1768597 - Use the utility functions for `IPCDataTransfer` conversion

Status: RESOLVED FIXED

(Core :: DOM: Copy & Paste and Drag & Drop, task)

Description

[Edgar Chen [:edgar]]

This bug is filed while working on bug 1524237.
In bug 1524237, we would like to use Shmem to pass the large string over IPC for clipboard operation. I found there are duplicate codes for IPCDataTransfer conversion. It would be nice to have a central place doing the conversion, so that changes in bug 1524237 don't need to be applied into multiple places.

Comment 1

[Edgar Chen [:edgar]]

Attachment: Bug 1768597 - Part 1: Ensure all Shmem data is deallocated in nsContentUtils::IPCTransferableToTransferable;

If a IPCDataTransferItem fails to be converted, the subsequent IPCDataTransferItems
will be ignored, and the data in Shmem won't be deallocated properly if any.

Comment 2

[Edgar Chen [:edgar]]

Attachment: Bug 1768597 - Part 2: Use nsContentUtils::IPCTransferableToTransferable to convert IPCDataTransfer into nsITransferable;

Depends on D145940

Comment 3

[Edgar Chen [:edgar]]

Attachment: Bug 1768597 - Part 3: Use utility function to convert IPCDataTransferItem into nsIVariant;

Depends on D145941

Comment 4

[Edgar Chen [:edgar]]

https://treeherder.mozilla.org/jobs?repo=try&group_state=expanded&revision=aeefaed172388a3b398d856c6ddec7e2a3e1a4fe

Comment 5

[Tom S [:evilpie]]

See also bug 1732920. I don't remember the exact data types involved anymore, but we do handle some types differently depending on whether the data is being send for drag and drop or copy/paste.

Comment 6

[Edgar Chen [:edgar]]

Yeah, we do differently on image type for dnd and copy/paste,

• dnd: we use imgIContainer, https://searchfox.org/mozilla-central/rev/390f7009e9e5a9585297aeea5fb9202f800eaf12/dom/events/RemoteDragStartData.cpp#61-68
• copy/paste: we use nsIInputStream, https://searchfox.org/mozilla-central/rev/390f7009e9e5a9585297aeea5fb9202f800eaf12/widget/nsClipboardProxy.cpp#78-85

But luckily, we setup IPCDataTransferImage only when covering imgIContainer into Shmem type, https://searchfox.org/mozilla-central/rev/390f7009e9e5a9585297aeea5fb9202f800eaf12/dom/base/nsContentUtils.cpp#7896-7901. So we could make IPCDataTransferImage "nullable" in https://searchfox.org/mozilla-central/rev/390f7009e9e5a9585297aeea5fb9202f800eaf12/dom/ipc/DOMTypes.ipdlh#122, and base on that to decide how to handle shmem data for image type.

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/e92cac424950
Part 1: Ensure all Shmem data is deallocated in nsContentUtils::IPCTransferableToTransferable; r=NeilDeakin
https://hg.mozilla.org/integration/autoland/rev/f41095466201
Part 2: Use nsContentUtils::IPCTransferableToTransferable to convert IPCDataTransfer into nsITransferable; r=NeilDeakin
https://hg.mozilla.org/integration/autoland/rev/ae2100095307
Part 3: Use utility function to convert IPCDataTransferItem into nsIVariant; r=NeilDeakin

Comment 8

[Narcis Beleuzu [:NarcisB]]

https://hg.mozilla.org/mozilla-central/rev/e92cac424950
https://hg.mozilla.org/mozilla-central/rev/f41095466201
https://hg.mozilla.org/mozilla-central/rev/ae2100095307