.example.testing","testMethod");
+  auto patt= new MessagePattern(msg);
+  patt.assertEqual(patt);
+  patt.sender.assertNull();
+  patt.path.assertEqual("/test");
+}
diff --git a/source/ddbus/thin.d b/source/ddbus/thin.d
index ad8bc76..f4802d0 100644
--- a/source/ddbus/thin.d
+++ b/source/ddbus/thin.d
@@ -5,6 +5,7 @@ import ddbus.conv;
 import ddbus.util;
 import std.string;
 import std.typecons;
+import std.exception;
 
 class DBusException : Exception {
   this(DBusError *err) {
@@ -24,6 +25,11 @@ T wrapErrors(T)(T delegate(DBusError *err) del) {
   return ret;
 }
 
+enum MessageType {
+  Invalid = 0,
+  Call, Return, Error, Signal
+}
+
 class Message {
   this(string dest, string path, string iface, string method) {
     msg = dbus_message_new_method_call(dest.toStringz(), path.toStringz(), iface.toStringz(), method.toStringz());
@@ -64,22 +70,67 @@ class Message {
     return ret;
   }
 
-  const(char)[] signature() {
-    const(char)* cSig = dbus_message_get_signature(msg);
-    return fromStringz(cSig);
+  Message createReturn() {
+    return new Message(dbus_message_new_method_return(msg));
+  }
+
+  MessageType type() {
+    return cast(MessageType)dbus_message_get_type(msg);
+  }
+
+  bool isCall() {
+    return type() == MessageType.Call;
+  }
+
+  // Various string members
+  // TODO: make a mixin to avoid this copy-paste
+  string signature() {
+    const(char)* cStr = dbus_message_get_signature(msg);
+    assert(cStr != null);
+    return cStr.fromStringz().assumeUnique();
+  }
+  string path() {
+    const(char)* cStr = dbus_message_get_path(msg);
+    assert(cStr != null);
+    return cStr.fromStringz().assumeUnique();
+  }
+  string iface() {
+    const(char)* cStr = dbus_message_get_interface(msg);
+    assert(cStr != null);
+    return cStr.fromStringz().assumeUnique();
+  }
+  string member() {
+    const(char)* cStr = dbus_message_get_member(msg);
+    assert(cStr != null);
+    return cStr.fromStringz().assumeUnique();
+  }
+  string sender() {
+    const(char)* cStr = dbus_message_get_sender(msg);
+    assert(cStr != null);
+    return cStr.fromStringz().assumeUnique();
   }
 
   DBusMessage *msg;
 }
 
+unittest {
+  import dunit.toolkit;
+  auto msg = new Message("org.example.test", "/test","org.example.testing","testMethod");
+  msg.path().assertEqual("/test");
+}
+
 class Connection {
   DBusConnection *conn;
   this(DBusConnection *connection) {
     conn = connection;
   }
 
+  void send(Message msg) {
+    dbus_connection_send(conn,msg.msg, null);
+  }
+
   void sendBlocking(Message msg) {
-    dbus_connection_send(conn,msg.msg,null);
+    send(msg);
     dbus_connection_flush(conn);
   }
 
diff --git a/source/ddbus/util.d b/source/ddbus/util.d
index 04560ef..c30bde2 100644
--- a/source/ddbus/util.d
+++ b/source/ddbus/util.d
@@ -64,6 +64,8 @@ string typeSig(T)() if(canDBus!T) {
     return "d";
   } else static if(is(T == string)) {
     return "s";
+  } else static if(is(T == void)) {
+    return "";
   } else static if(isTuple!T) {
     string sig = "(";
     foreach(i, S; T.Types) {