This is an attempt to eliminate a lot of redundant
code from the read ("decompression") filters by
changing them to juggle arbitrary-sized blocks
and consolidate reblocking code at a single point
in archive_read.c.
Along the way, I've changed the internal read/consume
API used by the format handlers to a slightly
different style originally suggested by des@. It
does seem to simplify a lot of common cases.
The most dramatic change is, of course, to
archive_read_support_compression_none(), which
has just evaporated into a no-op as the blocking
code this used to hold has all been moved up
a level.
There's at least one more big round of refactoring
yet to come before the individual filters are as
straightforward as I think they should be...
that I've been working on but put off committing until after the
RELENG_7 branch, including:
* New manpages: cpio.5 mtree.5
* New archive_entry_strmode()
* New archive_entry_link_resolver()
* New read support: mtree format
* Internal API change: read format auction only runs once
* Running the auction only once allowed simplifying a lot of bid logic.
* Cpio robustness: search for next header after a sync error
* Support device nodes on ISO9660 images
* Eliminate a lot of unnecessary copies for uncompressed archives
* Corrected handling of new GNU --sparse --posix formats
* Correctly handle a zero-byte write to a compressed archive
* Fixed memory leaks
Many of these improvements were motivated by the upcoming bsdcpio
front-end.
There have also been extensive improvements to the libarchive_test
test harness, which I'll commit separately.
This can only happen on 32-bit systems when you're reading
an uncompressed archive and the skip request is an exact
multiple of 4G (e.g., skipping a tar entry with an 8G body).
The symptom is that the read_ahead() ends up returning zero
bytes, and the extraction stops with a premature end-of-file.
Using '1' here is more correct anyway, as it allows read_ahead()
to function opportunistically and minimize copying.
MFC after: 5 days
* "compression_program" support uses an external program
* Portability: no longer uses "struct stat" as a primary
data interchange structure internally
* Part of the above: refactor archive_entry to separate
out copy_stat() and stat() functions
* More complete tests for archive_entry
* Finish archive_entry_clone()
* Isolate major()/minor()/makedev() in archive_entry; remove
these from everywhere else.
* Bug fix: properly handle decompression look-ahead at end-of-data
* Bug fixes to 'ar' support
* Fix memory leak in ZIP reader
* Portability: better timegm() emulation in iso9660 reader
* New write_disk flags to suppress auto dir creation and not
overwrite newer files (for future cpio front-end)
* Simplify trailing-'/' fixup when writing tar and pax
* Test enhancements: fix various compiler warnings, improve
portability, add lots of new tests.
* Documentation: document new functions, first draft of
libarchive_internals.3
MFC after: 14 days
Thanks to: Joerg Sonnenberger (compression_program)
Thanks to: Kai Wang (ar)
Thanks to: Colin Percival (many small fixes)
Thanks to: Many others who sent me various patches and problem reports.
* libarchive_test program exercises many of the core features
* Refactored old "read_extract" into new "archive_write_disk", which
uses archive_write methods to put entries onto disk. In particular,
you can now use archive_write_disk to create objects on disk
without having an archive available.
* Pushed some security checks from bsdtar down into libarchive, where
they can be better optimized.
* Rearchitected the logic for creating objects on disk to reduce
the number of system calls. Several common cases now use a
minimum number of system calls.
* Virtualized some internal interfaces to provide a clearer separation
of read and write handling and make it simpler to override key
methods.
* New "empty" format reader.
* Corrected return types (this ABI breakage required the "2.0" version bump)
* Many bug fixes.
Fallout from changing the skip API to use off_t instead of size_t: Print
the skip length using %jd and cast to (intmax_t) instead of %d / (int),
and if ARCHIVE_API_VERSION >= 2, allow the client skipper to be called
for requests longer than SSIZE_MAX. [2]
Approved by: kientzle
Pointy hats to: kientzle [1], cperciva [2]
MFC after: 3 days
a vanilla 2-clause BSD license, but somehow some confusing
extra verbage get copied from somewhere.
