def merge_sort_stupid(fin: io.BufferedIOBase, fout: io.BufferedIOBase, memory_size: int, left=0, count=None):
fout.seek(0)
if count is None:
count = content_length(fin, preserve_pos=False)
if count <= memory_size:
go_to_pos(fin, left)
write_content(fout, sorted(read_content(fin, count=count)), batch_size=memory_size)
return
with tmp_file() as left_f, tmp_file() as right_f:
merge_sort_stupid(fin, left_f, memory_size, left, count=count // 2)
merge_sort_stupid(fin, right_f, memory_size, left + count // 2, count=count - count // 2)
left_f.seek(0)
right_f.seek(0)
write_content(fout, heapq.merge(read_content(left_f, batch_size=memory_size // 2),
read_content(right_f, batch_size=memory_size // 2)),
batch_size=memory_size)
def _to_sorted_blocks(fin: io.BufferedIOBase, memory_size):
while True:
sorted_values = sorted(read_content(fin, memory_size))
if not sorted_values:
break
f = tmp_file()
write_content(f, sorted_values)
f.close()
yield f
def merge_sort_k_blocks_two_passes(fin: io.BufferedIOBase, fout: io.BufferedIOBase, memory_size: int):
tmp_files = list(_to_sorted_blocks(fin, memory_size))
if len(tmp_files) < 10:
larger_tmp_files = tmp_files
else:
larger_tmp_files = []
larger_blocks_count = int(sqrt(len(tmp_files)))
for i in range(0, len(tmp_files), larger_blocks_count):
larger_f = tmp_file()
_merge_blocks(tmp_files[i:min(len(tmp_files), i + larger_blocks_count)], larger_f, memory_size)
larger_f.close()
larger_tmp_files.append(larger_f)
_merge_blocks(larger_tmp_files, fout, memory_size)
def _test_simple(self, values, sort_f, memory_size=None):
with tmp_file() as input_file, tmp_file() as output_file:
write_content(input_file, values)
input_file.seek(0)
sort_f(input_file, output_file, memory_size=self._memory_size if memory_size is None else memory_size)
self._check_sorted(input_file, output_file)
