return FilemapFiemap(image, log)
except ErrorNotSupp:
return FilemapSeek(image, log)
+
+def sparse_copy(src_fname, dst_fname, offset=0, skip=0):
+ """Efficiently copy sparse file to or into another file."""
+ fmap = filemap(src_fname)
+ try:
+ dst_file = open(dst_fname, 'r+b')
+ except IOError:
+ dst_file = open(dst_fname, 'wb')
+
+ for first, last in fmap.get_mapped_ranges(0, fmap.blocks_cnt):
+ start = first * fmap.block_size
+ end = (last + 1) * fmap.block_size
+
+ if start < skip < end:
+ start = skip
+
+ fmap._f_image.seek(start, os.SEEK_SET)
+ dst_file.seek(offset + start, os.SEEK_SET)
+
+ chunk_size = 1024 * 1024
+ to_read = end - start
+ read = 0
+
+ while read < to_read:
+ if read + chunk_size > to_read:
+ chunk_size = to_read - read
+ chunk = fmap._f_image.read(chunk_size)
+ dst_file.write(chunk)
+ read += chunk_size
+ dst_file.close()
