INTRODUCTION
-This is wimlib version 1.7.2-BETA (August 2014). wimlib is a C library for
+This is wimlib version 1.8.0-BETA (February 2015). wimlib is a C library for
creating, modifying, extracting, and mounting files in the Windows Imaging
Format (WIM files). wimlib and its command-line frontend 'wimlib-imagex'
provide a free and cross-platform alternative to Microsoft's WIMGAPI, ImageX,
wimlib includes its own compression codecs and does not use the compression API
available on some versions of Windows.
-I have gradually been improving the compression codecs in wimlib. For XPRESS
-and LZX, they now usually outperform and outcompress the equivalent Microsoft
+I have gradually been improving the compression codecs in wimlib. For all three
+codecs, they now usually outperform and outcompress the equivalent Microsoft
implementations. Although results will vary depending on the data being
compressed, in the table below I present the results for a common use case:
compressing an x86 Windows PE image. Each row displays the compression type,
implementation in WIMGAPI is included.
=============================================================================
- | Compression || wimlib (v1.7.2-BETA) | WIMGAPI (Windows 8.1) |
+ | Compression || wimlib (v1.8.0) | WIMGAPI (Windows 8.1) |
=============================================================================
- | None [1] || 361,404,682 in 3.4s | 361,364,994 in 4.2s |
- | XPRESS [2] || 138,398,747 in 4.2s | 140,468,002 in 5.1s |
- | XPRESS (slow) [3] || 135,284,950 in 10.3s | N/A |
- | LZX (quick) [4] || 131,861,913 in 4.7s | N/A |
- | LZX (normal) [5] || 126,855,247 in 14.9s | 127,301,774 in 18.2s |
- | LZX (slow) [6] || 126,245,561 in 32.1s | N/A |
- | LZMS (non-solid) [7] || 122,126,328 in 16.4s | N/A |
- | LZMS (solid) [8] || 93,795,440 in 47.4s | 88,789,426 in 96.8s |
- | "WIMBoot" [9] || 167,121,495 in 5.3s | 169,124,968 in 9.3s |
- | "WIMBoot" (slow) [10] || 165,219,818 in 9.4s | N/A |
+ | None [1] || 361,314,224 in 2.4s | 361,315,338 in 4.5s |
+ | XPRESS [2] || 138,218,750 in 3.0s | 140,457,436 in 6.0s |
+ | XPRESS (slow) [3] || 135,173,511 in 8.9s | N/A |
+ | LZX (quick) [4] || 130,207,195 in 3.8s | N/A |
+ | LZX (normal) [5] || 126,522,539 in 10.4s | 127,293,240 in 19.2s |
+ | LZX (slow) [6] || 126,042,313 in 17.3s | N/A |
+ | LZMS (non-solid) [7] || 116,150,682 in 25.3s | N/A |
+ | LZMS (solid) [8] || 88,107,484 in 61.7s | 88,769,830 in 102.3s |
+ | "WIMBoot" [9] || 167,023,719 in 3.5s | 169,109,211 in 10.4s |
+ | "WIMBoot" (slow) [10] || 165,027,583 in 7.9s | N/A |
=============================================================================
Notes:
[8] '--solid' for wimlib-imagex. Should be '/compress:recovery' for DISM,
but only works for /Export-Image, not /Capture-Image. Compression chunk
- size in solid blocks defaults to 33554432 for wimlib, 67108864 for DISM.
+ size in solid resources defaults to 67108864 bytes in both cases.
[9] '--wimboot' for wimlib-imagex; '/wimboot' for DISM.
