Add memcpy-based i8 array constructor and reader to ArrayRef#13716
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somdoron wants to merge 1 commit into
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Add memcpy-based i8 array constructor and reader to ArrayRef#13716somdoron wants to merge 1 commit into
somdoron wants to merge 1 commit into
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Building a GC arrayref of bytes from host code today goes through ArrayRef::new_fixed, which takes a &[Val] (32 bytes each) and writes the elements one Val at a time. For a host bridging byte buffers into GC arrays (streaming I/O, codecs, etc.) that's a large transient allocation plus a per-element decode, and there's no faster path. Add ArrayRef::new_from_i8_slice / new_from_i8_slice_async, which take a &[u8] and fill the element body in a single memcpy, plus copy_to_i8_slice for the reverse. Both bypass Val entirely. This only covers i8 arrays for now: byte buffers are by far the most common case, and i8 needs no endianness handling, so the slice maps directly onto the heap layout with no unsafe. Wider element types can be added later on top of this.
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Building a GC array of bytes from the host currently has to go through ArrayRef::new_fixed, which takes a slice of Val (32 bytes each) and writes one element at a time — a big transient allocation plus a per-element decode, with no faster path.
This adds new_from_i8_slice (+ async) and copy_to_i8_slice, which take a slice of u8 and fill/read the element body in a single memcpy, bypassing Val.