releasetools: Allow generating BBOTA for images with shared blocks.
When target defines 'BOARD_EXT4_SHARE_DUP_BLOCKS := true', the generated
system/vendor images may contain shared blocks (i.e. some blocks will
show up in multiple files' block list), which violates the current
assumptions in BBOTA script.
This CL allows generating BBOTAs by considering the first occurrence as
the "owner" of the shared blocks. All the later users of the shared
blocks will have an incomplete block list, whose RangeSet's will be
tagged with 'uses_shared_blocks'.
Files with 'uses_shared_blocks' tag will not be diff'd with imgdiff,
potentially with patch size penalty. Such files will be accounted for in
imgdiff stats report, where we can revisit for a better solution.
Bug: 64109868
Test: Generate BBOTA full and incremental package with targets defining
'BOARD_EXT4_SHARE_DUP_BLOCKS := true'.
Change-Id: I87fbc22eef7fafe2a470a03fdcfa1babf088ea8d
diff --git a/tools/releasetools/common.py b/tools/releasetools/common.py
index 16600ed..370710e 100644
--- a/tools/releasetools/common.py
+++ b/tools/releasetools/common.py
@@ -625,7 +625,7 @@
return tmp, zipfile.ZipFile(filename, "r")
-def GetSparseImage(which, tmpdir, input_zip):
+def GetSparseImage(which, tmpdir, input_zip, allow_shared_blocks):
"""Returns a SparseImage object suitable for passing to BlockImageDiff.
This function loads the specified sparse image from the given path, and
@@ -637,6 +637,7 @@
which: The partition name, which must be "system" or "vendor".
tmpdir: The directory that contains the prebuilt image and block map file.
input_zip: The target-files ZIP archive.
+ allow_shared_blocks: Whether having shared blocks is allowed.
Returns:
A SparseImage object, with file_map info loaded.
@@ -655,7 +656,8 @@
# unconditionally. Note that they are still part of care_map. (Bug: 20939131)
clobbered_blocks = "0"
- image = sparse_img.SparseImage(path, mappath, clobbered_blocks)
+ image = sparse_img.SparseImage(path, mappath, clobbered_blocks,
+ allow_shared_blocks=allow_shared_blocks)
# block.map may contain less blocks, because mke2fs may skip allocating blocks
# if they contain all zeros. We can't reconstruct such a file from its block
@@ -669,6 +671,13 @@
info = input_zip.getinfo(arcname)
ranges = image.file_map[entry]
+
+ # If a RangeSet has been tagged as using shared blocks while loading the
+ # image, its block list must be already incomplete due to that reason. Don't
+ # give it 'incomplete' tag to avoid messing up the imgdiff stats.
+ if ranges.extra.get('uses_shared_blocks'):
+ continue
+
if RoundUpTo4K(info.file_size) > ranges.size() * 4096:
ranges.extra['incomplete'] = True