https://github.com/powturbo/TurboBench links zlib and zlib-ng into the
same binary, causing non-static symbol conflicts. Fix by using PREFIX()
for flush_pending(), bi_reverse(), inflate_ensure_window() and all of
the IBM Z symbols.
Note: do not use an explicit zng_, since one of the long-term goals is
to be able to link two versions of zlib-ng into the same binary for
benchmarking [1].
[1] https://github.com/zlib-ng/zlib-ng/pull/1248#issuecomment-1096648932
The attached test fails with "inflate() failed", because the deflate
stream that it produces ends up being corrupted. Bisect points to the
commit e7bb6db09a ("Replace hash_bits, hash_size and hash_mask with
defines."), but it's most likely a coincidence.
In any case, the reason is that if we happen to simultaneously exhaust
all the buffers (in, out and bi), we return finish_started without
writing the end of block symbol, which will never happen afterwards.
Fix by adding another check to the tricky condition: if we are in the
middle of a block, return need_more instead of finish_started.
The attached test started failing after commit ad89d5131b ("Don't
write end of last block when returning finish_started."): either with
"bi_buf not flushed" message in debug builds, or by producing corrupted
output in release builds.
The problem is that we must not return finish_started when bi_buf is
not empty, because the bits there will be lost. Fix by checking that
bi_valid is not 0.
zlib-ng/deflate_medium.c:244:47: runtime error: unsigned integer overflow: 58442 - 58452 cannot be represented in type 'unsigned int'
Co-authored-by: Mika Lindqvist <postmaster@raasu.org>
Co-authored-by: Hans Kristian Rosbach <hk-git@circlestorm.org>
Fixed ending block when returning need_more caused problems with inflate.
So instead of ending the block each time the function returns to finish the last block, we check upon start to see if it is the last block and if the last block has been started, and if not it will close the previous block and start the last block.
The deflate_quick strategy is designed to provide maximum
deflate performance.
deflate_quick achieves this through:
- only checking the first hash match
- using a small inline SSE4.2-optimized longest_match
- forcing a window size of 8K, and using a precomputed dist/len
table
- forcing the static Huffman tree and emitting codes immediately
instead of tallying
This patch changes the scope of flush_pending, bi_windup, and
static_ltree to ZLIB_INTERNAL and moves END_BLOCK, send_code,
put_short, and send_bits to deflate.h.
Updates the configure script to enable by default for x86. On systems
without SSE4.2, fallback is to deflate_fast strategy.
Fixes#6Fixes#8
