mirror of https://github.com/k3s-io/k3s
36 lines
1.1 KiB
Go
36 lines
1.1 KiB
Go
package mesos
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// fixed point scalar math from mesos:src/common/values.cpp
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// --
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// We manipulate scalar values by converting them from floating point to a
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// fixed point representation, doing a calculation, and then converting
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// the result back to floating point. We deliberately only preserve three
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// decimal digits of precision in the fixed point representation. This
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// ensures that client applications see predictable numerical behavior, at
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// the expense of sacrificing some precision.
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import "math"
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func convertToFloat64(f int64) float64 {
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// NOTE: We do the conversion from fixed point via integer division
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// and then modulus, rather than a single floating point division.
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// This ensures that we only apply floating point division to inputs
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// in the range [0,999], which is easier to check for correctness.
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var (
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quotient = float64(f / 1000)
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remainder = float64(f%1000) / 1000.0
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)
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return quotient + remainder
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}
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func convertToFixed64(f float64) int64 {
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return round64(f * 1000)
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}
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func round64(f float64) int64 {
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if math.Abs(f) < 0.5 {
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return 0
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}
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return int64(f + math.Copysign(0.5, f))
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}
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