/usr/share/pyshared/imposm/merge.py is in python-imposm 2.3.2-2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 | # Copyright 2011 Omniscale (http://omniscale.com)
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import difflib
def merge(a, b):
sqm = difflib.SequenceMatcher(None, a, b)
matching_blocks = sqm.get_matching_blocks()
matching_blocks.pop(-1)
if not matching_blocks:
return None
a_idx = b_idx = 0
result = []
for block in matching_blocks:
if a_idx < block[0]:
result.extend(a[a_idx:block[0]])
if b_idx < block[1]:
result.extend(b[b_idx:block[1]])
a_idx = block[0]+block[-1]
b_idx = block[1]+block[-1]
result.extend(a[block[0]:block[0]+block[-1]])
if a_idx < len(a):
result.extend(a[a_idx:])
if b_idx < len(b):
result.extend(b[b_idx:])
return result
def multimerge(candidates, merge_func=merge):
candidates = list(candidates)
while len(candidates) > 1:
a, b, res = multimerge_(candidates, merge_func)
if res is None:
return candidates
candidates.remove(b)
if a is not res:
candidates.remove(a)
candidates.append(res)
# else: in place merge
return candidates[0]
def multimerge_(candidates, merge_func):
for a, b in permutations(candidates, 2):
res = merge_func(a, b)
if res is not None:
return a, b, res
return None, None, None
try:
from itertools import permutations
permutations # prevent warning
except ImportError:
def permutations(iterable, r=None):
# permutations('ABCD', 2) --> AB AC AD BA BC BD CA CB CD DA DB DC
# permutations(range(3)) --> 012 021 102 120 201 210
pool = tuple(iterable)
n = len(pool)
r = n if r is None else r
if r > n:
return
indices = range(n)
cycles = range(n, n-r, -1)
yield tuple(pool[i] for i in indices[:r])
while n:
for i in reversed(range(r)):
cycles[i] -= 1
if cycles[i] == 0:
indices[i:] = indices[i+1:] + indices[i:i+1]
cycles[i] = n - i
else:
j = cycles[i]
indices[i], indices[-j] = indices[-j], indices[i]
yield tuple(pool[i] for i in indices[:r])
break
else:
return
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