`SyncOp::Invalidate` means _invalidating_ a particular range. When a
room is `Filled`, it becomes `Invalidated`, when it is `Invalidated` it
stays `Invalidated`, and when it is `Empty` it stays `Empty`.
Before this patch, `Empty` was becoming `Invalidated`, which apparently
is a bug.
This patch also fixes out-of-bound accesses, and adds many tests.
Finally, this patch renames `update_state` to `update_room_lists`.
`SyncOp::Insert` means _inserting_ a new room ID. The `rooms_list`
contains all possible rooms (based on `maximum_number_of_rooms`, a value
returned by the server). Here, inserting = setting
`RoomListEntry::Filled` at a particular index of `rooms_list`, that's
it.
The previous code was doing very complex stuff, like removing things
around the `index` if something etc. It was using the requested ranges
(the range passed to the request) etc.
Applying `SyncOp` should be simple and is focused on updating
`rooms_list` only: the requested ranges have nothing to do here.
This patch also prevents against out-of-bounds acccesses, which wasn't
the case before.
This patch prevents out of bounds acceses for `SyncOp::Delete`, and adds
more tests.
This patch also removes a cast from `UInt` to `u32` to `usize`. It's now
from `UInt` to `usize` directly.
First off, this patch renames `ops` to `sync_operations` and `room_ops`
to `apply_sync_operations`.
Second, the `SlidingOp::Sync` was creating an out-of-bounds access
depending of the range present in the server's response. For example, if
the `rooms_list` contains 5 elements (because the
`maximum_number_of_rooms` is set to 5), and the server replies with:
```json
{
"op": "SYNC",
"ranges": [3, 17],
"room_ids": […]
}
```
the previous code was setting a new `RoomListEntry` at indices `3..=17`,
whilst the `rooms_list` contains only indices from `0..=4`. That's
annoying.
The previous code was also counting the number of `room_ids` for
nothing, just to execute the iterator that was applying the actual
changes in a `map`. Well, everything was fishy.
This patch updates the code to protect against an unexpected server's
reply by raising an `Err`. This patch also adds tests.
The `updated_rooms` argument was passed to `find_rooms_in_list` to
update the `room_list`: the update is setting the filtered room list
entry to `RoomListEntry::Filled`.
_But_, `find_rooms_in_list` was already filtering rooms which are
`Filled`. So it does… nothing: it filters rooms which are `Filled` to
update them to `Filled`.
So we can remove `find_rooms_in_list` because it becomes useless. And we
can remove `updated_rooms` too.
The `rooms_list` is updated by `rooms_ops` itself. Let's keep
modifications in one unique place.
The `update_state` method of `SlidingSyncListInner` has basically
2 cases:
1. For an initial response,
2. For other responses.
The code between the 2 cases were almost identical. Or, they could be
identical. The few exceptions are:
* In the first case, the `rooms_list` updates were taking the
form of a `VectorDiff::Append`, while the second case, it was a
`VectorDiff::PushBack`.
* In the first case, the `is_cold` flag was set to `false`.
It's fine for the clients to receive only a `VectorDiff::Append` event
only. So let's make it uniform.
And it appears that the `is_cold` field is now private, and never read
anywhere else. So… it's… basically useless. We can remove it! It was
previously used here to know which flow to use, but since we can make
both flows identical, its role becomes insignificant.
`create_range` and `SlidingSyncList::next_request` return a `Result`
instead of an `Option`. It was a legacy from the old `impl Iterator` of
`SlidingSyncListRequestGenerator`. But actually, when `create_range`
fails, it must return a `Err` value, not a `None` value.
And since it's a regular error, `sync_once` can propagate the
error. Thus, it is no longer necessary to “update” the list of
`SlidingSyncList`. It's not necessary to remove some items in this list
when the `next_request` method can no return a value: it always returns
a value, except when a error happens.
First off, `set_ranges`, `set_range`, `add_range` and `reset_ranges`
take a `&[(U, U)]` instead of a `Vec<(U, U)>` when a vector was needed,
or takes a `(U, U)` instead of 2 arguments when it was needed.
Second, all those methods now return a `Result<(), Error>`. The
`Error::CannotModifyRanges` is raised if the chosen `SlidingSyncMode`
doesn't allow to modify ranges. Basically, `Selective` does allow a
user to modufy the ranges, but there is no real ranges with `Growing` or
`Paging`. Let's make it an explicit error.
Finally, `SlidingSyncListInner` has 2 methods: `set_ranges` and
`add_range`, but without any “ranges check”; `SlidingSyncList` does call
the inner methods, but does the checks.
