6d3a4f1db8
When preparing a tutorial for netxlite, I figured it is easier to tell people "hey, this is the package you should use for all low-level networking stuff" rather than introducing people to a set of packages working together where some piece of functionality is here and some other piece is there. Part of https://github.com/ooni/probe/issues/1591
80 lines
2.0 KiB
Go
80 lines
2.0 KiB
Go
package errorsx
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import (
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"context"
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"net"
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"github.com/ooni/probe-cli/v3/internal/netxlite"
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)
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// Dialer establishes network connections.
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type Dialer interface {
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// DialContext behaves like net.Dialer.DialContext.
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DialContext(ctx context.Context, network, address string) (net.Conn, error)
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}
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// ErrorWrapperDialer is a dialer that performs error wrapping. The connection
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// returned by the DialContext function will also perform error wrapping.
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type ErrorWrapperDialer struct {
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// Dialer is the underlying dialer.
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Dialer
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}
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// DialContext implements Dialer.DialContext.
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func (d *ErrorWrapperDialer) DialContext(ctx context.Context, network, address string) (net.Conn, error) {
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conn, err := d.Dialer.DialContext(ctx, network, address)
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if err != nil {
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return nil, SafeErrWrapperBuilder{
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Classifier: netxlite.ClassifyGenericError,
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Operation: netxlite.ConnectOperation,
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Error: err,
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}.MaybeBuild()
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}
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return &errorWrapperConn{Conn: conn}, nil
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}
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// errorWrapperConn is a net.Conn that performs error wrapping.
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type errorWrapperConn struct {
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// Conn is the underlying connection.
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net.Conn
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}
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// Read implements net.Conn.Read.
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func (c *errorWrapperConn) Read(b []byte) (int, error) {
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count, err := c.Conn.Read(b)
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if err != nil {
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return 0, SafeErrWrapperBuilder{
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Classifier: netxlite.ClassifyGenericError,
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Operation: netxlite.ReadOperation,
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Error: err,
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}.MaybeBuild()
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}
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return count, nil
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}
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// Write implements net.Conn.Write.
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func (c *errorWrapperConn) Write(b []byte) (int, error) {
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count, err := c.Conn.Write(b)
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if err != nil {
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return 0, SafeErrWrapperBuilder{
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Classifier: netxlite.ClassifyGenericError,
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Operation: netxlite.WriteOperation,
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Error: err,
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}.MaybeBuild()
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}
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return count, nil
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}
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// Close implements net.Conn.Close.
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func (c *errorWrapperConn) Close() error {
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err := c.Conn.Close()
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if err != nil {
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return SafeErrWrapperBuilder{
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Classifier: netxlite.ClassifyGenericError,
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Operation: netxlite.CloseOperation,
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Error: err,
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}.MaybeBuild()
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}
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return nil
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}
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