ooni-probe-cli/internal/engine/netx/dialer/bytecounter.go
Simone Basso 760ac905d6
refactor: move bytecounting conn in bytecounter pkg (#392)
* refactor: move bytecounting conn in bytecounter pkg

This enables other pieces of code to request bytecounting without
depending on netx or on the perverse using-the-context-to-configure-
byte-counting mechanism.

Also occurred when working on https://github.com/ooni/probe/issues/1687

* fix: add missing docs
2021-06-22 13:44:36 +02:00

57 lines
1.8 KiB
Go

package dialer
import (
"context"
"net"
"github.com/ooni/probe-cli/v3/internal/bytecounter"
)
// byteCounterDialer is a byte-counting-aware dialer. To perform byte counting, you
// should make sure that you insert this dialer in the dialing chain.
type byteCounterDialer struct {
Dialer
}
// DialContext implements Dialer.DialContext
func (d *byteCounterDialer) DialContext(
ctx context.Context, network, address string) (net.Conn, error) {
conn, err := d.Dialer.DialContext(ctx, network, address)
if err != nil {
return nil, err
}
if exp := contextExperimentByteCounter(ctx); exp != nil {
conn = &bytecounter.Conn{Conn: conn, Counter: exp}
}
if sess := contextSessionByteCounter(ctx); sess != nil {
conn = &bytecounter.Conn{Conn: conn, Counter: sess}
}
return conn, nil
}
type byteCounterSessionKey struct{}
// contextSessionByteCounter retrieves the session byte counter from the context
func contextSessionByteCounter(ctx context.Context) *bytecounter.Counter {
counter, _ := ctx.Value(byteCounterSessionKey{}).(*bytecounter.Counter)
return counter
}
// WithSessionByteCounter assigns the session byte counter to the context.
func WithSessionByteCounter(ctx context.Context, counter *bytecounter.Counter) context.Context {
return context.WithValue(ctx, byteCounterSessionKey{}, counter)
}
type byteCounterExperimentKey struct{}
// contextExperimentByteCounter retrieves the experiment byte counter from the context
func contextExperimentByteCounter(ctx context.Context) *bytecounter.Counter {
counter, _ := ctx.Value(byteCounterExperimentKey{}).(*bytecounter.Counter)
return counter
}
// WithExperimentByteCounter assigns the experiment byte counter to the context.
func WithExperimentByteCounter(ctx context.Context, counter *bytecounter.Counter) context.Context {
return context.WithValue(ctx, byteCounterExperimentKey{}, counter)
}