From 433ce470115af565a0ed7b771fe09c3c4687a439 Mon Sep 17 00:00:00 2001 From: "W. Trevor King" Date: Mon, 16 Jul 2012 15:51:14 -0400 Subject: [PATCH] Pull null-buffer check out into its own function: binarywave.assert_null. --- igor/binarywave.py | 62 +++++++++++++++++++++++++++++++++++----------- 1 file changed, 48 insertions(+), 14 deletions(-) diff --git a/igor/binarywave.py b/igor/binarywave.py index 09d06dc..3429ad1 100644 --- a/igor/binarywave.py +++ b/igor/binarywave.py @@ -423,6 +423,52 @@ def checksum(buffer, byte_order, oldcksum, numbytes): oldcksum -= 2**31 return oldcksum & 0xffff +def hex_bytes(buffer, spaces=None): + r"""Pretty-printing for binary buffers. + + >>> hex_bytes(buffer('\x00\x01\x02\x03\x04')) + '0001020304' + >>> hex_bytes(buffer('\x00\x01\x02\x03\x04'), spaces=1) + '00 01 02 03 04' + >>> hex_bytes(buffer('\x00\x01\x02\x03\x04'), spaces=2) + '0001 0203 04' + >>> hex_bytes(buffer('\x00\x01\x02\x03\x04\x05\x06'), spaces=2) + '0001 0203 0405 06' + >>> hex_bytes(buffer('\x00\x01\x02\x03\x04\x05\x06'), spaces=3) + '000102 030405 06' + """ + hex_bytes = ['{:02x}'.format(ord(x)) for x in buffer] + if spaces is None: + return ''.join(hex_bytes) + elif spaces is 1: + return ' '.join(hex_bytes) + for i in range(len(hex_bytes)//spaces): + hex_bytes.insert((spaces+1)*(i+1)-1, ' ') + return ''.join(hex_bytes) + +def assert_null(buffer, strict=True): + r"""Ensure an input buffer is entirely zero. + + >>> assert_null(buffer('')) + >>> assert_null(buffer('\x00\x00')) + >>> assert_null(buffer('\x00\x01\x02\x03')) + Traceback (most recent call last): + ... + ValueError: 00 01 02 03 + >>> stderr = sys.stderr + >>> sys.stderr = sys.stdout + >>> assert_null(buffer('\x00\x01\x02\x03'), strict=False) + warning: post-data padding not zero: 00 01 02 03 + >>> sys.stderr = stderr + """ + if buffer and ord(max(buffer)) != 0: + hex_string = hex_bytes(buffer, spaces=1) + if strict: + raise ValueError(hex_string) + else: + sys.stderr.write( + 'warning: post-data padding not zero: {}\n'.format(hex_string)) + # Translated from ReadWave() def loadibw(filename, strict=True): if hasattr(filename, 'read'): @@ -486,13 +532,7 @@ def loadibw(filename, strict=True): # * 16 bytes of padding # * Optional wave note data pad_b = buffer(f.read(16)) # skip the padding - if max(pad_b) != 0: - if strict: - assert max(pad_b) == 0, pad_b - else: - sys.stderr.write( - 'warning: post-data padding not zero: {}\n'.format( - pad_b)) + assert_null(pad_b, strict=strict) bin_info['note'] = str(f.read(bin_info['noteSize'])).strip() elif version == 3: # Post-data info: @@ -507,13 +547,7 @@ def loadibw(filename, strict=True): no trailing null byte. """ pad_b = buffer(f.read(16)) # skip the padding - if max(pad_b) != 0: - if strict: - assert max(pad_b) == 0, pad_b - else: - sys.stderr.write( - 'warning: post-data padding not zero: {}\n'.format( - pad_b)) + assert_null(pad_b, strict=strict) bin_info['note'] = str(f.read(bin_info['noteSize'])).strip() bin_info['formula'] = str(f.read(bin_info['formulaSize'])).strip() elif version == 5: -- 2.26.2