feat: run VortexFileArrayStream on dedicated IoDispatcher (#1232)

This PR separates IO for the `LayoutBatchStream` from the calling
thread's runtime. This is beneficial for a few reasons

1. Now decoding into Arrow will not block the executor where IO occurs,
which previously could lead to timeouts
2. It allows us to use non-Tokio runtimes such as compio which uses
io_uring

To enable (2), we revamp the `VortexReadAt ` trait to return `!Send`
futures that can be launched on thread-per-core runtimes. We also
enforce the `VortexReadAt` implementers are clonable, again so they can
be shared across several concurrent futures. We implement a clonable
`TokioFile` type, and un-implement for things like `Vec<u8>` and `&[u8]`
that don't have cheap cloning.


Although read operations are now `!Send`, it is preferable
for`LayoutBatchStream` to be `Send` so that it can be polled from Tokio
or any other runtime. To achieve this, we add an `IoDispatcher`, which
sits in front of either a tokio or compio executor to dispatch read
requests.

A couple of things to consider:

* **Cancellation safety**: On Drop, the dispatcher will join its worker
threads, gracefully awaiting any already-submitted tasks before it
completes. It's probably more preferable to find a way to force an
immediate shutdown, so we may want to ferry a `shutdown_now` channel and
`select!` over both of them inside of the inner loop of the dispatcher
* **Async runtime safety**: The way you can implement cross-runtime IO
is that you provide both a reader (`VortexReadAt`) and a `IoDispatcher`
to the `LayoutBatchStreamBuilder`. There is nothing at compile time that
enforces that the reader and the dispatcher are compatible. Perhaps we
should parameterize `VortexReadAt` on a runtime and then we can do
type-level checks to ensure that all IO operations can only be paired
with the right runtime. That would likely inflate the PR a good bit

Author: a10y

.github/workflows/ci.yml

@@ -2,15 +2,15 @@ name: CI
 
 on:
   push:
-    branches: [ "develop" ]
-  pull_request: { }
-  workflow_dispatch: { }
+    branches: ["develop"]
+  pull_request: {}
+  workflow_dispatch: {}
 
 permissions:
   actions: read
   contents: read
-  checks: write  # audit-check creates checks
-  issues: write  # audit-check creates issues
+  checks: write # audit-check creates checks
+  issues: write # audit-check creates issues
 
 env:
   CARGO_TERM_COLOR: always
@@ -140,7 +140,7 @@ jobs:
     name: "miri"
     runs-on: ubuntu-latest
     env:
-      MIRIFLAGS: -Zmiri-strict-provenance -Zmiri-symbolic-alignment-check -Zmiri-backtrace=full
+      MIRIFLAGS: -Zmiri-strict-provenance -Zmiri-symbolic-alignment-check -Zmiri-backtrace=full -Zmiri-disable-isolation
     steps:
       - uses: rui314/setup-mold@v1
       - uses: actions/checkout@v4
@@ -182,4 +182,3 @@ jobs:
       - name: "Make sure no files changed after regenerating"
         run: |
           test -z "$(git status --porcelain)"
-

.zed/tasks.json

@@ -0,0 +1,10 @@
+// Static tasks configuration.
+//
+// Example:
+[
+  {
+    "label": "clippy (workspace)",
+    "command": "cargo clippy --all-targets --all-features",
+    "shell": "system"
+  }
+]