forked from vikunja/vikunja
konrad
d28f005552
Fix limit for databases other than sqlite go mod tidy && go mod vendor Remove unneeded break statements Make everything work with the new xorm version Fix xorm logging Fix lint Fix redis init Fix using id field Fix database init for testing Change default database log level Add xorm logger Use const for postgres go mod tidy Merge branch 'master' into update/xorm # Conflicts: # go.mod # go.sum # vendor/modules.txt go mod vendor Fix loading fixtures for postgres Go mod vendor1 Update xorm to version 1 Co-authored-by: kolaente <k@knt.li> Reviewed-on: vikunja/api#323
82 lines
1.8 KiB
Go
82 lines
1.8 KiB
Go
/*
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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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