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  	return c.Reader.Read(p)
    63  }
    64  
    65  // Write implements the io.Writer interface
    66  func (c *Conn) Write(p []byte) (int, error) {
    67  	if !c.ReadDeadline.IsZero() && time.Now().After(c.WriteDeadline) {
    68  		return 0, ErrTimeout
    69  	}
    70  	return c.Writer.Write(p)
    71  }
    72  
    73  // LocalAddr returns the Local Address
    74  func (c *Conn) LocalAddr() net.Addr {
    75  	return c.Local
    76  }
    77  
    78  // RemoteAddr returns the Remote Address
    79  func (c *Conn) RemoteAddr() net.Addr {
    80  	return c.Remote
    81  }
    82  
    83  // SetDeadline implements the Conn SetDeadline method
    84  func (c *Conn) SetDeadline(t time.Time) error {
    85  	err := c.SetReadDeadline(t)
    86  	err2 := c.SetWriteDeadline(t)
    87  	if err != nil {
    88  		return err
    89  	}
    90  	return err2
    91  }
    92  
    93  // SetReadDeadline implements the Conn SetReadDeadline method
    94  func (c *Conn) SetReadDeadline(t time.Time) error {
    95  	c.ReadDeadline = t
    96  	if rd, ok := c.Writer.(interface {
    97  		SetReadDeadline(time.Time) error
    98  	}); ok {
    99  		return rd.SetReadDeadline(t)
   100  	}
   101  	return nil
   102  }
   103  
   104  // SetWriteDeadline implements the Conn SetWriteDeadline method
   105  func (c *Conn) SetWriteDeadline(t time.Time) error {
   106  	c.WriteDeadline = t
   107  	if wd, ok := c.Writer.(interface {
   108  		SetWriteDeadline(time.Time) error
   109  	}); ok {
   110  		return wd.SetWriteDeadline(t)
   111  	}
   112  	return nil
   113  }
   114  
   115  // Errors
   116  var (
   117  	ErrTimeout = errors.New("timeout occurred")
   118  )