This change removes all references to `Stream` from
within the `tokio` crate and moves them into a new
`tokio-stream` crate. Most types have had their
`impl Stream` removed as well in-favor of their
inherent methods.
Closes#2870
## Motivation
In Tokio 0.2, `AsyncRead` and `AsyncWrite` had `poll_write_buf` and
`poll_read_buf` methods for reading and writing to implementers of
`bytes` `Buf` and `BufMut` traits. In 0.3, these were removed, but
`poll_read_buf` was added as a free function in `tokio-util`. However,
there is currently no `poll_write_buf`.
Now that `AsyncWrite` has regained support for vectored writes in #3149,
there's a lot of potential benefit in having a `poll_write_buf` that
uses vectored writes when supported and non-vectored writes when not
supported, so that users don't have to reimplement this.
## Solution
This PR adds a `poll_write_buf` function to `tokio_util::io`, analogous
to the existing `poll_read_buf` function.
This function writes from a `Buf` to an `AsyncWrite`, advancing the
`Buf`'s internal cursor. In addition, when the `AsyncWrite` supports
vectored writes (i.e. its `is_write_vectored` method returns `true`),
it will use vectored IO.
I copied the documentation for this functions from the docs from Tokio
0.2's `AsyncWrite::poll_write_buf` , with some minor modifications as
appropriate.
Finally, I fixed a minor issue in the existing docs for `poll_read_buf`
and `read_buf`, and updated `tokio_util::codec` to use `poll_write_buf`.
Signed-off-by: Eliza Weisman <[email protected]>
This reverts commit fe2b997.
We are avoiding adding poll_read_buf to tokio itself for now. The patch is
reverted now in order to not block the v0.3.2 release (#3059).
These functions have object safety issues. It also has been decided to
avoid vectored operations on the I/O traits. A later PR will bring back
vectored operations on specific types that support them.
Refs: #2879, #2716
Adds a method to retrieve a mutable reference to the Framed stream's read buffer.
This makes it possible to e.g. externally clear the buffer to prevent the codec from
parsing stale data.
Framed was designed to encapsulate both AsyncRead and AsyncWrite so
that it could wrap two-way connections. It used Fuse to manage the pinned
io object between the FramedWrite and FramedRead structs.
I replaced the Fuse struct by isolating the state used in reading and
writing, and making the code generic over that instead. This means
the FramedImpl struct now has a parameter for the state, and contains
the logic for both directions. The Framed* structs are now simply
wrappers around this type
Hopefully removing the `Pin` handling made things easier to
understand, too.
The link to tokio::main was relative to tokio_macros crate in the source
directory. This is why it worked in local build of documentation and not
in doc.rs.
Refs: #1473
Included changes
- all simple references like `<type>.<name>.html` for these types
- enum
- fn
- struct
- trait
- type
- simple references for methods, like struct.DelayQueue.html#method.poll
Refs: #1473
Introduces `StreamExt` trait. This trait will be used to add utility functions
to make working with streams easier. This patch includes two functions:
* `next`: a future returning the item in the stream.
* `map`: transform each item in the stream.
In an effort to reach API stability, the `tokio` crate is shedding its
_public_ dependencies on crates that are either a) do not provide a
stable (1.0+) release with longevity guarantees or b) match the `tokio`
release cadence. Of course, implementing `std` traits fits the
requirements.
The on exception, for now, is the `Stream` trait found in `futures_core`.
It is expected that this trait will not change much and be moved into `std.
Since Tokio is not yet going reaching 1.0, I feel that it is acceptable to maintain
a dependency on this trait given how foundational it is.
Since the `Stream` implementation is optional, types that are logically
streams provide `async fn next_*` functions to obtain the next value.
Avoiding the `next()` name prevents fn conflicts with `StreamExt::next()`.
Additionally, some misc cleanup is also done:
- `tokio::io::io` -> `tokio::io::util`.
- `delay` -> `delay_until`.
- `Timeout::new` -> `timeout(...)`.
- `signal::ctrl_c()` returns a future instead of a stream.
- `{tcp,unix}::Incoming` is removed (due to lack of `Stream` trait).
- `time::Throttle` is removed (due to lack of `Stream` trait).
- Fix: `mpsc::UnboundedSender::send(&self)` (no more conflict with `Sink` fns).
I need this to implement SMTP pipelining checks. I mostly need to
flush my send buffer when the read buffer is empty before waiting for
the next command.
A step towards collapsing Tokio sub crates into a single `tokio`
crate (#1318).
The `io` implementation is now provided by the main `tokio` crate.
Functionality can be opted out of by using the various net related
feature flags.
Related to #1318, Tokio APIs that are "less stable" are moved into a new
`tokio-util` crate. This crate will mirror `tokio` and provide
additional APIs that may require a greater rate of breaking changes.
As examples require `tokio-util`, they are moved into a separate
crate (`examples`). This has the added advantage of being able to avoid
example only dependencies in the `tokio` crate.
somethingelseentirely