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package reedsolomon
import (
"runtime"
"github.com/klauspost/cpuid"
)
// Option allows to override processing parameters.
type Option func(*options)
type options struct {
maxGoroutines int
minSplitSize int
useAVX2, useSSSE3, useSSE2 bool
usePAR1Matrix bool
useCauchy bool
}
var defaultOptions = options{
maxGoroutines: 384,
minSplitSize: 512,
}
func init() {
if runtime.GOMAXPROCS(0) <= 1 {
defaultOptions.maxGoroutines = 1
}
// Detect CPU capabilities.
defaultOptions.useSSSE3 = cpuid.CPU.SSSE3()
defaultOptions.useAVX2 = cpuid.CPU.AVX2()
defaultOptions.useSSE2 = cpuid.CPU.SSE2()
}
// WithMaxGoroutines is the maximum number of goroutines number for encoding & decoding.
// Jobs will be split into this many parts, unless each goroutine would have to process
// less than minSplitSize bytes (set with WithMinSplitSize).
// For the best speed, keep this well above the GOMAXPROCS number for more fine grained
// scheduling.
// If n <= 0, it is ignored.
func WithMaxGoroutines(n int) Option {
return func(o *options) {
if n > 0 {
o.maxGoroutines = n
}
}
}
// WithMinSplitSize is the minimum encoding size in bytes per goroutine.
// See WithMaxGoroutines on how jobs are split.
// If n <= 0, it is ignored.
func WithMinSplitSize(n int) Option {
return func(o *options) {
if n > 0 {
o.minSplitSize = n
}
}
}
func withSSE3(enabled bool) Option {
return func(o *options) {
o.useSSSE3 = enabled
}
}
func withAVX2(enabled bool) Option {
return func(o *options) {
o.useAVX2 = enabled
}
}
func withSSE2(enabled bool) Option {
return func(o *options) {
o.useSSE2 = enabled
}
}
// WithPAR1Matrix causes the encoder to build the matrix how PARv1
// does. Note that the method they use is buggy, and may lead to cases
// where recovery is impossible, even if there are enough parity
// shards.
func WithPAR1Matrix() Option {
return func(o *options) {
o.usePAR1Matrix = true
o.useCauchy = false
}
}
// WithCauchyMatrix will make the encoder build a Cauchy style matrix.
// The output of this is not compatible with the standard output.
// A Cauchy matrix is faster to generate. This does not affect data throughput,
// but will result in slightly faster start-up time.
func WithCauchyMatrix() Option {
return func(o *options) {
o.useCauchy = true
o.usePAR1Matrix = false
}
}
|
