frostfs-node/pkg/policy/encode.go
Alex Vanin 643e81254c [#25] Add placement policy QL encoder
Signed-off-by: Alex Vanin <alexey@nspcc.ru>
2020-10-17 13:16:59 +03:00

163 lines
3.4 KiB
Go

package policy
import (
"fmt"
"strconv"
"strings"
"github.com/nspcc-dev/neofs-api-go/v2/netmap"
)
func Encode(p *netmap.PlacementPolicy) []string {
if p == nil {
return nil
}
var (
replicas = p.GetReplicas()
selectors = p.GetSelectors()
filters = p.GetFilters()
)
// 1 for container backup factor
result := make([]string, 0, len(replicas)+len(selectors)+len(filters)+1)
// first print replicas
encodeReplicas(replicas, &result)
// then backup factor
if backupFactor := p.GetContainerBackupFactor(); backupFactor != 0 {
result = append(result, fmt.Sprintf("CBF %d", backupFactor))
}
// then selectors
encodeSelectors(selectors, &result)
// then filters
encodeFilters(filters, &result)
return result
}
func encodeReplicas(replicas []*netmap.Replica, dst *[]string) {
builder := new(strings.Builder)
for _, replica := range replicas {
builder.WriteString("REP ")
builder.WriteString(strconv.FormatUint(uint64(replica.GetCount()), 10))
if s := replica.GetSelector(); s != "" {
builder.WriteString(" IN ")
builder.WriteString(s)
}
*dst = append(*dst, builder.String())
builder.Reset()
}
}
func encodeSelectors(selectors []*netmap.Selector, dst *[]string) {
builder := new(strings.Builder)
for _, selector := range selectors {
builder.WriteString("SELECT ")
builder.WriteString(strconv.FormatUint(uint64(selector.GetCount()), 10))
if a := selector.GetAttribute(); a != "" {
builder.WriteString(" IN")
switch selector.GetClause() {
case netmap.Same:
builder.WriteString(" SAME ")
case netmap.Distinct:
builder.WriteString(" DISTINCT ")
default:
builder.WriteString(" ")
}
builder.WriteString(a)
}
if f := selector.GetFilter(); f != "" {
builder.WriteString(" FROM ")
builder.WriteString(f)
}
if n := selector.GetName(); n != "" {
builder.WriteString(" AS ")
builder.WriteString(n)
}
*dst = append(*dst, builder.String())
builder.Reset()
}
}
func encodeFilters(filters []*netmap.Filter, dst *[]string) {
builder := new(strings.Builder)
for _, filter := range filters {
builder.WriteString("FILTER ")
builder.WriteString(encodeFilter(filter))
*dst = append(*dst, builder.String())
builder.Reset()
}
}
func operationString(operation netmap.Operation) string {
switch operation {
case netmap.EQ:
return "EQ"
case netmap.NE:
return "NE"
case netmap.GT:
return "GT"
case netmap.GE:
return "GE"
case netmap.LT:
return "LT"
case netmap.LE:
return "LE"
case netmap.OR:
return "OR"
case netmap.AND:
return "AND"
default:
return ""
}
}
func encodeFilter(filter *netmap.Filter) string {
builder := new(strings.Builder)
unspecified := filter.GetOp() == netmap.UnspecifiedOperation
if k := filter.GetKey(); k != "" {
builder.WriteString(k)
builder.WriteString(" ")
builder.WriteString(operationString(filter.GetOp()))
builder.WriteString(" ")
builder.WriteString(filter.GetValue())
} else if n := filter.GetName(); unspecified && n != "" {
builder.WriteString("@")
builder.WriteString(n)
}
for i, subfilter := range filter.GetFilters() {
if i != 0 {
builder.WriteString(" ")
builder.WriteString(operationString(filter.GetOp()))
builder.WriteString(" ")
}
builder.WriteString(encodeFilter(subfilter))
}
if n := filter.GetName(); n != "" && !unspecified {
builder.WriteString(" AS ")
builder.WriteString(n)
}
return builder.String()
}