Motivation:
As requested in #596, it can be handy to have a lower-level access to
channels (HTTP/1 connection, HTTP/2 connection, or HTTP/2 stream) to
enable a more fine-grained interaction for, say, observability, testing,
etc.
Modifications:
- Add 3 new properties (`http1_1ConnectionDebugInitializer`,
`http2ConnectionDebugInitializer` and
`http2StreamChannelDebugInitializer`) to `HTTPClient.Configuration` with
access to the respective channels. These properties are of `Optional`
type `@Sendable (Channel) -> EventLoopFuture<Void>` and are called when
creating a connection/stream.
Result:
Provides APIs for a lower-level access to channels.
---------
Co-authored-by: Cory Benfield <lukasa@apple.com>
Co-authored-by: David Nadoba <d_nadoba@apple.com>
Co-authored-by: George Barnett <gbarnett@apple.com>
### Motivation:
In some cases we can crash because of a precondition failure when the
write timeout fires and we aren't in the running state. This can happen
for example if the connection is closed whilst the write timer is
active.
### Modifications:
* Remove the precondition and instead take no action if the timeout
fires outside of the running state. Instead we take a new `Action`,
`.noAction` when the timer fires.
* Clear write timeouts upon request completion. When a request completes
we have no use for the idle write timer, we clear the read timer and we
should clear the write one too.
### Result:
Fewer crashes.
The supplied tests fails without these changes and passes with either of them.
# Motivation
The NIO 2.78 release introduced a bunch of new warnings. These warnings
cause us a bunch of trouble, so we should fix them.
# Modifications
Mostly use a bunch of assumeIsolated() and syncOperations.
# Result
CI passes again.
Note that Swift 6 has _many_ more warnings than this, but we expect more
to come and we aren't using warnings-as-errors on that mode at the
moment. We'll be cleaning that up soon.
fixes#784
`writeChunks` had 3 bugs:
1. An actually wrong `UnsafeMutableTransferBox` -> removed that type
which should never be created
2. A loooong future chain (instead of one final promise) -> implemented
3. Potentially infinite recursion which lead to the crash in #784) ->
fixed too
Migrate CI to use GitHub Actions.
### Motivation:
To migrate to GitHub actions and centralised infrastructure.
### Modifications:
Changes of note:
* Adopt swift-format using rules from SwiftNIO.
* Remove scripts and docker files which are no longer needed.
* Disabled warnings-as-errors on Swift 6.0 CI pipelines for now.
### Result:
Feature parity with old CI.
### Motivation:
A performance test executing 100,000 sequential requests against a
simple
[`NIOHTTP1Server`](https://github.com/apple/swift-nio/blob/main/Sources/NIOHTTP1Server/README.md)
revealed that 7% of total run time is spent in the setter of the
`request` property in `HTTP1ClientChannelHandler` (GitHub Issue #754).
The poor performance comes from [processing the string interpolation
`"\(self.eventLoop)"`](https://github.com/swift-server/async-http-client/blob/6df8e1c17e68f0f93de2443b8c8cafca9ddcc89a/Sources/AsyncHTTPClient/ConnectionPool/HTTP1/HTTP1ClientChannelHandler.swift#L39C17-L39C75)
which under the hood calls a computed property.
This problem can entirely be avoided by storing `eventLoop.description`
when initializing `HTTP1ClientChannelHandler`, and using that stored
value in `request`'s setter, rather than computing the property each
time.
### Modifications:
- Created a new property `let eventLoopDescription:
Logger.MetadataValue` in `HTTP1ClientChannelHandler` that stores the
description of the `eventLoop` argument that is passed into the
initializer.
- Replaced the string interpolation `"\(self.eventLoop)"` in `request`'s
setter with `self.eventLoopDescription`.
### Result:
`HTTP1ClientChannelHandler.eventLoop`'s `description` property is cached
upon initialization rather than being computed each time in the
`request` property's setter.
