37 lines
965 B
C
37 lines
965 B
C
#include "utility/sequencenumber.h"
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#define SN_MASK 0xffffff
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/**
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* Mask a given sequence number to get rid of MSB.
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*/
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#define GET_MASKED_SN(x) (x & SN_MASK)
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bool sn_equal(record_sequence_number_t a, record_sequence_number_t b) {
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return GET_MASKED_SN(a) == GET_MASKED_SN(b);
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}
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record_sequence_number_t sn_increment(record_sequence_number_t sn) {
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return GET_MASKED_SN(++sn);
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}
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record_sequence_number_t sn_decrement(record_sequence_number_t sn) {
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if (sn > 0) {
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return GET_MASKED_SN((sn-1));
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} else {
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return SN_MASK;
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}
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}
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record_sequence_number_t sn_increment_by(record_sequence_number_t sn, uint32_t amount) {
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return GET_MASKED_SN((sn + amount));
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}
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record_sequence_number_t sn_get_middle_sn(record_sequence_number_t older, record_sequence_number_t newer) {
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if (older <= newer) {
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return GET_MASKED_SN(((older + newer) / 2));
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} else {
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return GET_MASKED_SN(((older + newer + SN_MASK) / 2));
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}
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}
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