3 from random import randint
4 from sys import stderr, stdout
8 def smaller_region(max_offset):
9 start = randint(0, max_offset)
10 return (start, min(max_offset, randint(start + 1, start + 5)))
13 def possibly_larger_region(max_offset, min_sparse_len):
14 start = randint(0, max_offset)
15 return (start, min(max_offset, randint(start + 1,
16 start + 3 * min_sparse_len)))
19 def initial_region(max_offset, min_sparse_len):
21 return (start, min(max_offset, randint(start + 1,
22 start + 3 * min_sparse_len)))
25 def final_region(max_offset, min_sparse_len):
26 start = max(0, randint(max_offset - 3 * min_sparse_len,
28 return (start, max_offset)
31 def region_around_min_len(max_offset, min_sparse_len):
32 start = randint(0, max_offset)
33 return (start, min(max_offset, randint(start + min_sparse_len - 5,
34 start + min_sparse_len + 5)))
41 return generators[randint(0, len(generators) - 1)]()
46 if len(sys.argv) == 2:
47 out = open(sys.argv[1], 'wb')
49 print >> stderr, "Usage: sparse-test-data [FILE]"
51 bup_read_size = 2 ** 16
52 bup_min_sparse_len = 512
53 out_size = randint(0, bup_read_size * 10)
55 generators = (lambda : smaller_region(out_size),
56 lambda : possibly_larger_region(out_size, bup_min_sparse_len),
57 lambda : initial_region(out_size, bup_min_sparse_len),
58 lambda : final_region(out_size, bup_min_sparse_len),
59 lambda : region_around_min_len(out_size, bup_min_sparse_len))
62 sparse.append(random_region())
63 sparse.append(random_region())
66 if sparse[1][0] < sparse[0][0]:
67 sparse[0], sparse[1] = sparse[1], sparse[0]
70 sparse_offsets.append(sparse[0][0])
71 if sparse[1][0] <= sparse[0][1]:
72 sparse_offsets.append(max(sparse[0][1], sparse[1][1]))
74 sparse_offsets.extend((sparse[0][1], sparse[1][0], sparse[1][1]))
76 if sparse[1][1] != out_size:
77 sparse_offsets.append(out_size)
79 # Now sparse_offsets indicates where to start/stop zero runs
82 print >> stderr, 'offsets:', sparse_offsets
83 for offset in sparse_offsets:
85 print >> stderr, 'write:', 'x' if data == 'x' else '0', count
86 out.write(data * (offset - pos))
88 data = '\0' if data == 'x' else 'x'