---------
Co-authored-by: Cory Benfield <lukasa@apple.com>
Multipath TCP (MPTCP) is a TCP extension allowing to enhance the
reliability of the network by using multiple interfaces. This extension
provides a seamless handover between interfaces in case of deterioration
of the connection on the original one. In the context of iOS and Mac OS
X, it could be really interesting to leverage the capabilities of MPTCP
as they could benefit from their multiple interfaces (ethernet + Wi-fi
for Mac OS X, Wi-fi + cellular for iOS).
This contribution introduces patches to HTTPClient.Configuration and
establishment of the Bootstraps. A supplementary field "enableMultipath"
was added to the configuration, allowing to request the use of MPTCP.
This flag is then used when creating the channels to configure the
client.
Note that in the future, it might also be potentially interesting to
offer more precise configuration options for MPTCP on MacOS, as the
Network framework allows also to select a type of service, instead of
just offering the option to create MPTCP connections. Currently, when
enabling MPTCP, only the Handover mode is used.
---------
Co-authored-by: Cory Benfield <lukasa@apple.com>
### Motivation
If the channel's writability changed to false just before we finished a
request, we currently run into a precondition.
### Changes
- Remove the precondition and handle the case appropiatly
### Result
A crash less.
Since most of the servers now conform to http2, the change here updates
the behaviour of assuming the connection to be http2 and not http1 by
default. It will migrate to http1 if the server only supports http1.
One can set the `httpVersion` in `ClientConfiguration` to `.http1Only`
which will start with http1 instead of http2.
Additional Changes:
- Fixed an off by one error in the maximum additional general purpose
connection check
- Updated tests
---------
Co-authored-by: Ayush Garg <ayushgarg@apple.com>
Co-authored-by: David Nadoba <d_nadoba@apple.com>
Co-authored-by: Fabian Fett <fabianfett@apple.com>
### Motivation:
When a user wishes to make the connection pool create as many concurrent
connections as possible, a natural way to achieve this would be to set
`.max` to the `concurrentHTTP1ConnectionsPerHostSoftLimit` property.
```swift
HTTPClient.Configuration().connectionPool = .init(
idleTimeout: .hours(1),
concurrentHTTP1ConnectionsPerHostSoftLimit: .max
)
```
The `concurrentHTTP1ConnectionsPerHostSoftLimit` property is of type
`Int`. Setting it to `Int.max` leads to `Int.max` being passed as an
argument to `Array`s `.reserveCapacity(_:)` method, causing an OOM
issue.
Addresses Github Issue #751
### Modifications:
Capped the argument to `self.connections.reserveCapacity(_:)` to 1024 in
`HTTPConnectionPool.HTTP1Connections`
### Result:
Users can now set the `concurrentHTTP1ConnectionsPerHostSoftLimit`
property to `.max` without causing an OOM issue.
### Motivation:
- The properties that store the request body length and the cumulative number of bytes sent as part of a request are of type `Int`.
- On 32-bit devices, when sending requests larger than `Int32.max`, these properties overflow and cause a crash.
- To solve this problem, the properties should use the explicit `Int64` type.
### Modifications:
- Changed the type of the `known` field of the `RequestBodyLength` enum to `Int64`.
- Changed the type of `expectedBodyLength` and `sentBodyBytes` in `HTTPRequestStateMachine` to `Int64?` and `Int64` respectively.
- Deprecated the `public var length: Int?` property of `HTTPClient.Body` and backed it with a new property: `contentLength: Int64?`
- Added a new initializer and "overloaded" the `stream` function in `HTTPClient.Body` to work with the new `contentLength` property.
- **Note:** The newly added `stream` function has different parameter names (`length` -> `contentLength` and `stream` -> `bodyStream`) to avoid ambiguity problems.
- Added a test case that streams a 3GB request -- verified this fails with the types of the properties set explicitly to `Int32`.
### Result:
- 32-bit devices can send requests larger than 2GB without integer overflow issues.
