ioconn - ioconn.go

     1  // Package ioconn allows any combination of an io.Reader, io.Writer and io.Closer to become a net.Conn.
     2  package ioconn // import "vimagination.zapto.org/ioconn"
     3  
     4  import (
     5  	"errors"
     6  	"io"
     7  	"net"
     8  	"time"
     9  )
    10  
    11  // CloserFunc is a func that implements the io.Closer interface allowing a
    12  // closure or other function to be io.Closer.
    13  type CloserFunc func() error
    14  
    15  // Close simply calls the CloserFunc func.
    16  func (c CloserFunc) Close() error {
    17  	return c()
    18  }
    19  
    20  // FileAddr is a net.Addr that represents a file. Should be a full path.
    21  type FileAddr string
    22  
    23  // Network always returns "file".
    24  func (f FileAddr) Network() string {
    25  	return "file"
    26  }
    27  
    28  // String returns file://path.
    29  func (f FileAddr) String() string {
    30  	return "file://" + string(f)
    31  }
    32  
    33  // Addr is a simple implementation of the net.Addr interface.
    34  type Addr struct {
    35  	Net, Str string
    36  }
    37  
    38  // Network returns the Net string.
    39  func (a Addr) Network() string {
    40  	return a.Net
    41  }
    42  
    43  // String returns the Str string.
    44  func (a Addr) String() string {
    45  	return a.Str
    46  }
    47  
    48  // Conn implements a net.Conn.
    49  type Conn struct {
    50  	io.Reader
    51  	io.Writer
    52  	io.Closer
    53  	Local, Remote               net.Addr
    54  	ReadDeadline, WriteDeadline time.Time
    55  }
    56  
    57  // Read implements the io.Reader interface.
    58  func (c *Conn) Read(p []byte) (int, error) {
    59  	if !c.ReadDeadline.IsZero() && time.Now().After(c.ReadDeadline) {
    60  		return 0, ErrTimeout
    61  	}
    62  
    63  	return c.Reader.Read(p)
    64  }
    65  
    66  // Write implements the io.Writer interface.
    67  func (c *Conn) Write(p []byte) (int, error) {
    68  	if !c.ReadDeadline.IsZero() && time.Now().After(c.WriteDeadline) {
    69  		return 0, ErrTimeout
    70  	}
    71  
    72  	return c.Writer.Write(p)
    73  }
    74  
    75  // LocalAddr returns the Local Address.
    76  func (c *Conn) LocalAddr() net.Addr {
    77  	return c.Local
    78  }
    79  
    80  // RemoteAddr returns the Remote Address.
    81  func (c *Conn) RemoteAddr() net.Addr {
    82  	return c.Remote
    83  }
    84  
    85  // SetDeadline implements the Conn SetDeadline method.
    86  func (c *Conn) SetDeadline(t time.Time) error {
    87  	err := c.SetReadDeadline(t)
    88  	err2 := c.SetWriteDeadline(t)
    89  
    90  	if err != nil {
    91  		return err
    92  	}
    93  
    94  	return err2
    95  }
    96  
    97  // SetReadDeadline implements the Conn SetReadDeadline method.
    98  func (c *Conn) SetReadDeadline(t time.Time) error {
    99  	c.ReadDeadline = t
   100  
   101  	if rd, ok := c.Writer.(interface {
   102  		SetReadDeadline(time.Time) error
   103  	}); ok {
   104  		return rd.SetReadDeadline(t)
   105  	}
   106  
   107  	return nil
   108  }
   109  
   110  // SetWriteDeadline implements the Conn SetWriteDeadline method.
   111  func (c *Conn) SetWriteDeadline(t time.Time) error {
   112  	c.WriteDeadline = t
   113  
   114  	if wd, ok := c.Writer.(interface {
   115  		SetWriteDeadline(time.Time) error
   116  	}); ok {
   117  		return wd.SetWriteDeadline(t)
   118  	}
   119  
   120  	return nil
   121  }
   122  
   123  // Errors.
   124  var (
   125  	ErrTimeout = errors.New("timeout occurred")
   126  )
   127