and deprecate LZ4_decompress_fast(),
with deprecation warnings enabled by default.
Note that, as a consequence of the fix,
LZ4_decompress_fast is now __slower__ than LZ4_decompress_safe().
That's because, since it doesn't know the input buffer size,
it must progress more cautiously into the input buffer
to ensure to out-of-bound read.
between lz4.c and lz4hc.c .
was left in a strange state after the "amalgamation" patch.
Now only 3 directives remain,
same name across both implementations,
single definition place.
Might allow some light simplification due to reduced nb of states possible.
they are classified as deprecated in the API documentation (lz4.h)
but do not yet trigger a warning,
to give time to existing applications to move away.
Also, the _fast() variants are still ~5% faster than the _safe() ones
after Dave's patch.
when one block was not compressible,
it would tag the context as `dirty`,
resulting in compression automatically bailing out of all future blocks,
making the rest of the frame uncompressible.
yet some overly cautious overflow risk flag,
while it's actually impossible, due to previous test just one line above.
Changing the cast position, just to be please the thing.
since Visual 2017,
worries about potential overflow, which are actually impossible.
Replaced (c * a) by (c ? a : 0).
Will likely replaced a * by a cmov.
Probably harmless for performance.
make it possible to generate LZ4-compressed block
with a controlled maximum offset (necessarily <= 65535).
This could be useful for compatibility with decoders
using a very limited memory budget (<64 KB).
Answer #154
it fails on x86 32-bit mode :
Visual reports an alignment of 8-bytes (even with alignof())
but actually only align LZ4_stream_t on 4 bytes.
The alignment check then fails, resulting in missed initialization.
- promoted LZ4_resetStream_fast() to stable
- moved LZ4_resetStream() into deprecate, but without triggering a compiler warning
- update all sources to no longer rely on LZ4_resetStream()
note : LZ4_initStream() proposal is slightly different :
it's able to initialize any buffer, provided that it's large enough.
To this end, it accepts a void*, and returns an LZ4_stream_t*.
- promoted LZ4_resetStreamHC_fast() to stable
- moved LZ4_resetStreamHC() to deprecated (but do not generate a warning yet)
- Updated doc, to highlight difference between init and reset
- switched all invocations of LZ4_resetStreamHC() onto LZ4_initStreamHC()
- misc: ensure `make all` also builds /tests
which remained undetected so far,
as it requires a fairly large number of conditions to be triggered,
starting with enabling Block checksum, which is disabled by default,
and which usage is known to be extremely rare.
For small offsets of size 1, 2, 4 and 8, we can set a single uint64_t,
and then use it to do a memset() variation. In particular, this makes
the somewhat-common RLE (offset 1) about 2-4x faster than the previous
implementation - we avoid not only the load blocked by store, but also
avoid the loads entirely.
Generally we want our wildcopy loops to look like the
memcpy loops from our libc, but without the final byte copy checks.
We can unroll a bit to make long copies even faster.
The only catch is that this affects the value of FASTLOOP_SAFE_DISTANCE.
