69 lines
1.8 KiB
Python
69 lines
1.8 KiB
Python
"""
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Digress comparers.
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"""
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from digress.errors import ComparisonError
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import os
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from itertools import imap, izip
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def compare_direct(value_a, value_b):
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if value_a != value_b:
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raise ComparisonError("%s is not %s" % (value_a, value_b))
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def compare_pass(value_a, value_b):
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"""
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Always true, as long as the test is passed.
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"""
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def compare_tolerance(tolerance):
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def _compare_tolerance(value_a, value_b):
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if abs(value_a - value_b) > tolerance:
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raise ComparisonError("%s is not %s (tolerance: %s)" % (
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value_a,
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value_b,
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tolerance
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))
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return _compare_tolerance
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def compare_files(file_a, file_b):
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size_a = os.path.getsize(file_a)
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size_b = os.path.getsize(file_b)
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print file_a, file_b
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if size_a != size_b:
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raise ComparisonError("%s is not the same size as %s" % (
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file_a,
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file_b
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))
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BUFFER_SIZE = 8196
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offset = 0
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with open(file_a) as f_a:
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with open(file_b) as f_b:
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for chunk_a, chunk_b in izip(
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imap(
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lambda i: f_a.read(BUFFER_SIZE),
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xrange(size_a // BUFFER_SIZE + 1)
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),
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imap(
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lambda i: f_b.read(BUFFER_SIZE),
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xrange(size_b // BUFFER_SIZE + 1)
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)
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):
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chunk_size = len(chunk_a)
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if chunk_a != chunk_b:
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for i in xrange(chunk_size):
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if chunk_a[i] != chunk_b[i]:
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raise ComparisonError("%s differs from %s at offset %d" % (
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file_a,
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file_b,
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offset + i
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))
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offset += chunk_size
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