[buffer] adding edge cases

pyrelacs/dataio/circbuffer.py

@@ -1,11 +1,18 @@
+from typing import Tuple
 import numpy as np
 
+from pyrelacs.util.logging import config_logging
+
+log = config_logging()
+
 
 class CircBuffer:
     def __init__(self, size: int, channels: int = 1):
         self._size = size
         self._channels = channels
-        self._buffer = np.zeros((channels, size), dtype=np.double)  # or dtype of your choice
+        self._buffer = np.zeros(
+            (channels, size), dtype=np.double
+        )  # or dtype of your choice
         self._index = [0 for i in range(channels)]
         self._is_full = [False for i in range(channels)]
         self._totalcount = [0 for i in range(channels)]
@@ -38,10 +45,14 @@ class CircBuffer:
         Return all valid values from the specified channel
         """
         if self._is_full[channel]:
-            return np.concatenate((self._buffer[channel, self._index[channel]:],
-                                   self._buffer[channel, :self._index[channel]]))
+            return np.concatenate(
+                (
+                    self._buffer[channel, self._index[channel] :],
+                    self._buffer[channel, : self._index[channel]],
+                )
+            )
         else:
-            return self._buffer[channel, :self._index[channel]]
+            return self._buffer[channel, : self._index[channel]]
 
     def has_value(self, index, channel):
         if index < 0 and self.is_full(channel):
@@ -52,59 +63,93 @@ class CircBuffer:
         if index >= self.size:
             return False
 
+        # test if the ring buffer is at the start but
+        # and the index is greater than the write index
         if index > self.write_index(channel) and self.is_full(channel):
             return True
+        elif index > self.write_index(channel) and not self.is_full(channel):
+            raise IndexError("Index has no value, not written")
+
         if index == self.write_index(channel) and self._totalcount[channel] == 0:
             return False
 
-        return True
+    def valid_range(self, channel: int = 0) -> Tuple[int, int]:
+        """
+        Return the start index that are valid within the buffer
 
-    def valid_range(self, channel: int = 0):
-        """ Return the start index that are valid within the buffer
+        Parameters
+        ----------
+        channel : int
+            channel of the buffer
+
+        Returns
+        -------
+        Tuple[int, int]
+            start, extend of the valid range
         """
         start = 0
-        count = 0
+        extend = 0
         if self._totalcount[channel] == 0:
-            return start, count
+            return start, extend
 
         if not self.is_full(channel):
-            count = self._totalcount[channel]
+            extend = self._totalcount[channel]
         else:
-            count = self.size
-        return start, count
+            extend = self.size
+        return start, extend
 
     def get(self, index: int = -1, channel: int = 0):
         # easy case first, we can spare the effort of further checking
         if index >= 0 and index < self.write_index(channel):
-            return self._buffer[channel, index]
+            if self.has_value(index, channel):
+                return self._buffer[channel, index]
+            else:
+                raise IndexError(
+                    f"Invalid index {index} on ring buffer for channel{channel}"
+                )
 
         if index < 0:
+            log.debug("index is smaller than 0")
+            log.debug(f"{self.write_index()}")
             index = self.write_index() - 1
         if self.has_value(index, channel):
+            log.debug("index has a value")
             return self._buffer[channel, index]
         else:
-            raise IndexError(f"Invalid index {index} on ring buffer for channel{channel}")
+            raise IndexError(
+                f"Invalid index {index} on ring buffer for channel{channel}"
+            )
 
     def read(self, start, count=1, channel=0):
-        """ Reads a numpy array from buffer"""
+        """Reads a numpy array from buffer"""
         if start < 0 or count < 0:
-            raise IndexError(f"Invalid start ({start}) or count ({count}) for channel{channel}")
+            raise IndexError(
+                f"Invalid start ({start}) or count ({count}) for channel{channel}"
+            )
 
         if count == 1:
             return np.array(self.get(start, channel))
 
         vs, vc = self.valid_range(channel)
         if start > self._totalcount[channel]:
-            raise IndexError(f"Invalid start index {start} is invalid with totalcount {self._totalcount[channel]} for channel{channel}")
+            raise IndexError(
+                f"Invalid start index {start} is invalid with totalcount {self._totalcount[channel]} for channel{channel}"
+            )
         if start > self.size:
-            raise IndexError(f"Invalid start index {start} for buffer with size {self.size}")
+            raise IndexError(
+                f"Invalid start index {start} for buffer with size {self.size}"
+            )
         if count > self.size:
             count = self.size
         if count > vc:
             count = vc
 
         if (start + count) < self.size:
-            return self._buffer[channel, start:start + count]
+            return self._buffer[channel, start : start + count]
         else:
-            return np.concatenate((self._buffer[channel, start:],
-                                   self._buffer[channel, :count - self.size + start]))
+            return np.concatenate(
+                (
+                    self._buffer[channel, start:],
+                    self._buffer[channel, : count - self.size + start],
+                )
+            )