From de95d30d41d92690212af05c2fbe15391ce1a05d Mon Sep 17 00:00:00 2001
From: Walter Bender <walter.bender@gmail.com>
Date: Sat, 19 Feb 2011 14:47:57 +0000
Subject: moving audio sensor-specific code to its own directrory

---
(limited to 'audio/ringbuffer.py')

diff --git a/audio/ringbuffer.py b/audio/ringbuffer.py
new file mode 100644
index 0000000..2afb5c9
--- /dev/null
+++ b/audio/ringbuffer.py
@@ -0,0 +1,108 @@
+#    Copyright (C) 2009, Benjamin Berg, Sebastian Berg
+#    Copyright (C) 2010, Walter Bender
+#
+#    This program is free software; you can redistribute it and/or modify
+#    it under the terms of the GNU General Public License as published by
+#    the Free Software Foundation; either version 2 of the License, or
+#    (at your option) any later version.
+#
+#    This program is distributed in the hope that it will be useful,
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#    GNU General Public License for more details.
+#
+#    You should have received a copy of the GNU General Public License
+#    along with this program; if not, write to the Free Software
+#    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+import numpy as np
+
+
+class RingBuffer1d(object):
+    """This class implements an array being written in as a ring and that can
+    be read from continuously ending with the newest data or starting with the
+    oldest. It returns a numpy array copy of the data;
+    """
+
+    def __init__(self, length, dtype=None):
+        """Initialize the 1 dimensional ring buffer with the given lengths.
+        The initial values are all 0s
+        """
+        self.offset = 0
+
+        self._data = np.zeros(length, dtype=dtype)
+
+        self.stored = 0
+
+    def fill(self, number):
+        self._data.fill(number)
+        self.offset = 0
+
+    def append(self, data):
+        """Append to the ring buffer (and overwrite old data). If len(data)
+        is greater then the ring buffers length, the newest data takes
+        precedence.
+        """
+        data = np.asarray(data)
+
+        if len(self._data) == 0:
+            return
+
+        if len(data) >= len(self._data):
+            self._data[:] = data[-len(self._data):]
+            self.offset = 0
+            self.stored = len(self._data)
+
+        elif len(self._data) - self.offset >= len(data):
+            self._data[self.offset: self.offset + len(data)] = data
+            self.offset = self.offset + len(data)
+            self.stored += len(data)
+        else:
+            self._data[self.offset:] = data[:len(self._data) - self.offset]
+            self._data[:len(data) - (len(self._data) - self.offset)] = \
+                data[-len(data) + (len(self._data) - self.offset):]
+            self.offset = len(data) - (len(self._data) - self.offset)
+            self.stored += len(data)
+
+        if len(self._data) <= self.stored:
+            self.read = self._read
+
+    def read(self, number=None, step=1):
+        """Read the ring Buffer. Number can be positive or negative.
+        Positive values will give the latest information, negative values will
+        give the newest added information from the buffer. (in normal order)
+
+        Before the buffer is filled once: This returns just None
+        """
+        return np.array([])
+
+    def _read(self, number=None, step=1):
+        """Read the ring Buffer. Number can be positive or negative.
+        Positive values will give the latest information, negative values will
+        give the newest added information from the buffer. (in normal order)
+        """
+        if number == None:
+            number = len(self._data) // step
+
+        number *= step
+        assert abs(number) <= len(self._data), \
+            'Number to read*step must be smaller then length'
+
+        if number < 0:
+            if abs(number) <= self.offset:
+                return self._data[self.offset + number:self.offset:step]
+
+            spam = (self.offset - 1) % step
+
+            return np.concatenate(
+                (self._data[step - spam - 1 + self.offset + number::step],
+                 self._data[spam:self.offset:step]))
+
+        if number - (len(self._data) - self.offset) > 0:
+            spam = ((self.offset + number) - self.offset - 1) % step
+            return np.concatenate(
+                (self._data[self.offset:self.offset + number:step],
+                 self._data[spam:number -
+                            (len(self._data) - self.offset):step]))
+
+        return self._data[self.offset:self.offset + number:step].copy()
--
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