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38 lines
728 B
C++
38 lines
728 B
C++
#ifndef __SEQUENCE_COUNTER_H__
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#define __SEQUENCE_COUNTER_H__
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#include <stdint.h>
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#define INT16_MAX 0x7fff
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#define INT16_MIN (-INT16_MAX - 1)
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const int64_t ShortRange = ((int64_t)1) << 16;
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class SequenceCounter {
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private:
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uint16_t prevShortId;
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int64_t prevLongId;
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// int64_t currentLongId;
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public:
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SequenceCounter() : prevShortId(0), prevLongId(0) {}
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int64_t convertNext(uint16_t nextShortId) {
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int64_t delta = (int64_t)nextShortId - (int64_t)prevShortId;
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if (delta > INT16_MAX) delta -= ShortRange;
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if (delta < INT16_MIN) delta += ShortRange;
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int64_t nextLongId = prevLongId + delta;
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prevShortId = nextShortId;
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prevLongId = nextLongId;
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return nextLongId;
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}
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};
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#endif |