ooni-probe-cli/internal/netxlite/iox/iox.go
Simone Basso 2e0118d1a6
refactor(netxlite): hide details without breaking the rest of the tree (#454)
## Description

This PR continues the refactoring of `netx` under the following principles:

1. do not break the rest of the tree and do not engage in extensive tree-wide refactoring yet
2. move under `netxlite` clearly related subpackages (e.g., `iox`, `netxmocks`)
3. move into `internal/netxlite/internal` stuff that is clearly private of `netxlite`
4. hide implementation details in `netxlite` pending new factories
5. refactor `tls` code in `netxlite` to clearly separate `crypto/tls` code from `utls` code

After each commit, I run `go test -short -race ./...` locally. Each individual commit explains what it does. I will squash, but this operation will preserve the original commit titles, so this will give further insight on each step.

## Commits

* refactor: rename netxmocks -> netxlite/mocks

Part of https://github.com/ooni/probe/issues/1591

* refactor: rename quicx -> netxlite/quicx

See https://github.com/ooni/probe/issues/1591

* refactor: rename iox -> netxlite/iox

Regenerate sources and make sure the tests pass.

See https://github.com/ooni/probe/issues/1591.

* refactor(iox): move MockableReader to netxlite/mocks

See https://github.com/ooni/probe/issues/1591

* refactor(netxlite): generator is an implementation detail

See https://github.com/ooni/probe/issues/1591

* refactor(netxlite): separate tls and utls code

See https://github.com/ooni/probe/issues/1591

* refactor(netxlite): hide most types but keep old names as legacy

With this change we avoid breaking the rest of the tree, but we start
hiding some implementation details a bit. Factories will follow.

See https://github.com/ooni/probe/issues/1591
2021-09-05 14:49:38 +02:00

59 lines
1.5 KiB
Go

// Package iox contains io extensions.
package iox
import (
"context"
"io"
)
// ReadAllContext is like io.ReadAll but reads r in a
// background goroutine. This function will return
// earlier if the context is cancelled. In which case
// we will continue reading from r in the background
// goroutine, and we will discard the result. To stop
// the long-running goroutine, you need to close the
// connection bound to the r reader, if possible.
func ReadAllContext(ctx context.Context, r io.Reader) ([]byte, error) {
datach, errch := make(chan []byte, 1), make(chan error, 1) // buffers
go func() {
data, err := io.ReadAll(r)
if err != nil {
errch <- err
return
}
datach <- data
}()
select {
case data := <-datach:
return data, nil
case <-ctx.Done():
return nil, ctx.Err()
case err := <-errch:
return nil, err
}
}
// CopyContext is like io.Copy but may terminate earlier
// when the context expires. This function has the same
// caveats of ReadAllContext regarding the temporary leaking
// of the background goroutine used to do I/O.
func CopyContext(ctx context.Context, dst io.Writer, src io.Reader) (int64, error) {
countch, errch := make(chan int64, 1), make(chan error, 1) // buffers
go func() {
count, err := io.Copy(dst, src)
if err != nil {
errch <- err
return
}
countch <- count
}()
select {
case count := <-countch:
return count, nil
case <-ctx.Done():
return 0, ctx.Err()
case err := <-errch:
return 0, err
}
}