GitHub - Kirow/lzmaSDK: lzmaSDK is an iOS port of the decoding logic from the LZMA SDK provided with 7zip

This branch is 12 commits behind mdejong/lzmaSDK:master.

Name	Name	Last commit message	Last commit date
Latest commit Moses DeJong adjust default min mmap size to 1 meg instead of 16 megs since 1 meg … Nov 12, 2014 33f7480 · Nov 12, 2014 History 41 Commits
Classes	Classes	adjust default min mmap size to 1 meg instead of 16 megs since 1 meg …	Nov 12, 2014
lzmaSDK-ios	lzmaSDK-ios	add lzmaSDK-ios patch from keigoi	Feb 18, 2013
lzmaSDK.xcodeproj	lzmaSDK.xcodeproj	add lzmaSDK-ios patch from keigoi	Feb 18, 2013
.gitignore	.gitignore	fixup easy clang analyzer warnings by commenting out code or explicit…	Jan 18, 2013
MainWindow.xib	MainWindow.xib	init with last working state from previous SDK release	Jul 12, 2010
README.txt	README.txt	update README with new port info and a bit about large file support	Jan 22, 2013
halfgig.7z	halfgig.7z	reimpl half gig decode test	Jan 21, 2013
lzmaSDK-Info.plist	lzmaSDK-Info.plist	import changes to update to lzma 921	Apr 20, 2011
lzmaSDK_Prefix.pch	lzmaSDK_Prefix.pch	init with last working state from previous SDK release	Jul 12, 2010
main.m	main.m	init with last working state from previous SDK release	Jul 12, 2010
onegig.7z	onegig.7z	rework logic related to mapping of huge 1 gigabyte file so that test …	Jan 21, 2013
sixfiftymeg_2blocks.7z	sixfiftymeg_2blocks.7z	decode a pair of 650 meg files in different blocks, add code to detec…	Jan 22, 2013
test.7z	test.7z	fixed up removal of CRC logic, imported LZMAExtractor, added logic fo…	Jul 12, 2010
update.tcl	update.tcl	add README and update script	Apr 20, 2011
writebig.tcl	writebig.tcl	decode a pair of 650 meg files in different blocks, add code to detec…	Jan 22, 2013

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This directory contains the LZMA SDK customized for an embedded system (iPhone/iOS)
Only the file extraction logic was included, all code related to creating
compressed streams was removed. CRC validation was removed to
improve performance. In addition, large file support was added so that iOS
is able to decompress files as large as 650 megs using memory mapped IO.
This code is based on lzma release 9.22 beta.

The code was modified as follows:

Embedded version does not need exe branch predictors.

Bra.c
Bcj2.c
Bra86.c

File List:

7zBuf.c 7zCrc.c 7zFile.c 7zStream.c Archive LzHash.h LzmaDec.h
7zBuf.h 7zCrc.h 7zFile.h 7zVersion.h CpuArch.h LzmaDec.c Types.h

Removed:

(XZ file format support)
Xz.*

MtCoder.c

Ppmd7Enc.c

Sha256.*

lzma Serch (encode) functions

rm LzFind*

rm Threads.*

rm Bra*

rm Bcj2.*

rm lzmaEnc* lzma2Enc.*

The 7z.h and 7zIn.c files were modified to support memory mapping the dictionary
cache file so that large files can be decompressed without having to break archives
up into blocks. While splitting into blocks makes it possible to create an archive
with lots of little files in different blocks, it makes compression much worse.
Large file support makes it possible to get maximum compression by putting all
the files into 1 block, but the downside is that the decode process is slower
due to the use of memory mapped IO writes. See the k7zUnpackMapDictionaryInMemoryMaxNumBytes
define in 7z.h if you want to change the size at which memory mapped IO kicks in,
currently archives larger than 1 meg will use memory mapped IO.

To update to a new version of the LZMA SDK, use the update.tcl to copy over those
files that were used in this version.

The example iOS application shows how to decode a small file and how some very large
files can be decoded without using up all the memory in an iOS application. Previously,
an archive with a dictionary around 30 to 40 megs would crash an iOS device, with
the mmap logic files as large as 650 megs can be decoded without going over the
virtual memory limits on iOS.