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authorEd Bartosh <ed.bartosh@linux.intel.com>2016-04-28 13:58:09 +0300
committerRichard Purdie <richard.purdie@linuxfoundation.org>2016-05-06 10:30:56 +0100
commitbfde62bdc03152a4d3d383512479b974fa867f94 (patch)
tree160ab04bd61131fda7893247e301e363e0473460
parent182639ddc9cda85c896a54c1c64fd1fb145071a1 (diff)
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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 <ed.bartosh@linux.intel.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
-rw-r--r--scripts/lib/wic/filemap.py30
1 files changed, 30 insertions, 0 deletions
diff --git a/scripts/lib/wic/filemap.py b/scripts/lib/wic/filemap.py
index 1d04328322d..f8b2ba71bbd 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()