mirror of
https://github.com/DCC-EX/CommandStation-EX.git
synced 2024-11-22 15:46:14 +01:00
97 lines
3.5 KiB
C++
97 lines
3.5 KiB
C++
/*
|
|
* © 2024 Vincent Hamp and Chris Harlow
|
|
* All rights reserved.
|
|
*
|
|
* This file is part of CommandStation-EX
|
|
*
|
|
* This is free software: you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation, either version 3 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* It is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with CommandStation. If not, see <https://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
|
|
/* Reader be aware:
|
|
This function implements the _hk data type so that a string keyword
|
|
is hashed to the same value as the DCCEXParser uses to hash incoming
|
|
keywords.
|
|
Thus "MAIN"_hk generates exactly the same run time vakue
|
|
as const int16_t HASH_KEYWORD_MAIN=11339
|
|
*/
|
|
#ifndef KeywordHasher_h
|
|
#define KeywordHasher_h
|
|
|
|
#include <Arduino.h>
|
|
constexpr uint16_t CompiletimeKeywordHasher(const char * sv, uint16_t running=0) {
|
|
return (*sv==0) ? running : CompiletimeKeywordHasher(sv+1,
|
|
(*sv >= '0' && *sv <= '9')
|
|
? (10*running+*sv-'0') // Numeric hash
|
|
: ((running << 5) + running) ^ *sv
|
|
); //
|
|
}
|
|
|
|
constexpr int16_t operator""_hk(const char * keyword, size_t len)
|
|
{
|
|
return (int16_t) CompiletimeKeywordHasher(keyword,len*0);
|
|
}
|
|
|
|
/* Some historical values for testing:
|
|
const int16_t HASH_KEYWORD_MAIN = 11339;
|
|
const int16_t HASH_KEYWORD_SLOW = -17209;
|
|
const int16_t HASH_KEYWORD_SPEED28 = -17064;
|
|
const int16_t HASH_KEYWORD_SPEED128 = 25816;
|
|
*/
|
|
|
|
static_assert("MAIN"_hk == 11339,"Keyword hasher error");
|
|
static_assert("SLOW"_hk == -17209,"Keyword hasher error");
|
|
static_assert("SPEED28"_hk == -17064,"Keyword hasher error");
|
|
static_assert("SPEED128"_hk == 25816,"Keyword hasher error");
|
|
|
|
// Compile time converter from "abcd"_s7 to the 7 segment nearest equivalent
|
|
|
|
constexpr uint8_t seg7Digits[]={
|
|
0b00111111,0b00000110,0b01011011,0b01001111, // 0..3
|
|
0b01100110,0b01101101,0b01111101,0b00000111, // 4..7
|
|
0b01111111,0b01101111 // 8..9
|
|
};
|
|
|
|
constexpr uint8_t seg7Letters[]={
|
|
0b01110111,0b01111100,0b00111001,0b01011110, // ABCD
|
|
0b01111001,0b01110001,0b00111101,0b01110110, // EFGH
|
|
0b00000100,0b00011110,0b01110010,0b00111000, //IJKL
|
|
0b01010101,0b01010100,0b01011100,0b01110011, // MNOP
|
|
0b10111111,0b01010000,0b01101101,0b01111000, // QRST
|
|
0b00111110,0b00011100,0b01101010,0b01001001, //UVWX
|
|
0b01100110,0b01011011 //YZ
|
|
};
|
|
constexpr uint8_t seg7Space=0b00000000;
|
|
constexpr uint8_t seg7Minus=0b01000000;
|
|
constexpr uint8_t seg7Equals=0b01001000;
|
|
|
|
|
|
constexpr uint32_t CompiletimeSeg7(const char * sv, uint32_t running, size_t rlen) {
|
|
return (*sv==0 || rlen==0) ? running << (8*rlen) : CompiletimeSeg7(sv+1,
|
|
(*sv >= '0' && *sv <= '9') ? (running<<8) | seg7Digits[*sv-'0'] :
|
|
(*sv >= 'A' && *sv <= 'Z') ? (running<<8) | seg7Letters[*sv-'A'] :
|
|
(*sv >= 'a' && *sv <= 'z') ? (running<<8) | seg7Letters[*sv-'a'] :
|
|
(*sv == '-') ? (running<<8) | seg7Minus :
|
|
(*sv == '=') ? (running<<8) | seg7Equals :
|
|
(running<<8) | seg7Space,
|
|
rlen-1
|
|
); //
|
|
}
|
|
|
|
constexpr uint32_t operator""_s7(const char * keyword, size_t len)
|
|
{
|
|
return CompiletimeSeg7(keyword,0*len,4);
|
|
}
|
|
#endif
|