1561876 - Remove support for de-serializing WebAssembly.Modules in IDB

Status: RESOLVED FIXED

(Core :: Storage: IndexedDB, task, P2)

Description

[Jan Varga [:janv]]

We can just return plain JS objects instead of de-serializing wasm modules.

Comment 1

[Jan Varga [:janv]]

Actually, most of the code for preprocessing of WASM modules can be recycled. De-serialization of big structured clones can be more efficient using preprocessing. Big structured clones are currently stored as separate files, but during de-serialization they are fully read in the parent and content is then sent to the child. We can just send them as blobs instead.
My plan is to convert existing code instead of removing it and then adding back. However, I want to keep this feature behind a pref for now.

Comment 2

[Jan Varga [:janv]]

Testing on try server:
https://treeherder.mozilla.org/#/jobs?repo=try&revision=c58c2a0760df62e152a06ba1216ed67c742f8025

Comment 3

[Jan Varga [:janv]]

Attachment: Bug 1561876 - Remove support for de-serializing WebAssembly.Modules in IDB; r=asuth

This patch removes support for de-serialization of WebAssembly.Modules. The
preprocessing which was added just for WebAssembly.Modules is not removed since
it can be reused for more efficient de-serialization of big structured clones
which are stored as standalone files. (standalone files can be read and
uncompressed in content process instead of the parent process). So this patch
also adjusts the preprocessing to support that. However the preprocessing is not
fully implemented (we lack support for indexes and cursors) and there's a
theoretical problem with ordering of IDB requests when preprocessing is
involved, so this feature is kept behind a pref for now.

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/8ce5f675ddcd
Remove support for de-serializing WebAssembly.Modules in IDB; r=asuth

Comment 5

[Daniel Varga [:dvarga]]

https://hg.mozilla.org/mozilla-central/rev/8ce5f675ddcd

Comment 6

[Kohei Yoshino [:kohei]]

Posted site compatibility note: https://www.fxsitecompat.dev/en-CA/docs/2019/indexeddb-de-serialization-support-has-been-removed-from-webassembly-module/