implement new buffer input / output api

csdr/chain/__init__.py

@@ -1,19 +1,34 @@
+from pycsdr import Buffer
+
+import logging
+logger = logging.getLogger(__name__)
+
+
 class Chain(object):
     def __init__(self, *workers):
+        self.input = None
+        self.output = None
         self.workers = workers
-        stage = None
-        for w in self.workers:
-            if stage is not None:
-                w.setInput(stage.getBuffer())
-            stage = w
-        self.buffer = stage.getBuffer()
+        for i in range(1, len(self.workers)):
+            self._connect(self.workers[i - 1], self.workers[i])
+
+    def _connect(self, w1, w2):
+        buffer = Buffer()
+        w1.setOutput(buffer)
+        w2.setInput(buffer)
 
     def stop(self):
         for w in self.workers:
             w.stop()
 
     def setInput(self, buffer):
+        if self.input == buffer:
+            return
+        self.input = buffer
         self.workers[0].setInput(buffer)
 
-    def getBuffer(self):
-        return self.buffer
+    def setOutput(self, buffer):
+        if self.output == buffer:
+            return
+        self.output = buffer
+        self.workers[-1].setOutput(buffer)