pygpt: Replace GetValidPartitions() by GetUsedPartitions().
The GetValidPartitions() is confusing because most other GPT tools don't
really stop processing when reached first empty (unused) entry.
We should change that to GetUsedPartitions(), especially Partition
objects now have meta 'number' so it is still possible to track back
the location in partition table.
BUG=chromium:834237
TEST=make test
Change-Id: I3234243ff88abfdee60d982cbd471e3301e9b816
Reviewed-on: https://chromium-review.googlesource.com/1017720
Commit-Ready: Hung-Te Lin <hungte@chromium.org>
Tested-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-by: Pi-Hsun Shih <pihsun@chromium.org>
diff --git a/py/utils/pygpt.py b/py/utils/pygpt.py
index 00d3edb..e14cfdb 100755
--- a/py/utils/pygpt.py
+++ b/py/utils/pygpt.py
@@ -525,22 +525,17 @@
ReadPartition(image, i) for i in range(header.PartitionEntriesNumber)]
return gpt
- def GetValidPartitions(self):
- """Returns the list of partitions before entry with empty type GUID.
+ def GetUsedPartitions(self):
+ """Returns a list of partitions with type GUID not set to unused.
- In partition table, the first entry with empty type GUID indicates end of
- valid partitions. In most implementations all partitions after that should
- be zeroed. However, few implementations for example cgpt, may create
- partitions in arbitrary order so use this carefully.
+ Use 'number' property to find the real location of partition in
+ self.partitions.
"""
- for i, p in enumerate(self.partitions):
- if p.IsUnused():
- return self.partitions[:i]
- return self.partitions
+ return [p for p in self.partitions if not p.IsUnused()]
def GetMaxUsedLBA(self):
"""Returns the max LastLBA from all used partitions."""
- parts = [p for p in self.partitions if not p.IsUnused()]
+ parts = self.GetUsedPartitions()
return (max(p.LastLBA for p in parts)
if parts else self.header.FirstUsableLBA - 1)
@@ -602,14 +597,16 @@
"""
# Assume no partitions overlap, we need to make sure partition[i] has
# largest LBA.
- if i < 0 or i >= len(self.GetValidPartitions()):
+ if i < 0 or i >= len(self.partitions):
raise GPTError('Partition number %d is invalid.' % (i + 1))
+ if self.partitions[i].IsUnused():
+ raise GPTError('Partition number %d is unused.' % (i + 1))
p = self.partitions[i]
max_used_lba = self.GetMaxUsedLBA()
+ # TODO(hungte) We can do more by finding free space after i.
if max_used_lba > p.LastLBA:
raise GPTError(
- 'Cannot expand partition %d because it is not the last allocated '
- 'partition.' % (i + 1))
+ 'Cannot expand %s because it is not allocated at last.' % p)
old_blocks = p.blocks
p = p.Clone(LastLBA=self.header.LastUsableLBA)
@@ -1011,24 +1008,19 @@
def Execute(self, args):
gpt = GPT.LoadFromFile(args.image_file)
- parts = gpt.GetValidPartitions()
number = args.number
if number is None:
- number = len(parts) + 1
- if number <= len(parts):
- is_new_part = False
- else:
- is_new_part = True
- index = number - 1
+ number = next(p for p in gpt.partitions if p.IsUnused()).number
# First and last LBA must be calculated explicitly because the given
# argument is size.
+ index = number - 1
part = gpt.partitions[index]
+ is_new_part = part.IsUnused()
if is_new_part:
part = part.ReadFrom(None, **part.__dict__).Clone(
- FirstLBA=(parts[-1].LastLBA + 1 if parts else
- gpt.header.FirstUsableLBA),
+ FirstLBA=gpt.GetMaxUsedLBA() + 1,
LastLBA=gpt.header.LastUsableLBA,
UniqueGUID=uuid.uuid4(),
TypeGUID=gpt.GetTypeGUID('data'))