frostfs-sdk-go/netmap/context.go

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package netmap
import (
"errors"
"github.com/nspcc-dev/hrw"
"github.com/nspcc-dev/neofs-api-go/v2/netmap"
)
// context of a placement build process.
type context struct {
// network map to operate on
netMap NetMap
// cache of processed filters
processedFilters map[string]*netmap.Filter
// cache of processed selectors
processedSelectors map[string]*netmap.Selector
// stores results of selector processing
selections map[string][]nodes
// cache of parsed numeric values
numCache map[string]uint64
hrwSeed []byte
// hrw.Hash of hrwSeed
hrwSeedHash uint64
// weightFunc is a weighting function for determining node priority
// which combines low price and high performance
weightFunc weightFunc
// container backup factor
cbf uint32
}
// Various validation errors.
var (
errInvalidFilterName = errors.New("filter name is invalid")
errInvalidNumber = errors.New("invalid number")
errInvalidFilterOp = errors.New("invalid filter operation")
errFilterNotFound = errors.New("filter not found")
errNonEmptyFilters = errors.New("simple filter contains sub-filters")
errNotEnoughNodes = errors.New("not enough nodes to SELECT from")
errUnnamedTopFilter = errors.New("unnamed top-level filter")
)
// newContext returns initialized context.
func newContext(nm NetMap) *context {
return &context{
netMap: nm,
processedFilters: make(map[string]*netmap.Filter),
processedSelectors: make(map[string]*netmap.Selector),
selections: make(map[string][]nodes),
numCache: make(map[string]uint64),
weightFunc: defaultWeightFunc(nm.nodes),
}
}
func (c *context) setPivot(pivot []byte) {
if len(pivot) != 0 {
c.hrwSeed = pivot
c.hrwSeedHash = hrw.Hash(pivot)
}
}
func (c *context) setCBF(cbf uint32) {
if cbf == 0 {
c.cbf = 3
} else {
c.cbf = cbf
}
}
func defaultWeightFunc(ns nodes) weightFunc {
mean := newMeanAgg()
min := newMinAgg()
for i := range ns {
mean.Add(float64(ns[i].capacity()))
min.Add(float64(ns[i].Price()))
}
return newWeightFunc(
newSigmoidNorm(mean.Compute()),
newReverseMinNorm(min.Compute()))
}