liblzma as easy as using zlib, because the easy API
don't require developers to know any fancy LZMA options.
Note that Multi-Block Stream encoding is currently broken.
The easy API should be OK, the bug(s) are elsewhere.
This leaves one known alignment bug unfixed: If repeat count
doesn't fit into 28-bit integer, the encoder has to split
this to multiple Subblocks with Subblock Type `Repeating Data'.
The extra Subblocks may have wrong alignment. Correct alignment
is restored after the split Repeating Data has been completely
written out.
Since the encoder doesn't even try to fix the alignment unless
the size of Data is at least 4 bytes, to trigger this bug you
need at least 4 GiB of repeating data with sequence length of
4 or more bytes. Since the worst thing done by this bug is
misaligned data (no data corruption), this bug simply isn't
worth fixing, because a proper fix isn't simple.
The API for handing Subfilters was changed to make it
consistent with LZMA_SYNC_FLUSH.
A few sanity checks were added for Subfilter handling. Some
small bugs were fixed. More comments were added.
function is still shared between encoder and decoder, but the
actual coding is in separate files for encoder and decoder.
There are now separate functions for the actual delta
calculation depending on if Delta is the last filter in the
chain or not. If it is the last, the new code copies the
data from input to output buffer and does the delta
calculation at the same time. The old code first copied the
data, then did the delta in the target buffer, which required
reading through the data twice.
Support for LZMA_SYNC_FLUSH was added to the Delta encoder.
This doesn't change anything in the file format.
too early if we hit End of Input while decoding a Subblock of
type Repeating Data. To keep the loop termination condition
elegant, the order of enumerations in coder->sequence were
changed.
To keep the case-labels in roughly the same order as the
enumerations in coder->sequence, large chunks of code was
moved around. This made the diff big and ugly compared to
the amount of the actual changes made.
in ia64_coder_init(). It triggered assert() in
simple_coder.c, and could have caused a buffer overflow.
This error was probably a copypaste mistake, since most
of the simple filters use unfiltered_max = 4.
table-based version from LZMA SDK 4.57. This should be
fast on most systems.
A simpler and smaller alternative version is also provided.
On some CPUs this can be even a little faster than the
default table-based version (see comments in fastpos.h),
but on most systems the table-based code is faster.
These changes implement support for LZMA_SYNC_FLUSH in LZMA
encoder, and move the temporary buffer needed by range encoder
from lzma_range_encoder structure to lzma_lz_encoder.
coder->lz.stream_end_was_reached. That variable
will be removed, and the check isn't required anyway.
Rearrange the check so that it doesn't make one to
think that there could be an integer overflow.
or no inttypes.h. This is useful when the compiler has
good enough support for C99, but libc headers don't.
Changed liblzma API so that sys/types.h and inttypes.h
have to be #included before #including lzma.h. On systems
that don't have C99 inttypes.h, it's the problem of the
applications to provide the required types and macros
before #including lzma.h.
If lzma.h defined the missing types and macros, it could
conflict with third-party applications whose configure
has detected that the types are missing and defined them
in config.h already. An alternative would have been
introducing lzma_uint32 and similar types, but that would
just be an extra pain on modern systems.
that use LZMA_SYNC_FLUSH with encoder (not implemented
yet). This is a new feature in the raw LZMA format,
which isn't supported by old decoders. This shouldn't
be a problem in practice, since lzma_alone_encoder()
will not allow LZMA_SYNC_FLUSH, and thus not allow
creating files on decodable with old decoders.
Made lzma_decoder.c to require tab width of 4 characters
if one wants to fit the code in 80 columns. This makes
the code easier to read.
so that the preprocessor removes the /* */ style comments,
which are not supported by some non-GNU assemblers (Solaris)
that otherwise work with this code.
It's not strictly needed there, and just complicates the
code. LZ encoder never even had this feature.
The primary reason to have uncompressed size tracking in
filter encoders was validating that the application
doesn't give different amount of input that it had
promised. A side effect was to validate internal workings
of liblzma.
Uncompressed size tracking is still present in the Block
encoder. Maybe it should be added to LZMA_Alone and raw
encoders too. It's simpler to have one coder just to
validate the uncompressed size instead of having it
in every filter.
Lasse Collin