Initial capability and event queue support

pymetaverse/viewer/agent.py

@@ -73,11 +73,26 @@ class Agent(EventTarget):
         self.send(msg, True)
     
     async def run(self):
+        lastAck = 0
         while True:
             try:
                 await asyncio.sleep(0.1)
                 if self.simulator == None:
                     break
+                
+                if not "EventQueueGet" in self.simulator.capabilities:
+                    lastAck = 0
+                    continue
+                
+                ack, events = await self.simulator.capabilities["EventQueueGet"].poll(lastAck, False)
+                if ack == None:
+                    lastAck = 0
+                    continue
+
+                if ack == lastAck:
+                    continue
+                
+                lastAck = ack
             
             except asyncio.exceptions.CancelledError:
                 # Attempt to gracefully logout

pymetaverse/viewer/capability.py

@@ -0,0 +1,72 @@
+from .. import httpclient
+from .. import llsd
+
+class CapabilityRegistry:
+    def __init__(self):
+        self.capabilities = {}
+    
+    def register(self, name):
+        def _(func):
+            self.capabilities[name] = func
+            return func
+        return _
+    
+    def __contains__(self, what):
+        return what in self.capabilities
+    
+    def get(self, name, url):
+        try:
+            return self.capabilities[name](url)
+        except KeyError:
+            raise ValueError("No such capability {}".format(name))
+
+Capabilities = CapabilityRegistry()
+
+class BaseCapability:
+    def __init__(self, url):
+        self.url = url
+
+# Please keep these in alphabetical order! :)
+
+@Capabilities.register("EventQueueGet")
+class EventQueueGet(BaseCapability):
+    async def poll(self, ack, done = False):
+        async with httpclient.HttpClient() as session:
+            async with await session.post(self.url,
+                data = llsd.llsdEncode({
+                    "ack": ack,
+                    "done": done
+                }),
+                headers = {
+                    "Content-Type": "application/llsd+xml"
+                },
+                timeout = 60 # Timeouts on the server are 30, twice that is more than enough
+            ) as response:
+                if response.status == 404:
+                    return None, []
+                
+                elif response.status == 200:
+                    data = await response.read()
+                    result = llsd.llsdDecode(data, format="xml")
+                    return result["id"], result["events"]
+                
+                else:
+                    return ack, []
+
+@Capabilities.register("Seed")
+class Seed(BaseCapability):
+    async def getCapabilities(self, caps):
+        async with httpclient.HttpClient() as session:
+            async with await session.post(self.url,
+                data = llsd.llsdEncode(list(caps.capabilities.keys())),
+                headers = {
+                    "Content-Type": "application/llsd+xml"
+                }
+            ) as response:
+                capList = llsd.llsdDecode(await response.read(), format="xml")
+                result = {}
+                for name, url in capList.items():
+                    if name in caps:
+                        result[name] = caps.get(name, url)
+                
+                return result

pymetaverse/viewer/simulator.py

@@ -1,5 +1,7 @@
+import asyncio
 from .circuit import Circuit
 from . import messages
+from .capability import Capabilities
 from . import region
 from .. import httpclient
 from .. import llsd
@@ -16,9 +18,16 @@ class Simulator(EventTarget):
         self.id = None
         self.circuit = None
         self.region = None
-        self.caps = {}
+        self.capabilities = {}
         self.messageTemplate = messages.getDefaultTemplate()
     
+    def __del__(self):
+        try:
+            loop = asyncio.get_running_loop()
+            loop.create_task(self.close())
+        except RuntimeError:
+            pass
+    
     def send(self, msg, reliable = False):
         self.circuit.send(msg, reliable)
     
@@ -74,8 +83,12 @@ class Simulator(EventTarget):
         except Exception as e:
             traceback.print_exc()
     
-    async def fetchCapabilities(self, seed):
-        pass
+    async def fetchCapabilities(self, url):
+        if "Seed" not in Capabilities:
+            return
+        
+        seed = Capabilities.get("Seed", url)
+        self.capabilities = await seed.getCapabilities(Capabilities)
     
     def __repr__(self):
         return f"<{self.__class__.__name__} \"{self.name}\" ({self.host[0]}:{self.host[1]})>"