This is the last phase of the "big decompression refactor" that
puts a lazy reblocking layer between each pair of read filters.
I've also changed the terminology for this area---the two kinds
of objects are now called "read filters" and "read filter bidders"---and
moved ownership of these objects to the archive_read core.
This greatly simplifies implementing new read filters, which
can now use peek/consume I/O semantics both for bidding (arbitrary
look-ahead!) and for reading streams (look-ahead simplifies handling
concatenated streams, for instance).
The first merge here is the overhaul proper; the remainder are small
fixes to correct errors in the initial implementation.
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...
* "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.
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
* 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.
simple errx() function.
Improve behavior when bzlib/zlib are missing by detecting and
issuing an error message on attempts to read gzip/bzip2 compressed
archives.
