Factor out the image classes to break circular dependency
This helps to break the circular dependency between common and
blockimgdiff.
Bug: 32379627
Test: unit tests pass
Change-Id: I90b5ff34782acbfac86f36265bd96c207d898bf6
diff --git a/tools/releasetools/blockimgdiff.py b/tools/releasetools/blockimgdiff.py
index ecb1d31..72f065d 100644
--- a/tools/releasetools/blockimgdiff.py
+++ b/tools/releasetools/blockimgdiff.py
@@ -28,12 +28,12 @@
import threading
import zlib
from collections import deque, namedtuple, OrderedDict
-from hashlib import sha1
import common
+from images import EmptyImage
from rangelib import RangeSet
-__all__ = ["EmptyImage", "DataImage", "BlockImageDiff"]
+__all__ = ["BlockImageDiff"]
logger = logging.getLogger(__name__)
@@ -60,209 +60,6 @@
return PatchInfo(imgdiff, f.read())
-class Image(object):
- def RangeSha1(self, ranges):
- raise NotImplementedError
-
- def ReadRangeSet(self, ranges):
- raise NotImplementedError
-
- def TotalSha1(self, include_clobbered_blocks=False):
- raise NotImplementedError
-
- def WriteRangeDataToFd(self, ranges, fd):
- raise NotImplementedError
-
-
-class EmptyImage(Image):
- """A zero-length image."""
-
- def __init__(self):
- self.blocksize = 4096
- self.care_map = RangeSet()
- self.clobbered_blocks = RangeSet()
- self.extended = RangeSet()
- self.total_blocks = 0
- self.file_map = {}
- self.hashtree_info = None
-
- def RangeSha1(self, ranges):
- return sha1().hexdigest()
-
- def ReadRangeSet(self, ranges):
- return ()
-
- def TotalSha1(self, include_clobbered_blocks=False):
- # EmptyImage always carries empty clobbered_blocks, so
- # include_clobbered_blocks can be ignored.
- assert self.clobbered_blocks.size() == 0
- return sha1().hexdigest()
-
- def WriteRangeDataToFd(self, ranges, fd):
- raise ValueError("Can't write data from EmptyImage to file")
-
-
-class DataImage(Image):
- """An image wrapped around a single string of data."""
-
- def __init__(self, data, trim=False, pad=False):
- self.data = data
- self.blocksize = 4096
-
- assert not (trim and pad)
-
- partial = len(self.data) % self.blocksize
- padded = False
- if partial > 0:
- if trim:
- self.data = self.data[:-partial]
- elif pad:
- self.data += '\0' * (self.blocksize - partial)
- padded = True
- else:
- raise ValueError(("data for DataImage must be multiple of %d bytes "
- "unless trim or pad is specified") %
- (self.blocksize,))
-
- assert len(self.data) % self.blocksize == 0
-
- self.total_blocks = len(self.data) // self.blocksize
- self.care_map = RangeSet(data=(0, self.total_blocks))
- # When the last block is padded, we always write the whole block even for
- # incremental OTAs. Because otherwise the last block may get skipped if
- # unchanged for an incremental, but would fail the post-install
- # verification if it has non-zero contents in the padding bytes.
