diff options
Diffstat (limited to 'import-layers/yocto-poky/scripts/lib/wic/filemap.py')
| -rw-r--r-- | import-layers/yocto-poky/scripts/lib/wic/filemap.py | 58 |
1 files changed, 43 insertions, 15 deletions
diff --git a/import-layers/yocto-poky/scripts/lib/wic/filemap.py b/import-layers/yocto-poky/scripts/lib/wic/filemap.py index 1f1aacc52..77e32b9ad 100644 --- a/import-layers/yocto-poky/scripts/lib/wic/filemap.py +++ b/import-layers/yocto-poky/scripts/lib/wic/filemap.py @@ -34,13 +34,9 @@ def get_block_size(file_obj): Returns block size for file object 'file_obj'. Errors are indicated by the 'IOError' exception. """ - - from fcntl import ioctl - import struct - # Get the block size of the host file-system for the image file by calling # the FIGETBSZ ioctl (number 2). - binary_data = ioctl(file_obj, 2, struct.pack('I', 0)) + binary_data = fcntl.ioctl(file_obj, 2, struct.pack('I', 0)) return struct.unpack('I', binary_data)[0] class ErrorNotSupp(Exception): @@ -228,7 +224,7 @@ class FilemapSeek(_FilemapBase): try: tmp_obj = tempfile.TemporaryFile("w+", dir=directory) except IOError as err: - raise ErrorNotSupp("cannot create a temporary in \"%s\": %s" + raise ErrorNotSupp("cannot create a temporary in \"%s\": %s" \ % (directory, err)) try: @@ -530,8 +526,18 @@ def filemap(image, log=None): except ErrorNotSupp: return FilemapSeek(image, log) -def sparse_copy(src_fname, dst_fname, offset=0, skip=0, api=None): - """Efficiently copy sparse file to or into another file.""" +def sparse_copy(src_fname, dst_fname, skip=0, seek=0, + length=0, api=None): + """ + Efficiently copy sparse file to or into another file. + + src_fname: path to source file + dst_fname: path to destination file + skip: skip N bytes at thestart of src + seek: seek N bytes from the start of dst + length: read N bytes from src and write them to dst + api: FilemapFiemap or FilemapSeek object + """ if not api: api = filemap fmap = api(src_fname) @@ -539,17 +545,32 @@ def sparse_copy(src_fname, dst_fname, offset=0, skip=0, api=None): dst_file = open(dst_fname, 'r+b') except IOError: dst_file = open(dst_fname, 'wb') - dst_file.truncate(os.path.getsize(src_fname)) + if length: + dst_size = length + seek + else: + dst_size = os.path.getsize(src_fname) + seek - skip + dst_file.truncate(dst_size) + written = 0 for first, last in fmap.get_mapped_ranges(0, fmap.blocks_cnt): start = first * fmap.block_size end = (last + 1) * fmap.block_size + if skip >= end: + continue + if start < skip < end: - fmap._f_image.seek(skip, os.SEEK_SET) - else: - fmap._f_image.seek(start, os.SEEK_SET) - dst_file.seek(offset + start, os.SEEK_SET) + start = skip + + fmap._f_image.seek(start, os.SEEK_SET) + + written += start - skip - written + if length and written >= length: + dst_file.seek(seek + length, os.SEEK_SET) + dst_file.close() + return + + dst_file.seek(seek + start - skip, os.SEEK_SET) chunk_size = 1024 * 1024 to_read = end - start @@ -558,7 +579,14 @@ def sparse_copy(src_fname, dst_fname, offset=0, skip=0, api=None): while read < to_read: if read + chunk_size > to_read: chunk_size = to_read - read - chunk = fmap._f_image.read(chunk_size) + size = chunk_size + if length and written + size > length: + size = length - written + chunk = fmap._f_image.read(size) dst_file.write(chunk) - read += chunk_size + read += size + written += size + if written == length: + dst_file.close() + return dst_file.close() |