ikey_base26.h

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/*
 * SPDX-License-Identifier: MIT
 * Copyright (c) 2024 IUPAC and InChI Trust
 */
 
 
#ifndef _IKEY_BASE26_H_
#define _IKEY_BASE26_H_
 
/*
    Base-26 encoding procedures.
 
    'Base26' characters here are considered to be uppercase English
    letters 'A..Z'
*/
 
 
/* Uncomment the next line to fix base-26 encoding bug */
/*#define FIX_BASE26_ENC_BUG 1*/
 
typedef unsigned int UINT32;
typedef unsigned short int UINT16;
 
#ifdef __cplusplus
extern "C" {
#endif
 
/*    Get a character representing 1st 14-bit triplet
    (bits 0..13 of contiguous array of octets)        */
    const char* base26_triplet_1( const unsigned char *a );
    /*    Get a character representing 2nd 14-bit triplet (bits 14..27)    */
    const char* base26_triplet_2( const unsigned char *a );
    /*    Get a character representing 3rd 14-bit triplet (bits 28..41)    */
    const char* base26_triplet_3( const unsigned char *a );
    /*    Get a character representing 4th 14-bit triplet (bits 42..55)    */
    const char* base26_triplet_4( const unsigned char *a );
 
    /*
        Tail dublets
    */
 
    /*    Get dublet (bits 28..36)    */
    const char* base26_dublet_for_bits_28_to_36( unsigned char *a );
    /*    Get dublet (bits 56..64)    */
    const char* base26_dublet_for_bits_56_to_64( unsigned char *a );
    /*    Get hash extension in hexadecimal representation for the major block.
        Len(extension) = 256 - 65 = 191 bit.                                */
    void get_xtra_hash_major_hex( const unsigned char *a, char* szXtra );
    /*    Get hash extension in hexadecimal representation for the minor block.
        Len(extension) = 256 - 37 = 219 bit.                                */
    void get_xtra_hash_minor_hex( const unsigned char *a, char* szXtra );
 
    /*    Used instead of isupper() to avoid locale interference.    */
#define isbase26(_c)    ( ((unsigned)(_c) >= 'A') && ((unsigned)(_c) <= 'Z') )
 
#ifdef __cplusplus
}
#endif
 
 
#endif    /* _IKEY_BASE26_H_ */