Partially supersedes #19016.
This migrates `spawn` and `spawn_blocking` to `deno_core`, and removes
the requirement for `spawn` tasks to be `Send` given our single-threaded
executor.
While we don't need to technically do anything w/`spawn_blocking`, this
allows us to have a single `JoinHandle` type that works for both cases,
and allows us to more easily experiment with alternative
`spawn_blocking` implementations that do not require tokio (ie: rayon).
Async ops (+~35%):
Before:
```
time 1310 ms rate 763358
time 1267 ms rate 789265
time 1259 ms rate 794281
time 1266 ms rate 789889
```
After:
```
time 956 ms rate 1046025
time 954 ms rate 1048218
time 924 ms rate 1082251
time 920 ms rate 1086956
```
HTTP serve (+~4.4%):
Before:
```
Running 10s test @ http://localhost:4500
2 threads and 10 connections
Thread Stats Avg Stdev Max +/- Stdev
Latency 68.78us 19.77us 1.43ms 86.84%
Req/Sec 68.78k 5.00k 73.84k 91.58%
1381833 requests in 10.10s, 167.36MB read
Requests/sec: 136823.29
Transfer/sec: 16.57MB
```
After:
```
Running 10s test @ http://localhost:4500
2 threads and 10 connections
Thread Stats Avg Stdev Max +/- Stdev
Latency 63.12us 17.43us 1.11ms 85.13%
Req/Sec 71.82k 3.71k 77.02k 79.21%
1443195 requests in 10.10s, 174.79MB read
Requests/sec: 142921.99
Transfer/sec: 17.31MB
```
Suggested-By: alice@ryhl.io
Co-authored-by: Bartek Iwańczuk <biwanczuk@gmail.com>
This commit introduces two new buffer wrapper types to `deno_core`. The
main benefit of these new wrappers is that they can wrap a number of
different underlying buffer types. This allows for a more flexible read
and write API on resources that will require less copying of data
between different buffer representations.
- `BufView` is a read-only view onto a buffer. It can be backed by
`ZeroCopyBuf`, `Vec<u8>`, and `bytes::Bytes`.
- `BufViewMut` is a read-write view onto a buffer. It can be cheaply
converted into a `BufView`. It can be backed by `ZeroCopyBuf` or
`Vec<u8>`.
Both new buffer views have a cursor. This means that the start point of
the view can be constrained to write / read from just a slice of the
view. Only the start point of the slice can be adjusted. The end point
is fixed. To adjust the end point, the underlying buffer needs to be
truncated.
Readable resources have been changed to better cater to resources that
do not support BYOB reads. The basic `read` method now returns a
`BufView` instead of taking a `ZeroCopyBuf` to fill. This allows the
operation to return buffers that the resource has already allocated,
instead of forcing the caller to allocate the buffer. BYOB reads are
still very useful for resources that support them, so a new `read_byob`
method has been added that takes a `BufViewMut` to fill. `op_read`
attempts to use `read_byob` if the resource supports it, which falls
back to `read` and performs an additional copy if it does not. For
Rust->JS reads this change should have no impact, but for Rust->Rust
reads, this allows the caller to avoid an additional copy in many
scenarios. This combined with the support for `BufView` to be backed by
`bytes::Bytes` allows us to avoid one data copy when piping from a
`fetch` response into an `ext/http` response.
Writable resources have been changed to take a `BufView` instead of a
`ZeroCopyBuf` as an argument. This allows for less copying of data in
certain scenarios, as described above. Additionally a new
`Resource::write_all` method has been added that takes a `BufView` and
continually attempts to write the resource until the entire buffer has
been written. Certain resources like files can override this method to
provide a more efficient `write_all` implementation.
