This change fixes some division-by-zero bugs introduced by the optimized
ring buffer read/write functions in d8c067966.
There are edge cases where decompression can use a length zero ring
buffer as the size of the ring buffer used is exactly the the window
size specified by a Zstandard frame, and this can be zero. Switching
away from loops to mem copies means that we need to ensure ring buffers
do not have length zero ring when attempting to read/write from them.
This reverts a change introduced in #17400 causing a bug when
decompressing an RLE block into a ring buffer.
RLE blocks contain only a single byte of data to copy into the output,
so attempting to copy a slice causes buffer overruns and incorrect
decompression.
Use inline to vastly simplify the exposed API. This allows a
comptime-known endian parameter to be propogated, making extra functions
for a specific endianness completely unnecessary.
* 128-bit integer multiplication with overflow
* more instruction encodings used by std inline asm
* implement the `try_ptr` air instruction
* follow correct stack frame abi
* enable full panic handler
* enable stack traces
This reverts commit 0c99ba1eab63865592bb084feb271cd4e4b0357e, reversing
changes made to 5f92b070bf284f1493b1b5d433dd3adde2f46727.
This caused a CI failure when it landed in master branch due to a
128-bit `@byteSwap` in std.mem.
Most of this migration was performed automatically with `zig fmt`. There
were a few exceptions which I had to manually fix:
* `@alignCast` and `@addrSpaceCast` cannot be automatically rewritten
* `@truncate`'s fixup is incorrect for vectors
* Test cases are not formatted, and their error locations change
Adress review comments from https://github.com/ziglang/zig/pull/13977
by using the same naming convention as zstd.
And by using `finish()` instead of `close()` for the finalisation of the compressed stream.
rationale:
- it is not the same as how close() is usually used, since it must be called to flush and write the final bytes. And as such it may fail.
- it is not the same `flush` in the deflate code, which allows to keep writting more bytes later, and doesn't write the final checksum.
- it is the same name as used in the original zlib library (Z_FINISH)
Also, use a packed struct for the header, which seems a better fit.
The majority of these are in comments, some in doc comments which might
affect the generated documentation, and a few in parameter names -
nothing that should be breaking, however.
* docs(std.math): elaborate on difference between absCast and absInt
* docs(std.rand.Random.weightedIndex): elaborate on likelihood
I think this makes it easier to understand.
* langref: add small reminder
* docs(std.fs.path.extension): brevity
* docs(std.bit_set.StaticBitSet): mention the specific types
* std.debug.TTY: explain what purpose this struct serves
This should also make it clearer that this struct is not supposed to provide unrelated terminal manipulation functionality such as setting the cursor position or something because terminals are complicated and we should keep this struct simple and focused on debugging.
* langref(package listing): brevity
* langref: explain what exactly `threadlocal` causes to happen
* std.array_list: link between swapRemove and orderedRemove
Maybe this can serve as a TLDR and make it easier to decide.
* PrefetchOptions.locality: clarify docs that this is a range
This confused me previously and I thought I can only use either 0 or 3.
* fix typos and more
* std.builtin.CallingConvention: document some CCs
* langref: explain possibly cryptic names
I think it helps knowing what exactly these acronyms (@clz and @ctz) and
abbreviations (@popCount) mean.
* variadic function error: add missing preposition
* std.fmt.format docs: nicely hyphenate
* help menu: say what to optimize for
I think this is slightly more specific than just calling it
"optimizations". These are speed optimizations. I used the word
"performance" here.
Previously `executeSequenceRingBuffer()` would not verify the offset
against the number of bytes already decoded, so it would happily copy
garbage bytes rather than return an error before the window was filled.
To fix this a new `written_count` is added to the decode state that
tracks the total number of bytes decoded.
