7f8e3192cd
* Allow common redis and leveldb connections Prevents multiple reopening of redis and leveldb connections to the same place by sharing connections. Further allows for more configurable redis connection type using the redisURI and a leveldbURI scheme. Signed-off-by: Andrew Thornton <art27@cantab.net> * add unit-test Signed-off-by: Andrew Thornton <art27@cantab.net> * as per @lunny Signed-off-by: Andrew Thornton <art27@cantab.net> * add test Signed-off-by: Andrew Thornton <art27@cantab.net> * Update modules/cache/cache_redis.go * Update modules/queue/queue_disk.go * Update modules/cache/cache_redis.go * Update modules/cache/cache_redis.go * Update modules/queue/unique_queue_disk.go * Update modules/queue/queue_disk.go * Update modules/queue/unique_queue_disk.go * Update modules/session/redis.go Co-authored-by: techknowlogick <techknowlogick@gitea.io> Co-authored-by: Lauris BH <lauris@nix.lv>
82 lines
1.8 KiB
Go
Vendored
82 lines
1.8 KiB
Go
Vendored
/*
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Copyright 2013 Google Inc.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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// Package consistenthash provides an implementation of a ring hash.
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package consistenthash
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import (
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"hash/crc32"
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"sort"
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"strconv"
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)
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type Hash func(data []byte) uint32
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type Map struct {
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hash Hash
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replicas int
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keys []int // Sorted
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hashMap map[int]string
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}
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func New(replicas int, fn Hash) *Map {
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m := &Map{
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replicas: replicas,
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hash: fn,
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hashMap: make(map[int]string),
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}
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if m.hash == nil {
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m.hash = crc32.ChecksumIEEE
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}
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return m
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}
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// Returns true if there are no items available.
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func (m *Map) IsEmpty() bool {
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return len(m.keys) == 0
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}
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// Adds some keys to the hash.
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func (m *Map) Add(keys ...string) {
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for _, key := range keys {
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for i := 0; i < m.replicas; i++ {
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hash := int(m.hash([]byte(strconv.Itoa(i) + key)))
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m.keys = append(m.keys, hash)
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m.hashMap[hash] = key
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}
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}
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sort.Ints(m.keys)
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}
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// Gets the closest item in the hash to the provided key.
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func (m *Map) Get(key string) string {
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if m.IsEmpty() {
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return ""
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}
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hash := int(m.hash([]byte(key)))
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// Binary search for appropriate replica.
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idx := sort.Search(len(m.keys), func(i int) bool { return m.keys[i] >= hash })
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// Means we have cycled back to the first replica.
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if idx == len(m.keys) {
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idx = 0
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}
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return m.hashMap[m.keys[idx]]
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}
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