From bfde62bdc03152a4d3d383512479b974fa867f94 Mon Sep 17 00:00:00 2001 From: Ed Bartosh Date: Thu, 28 Apr 2016 13:58:09 +0300 Subject: wic: add sparse_copy API In order to make wic images sparse sparse_copy function has been copied from meta-ostro: https://github.com/kad/meta-ostro/blob/master/meta-ostro/lib/image-dsk.py This function uses filemap APIs to copy source sparse file into destination file preserving sparseness. The function has been modified to satisfy wic requirements: parameter 'skip' has been added. [YOCTO #9099] Signed-off-by: Ed Bartosh Signed-off-by: Richard Purdie --- scripts/lib/wic/filemap.py | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/scripts/lib/wic/filemap.py b/scripts/lib/wic/filemap.py index 1d04328322..f8b2ba71bb 100644 --- a/scripts/lib/wic/filemap.py +++ b/scripts/lib/wic/filemap.py @@ -529,3 +529,33 @@ def filemap(image, log=None): 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() -- cgit 1.2.3-korg