42 lines
885 B
Go
42 lines
885 B
Go
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//go:build !noasm && !nounsafe && !gccgo && !appengine
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/**
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* Reed-Solomon Coding over 8-bit values.
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*
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* Copyright 2023, Klaus Post
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*/
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package reedsolomon
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import (
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"unsafe"
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)
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// AllocAligned allocates 'shards' slices, with 'each' bytes.
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// Each slice will start on a 64 byte aligned boundary.
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func AllocAligned(shards, each int) [][]byte {
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if false {
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res := make([][]byte, shards)
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for i := range res {
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res[i] = make([]byte, each)
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}
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return res
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}
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const (
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alignEach = 64
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alignStart = 64
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)
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eachAligned := ((each + alignEach - 1) / alignEach) * alignEach
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total := make([]byte, eachAligned*shards+63)
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align := uint(uintptr(unsafe.Pointer(&total[0]))) & (alignStart - 1)
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if align > 0 {
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total = total[alignStart-align:]
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}
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res := make([][]byte, shards)
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for i := range res {
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res[i] = total[:each:eachAligned]
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total = total[eachAligned:]
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}
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return res
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}
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