ACE/ace/Codecs.h

   1 // -*- C++ -*-
   2
   3 //=============================================================================
   4 /**
   5  *  @file   Codecs.h
   6  *
   7  *  @author Krishnakumar B <kitty@cs.wustl.edu>
   8  *
   9  *  Codecs is a generic wrapper for various encoding and decoding
  10  *  mechanisms. Currently it includes Base64 content transfer-encoding as
  11  *  specified by RFC 2045, Multipurpose Internet Mail Extensions (MIME) Part
  12  *  One: Format of Internet Message Bodies.
  13  */
  14 //=============================================================================
  15
  16 #ifndef ACE_CODECS_H
  17 #define ACE_CODECS_H
  18
  19 #include /**/ "ace/pre.h"
  20
  21 #include /**/ "ace/ACE_export.h"
  22
  23 #if !defined (ACE_LACKS_PRAGMA_ONCE)
  24 # pragma once
  25 #endif /* ACE_LACKS_PRAGMA_ONCE */
  26
  27 #include "ace/Basic_Types.h"
  28 #include "ace/Global_Macros.h"
  29
  30 ACE_BEGIN_VERSIONED_NAMESPACE_DECL
  31
  32 /**
  33  * @class ACE_Base64
  34  *
  35  * @brief Encode/Decode a stream of bytes according to Base64 encoding.
  36  *
  37  * This class provides methods to encode or decode a stream of bytes
  38  * to/from Base64 encoding. It doesn't convert the input stream to a
  39  * canonical form before encoding.
  40  */
  41 class ACE_Export ACE_Base64
  42 {
  43 public:
  44   //@{
  45
  46   /**
  47    * Encodes a stream of bytes to Base64 data
  48    *
  49    * @param input Binary data in byte stream.
  50    * @param input_len Length of the byte stream.
  51    * @param output_len Length of the encoded Base64 byte stream.
  52    * @param is_chunked If true, terminate 72 character blocks with newline
  53    * @return Encoded Base64 data in byte stream or NULL if input data cannot
  54    *         be encoded.
  55    */
  56   static ACE_Byte* encode (const ACE_Byte* input,
  57                            const size_t input_len,
  58                            size_t* output_len,
  59                            bool is_chunked = true);
  60   /**
  61    * Decodes a stream of Base64 to bytes data
  62    *
  63    * @param input Encoded Base64 data in byte stream.
  64    * @param output_len Length of the binary byte stream.
  65    * @return Binary data in byte stream or NULL if input data cannot
  66    *         be encoded.
  67    */
  68   static ACE_Byte* decode (const ACE_Byte* input,
  69                            size_t* output_len);
  70
  71   /**
  72    * Return the length of the encoded input data
  73    *
  74    * @param input Encoded Base64 data in byte stream.
  75    * @return Length of the encoded Base64 data.
  76    *
  77    */
  78   static size_t length (const ACE_Byte* input);
  79
  80   //@}
  81
  82 protected:
  83   // Prevent default construction.
  84   ACE_Base64 (void) {}
  85
  86 private:
  87   // Preventing copying and assignment.
  88   ACE_Base64 (ACE_Base64 const &);
  89   ACE_Base64 & operator= (ACE_Base64 const &);
  90
  91   /// Initialize the tables for encoding/decoding.
  92   static void init (void);
  93
  94 private:
  95   /// Alphabet used for decoding i.e decoder_[alphabet_[i = 0..63]] = i
  96   static ACE_Byte decoder_[];
  97
  98   /// Alphabet used to check valid range of encoded input i.e
  99   /// member_[alphabet_[0..63]] = 1
 100   static ACE_Byte member_[];
 101
 102   /// Boolean to denote whether initialization is complete
 103   static bool init_;
 104 };
 105
 106 ACE_END_VERSIONED_NAMESPACE_DECL
 107
 108 #include /**/ "ace/post.h"
 109
 110 #endif /* ACE_CODECS_H */