Motivation:
We would like to make this work for Musl so that we can build fully
statically linked binaries that use AsyncHTTPClient.
Modifications:
Define `_GNU_SOURCE` as a compiler argument; doing it in a source file
doesn't work properly with modular headers.
Add imports of `Musl` in appropriate places.
`Musl` doesn't have `strptime_l`, so avoid using that.
Result:
async-http-client will build for Musl.
Motivation:
Sometimes it can be helpful to limit the number of times a connection
can be used before discarding it. AHC has no such support for this at
the moment.
Modifications:
- Add a `maximumUsesPerConnection` configuration option which defaults
to `nil` (i.e. no limit).
- For HTTP1 we count down uses in the state machine and close the
connection if it hits zero.
- For HTTP2, each use maps to a stream so we count down remaining uses
in the state machine which we combine with max concurrent streams to
limit how many streams are available per connection. We also count
remaining uses in the HTTP2 idle handler: we treat no remaining uses
as receiving a GOAWAY frame and notify the pool which then drains the
streams and replaces the connection.
Result:
Users can control how many times each connection can be used.
Sometimes it can be useful to connect to one host e.g. `x.example.com` but request and validate the certificate chain as if we would connect to `y.example.com`. This is what this PR adds support for by adding a `dnsOverride` configuration to `HTTPClient.Configuration`. This is similar to curls `—resolve-to` option but only allows overriding host and not ports for now.
* Fix crash if connection is closed very early
If the channel is closed before flatMap is executed, all ChannelHandler are removed and `TLSEventsHandler` is therefore not present either. We need to tolerate this even though it is very rare.
Testing ideas welcome.
Fixes#670
* drop precondition to assert
* Reproducer
* Refactor test case
* Refactor tests
* Remove debugging artefacts
* Fix typo
* Fix formatting
* Remove `promise?.succeed(())`
* Add test for HTTP2 request with large header
Motivation
We currently don't handle large headers well which trigger a channel writability change event.
Modification
Add failing (but currently skipped) tests which reproduces the issue
Result
We can reliably reproduce the large request header issue in an integration and unit test.
Note that the actual fix is not included to make reviewing easier and will come in a follow up PR.
* Remove logging
* Fix crash for large HTTP request headers
Fix crash for when sending HTTP request headers result in a channel writability change event
* Formatting and linux tests
* Formatting and linux tests
* Generate linux tests
* Use previous default max concurrent streams value of 10
* Fix crash if request is canceled after request header is send
* generate linux tests and run swift format
---------
Co-authored-by: Cory Benfield <lukasa@apple.com>
* Tolerate shutdown message after channel is closed
### Motivation
A channel can close unexpectedly if something goes wrong. We may in the meantime have scheduled the connection for graceful shutdown but the connection has not yet seen the message. We need to still accept the shutdown message and just ignore it if we are already closed.
### Modification
- ignore calls to shutdown if the channel is already closed
- add a test which would previously crash because we have transition from the closed state to the closing state and we hit the deinit precondition
- include the current state in preconditions if we are in the wrong state
### Result
We don’t hit the precondition in the deinit in the scenario described above and have more descriptive crashes if something still goes wrong.
SwiftNIO 2.42.0 has deprecated Lock and replaced it with a new NIOLock. This commit removes all uses of Lock and replaces them with NIOLock. Further, now, we must require SwiftNIO 2.42.0
Motivation
If we receive an early HTTP response, the last action on a HTTP/1.1
connection is to send the .end message. While we had an error handling
path in the code, it wasn't tested, and when executed it would end up
leaking the connection by failing to close it _or_ return it to the
pool.
This patch fixes the issue by appropriately terminating the connection
and adding a test.
Modifications
Add a test
Terminate the connection if sendEnd fails
Result
Fewer connection leaks
Motivation
When users stream their bodies they may still want to send Connection:
close headers and terminate the connection early. This should work
properly.
