API cleanup for binarywave (loadibw->load, move checksum to util, ...).

Also moved byte_order to the util module and renamed a few functions
internal to the binarywave module so they start with an underscore.

The loadibw -> load (and saveibw -> save) change is because

  from igor.binarywave import load

gives you enough of an idea about what you're importing.  If you want
to keep it explicit in your client module, use

  from igor.binarywave import load as loadibw

which we do in the test.py module.

diff --git a/igor/binarywave.py b/igor/binarywave.py
index a79c6be67cbc499f463d8b2c34a1390e6cfdde9b..70af3107b61bf5bdbe9df90cb24c9dda394f3c9c 100644 (file)
--- a/igor/binarywave.py
+++ b/igor/binarywave.py
@@ -35,6 +35,8 @@ import numpy as _numpy
 from .struct import Structure as _Structure
 from .struct import Field as _Field
 from .util import assert_null as _assert_null
+from .util import byte_order as _byte_order
+from .util import checksum as _checksum
 
 
 # Numpy doesn't support complex integers by default, see
@@ -226,22 +228,14 @@ WaveHeader5 = _Structure(
 
 # Begin functions from ReadWave.c
 
-def need_to_reorder_bytes(version):
+def _need_to_reorder_bytes(version):
     # If the low order byte of the version field of the BinHeader
     # structure is zero then the file is from a platform that uses
     # different byte-ordering and therefore all data will need to be
     # reordered.
     return version & 0xFF == 0
 
-def byte_order(needToReorderBytes):
-    little_endian = _sys.byteorder == 'little'
-    if needToReorderBytes:
-        little_endian = not little_endian
-    if little_endian:
-        return '<'  # little-endian
-    return '>'  # big-endian    
-
-def version_structs(version, byte_order):
+def _version_structs(version, byte_order):
     if version == 1:
         bin = BinHeader1
         wave = WaveHeader2
@@ -265,20 +259,8 @@ def version_structs(version, byte_order):
     wave.set_byte_order(byte_order)
     return (bin, wave, checkSumSize)
 
-def checksum(buffer, byte_order, oldcksum, numbytes):
-    x = _numpy.ndarray(
-        (numbytes/2,), # 2 bytes to a short -- ignore trailing odd byte
-        dtype=_numpy.dtype(byte_order+'h'),
-        buffer=buffer)
-    oldcksum += x.sum()
-    if oldcksum > 2**31:  # fake the C implementation's int rollover
-        oldcksum %= 2**32
-        if oldcksum > 2**31:
-            oldcksum -= 2**31
-    return oldcksum & 0xffff
-
 # Translated from ReadWave()
-def loadibw(filename, strict=True):
+def load(filename, strict=True):
     if hasattr(filename, 'read'):
         f = filename  # filename is actually a stream object
     else:
@@ -287,16 +269,17 @@ def loadibw(filename, strict=True):
         BinHeaderCommon.set_byte_order('=')
         b = buffer(f.read(BinHeaderCommon.size))
         version = BinHeaderCommon.unpack_dict_from(b)['version']
-        needToReorderBytes = need_to_reorder_bytes(version)
-        byteOrder = byte_order(needToReorderBytes)
+        needToReorderBytes = _need_to_reorder_bytes(version)
+        byteOrder = _byte_order(needToReorderBytes)
         
         if needToReorderBytes:
             BinHeaderCommon.set_byte_order(byteOrder)
             version = BinHeaderCommon.unpack_dict_from(b)['version']
-        bin_struct,wave_struct,checkSumSize = version_structs(version, byteOrder)
+        bin_struct,wave_struct,checkSumSize = _version_structs(
+            version, byteOrder)
 
         b = buffer(b + f.read(bin_struct.size + wave_struct.size - BinHeaderCommon.size))
-        c = checksum(b, byteOrder, 0, checkSumSize)
+        c = _checksum(b, byteOrder, 0, checkSumSize)
         if c != 0:
             raise ValueError(
                 ('This does not appear to be a valid Igor binary wave file.  '
@@ -431,5 +414,5 @@ def loadibw(filename, strict=True):
     return data, bin_info, wave_info
 
 
-def saveibw(filename):
+def save(filename):
     raise NotImplementedError

diff --git a/igor/util.py b/igor/util.py
index 7b2c34fe6e3fb84bb4b7c720fbe8d4582e957468..55c015c00fd5fef44823832f34f76b2700ded39c 100644 (file)
--- a/igor/util.py
+++ b/igor/util.py
@@ -4,6 +4,8 @@
 
 import sys as _sys
 
+import numpy as _numpy
+
 
 def hex_bytes(buffer, spaces=None):
     r"""Pretty-printing for binary buffers.
@@ -51,3 +53,25 @@ def assert_null(buffer, strict=True):
         else:
             _sys.stderr.write(
                 'warning: post-data padding not zero: {}\n'.format(hex_string))
+
+# From ReadWave.c
+def byte_order(needToReorderBytes):
+    little_endian = _sys.byteorder == 'little'
+    if needToReorderBytes:
+        little_endian = not little_endian
+    if little_endian:
+        return '<'  # little-endian
+    return '>'  # big-endian    
+
+# From ReadWave.c
+def checksum(buffer, byte_order, oldcksum, numbytes):
+    x = _numpy.ndarray(
+        (numbytes/2,), # 2 bytes to a short -- ignore trailing odd byte
+        dtype=_numpy.dtype(byte_order+'h'),
+        buffer=buffer)
+    oldcksum += x.sum()
+    if oldcksum > 2**31:  # fake the C implementation's int rollover
+        oldcksum %= 2**32
+        if oldcksum > 2**31:
+            oldcksum -= 2**31
+    return oldcksum & 0xffff

diff --git a/test/test.py b/test/test.py
index efe701934b849121d8dc5bb7c7e08f38251061b4..f52df5d5325e419ee154dae4135e2525fd55a3ef 100644 (file)
--- a/test/test.py
+++ b/test/test.py
@@ -699,7 +699,7 @@ import os.path
 from pprint import pformat
 import sys
 
-from igor.binarywave import loadibw
+from igor.binarywave import load as loadibw
 from igor.packed import load as loadpxp