80 lines
1.4 KiB
C
80 lines
1.4 KiB
C
#include <assert.h>
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#include "ringbuffer.h"
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static unsigned int
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normalize (unsigned int a, unsigned int size)
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{
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return a % size;
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}
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static unsigned int
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distance (unsigned int a, unsigned int b, unsigned int size)
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{
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if (a <= b) {
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return (b - a) % size;
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} else {
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return size - (a - b) % size;
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}
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}
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static unsigned int
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increment (unsigned int a, unsigned int delta, unsigned int size)
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{
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return (a + delta) % size;
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}
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static unsigned int
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decrement (unsigned int a, unsigned int delta, unsigned int size)
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{
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if (delta <= a) {
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return (a - delta) % size;
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} else {
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return size - (delta - a) % size;
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}
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}
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unsigned int
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ringbuffer_normalize (unsigned int a, unsigned int begin, unsigned int end)
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{
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assert (end >= begin);
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assert (a >= begin);
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return normalize (a, end - begin);
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}
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unsigned int
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ringbuffer_distance (unsigned int a, unsigned int b, unsigned int begin, unsigned int end)
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{
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assert (end >= begin);
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assert (a >= begin);
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return distance (a, b, end - begin);
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}
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unsigned int
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ringbuffer_increment (unsigned int a, unsigned int delta, unsigned int begin, unsigned int end)
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{
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assert (end >= begin);
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assert (a >= begin);
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return increment (a - begin, delta, end - begin) + begin;
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}
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unsigned int
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ringbuffer_decrement (unsigned int a, unsigned int delta, unsigned int begin, unsigned int end)
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{
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assert (end >= begin);
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assert (a >= begin);
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return decrement (a - begin, delta, end - begin) + begin;
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}
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