This is really XPRESS compression with 4096 byte chunks, so the same as
The compression ratio provided by wimlib is also competitive with commonly used
archive formats. Below are file sizes that result when the Canterbury corpus is
-compressed with wimlib (v1.7.0), WIMGAPI (Windows 8), and some other
+compressed with wimlib (v1.8.0), WIMGAPI (Windows 8.1), and some other
formats/programs:
- =================================================
- | Format | Size (bytes) |
- =================================================
- | tar | 2,826,240 |
- | WIM (WIMGAPI, None) | 2,814,278 |
- | WIM (wimlib, None) | 2,813,856 |
- | WIM (WIMGAPI, XPRESS) | 825,410 |
- | WIM (wimlib, XPRESS) | 792,024 |
- | tar.gz (gzip, default) | 738,796 |
- | ZIP (Info-ZIP, default) | 735,334 |
- | tar.gz (gzip, -9) | 733,971 |
- | ZIP (Info-ZIP, -9) | 732,297 |
- | WIM (wimlib, LZX quick) | 722,196 |
- | WIM (WIMGAPI, LZX) | 651,766 |
- | WIM (wimlib, LZX normal) | 649,204 |
- | WIM (wimlib, LZX slow) | 639,618 |
- | WIM (wimlib, LZMS non-solid) | 592,136 |
- | tar.bz2 (bzip, default) | 565,008 |
- | tar.bz2 (bzip, -9) | 565,008 |
- | WIM (wimlib, LZMS solid) | 525,270 |
- | WIM (wimlib, LZMS solid, slow) | 521,700 |
- | WIM (WIMGAPI, LZMS solid) | 521,232 |
- | tar.xz (xz, default) | 486,916 |
- | tar.xz (xz, -9) | 486,904 |
- | 7z (7-zip, default) | 484,700 |
- | 7z (7-zip, -9) | 483,239 |
- =================================================
+ =====================================================
+ | Format | Size (bytes) |
+ =====================================================
+ | tar | 2,826,240 |
+ | WIM (WIMGAPI, None) | 2,814,254 |
+ | WIM (wimlib, None) | 2,814,216 |
+ | WIM (WIMGAPI, XPRESS) | 825,536 |
+ | WIM (wimlib, XPRESS) | 789,296 |
+ | tar.gz (gzip, default) | 738,796 |
+ | ZIP (Info-ZIP, default) | 735,334 |
+ | tar.gz (gzip, -9) | 733,971 |
+ | ZIP (Info-ZIP, -9) | 732,297 |
+ | WIM (wimlib, LZX quick) | 690,110 |
+ | WIM (WIMGAPI, LZX) | 651,866 |
+ | WIM (wimlib, LZX normal) | 624,634 |
+ | WIM (wimlib, LZX slow) | 620,728 |
+ | WIM (wimlib, LZMS non-solid) | 581,046 |
+ | tar.bz2 (bzip, default) | 565,008 |
+ | tar.bz2 (bzip, -9) | 565,008 |
+ | WIM (WIMGAPI, LZMS solid) | 521,366 |
+ | WIM (wimlib, LZMS solid) | 515,800 |
+ | tar.xz (xz, default) | 486,916 |
+ | tar.xz (xz, -9) | 486,904 |
+ | 7z (7-zip, default) | 484,700 |
+ | 7z (7-zip, -9) | 483,239 |
+ =====================================================
Note: WIM does even better on directory trees containing duplicate files, which
the Canterbury corpus doesn't have.
dependencies were already included and this section is irrelevant.
* libxml2 (required)
- This is a commonly used free library to read and write XML files. You
- likely already have it installed as a dependency for some other program.
- For more information see http://xmlsoft.org/.
-
-* libfuse (optional but highly recommended)
- Unless configured with --without-fuse, wimlib requires a non-ancient
- version of libfuse to be installed. Most Linux distributions already
- include this, but make sure you have the libfuse package installed, and
- also libfuse-dev if your distribution distributes header files
- separately. FUSE also requires a kernel module. If the kernel module
- is available it will automatically be loaded if you try to mount a WIM
- file. For more information see http://fuse.sourceforge.net/. FUSE is
- also available for FreeBSD.
-
-* libntfs-3g (optional but highly recommended)
- Unless configured with --without-ntfs-3g, wimlib requires the library
- and headers for libntfs-3g version 2011-4-12 or later to be installed.
- Versions dated 2010-3-6 and earlier do not work because they are missing
- the header xattrs.h (and the file xattrs.c, which contains functions we
- need). libntfs-3g version 2013-1-13 is compatible only with wimlib
- 1.2.4 and later.
+ This is a commonly used free library to read and write XML documents.
+ Almost all Linux distributions should include this; however, you may
+ need to install the header files, which might be in a package named
+ "libxml2-dev" or similar. For more information see http://xmlsoft.org/.
+
+* libfuse (optional but recommended)
+ Unless configured --without-fuse, wimlib requires a non-ancient version
+ of libfuse. Most Linux distributions already include this, but make
+ sure you have the libfuse package installed, and also libfuse-dev if
+ your distribution distributes header files separately. FUSE also
+ requires a kernel module. If the kernel module is available it should
+ automatically be loaded if you try to mount a WIM image. For more
+ information see http://fuse.sourceforge.net/.