Unfortunately it became clear that we didn't correctly pass the
information that the connection needed to be closed. As a result, we'd
inappropriately re-use the connection, potentially causing unnecessary
HTTP errors.
Modifications
Signal whether the connection needs to be closed when the final
connection action is to send .end.
Results
We behave better with streaming uploads.
Motivation
In some cases, the last thing that happens in a request-response pair is
that we send our HTTP/1.1 .end. This can happen when the peer has sent
an early response, before we have finished uploading our body. When it
does, we need to be diligent about cleaning up our connection state.
Unfortunately, there was an edge in the HTTP1ConnectionStateMachine that
processed .succeedRequest but that did not transition the state into
either .idle or .closing. That was an error, and needed to be fixed.
Modifications
Transition to .idle when we're returning
.succeedRequest(.sendRequestEnd).
Result
Fewer crashes
Motivation
It's totally acceptable for a HTTP server to respond before a request
upload has completed. If the response is an error, we should abort the
upload (and we do), but if the response is a 2xx we should probably just
finish the upload.
In this case it turns out we'll actually hit a crash when we attempt to
deliver an empty body message. his is no good!
Once that bug was fixed it revealed another: while we'd attempted to
account for this case, we hadn't tested it, and so it turns out that
shutdown would hang. As a result, I've also cleaned that up.
Modifications
- Tolerate empty circular buffers of bytes when streaming an upload.
- Notify the connection that the task is complete when we're done.
Result
Fewer crashes and hangs.
Motivation
Currently error reporting with NIO Transport Services is often sub-par.
This occurs because the Network.framework connections may enter the
waiting state until the network connectivity state changes. We were not
watching for the user event that contains the error in that state, so if
we timed out in that state we'd just give a generic timeout error,
instead of telling the user anything more detailed.
Additionally, several of our tests assume that failure will be fast, but
in NIO Transport Services we will enter that .waiting state. This is
reasonable, as changed network connections may make a connection that
was not succeeding suddenly viable. However, it's inconvenient for
testing, where we're mostly interested in confirming that the error path
works as expected.
Modifications
- Add an observer of the WaitingForConnectivity event that records it
into our state machine for later reporting.
- Add support for disabling waiting for connectivity for testing
purposes.
- Add annotations to several tests to stop them waiting for
connectivity.
Results
Faster tests, better coverage, better errors for our users.
Co-authored-by: David Nadoba <dnadoba@gmail.com>
### Motivation
Today `didSendRequestPart` is called after a request body part has been passed to the executor. However, this does not mean that the write hit the socket. Users may depend on this behavior to implement back-pressure. For this reason, we should only call this `didSendRequestPart` once the write was successful.
### Modification
Pass a promise to the actual channel write and only call the delegate once that promise succeeds.
### Result
The delegate method `didSendRequestPart` is only called after the write was successful. Fixes#565.
Co-authored-by: Fabian Fett <fabianfett@apple.com>
Same fix for HTTP/1 that landed for HTTP/2 in #558.
### Motivation
`HTTP1ClientChannelHandler` currently does not tolerate immediate write errors.
### Changes
Make `HTTP1ClientChannelHandler` resilient to failing writes.
### Result
Less crashes in AHC HTTP/1.
Swift tools version 5.3 and higher (the version that is specified at very top of a Package.swift file) excludes folders with a dot in the name by default. It luckily produces a warning "found 1 file(s) which are unhandled; explicitly declare them as resources or exclude from the target". However, this issue is buried under a lot of missing types Errors because of the 3 excluded files.
I run into this issue and it took me some time to figure out what the actual problem was. As we will eventually move from 5.2 to 5.3 we can already save the next person some time by resolving this issue now.
Clinton Nkwocha
Allan Shortlidge
Rick Newton-Rogers
Marc Prud'hommeaux
Cory Benfield
Johannes Weiss
aryan-25
Anthony Doeraene
Fabian Fett
Ayush Garg
Gustavo Cairo
Alastair Houghton
David Nadoba
George Barnett
iMike
Franz Busch