Add v8::ArrayBuffer::CopyArrayBufferBytes and
v8::SharedArrayBuffer::CopyArrayBufferBytes, which copy a byte range
from one backing store to another. V8 clamps the byte range and handles
detached and immutable buffers: nothing is copied when the source is
detached or the target is detached or immutable, and the number of bytes
actually copied is returned. The SharedArrayBuffer overload uses a
relaxed-atomic memmove that honors the SharedArrayBuffer memory model.
Carried as a floating patch cherry-picked from:
https://chromium-review.googlesource.com/c/v8/v8/+/7735151
That CL is authored by a Node.js collaborator (Ben Noordhuis) and is
expected to land upstream, so the floating patch should be easy to
maintain: it touches nothing but the public ArrayBuffer API and can be
dropped wholesale on the next V8 upgrade that includes it.
v8_embedder_string is bumped to -node.21 accordingly.
Refs: https://chromium-review.googlesource.com/c/v8/v8/+/7735151
Signed-off-by: Robert Nagy <ronagy@icloud.com>
PR-URL: https://github.com/nodejs/node/pull/63828
Reviewed-By: Yagiz Nizipli <yagiz@nizipli.com>
Reviewed-By: René <contact.9a5d6388@renegade334.me.uk>
