Halkyon Learn uses this fork as a git dependency, from
https://code.halkyon.app/project-halkyon/pure-zstd, until upstream decodes frames
without a content size. The package name pure_zstd belongs to upstream on pub.dev,
so `dart pub publish` should refuse outright rather than depend on pub.dev refusing
the upload.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Eighteen commits of history, grafted onto the scaffold rather than over
it. It leaves behind everything that only meant something inside that
project: paths under one machine's mount, references to a transcoder
that is not here, and a benchmark defaulting to a tile nobody else has.
One fixture is real terrain and stays, because it is the only small
input that exercises the direct-nibble Huffman weight form. Its licence
requires attribution to travel with it, so the README's
acknowledgements and the corpus manifest both carry the Copernicus
notice now. Everything else committed here is synthetic or was written
by the zstd CLI, including the .hgtz container, whose name looks like a
tile and whose samples are a function of their position.
description, repository, issue_tracker and topics, plus a changelog,
which between them are most of a package's discoverability. The
repository URLs are a guess at the new home and want checking before the
first publish.
publish_to stays none so an accidental publish from inside this checkout
cannot succeed. Remove it in the new repository.
Version 0.1.0 rather than 0.0.1: a published version can be retracted
but never deleted, so the first one should mean something.
A feasibility spike, standalone so it can move to its own repository. Not
wired into the app and not a dependency of it.
Decompression only, and only what our containers need: no dictionaries, no
multi-frame, no streaming, and the content checksum is parsed but never
verified. Native only, since the bit reader carries 56 bits in an int.
It is correct on real data. The committed fixture decodes to the samples
the generator wrote, and tool/oracle.py drives a byte-for-byte comparison
against pyzstd over 32 containers and 2,615 blocks from both tiers, every
thinned column count from 3601 to 361, and 88 S to 80 N. All identical.
The numbers, AOT on this box, 131,072 bytes a block: 0.66 ms median
against pyzstd's 0.175, so about 200 MB/s against 750. Across three tiles
the range is 0.66 to 0.94 ms, and a 113 block sweep is 67 to 105 ms. The
cost is the sequence loop and nothing else: a terrain block at level 19
carries around 1,700 literals and 14,400 sequences, so optimising the
literal path bought nothing.
