char* FastInt64ToBufferLeft(int64_t i, char* buffer) {
uint64_t u = i;
if (i < 0) {
*buffer++ = '-';
u = -i;
}
return FastUInt64ToBufferLeft(u, buffer);
}
char* FastUInt64ToBufferLeft(uint64_t u64, char* buffer) {
int digits;
const char *ASCII_digits = NULL;
uint32_t u = static_cast<uint32_t>(u64);
if (u == u64) return FastUInt32ToBufferLeft(u, buffer);
uint64_t top_11_digits = u64 / 1000000000;
buffer = FastUInt64ToBufferLeft(top_11_digits, buffer);
u = u64 - (top_11_digits * 1000000000);
digits = u / 10000000; // 10,000,000
GOOGLE_DCHECK_LT(digits, 100);
ASCII_digits = two_ASCII_digits[digits];
buffer[0] = ASCII_digits[0];
buffer[1] = ASCII_digits[1];
buffer += 2;
u -= digits * 10000000; // 10,000,000
digits = u / 100000; // 100,000
ASCII_digits = two_ASCII_digits[digits];
buffer[0] = ASCII_digits[0];
buffer[1] = ASCII_digits[1];
buffer += 2;
u -= digits * 100000; // 100,000
digits = u / 1000; // 1,000
ASCII_digits = two_ASCII_digits[digits];
buffer[0] = ASCII_digits[0];
buffer[1] = ASCII_digits[1];
buffer += 2;
u -= digits * 1000; // 1,000
digits = u / 10;
ASCII_digits = two_ASCII_digits[digits];
buffer[0] = ASCII_digits[0];
buffer[1] = ASCII_digits[1];
buffer += 2;
u -= digits * 10;
digits = u;
*buffer++ = '0' + digits;
*buffer = 0;
return buffer;
}
string SimpleItoa(unsigned long long i) { // NOLINT(runtime/int)
char buffer[kFastToBufferSize];
return string(buffer, (sizeof(i) == 4) ?
FastUInt32ToBufferLeft(i, buffer) :
FastUInt64ToBufferLeft(i, buffer));
}
string SimpleItoa(unsigned int i) {
char buffer[kFastToBufferSize];
return string(buffer, (sizeof(i) == 4) ?
FastUInt32ToBufferLeft(i, buffer) :
FastUInt64ToBufferLeft(i, buffer));
}
inline char* FastUInt64ToBuffer(uint64 i, char* buffer) {
FastUInt64ToBufferLeft(i, buffer);
return buffer;
}