Changes between Version 20 and Version 21 of Obsolete/MovedToTree/PackageManagement/FileFormat

Timestamp:

Oct 6, 2013, 1:15:40 PM (11 years ago)

Author:

bonefish

Comment:

--

Obsolete/MovedToTree/PackageManagement/FileFormat

@@ -109 +109 @@
 ||1||B_HPKG_COMPRESSION_ZLIB||zlib (LZ77) compression||
 
-The uncompressed heap data are divided into equally sized chunks (64 KiB). Each individual chunk may be stored compressed or not. A uint16 array at the end of the heap contains the actual in-file (compressed) size of each chunk (minus 1 -- 0 means 1 byte), save for the last one, which is omitted since it is implied. A chunk is only stored compressed, if compression actually saves space. That is if the chunk's compressed size equals its uncompressed size, the data aren't compressed.
+The uncompressed heap data are divided into equally sized chunks (64 KiB). The last chunk in the heap may have a different uncompressed length from the preceding chunks. The uncompressed length of the last chunk can be derived. Each individual chunk may be stored compressed or not. A uint16 array at the end of the heap contains the actual in-file (compressed) size of each chunk (minus 1 -- 0 means 1 byte), save for the last one, which is omitted since it is implied. A chunk is only stored compressed, if compression actually saves space. That is if the chunk's compressed size equals its uncompressed size, the data aren't compressed.
 
 The TOC and the package attributes sections are stored (in this order) at the end of the uncompressed heap. The offset of the package attributes section data is therefore `heap_size_uncompressed - attributes_length` and the offset of the TOC section data `heap_size_uncompressed - attributes_length - toc_length`.