changed to a more reasonable datatype

This commit is contained in:
overflowerror 2019-01-21 15:36:28 +01:00
parent 1d7088128e
commit 8e0c5af695

56
main.c
View file

@ -21,8 +21,8 @@ bool verbose = false;
#define verbose(...) if (verbose) printf(__VA_ARGS__);
#define error(...) fprintf(stderr, __VA_ARGS__)
int convertToString(char* string, unsigned long long number) {
unsigned charsetLength = strlen(charset);
int convertToString(char* string, uint64_t number) {
int charsetLength = strlen(charset);
int length = 0;
do {
@ -45,8 +45,8 @@ int convertToString(char* string, unsigned long long number) {
return length;
}
unsigned long long convertFromString(const char* string) {
unsigned long long result = 0;
uint64_t convertFromString(const char* string) {
uint64_t result = 0;
int stringLength = strlen(string);
int charsetLength = strlen(charset);
@ -58,14 +58,14 @@ unsigned long long convertFromString(const char* string) {
error("Parsing error.\nUnexpected character '%c'.\n", string[i]);
exit(3);
}
unsigned long long val = ((unsigned long long) pow(charsetLength, stringLength - i - 1));
result += ((unsigned long long) tmp) * val;
uint64_t val = ((uint64_t) pow(charsetLength, stringLength - i - 1));
result += ((uint64_t) tmp) * val;
}
return result;
}
unsigned long long primelist[] = {
uint64_t primelist[] = {
1, 1, 1, 3, 7, 13, 29, 61, 113, 251, 509, 1021, 2039, 4093, 8179, 16381,
32749, 65521, 131063, 262139, 524269, 1048573, 2097143, 4194301,
8388593, 16777213, 33554393, 67108859, 134217689, 268435399,
@ -81,9 +81,9 @@ unsigned long long primelist[] = {
1152921504606846883ll, 2305843009213693921ll // 61
};
int findMax(unsigned long long theoreticalMax) {
int findMax(uint64_t theoreticalMax) {
int result = 0;
unsigned long long tmp = 0;
uint64_t tmp = 0;
while(true) {
if (tmp >= theoreticalMax)
break;
@ -92,7 +92,7 @@ int findMax(unsigned long long theoreticalMax) {
return result - 1;
}
unsigned long long findPrime(int maxBit) {
uint64_t findPrime(int maxBit) {
int primelistLength = (sizeof primelist) / (sizeof (long long));
if (maxBit >= primelistLength)
return primelist[primelistLength - 1];
@ -100,17 +100,17 @@ unsigned long long findPrime(int maxBit) {
return primelist[maxBit - 1];
}
unsigned long long encode(unsigned long long value, unsigned long long prime, unsigned long long maxValue) {
uint64_t encode(uint64_t value, uint64_t prime, uint64_t maxValue) {
uint128_t result = value;
result *= prime;
result &= (maxValue);
return (unsigned long long) result;
return (uint64_t) result;
}
unsigned long long multiplicativeInverse(unsigned long long prime, unsigned long long maxValue) {
uint64_t multiplicativeInverse(uint64_t prime, uint64_t maxValue) {
/*
* I didn't write this.
* I got this from https://rosettacode.org/wiki/Modular_inverse#C
@ -137,7 +137,7 @@ unsigned long long multiplicativeInverse(unsigned long long prime, unsigned long
return x1;
}
unsigned long long decode(unsigned long long value, unsigned long long prime, unsigned long long maxValue) {
uint64_t decode(uint64_t value, uint64_t prime, uint64_t maxValue) {
/*
* (x * p) mod m = v
* (x * p) == v (mod m)
@ -148,32 +148,32 @@ unsigned long long decode(unsigned long long value, unsigned long long prime, un
uint128_t tmp = value;
unsigned long long inverse = multiplicativeInverse(prime, maxValue);
uint64_t inverse = multiplicativeInverse(prime, maxValue);
//verbose("inverse: %llu\n", inverse);
tmp *= inverse;
tmp &= (maxValue);
return (unsigned long long) tmp;
return (uint64_t) tmp;
}
typedef struct settings {
unsigned long long max;
unsigned long long prime;
uint64_t max;
uint64_t prime;
} settings_t;
settings_t getSettings() {
verbose("charset length: %d\n", strlen(charset));
double maxValueDouble = pow(strlen(charset), resultLength);
unsigned long long maxValue;
uint64_t maxValue;
int maxBits;
if (maxValueDouble >= pow(2, 65)) {
verbose("Max value %.0lf > 2^64, caping to 64 bits.\n", maxValueDouble);
maxBits = 64;
} else {
maxValue = (unsigned long long) maxValueDouble;
maxValue = (uint64_t) maxValueDouble;
verbose("theoer max: %llu\n", maxValue);
maxBits = findMax(maxValue);
@ -200,14 +200,14 @@ settings_t getSettings() {
verbose("max: %llu\n", maxValue);
verbose("usage: %.1f%\n", (100.0 * maxValue / maxValueDouble));
unsigned long long prime = findPrime(maxBits);
uint64_t prime = findPrime(maxBits);
verbose("prime: %llu\n", prime);
return (settings_t) {.max = maxValue, .prime = prime};
}
void toString(char* string, unsigned long long value, settings_t settings) {
void toString(char* string, uint64_t value, settings_t settings) {
#ifdef BENCHMARK
struct timespec before, after;
clock_gettime(CLOCK_MONOTONIC, &before);
@ -220,25 +220,25 @@ void toString(char* string, unsigned long long value, settings_t settings) {
#ifdef BENCHMARK
clock_gettime(CLOCK_MONOTONIC, &after);
unsigned long long diff = (int64_t)(after.tv_sec - before.tv_sec) * (int64_t) 1000000000UL + (int64_t)(after.tv_nsec - before.tv_nsec);
uint64_t diff = (int64_t)(after.tv_sec - before.tv_sec) * (int64_t) 1000000000UL + (int64_t)(after.tv_nsec - before.tv_nsec);
fprintf(stderr, "Time for conversion: %llu ns\n", diff);
#endif
}
unsigned long long fromString(const char* string, settings_t settings) {
uint64_t fromString(const char* string, settings_t settings) {
#ifdef BENCHMARK
struct timespec before, after;
clock_gettime(CLOCK_MONOTONIC, &before);
#endif
unsigned long long result = convertFromString(string);
uint64_t result = convertFromString(string);
verbose("encoded: %llu\n", result);
result = decode(result, settings.prime, settings.max);
#ifdef BENCHMARK
clock_gettime(CLOCK_MONOTONIC, &after);
unsigned long long diff = (int64_t)(after.tv_sec - before.tv_sec) * (int64_t) 1000000000UL + (int64_t)(after.tv_nsec - before.tv_nsec);
uint64_t diff = (int64_t)(after.tv_sec - before.tv_sec) * (int64_t) 1000000000UL + (int64_t)(after.tv_nsec - before.tv_nsec);
fprintf(stderr, "Time for conversion: %llu ns\n", diff);
#endif
@ -388,11 +388,11 @@ int main(int argc, char** argv) {
verbose("decode mode\n");
const char* string = argv[optind];
verbose("string: %s\n", string);
unsigned long long value = fromString(string, settings);
uint64_t value = fromString(string, settings);
value -= offset;
printf("%llu\n", value);
} else {
unsigned long long value = strtoull(argv[optind], &endptr, 10);
uint64_t value = strtoull(argv[optind], &endptr, 10);
if (*endptr != 0) {
error("Value has to be a number for encoding.\n");
exit(2);