Replace godep with dep

This commit is contained in:
Manuel de Brito Fontes 2017-10-06 17:26:14 -03:00
parent 1e7489927c
commit bf5616c65b
14883 changed files with 3937406 additions and 361781 deletions

View file

@ -0,0 +1,81 @@
/*
Copyright 2013 Google Inc.
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 consistenthash provides an implementation of a ring hash.
package consistenthash
import (
"hash/crc32"
"sort"
"strconv"
)
type Hash func(data []byte) uint32
type Map struct {
hash Hash
replicas int
keys []int // Sorted
hashMap map[int]string
}
func New(replicas int, fn Hash) *Map {
m := &Map{
replicas: replicas,
hash: fn,
hashMap: make(map[int]string),
}
if m.hash == nil {
m.hash = crc32.ChecksumIEEE
}
return m
}
// Returns true if there are no items available.
func (m *Map) IsEmpty() bool {
return len(m.keys) == 0
}
// Adds some keys to the hash.
func (m *Map) Add(keys ...string) {
for _, key := range keys {
for i := 0; i < m.replicas; i++ {
hash := int(m.hash([]byte(strconv.Itoa(i) + key)))
m.keys = append(m.keys, hash)
m.hashMap[hash] = key
}
}
sort.Ints(m.keys)
}
// Gets the closest item in the hash to the provided key.
func (m *Map) Get(key string) string {
if m.IsEmpty() {
return ""
}
hash := int(m.hash([]byte(key)))
// Binary search for appropriate replica.
idx := sort.Search(len(m.keys), func(i int) bool { return m.keys[i] >= hash })
// Means we have cycled back to the first replica.
if idx == len(m.keys) {
idx = 0
}
return m.hashMap[m.keys[idx]]
}