+
+* libattr (optional but recommended)
+ Unless configured --without-fuse, wimlib also requires libattr. Almost
+ all Linux distributions should include this; however, you may need to
+ install the header files, which might be in a package named "attr-dev",
+ "libattr1-dev", or similar.
+
+* libntfs-3g (optional but recommended)
+ Unless configured --without-ntfs-3g, wimlib requires the library and
+ headers for libntfs-3g version 2011-4-12 or later to be installed.
* OpenSSL / libcrypto (optional)
- wimlib can use the SHA1 message digest code from OpenSSL instead of
- compiling in yet another SHA1 implementation. (See LICENSE section.)
+ wimlib can use the SHA-1 message digest implementation from libcrypto
+ (usually provided by OpenSSL) instead of compiling in yet another SHA-1
+ implementation.
* cdrkit (optional)
* mtools (optional)
--without-ntfs-3g
If libntfs-3g is not available or is not version 2011-4-12 or later,
wimlib can be built without it, in which case it will not be possible to
- apply or capture images directly to/from NTFS volumes.
+ capture or apply WIM images directly from/to NTFS volumes.
---without-fuse
- If libfuse or the FUSE kernel module is not available, wimlib can be
- compiled with --without-fuse. This will remove the ability to mount and
- unmount WIM files.
-
---without-libcrypto
- Build in functions for SHA1 rather than using external SHA1 functions
- from libcrypto (part of OpenSSL). The default is to use libcrypto if it
- is found on the system.
+ The default is --with-ntfs-3g when building for any UNIX-like system,
+ and --without-ntfs-3g when building for Windows.
---disable-multithreaded-compression
- By default, data will be compressed using multiple threads when writing
- a WIM, unless only 1 processor is detected. Specify this option to
- disable support for this.
+--without-fuse
+ The --without-fuse option completely disables support for mounting WIM
+ images. This removes dependencies on libfuse, librt, and libattr. The
+ wimmount, wimmountrw, and wimunmount commands will not work.
---enable-ssse3-sha1
- Use a very fast assembly language implementation of SHA1 from Intel.
- Only use this if the build target supports the SSSE3 instructions.
+ The default is --with-fuse when building for Linux, and --without-fuse
+ otherwise.
---disable-error-messages
- Save some space by removing all error messages from the library.
+--without-libcrypto
+ Build in functions for SHA-1 rather than using external SHA-1 functions
+ from libcrypto (usually provided by OpenSSL).
---disable-assertions
- Remove assertions included by default.
+ The default is to use libcrypto if it is found on your system.
PORTABILITY
wimlib works on both UNIX-like systems (Linux, Mac OS X, FreeBSD, etc.) and
Windows (XP and later).
-On UNIX-like systems other than Linux, you must compile --without-fuse.
-In addition, --without-ntfs-3g and --without-libcrypto are needed if the
-corresponding libraries are not available on your system.
+As much code as possible is shared among all supported platforms, but there
+necessarily are some differences in what features are supported on each platform
+and how they are implemented. Most notable is that file tree scanning and
+extraction are implemented separately for Windows, UNIX, and UNIX (NTFS-3g
+mode), to ensure a fast and feature-rich implementation of each platform/mode.
+
+wimlib is mainly used on x86 and x86_64 CPUs, but it should also work on a
+number of other GCC-supported 32-bit or 64-bit architectures. It has been
+tested on the ARM architecture.
-wimlib works on x86 and x86_64, but it should work on any other GCC-supported
-32-bit or 64-bit architecture.
+Currently, gcc and clang are the only supported compilers. A few nonstandard
+extensions are used in the code.
REFERENCES
The WIM file format is partially specified in a document that can be found in
the Microsoft Download Center. However, this document really only provides an
overview of the format and is not a formal specification. It also does not
-cover later extensions of the format, such as solid blocks.
+cover later extensions of the format, such as solid resources.
With regards to the supported compression formats:
neither of which is completely applicable to its use in the WIM format, and
the first of which contains multiple errors.
- There does not seem to be any official documentation for LZMS, so my comments
- and code in src/lzms-decompress.c may in fact be the best documentation
+ and code in src/lzms_decompress.c may in fact be the best documentation
available for this particular compression format.
The algorithms used by wimlib's compression and decompression codecs are
git://wimlib.net / wimlib / blobdiff