Lina Cambridge 534fd0e715 Bug 1622949 - Add HashPropertyBag::clone_from_bag. r=froydnj ...

`clone_from_bag` lets Rust code create a thread-safe `HashPropertyBag`
from any kind of `nsIPropertyBag` by cloning its contents. This is
important when you want to use a property bag that's passed to an XPIDL
method off the main thread. An `nsIPropertyBag` passed from JS isn't
thread-safe, since it's cycle-collected, and its properties are
`XPCVariant`s. But a Rust `HashPropertyBag` is, because it's backed by
a non-cycle collected `nsHashPropertyBag`, and the only supported
properties are thread-safe storage variants.

It also marks `HashPropertyBag` as `Send + Sync`, given that the only
way to construct one is through `HashPropertyBag::new`, and
`VariantType` is only implemented for storage variants.

Finally, it adds more type tags for string (narrow and wide) variants,
and changes the `VariantType for nsCString` getter to use
`GetAsAUTF8String`, since that's what mozStorage implements for its
text variant, not `GetAsACString`.

Differential Revision: https://phabricator.services.mozilla.com/D67075

--HG--
extra : moz-landing-system : lando

2020-03-17 23:33:45 +00:00

..

src

Bug 1622949 - Add HashPropertyBag::clone_from_bag. r=froydnj

2020-03-17 23:33:45 +00:00

Cargo.toml

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