From 40915f4f1535e823c4e9f67fa06370feafec739e Mon Sep 17 00:00:00 2001
From: Roman Zeyde <roman@cloudendure.com>
Date: Fri, 4 Jul 2014 08:37:55 +0300
Subject: [PATCH] Refactor iteration.

---
 common.py      | 22 ++++++++++++++++++++++
 recv.py        | 10 ----------
 test_common.py | 18 ++++++++++++++++++
 3 files changed, 40 insertions(+), 10 deletions(-)
 create mode 100644 test_common.py

diff --git a/common.py b/common.py
index de9cdc3..e9c1b49 100644
--- a/common.py
+++ b/common.py
@@ -52,6 +52,28 @@ def dumps(sym, n=1):
 def norm(x):
     return np.sqrt(np.dot(x.conj(), x).real)
 
+
+def iterate(data, bufsize, offset=0, advance=1, func=None):
+    assert bufsize > 0
+    assert offset >= 0
+    assert advance > 0
+    buf = np.zeros(bufsize)
+    buf_index = 0
+    for data_index, value in enumerate(data):
+        if data_index < offset:
+            continue
+
+        buf[buf_index] = value
+        buf_index += 1
+
+        if buf_index == bufsize:
+            result = func(buf) if func else buf
+            print offset, result
+            yield offset, result
+            buf[:-advance] = buf[advance:]
+            buf_index = max(0, buf_index - advance)
+            offset += advance
+
 if __name__ == '__main__':
 
     import pylab
diff --git a/recv.py b/recv.py
index c00dd2c..113c935 100644
--- a/recv.py
+++ b/recv.py
@@ -17,16 +17,6 @@ CARRIER_THRESHOLD = int(0.9 * CARRIER_DURATION)
 def power(x):
     return np.dot(x.conj(), x).real / len(x)
 
-def iterate(x, bufsize, offset=0, advance=1, func=None):
-    while True:
-        buf = x[offset:offset+bufsize]
-        if len(buf) == bufsize:
-            result = func(buf) if func else buf
-            yield offset, result
-        else:
-            return
-        offset += advance
-
 def exp_iwt(freq, n):
     iw = 2j * np.pi * freq
     t = np.arange(n) * Ts
diff --git a/test_common.py b/test_common.py
new file mode 100644
index 0000000..5825ced
--- /dev/null
+++ b/test_common.py
@@ -0,0 +1,18 @@
+import common
+import numpy as np
+
+def iterlist(x, *args, **kwargs):
+    x = np.array(x)
+    return [(offset, list(buf)) for offset, buf in common.iterate(x, *args, **kwargs)]
+
+def test_iterate():
+    N = 10
+    assert iterlist(range(N), 1) == [(i, [i]) for i in range(N)]
+    assert iterlist(range(N), 1) == [(i, [i]) for i in range(N)]
+    assert iterlist(range(N), 2) == [(i, [i, i+1]) for i in range(N-1)]
+    assert iterlist(range(N), 3) == [(i, [i, i+1, i+2]) for i in range(N-2)]
+    assert iterlist(range(N), 3, advance=2) == [(i, [i, i+1, i+2]) for i in range(0, N-2, 2)]
+    assert iterlist(range(N), 3, advance=3) == [(i, [i, i+1, i+2]) for i in range(0, N-2, 3)]
+    assert iterlist(range(N), 2, offset=5) == [(i, [i, i+1]) for i in range(5, N-1)]
+    assert iterlist(range(N), 1, func=lambda b: -b) == [(i, [-i]) for i in range(N)]
+