diff options
Diffstat (limited to 'tools/releasetools/blockimgdiff.py')
| -rw-r--r-- | tools/releasetools/blockimgdiff.py | 76 |
1 files changed, 50 insertions, 26 deletions
diff --git a/tools/releasetools/blockimgdiff.py b/tools/releasetools/blockimgdiff.py index 931026b119..f1cb6dba88 100644 --- a/tools/releasetools/blockimgdiff.py +++ b/tools/releasetools/blockimgdiff.py @@ -191,7 +191,6 @@ class Transfer(object): self.tgt_sha1 = tgt_sha1 self.src_sha1 = src_sha1 self.style = style - self.intact = tgt_ranges.monotonic and src_ranges.monotonic # We use OrderedDict rather than dict so that the output is repeatable; # otherwise it would depend on the hash values of the Transfer objects. @@ -333,6 +332,45 @@ class BlockImageDiff(object): def max_stashed_size(self): return self._max_stashed_size + @staticmethod + def FileTypeSupportedByImgdiff(filename): + """Returns whether the file type is supported by imgdiff.""" + return filename.lower().endswith(('.apk', '.jar', '.zip')) + + def CanUseImgdiff(self, name, tgt_ranges, src_ranges): + """Checks whether we can apply imgdiff for the given RangeSets. + + For files in ZIP format (e.g., APKs, JARs, etc.) we would like to use + 'imgdiff -z' if possible. Because it usually produces significantly smaller + patches than bsdiff. + + This is permissible if all of the following conditions hold. + - The imgdiff hasn't been disabled by the caller (e.g. squashfs); + - The file type is supported by imgdiff; + - The source and target blocks are monotonic (i.e. the data is stored with + blocks in increasing order); + - We haven't removed any blocks from the source set. + + If all these conditions are satisfied, concatenating all the blocks in the + RangeSet in order will produce a valid ZIP file (plus possibly extra zeros + in the last block). imgdiff is fine with extra zeros at the end of the file. + + Args: + name: The filename to be diff'd. + tgt_ranges: The target RangeSet. + src_ranges: The source RangeSet. + + Returns: + A boolean result. + """ + return ( + not self.disable_imgdiff and + self.FileTypeSupportedByImgdiff(name) and + tgt_ranges.monotonic and + src_ranges.monotonic and + not tgt_ranges.extra.get('trimmed') and + not src_ranges.extra.get('trimmed')) + def Compute(self, prefix): # When looking for a source file to use as the diff input for a # target file, we try: @@ -711,28 +749,13 @@ class BlockImageDiff(object): # transfer is intact. assert not self.disable_imgdiff imgdiff = True - if not xf.intact: + if (xf.src_ranges.extra.get('trimmed') or + xf.tgt_ranges.extra.get('trimmed')): imgdiff = False xf.patch = None else: - # For files in zip format (eg, APKs, JARs, etc.) we would - # like to use imgdiff -z if possible (because it usually - # produces significantly smaller patches than bsdiff). - # This is permissible if: - # - # - imgdiff is not disabled, and - # - the source and target files are monotonic (ie, the - # data is stored with blocks in increasing order), and - # - we haven't removed any blocks from the source set. - # - # If these conditions are satisfied then appending all the - # blocks in the set together in order will produce a valid - # zip file (plus possibly extra zeros in the last block), - # which is what imgdiff needs to operate. (imgdiff is - # fine with extra zeros at the end of the file.) - imgdiff = (not self.disable_imgdiff and xf.intact and - xf.tgt_name.split(".")[-1].lower() - in ("apk", "jar", "zip")) + imgdiff = self.CanUseImgdiff( + xf.tgt_name, xf.tgt_ranges, xf.src_ranges) xf.style = "imgdiff" if imgdiff else "bsdiff" diff_queue.append((index, imgdiff, patch_num)) patch_num += 1 @@ -977,7 +1000,7 @@ class BlockImageDiff(object): out_of_order += 1 assert xf.src_ranges.overlaps(u.tgt_ranges) xf.src_ranges = xf.src_ranges.subtract(u.tgt_ranges) - xf.intact = False + xf.src_ranges.extra['trimmed'] = True if xf.style == "diff" and not xf.src_ranges: # nothing left to diff from; treat as new data @@ -1261,11 +1284,12 @@ class BlockImageDiff(object): style, by_id) return - if tgt_name.split(".")[-1].lower() in ("apk", "jar", "zip"): - split_enable = (not self.disable_imgdiff and src_ranges.monotonic and - tgt_ranges.monotonic) - if split_enable and (self.tgt.RangeSha1(tgt_ranges) != - self.src.RangeSha1(src_ranges)): + # Split large APKs with imgdiff, if possible. We're intentionally checking + # file types one more time (CanUseImgdiff() checks that as well), before + # calling the costly RangeSha1()s. + if (self.FileTypeSupportedByImgdiff(tgt_name) and + self.tgt.RangeSha1(tgt_ranges) != self.src.RangeSha1(src_ranges)): + if self.CanUseImgdiff(tgt_name, tgt_ranges, src_ranges): large_apks.append((tgt_name, src_name, tgt_ranges, src_ranges)) return |