storj/satellite/nodeselection/state.go
Márton Elek 70cdca5d3c
satellite: move satellite/nodeselection/uploadselection => satellite/nodeselection
All the files in uploadselection are (in fact) related to generic node selection, and used not only for upload,
but for download, repair, etc...

Change-Id: Ie4098318a6f8f0bbf672d432761e87047d3762ab
2023-07-07 10:32:03 +02:00

134 lines
3.5 KiB
Go

// Copyright (C) 2020 Storj Labs, Inc.
// See LICENSE for copying information.
package nodeselection
import (
"context"
"sync"
"github.com/zeebo/errs"
"storj.io/common/storj"
)
// ErrNotEnoughNodes is when selecting nodes failed with the given parameters.
var ErrNotEnoughNodes = errs.Class("not enough nodes")
// State defines a node selector state that allows for selection.
type State struct {
mu sync.RWMutex
stats Stats
// netByID returns subnet based on storj.NodeID
netByID map[storj.NodeID]string
// distinct contains selectors for distinct selection.
distinct struct {
Reputable SelectBySubnet
New SelectBySubnet
}
}
// Stats contains state information.
type Stats struct {
New int
Reputable int
}
// Selector defines interface for selecting nodes.
type Selector interface {
// Count returns the number of maximum number of nodes that it can return.
Count() int
// Select selects up-to n nodes which are included by the criteria.
// empty criteria includes all the nodes
Select(n int, nodeFilter NodeFilter) []*SelectedNode
}
// NewState returns a state based on the input.
func NewState(reputableNodes, newNodes []*SelectedNode) *State {
state := &State{}
state.netByID = map[storj.NodeID]string{}
for _, node := range reputableNodes {
state.netByID[node.ID] = node.LastNet
}
for _, node := range newNodes {
state.netByID[node.ID] = node.LastNet
}
state.distinct.Reputable = SelectBySubnetFromNodes(reputableNodes)
state.distinct.New = SelectBySubnetFromNodes(newNodes)
state.stats = Stats{
New: state.distinct.New.Count(),
Reputable: state.distinct.Reputable.Count(),
}
return state
}
// Request contains arguments for State.Request.
type Request struct {
Count int
NewFraction float64
NodeFilters NodeFilters
}
// Select selects requestedCount nodes where there will be newFraction nodes.
func (state *State) Select(ctx context.Context, request Request) (_ []*SelectedNode, err error) {
defer mon.Task()(&ctx)(&err)
state.mu.RLock()
defer state.mu.RUnlock()
totalCount := request.Count
newCount := int(float64(totalCount) * request.NewFraction)
var selected []*SelectedNode
var reputableNodes Selector
var newNodes Selector
reputableNodes = state.distinct.Reputable
newNodes = state.distinct.New
// Get a random selection of new nodes out of the cache first so that if there aren't
// enough new nodes on the network, we can fall back to using reputable nodes instead.
selected = append(selected,
newNodes.Select(newCount, request.NodeFilters)...)
// Get all the remaining reputable nodes.
reputableCount := totalCount - len(selected)
selected = append(selected,
reputableNodes.Select(reputableCount, request.NodeFilters)...)
if len(selected) < totalCount {
return selected, ErrNotEnoughNodes.New("requested from cache %d, found %d", totalCount, len(selected))
}
return selected, nil
}
// Stats returns state information.
func (state *State) Stats() Stats {
state.mu.RLock()
defer state.mu.RUnlock()
return state.stats
}
// ExcludeNetworksBasedOnNodes will create a NodeFilter which exclude all nodes which shares subnet with the specified ones.
func (state *State) ExcludeNetworksBasedOnNodes(ds []storj.NodeID) NodeFilter {
uniqueExcludedNet := make(map[string]struct{}, len(ds))
for _, id := range ds {
net := state.netByID[id]
uniqueExcludedNet[net] = struct{}{}
}
excludedNet := make([]string, len(uniqueExcludedNet))
i := 0
for net := range uniqueExcludedNet {
excludedNet[i] = net
i++
}
return ExcludedNetworks(excludedNet)
}