* replace assert with test for LZ4F_uncompressedUpdate
* update documentation to incldue correct docstring
* remove unecessary entry point
* remove compress_linked_block_mode from fuzzing test
Signed-off-by: Alexander Mohr <alexander.m.mohr@mercedes-benz.com>
new method `uncompressed_update` allows to insert blocks without
compression into the lz4 stream.
The usage is documented in the frameCompress example
Signed-off-by: Alexander Mohr <alexander.m.mohr@mercedes-benz.com>
to specifically call attention to offset==0 scenario,
which is invalid, and could lead to some form of security issue
if incorrectly dealt with (ignored).
EndMark, the 4-bytes value indicating the end of frame,
must be `0x00000000`.
Previously, it was just mentioned as a `0-size` block.
But such definition could encompass uncompressed blocks of size 0,
with a header of value `0x80000000`.
But the intention was to also support uncompressed empty blocks.
They could be used as a keep-alive signal.
Note that compressed empty blocks are already supported,
it's just that they have a size 1 instead of 0 (for the `0` token).
Unfortunately, the decoder implementation was also wrong,
and would also interpret a `0x80000000` block header as an endMark.
This issue evaded detection so far simply because
this situation never happens, as LZ4Frame always issues
a clean 0x00000000 value as a endMark.
It also does not flush empty blocks.
This is fixed in this PR.
The decoder can now deal with empty uncompressed blocks,
and do not confuse them with EndMark.
The specification is also clarified.
Finally, FrameTest is updated to randomly insert empty blocks during fuzzing.
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
- 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*.
these functions are now unpublished in dll by default.
One needs to opt-in, using macro LZ4_PUBLISH_STATIC_FUNCTIONS.
used this opportunity to update a bunch of api comments in lz4.h