Every `*_in` core and the read helpers take `file: &S` with
`S: Storage + ?Sized` instead of `&dyn Storage`, and the `&[u8]`
wrappers pass the slice itself, so they compile to a `[u8]` instance:
`as_contiguous()` inlines to `Some(self)` and each structure read is the
slice code's bounds check again, with no indirect call. `&dyn Storage`
still works (`S = dyn Storage`); there is one parser implementation.
Also, so the structure reads cost no more than the slice checks did:
- ObjectHeader::parse_in reads the prefix once (signature included)
instead of the signature and then the prefix: two reads for a
one-chunk header instead of three on a range backend;
- the symbol-table node and group B-tree (v1) loops walk their entries
with chunks_exact over the bytes read, and the node's redundant second
bounds check is gone (the entries' read is the check, same error);
- a version-1 header's message list is sized from its (capped) count.
Same results and errors; the unit and equivalence tests are unchanged.
New Criterion bench `clawhdf5/benches/local_metadata_bench.rs` over a
400-group version-1 file written by h5py (new fixture
`v1_groups_400.h5`): ObjectHeader::parse, symbol-table nodes, the group
B-tree walk and a facade listing, using only APIs that exist at f2ff2c4
so it builds there for an A/B.
Provisional A/B against f2ff2c4 (busy machine, not for docs): both
builds linked into one binary and timed in alternation, 200 rounds;
median ratio new/old: facade listing -0.5% to -3.5% (was +14%),
ObjectHeader::parse +1% to +2% (was +25%), symbol-table nodes -18%,
group B-tree walk -18%, local-heap names and resolve_group_children
within +-1.5%. An old-vs-old-copy run shows +-2% from code layout alone.
Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]>
SymbolTableNode::parse_in reads the node's 8-byte header, checks the
entries against the end of the file as before, and reads them in one
bounded read. parse is a wrapper. New test: nodes with 4- and 8-byte
offsets, valid and with a bad version, at two offsets and cut at every
length, parse identically through a read_at-only CountingStorage.
Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]>
Formatting only. cargo fmt --check was already failing on main (accel SIMD
kernels, agent, format, migrate, bench); CI now enforces it.
Co-Authored-By: Claude Fable 5.1 <[email protected]>
SymbolTableNode::parse used raw offset+8 arithmetic that can overflow
on a crafted v1-group B-tree leaf with a near-u64::MAX SNOD child
pointer (group_v1.rs passes such offsets through unchecked). Switch to
checked_add, matching read_offset in the same file. Also harden the
entries_start + num_symbols*entry_size computation with checked_add
for consistency, even though num_symbols being u16 already bounds
that multiply. Add regression tests.
INT-02
