Class: Base32Coder

• Inheritance
• Description
• Class protocol
  • initialization
• Instance protocol
  • encoding
  • misc
  • private
• Examples

Inheritance:

   Object
   |
   +--Visitor
      |
      +--AspectVisitor
         |
         +--ObjectCoder
            |
            +--BaseNCoder
               |
               +--Base32Coder

Package:

stx:libbasic2

Category:

System-Storage

Version:

rev: 1.9 date: 2024/01/29 20:32:43

user: cg

file: Base32Coder.st directory: libbasic2

module: stx stc-classLibrary: libbasic2

Description:

Instances of this class perform Base32 en- and decoding as defined in RFC 3548
5 bytes are mapped to 8 characters, representing 5 bits each.



[instance variables:]

[class variables:]
    Base32Mapping         String   Mapping from bytes (with 5 valid bits)   
                                   to Base32 characters
    Base32ReverseMapping  Array    Mapping from Base32 characters to 5-bit-Bytes

copyright
COPYRIGHT (c) 2002 by eXept Software AG
             All Rights Reserved

This software is furnished under a license and may be used
only in accordance with the terms of that license and with the
inclusion of the above copyright notice.   This software may not
be provided or otherwise made available to, or used by, any
other person.  No title to or ownership of the software is
hereby transferred.

Class protocol:

 initializeMappings

initialize class variables

Usage example(s):

Base32Mapping := nil. self initializeMappings

 mapping

 reverseMapping

Instance protocol:

 nextPutByte: aByte

encode aByte on the output stream

 flush

flush the remaining bits of buffer.
The number of bits in buffer is not a multiple of 6, so we pad
the buffer and signal that padding has been done via $= characters.

 fillBuffer

fill buffer with next 8 characters each representing 5 bits

Examples:

   |data1 text data2|

   data1 := #[0 1 16r7F 16r80 16r81 16rFE 16rFF].
   text := Base32Coder encode:data1.
   data2 := Base32Coder decode:text.
   self assert:(data2 = data1)

   |coder|

   coder := Base32Coder on:'' writeStream.
   coder nextPutAll:#[0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19].
   coder flush.
   coder contents inspect.
   coder reset.
   coder nextPut:254.
   coder contents inspect.

   |coder decoder|

   coder := Base32Coder on:'' writeStream.
   coder nextPutAll:#[0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20].
   coder flush.

   decoder := Base32Coder on:(coder contents readStream).
   [decoder atEnd] whileFalse:[
      Transcript show:decoder next
   ].
   Transcript cr.

   |coder|

   coder := Base32Coder on:'' writeStream.
   coder nextPutAll:(0 to:200) asByteArray.
   coder flush.

   Transcript showCR:(coder contents).

   |bytes encoded decoded|

   bytes := #[0 0 0] copy.
   0 to:255 do:[:b1 |
       Transcript showCR:b1.  
       bytes at:1 put:b1.  
       0 to:255 do:[:b2 |
           bytes at:2 put:b2.  
           0 to:255 do:[:b3 |
               bytes at:3 put:b3.  
               encoded := Base32Coder encode:bytes.
               decoded := Base32Coder decode:encoded.
               self assert:(decoded = bytes).
           ]
       ]
   ].