featurebase/test/cluster.go

55 lines
1.5 KiB
Go

// Copyright 2017 Pilosa Corp.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package test
import (
"fmt"
"github.com/pilosa/pilosa"
)
// NewCluster returns a cluster with n nodes and uses a mod-based hasher.
func NewCluster(n int) *pilosa.Cluster {
c := pilosa.NewCluster()
c.ReplicaN = 1
c.Hasher = NewModHasher()
for i := 0; i < n; i++ {
c.Nodes = append(c.Nodes, &pilosa.Node{
Scheme: "http",
Host: fmt.Sprintf("host%d", i),
})
}
return c
}
// ModHasher represents a simple, mod-based hashing.
type ModHasher struct{}
// NewModHasher returns a new instance of ModHasher with n buckets.
func NewModHasher() *ModHasher { return &ModHasher{} }
func (*ModHasher) Hash(key uint64, n int) int { return int(key) % n }
// ConstHasher represents hash that always returns the same index.
type ConstHasher struct {
i int
}
// NewConstHasher returns a new instance of ConstHasher that always returns i.
func NewConstHasher(i int) *ConstHasher { return &ConstHasher{i: i} }
func (h *ConstHasher) Hash(key uint64, n int) int { return h.i }