- # Bug: 23828506
- if padded:
- clobbered_blocks = [self.total_blocks-1, self.total_blocks]
- else:
- clobbered_blocks = []
- self.clobbered_blocks = clobbered_blocks
- self.extended = RangeSet()
-
- zero_blocks = []
- nonzero_blocks = []
- reference = '\0' * self.blocksize
-
- for i in range(self.total_blocks-1 if padded else self.total_blocks):
- d = self.data[i*self.blocksize : (i+1)*self.blocksize]
- if d == reference:
- zero_blocks.append(i)
- zero_blocks.append(i+1)
- else:
- nonzero_blocks.append(i)
- nonzero_blocks.append(i+1)
-
- assert zero_blocks or nonzero_blocks or clobbered_blocks
-
- self.file_map = dict()
- if zero_blocks:
- self.file_map["__ZERO"] = RangeSet(data=zero_blocks)
- if nonzero_blocks:
- self.file_map["__NONZERO"] = RangeSet(data=nonzero_blocks)
- if clobbered_blocks:
- self.file_map["__COPY"] = RangeSet(data=clobbered_blocks)
-
- def _GetRangeData(self, ranges):
- for s, e in ranges:
- yield self.data[s*self.blocksize:e*self.blocksize]
-
- def RangeSha1(self, ranges):
- h = sha1()
- for data in self._GetRangeData(ranges): # pylint: disable=not-an-iterable
- h.update(data)
- return h.hexdigest()
-
- def ReadRangeSet(self, ranges):
- return list(self._GetRangeData(ranges))
-
- def TotalSha1(self, include_clobbered_blocks=False):
- if not include_clobbered_blocks:
- return self.RangeSha1(self.care_map.subtract(self.clobbered_blocks))
- return sha1(self.data).hexdigest()
-
- def WriteRangeDataToFd(self, ranges, fd):
- for data in self._GetRangeData(ranges): # pylint: disable=not-an-iterable
- fd.write(data)
-
-
-class FileImage(Image):
- """An image wrapped around a raw image file."""
-
- def __init__(self, path, hashtree_info_generator=None):
- self.path = path
- self.blocksize = 4096
- self._file_size = os.path.getsize(self.path)
- self._file = open(self.path, 'rb')
-
- if self._file_size % self.blocksize != 0:
- raise ValueError("Size of file %s must be multiple of %d bytes, but is %d"
- % self.path, self.blocksize, self._file_size)
-
- self.total_blocks = self._file_size // self.blocksize
- self.care_map = RangeSet(data=(0, self.total_blocks))
- self.clobbered_blocks = RangeSet()
- self.extended = RangeSet()
-
- self.generator_lock = threading.Lock()
-
- self.hashtree_info = None
- if hashtree_info_generator:
- self.hashtree_info = hashtree_info_generator.Generate(self)
-
- zero_blocks = []
- nonzero_blocks = []
- reference = '\0' * self.blocksize
-
- for i in range(self.total_blocks):
- d = self._file.read(self.blocksize)
- if d == reference:
- zero_blocks.append(i)
- zero_blocks.append(i+1)
- else:
- nonzero_blocks.append(i)
- nonzero_blocks.append(i+1)
-
- assert zero_blocks or nonzero_blocks
-
- self.file_map = {}
- if zero_blocks:
- self.file_map["__ZERO"] = RangeSet(data=zero_blocks)
- if nonzero_blocks:
- self.file_map["__NONZERO"] = RangeSet(data=nonzero_blocks)
- if self.hashtree_info:
- self.file_map["__HASHTREE"] = self.hashtree_info.hashtree_range
-
- def __del__(self):
- self._file.close()
-
- def _GetRangeData(self, ranges):
- # Use a lock to protect the generator so that we will not run two
- # instances of this generator on the same object simultaneously.
- with self.generator_lock:
- for s, e in ranges:
- self._file.seek(s * self.blocksize)
- for _ in range(s, e):
- yield self._file.read(self.blocksize)
-
- def RangeSha1(self, ranges):
- h = sha1()
- for data in self._GetRangeData(ranges): # pylint: disable=not-an-iterable
- h.update(data)
- return h.hexdigest()
-
- def ReadRangeSet(self, ranges):
- return list(self._GetRangeData(ranges))
-
- def TotalSha1(self, include_clobbered_blocks=False):
- assert not self.clobbered_blocks
- return self.RangeSha1(self.care_map)
-
- def WriteRangeDataToFd(self, ranges, fd):
- for data in self._GetRangeData(ranges): # pylint: disable=not-an-iterable
- fd.write(data)
-
-
class Transfer(object):
def __init__(self, tgt_name, src_name, tgt_ranges, src_ranges, tgt_sha1,
src_sha1, style, by_id):