Also, update the copyright dates to 2007 for all of the files.
Prompted by: several questions about what those extra words really mean
returning the length skipped in a ssize_t to using off_t for both. This
does not break any A[BP]Is, since compression_skip is entirely internal
to libarchive.
If a skip request is > SSIZE_MAX, don't pass it down to the client layer
skip function, since those still uses size_t / ssize_t. Instead, just
read the data and throw it away.
With this commit, libarchive/bsdtar should now successfully skip archive
entries of >2GB on 32-bit systems, but does so slower than necessary.
The performance will improve with a future A[BP]I breaking commit which
makes client layer skip functions use off_t.
Discussed with: kientzle
MFC after: 1 week
* Actually use the HAVE_<header>_H macros to conditionally include
system headers. They've been defined for a long time, but only
used in a few places. Now they're used pretty consistently
throughout.
* Fill in a lot of missing casts for conversions from void*.
Although Standard C doesn't require this, some people have been
trying to use C++ compilers with this code, and they do require it.
Bit-for-bit, the compiled object files are identical, except for
one assert() whose line number changed, so I'm pretty confident I
didn't break anything. ;-)
increases performance when extracting a single entry from a large
uncompressed archive, especially on slow devices such as USB hard
drives.
Requires a number of changes:
* New archive_read_open2() supports a 'skip' client function
* Old archive_read_open() is implemented as a wrapper now, to
continue supporting the old API/ABI.
* _read_open_fd and _read_open_file sprout new 'skip' functions.
* compression layer gets a new 'skip' operation.
* compression_none passes skip requests through to client.
* compression_{gzip,bzip2,compress} simply ignore skip requests.
Thanks to: Benjamin Lutz, who designed and implemented the whole thing.
I'm just committing it. ;-)
TODO: Need to update the documentation a little bit.
occurred with large read-ahead requests. This only affected
formats that incorrectly make large requests (ZIP did this until
recently) or with block sizes over 32k.
try to set ACLs even if fflag restore fails, first cut at reading
Solaris tar ACLs
Code improvement: merge gnu tar read support into main tar reader;
this eliminates a lot of duplicate code and generalizes the tar
reader to handle formats with GNU-like extensions.
Style: Makefile cleanup, eliminate 'dmalloc' references, remove 'tartype'
from archive_entry (this makes archive_entry more format-agnostic)
Thanks to: David Magda for providing Solaris tar test files
with 'star' ACL handling, though there's still a
bit more work needed in this area.
Added 'write_open_fd' and 'read_open_fd' to simplify, e.g.,
tar's u and r modes. Eliminated old 'write_open_file_position'
as a bad idea. (It required closing/reopening files to
do updates, which led to unpleasant implications.)
Various other minor fixes, API tweaks, etc.
Portability: Thanks to Juergen Lock, libarchive now compiles cleanly
on Linux. Along the way, I cleaned up a lot of error return codes and
reorganized some code to simplify conditional compilation of certain
sections.
Bug fixes:
* pax format now actually stores filenames that are 101-154
characters long.
* pax format now allows newline characters in extended attributes
(this fixes a long-standing bug in ACL handling)
* mtime/atime are now restored for directories
* directory list is now sorted prior to fix-up to permit
correct restore of non-writable dir heirarchies
What it is:
A library for reading and writing various streaming archive
formats, especially tar and cpio. Being a library, it should
be easy to incorporate into pkg_* tools, sysinstall, and any
other place that needs to read or write such archives.
Features:
* Full automatic detection of both compression and archive format.
* Extensible internal architecture to make it easy to add new formats.
* Support for "pax interchange format," a new POSIX-standard tar format
that eliminates essentially all of the restrictions of historic formats.
* BSD license
Thanks to: jkh for pushing me to start this work, gordon for
encouraging me to commit it, bde for answering endless style
questions, and many others for feedback and encouragement.
Status: Pretty good overall, though there are still a few rough edges and
the library could always use more testing. Feedback eagerly solicited.
