Changeset 56:1d491f271eaf in xplra

Timestamp:

03/07/13 16:48:41 (11 years ago)

Author:

István Váradi <ivaradi@…>

Branch:

default

hg-Phase:

(<MercurialRepository 3 'hg:/home/ivaradi/xplane/hg/xplra' '/'>, 'public')

Message:

Implemented a more proper handling of a broken connection in the Python client

File:

• src/client/python/xplra.py (modified) (7 diffs)

src/client/python/xplra.py

@@ -133 +133 @@
         """Construct the object."""
         self._stream = None
+        self._multiBuffers = []
 
     def connect(self):
@@ -147 +148 @@
             self._stream = s.makefile()
 
+        for multiBuffer in self._multiBuffers:
+            multiBuffer._reregister()
+
     @property
     def isConnected(self):
@@ -154 +158 @@
     def createMultiGetter(self):
         """Create a new multi-dataref getter for this X-Plane object."""
-        return MultiGetter(self)
+        multiGetter = MultiGetter(self)
+        self._multiBuffers.append(multiGetter)
+        return multiGetter
 
     def createMultiSetter(self):
         """Create a new multi-dataref setter for this X-Plane object."""
-        return MultiSetter(self)
+        multiSetter = MultiSetter(self)
+        self._multiBuffers.append(multiSetter)
+        return multiSetter
+
+    def destroyMultiBuffer(self, multiBuffer):
+        """Destroy the given multi-dataref buffer.
+
+        It actually removes it from the list of multiple buffers and
+        unregisters it safely.
+
+        Returns the result of the safe unregistration if the buffer was found,
+        None otherwise.
+        """
+        if multiBuffer in self._multiBuffers:
+            self._multiBuffers.remove(multiBuffer)
+            return multiBuffer.unregisterSafely()
+        else:
+            return None
 
     def getVersions(self):
@@ -283 +306 @@
         """Disconnect from X-Plane."""
         if self._stream is not None:
-            self._stream.close()
-            self._stream = None
+            try:
+                self._stream.close()
+            finally:
+                self._stream = None
 
     def _checkResult(self, resultCode = None, parameter = None, multi = False):
@@ -484 +509 @@
         return self._values
 
+    @property
+    def wasRegistered(self):
+        """Determine if this buffer was registered."""
+        return self._wasRegistered
+
     def addInt(self, name):
         """Add an integer to the buffer with the given name
@@ -544 +574 @@
             self._xplane._flush()
             self._xplane._checkResult()
+            self._registeredID = None
+
+    def unregisterSafely(self):
+        """Unregister the buffer from X-Plane, ignoring exceptions.
+
+        Returns True if the unregistration succeeded, False otherwise.
+        """
+        try:
+            self.unregister()
+            return True
+        except:
+            return False
+        finally:
             self._registeredID = None
 
@@ -576 +619 @@
             s += chr(c)
         return s
+
+    def _reregister(self):
+        """Re-register the buffer in X-Plane, if it has been registered earlier
+
+        If it has not been registered, nothing is done. Otherwise the buffer
+        gets registered, and the old ID is forgotten. This function is meant to
+        be used by the XPlane object when it creates a new connection. If the
+        registration fails, the original ID is restored, so the _reregister()
+        could be called again
+        """
+        if self._registeredID is not None:
+            origRegisteredID = self._registeredID
+            try:
+                self._registeredID = None
+                self.register()
+            except:
+                self._registeredID = origRegisteredID
+                raise
 
     def _add(self, name, type, length = None, offset = None):