cache

erqi-cache

Overview

An cache reconstructed and optimized based on go-cache. It uses sharding and atomic operations to reduce the scope of lock usage and improve concurrency. At the same time, it expands the original cleanupJanitor cleaning conditions (Maxbytes) and cleaning methods (LRU), adds an automatically saved janitor, and supports dynamic mounting of janitors. In addition, the OnExited method is added to ensure cache data security.

Installation

go get github.com/ErQi22577/erqi-cache

Usage

Create Cache with Config

package main

import (
	"fmt"
	"github.com/ErQi22577/erqi-cache"
	"time"
)

func main() {
	c := cache.New(chache.Config{
		DefaultExpiration: 0, // Never expire.
		CleanupInterval:   0, // Disable cleanupJanitor.
		SavingInterval:    0, // Disable cleanupJanitor.
		ShardCount:        0, // Number of shard maps(0 mean that default 32). 
		MaxBytes:          0, // Max use memory(0 mean that default 16G).
	})
	
	err := c.Add("key", "value", 0) // false Disable overwrite.
	if err != nil {
		fmt.Println(err)
    }
	val, found := c.Get("key1")
	if !found {
		fmt.Println("Not Found.")
    }
}

Create Cache with Items and Use Janitor

package main

import (
	"fmt"
	"github.com/ErQi22577/erqi-cache"
	"time"
)

func main() {
	// First, items must exist.
	C := cache.New(chache.Config{})
	_ = C.Add("key", "value", 0)
	items := C.Items()

	// Set the cleanup interval and save interval, 
	// and you will get the corresponding janitor.
	c := cache.NewFrom(chache.Config{
		CleanupInterval: time.Duration(14400) * time.Minute,
		SavingInterval:  time.Duration(14400) * time.Minute,
	}, items)

	// Of course, you can also choose to mount the corresponding janitor at any time.
	C.CleanupJanitor = &cache.Janitor{
		Interval: time.Duration(14400) * time.Minute,
		StopChan: make(chan bool),
		Type: cache.Cleanup,
	}
	C.RunJanitor(cache.Cleanup)
	C.StopJanitor(cache.Cleanup)
}

For more usage, see cache_test.

Methods

Add

Add(k string, x any, d time.Duration) error

k key, x value, d defaultExpiration(0:Never expire.).

Set

Add(k string, x any, d time.Duration) error

k key, x value, d defaultExpiration(0:Never expire.). If the key exists, it will be overwritten.

Delete

Delete(k string)

really remove item.

UnsafeDelete

UnsafeDelete(k string)

Only modifies item.IsDeleted to make it invisible.

Update

Update(k string, x any) error

Alter item.V if item can be found.

UpdateExpiration

UpdateExpiration(k string, d time.Duration) error

Alter item.ExpirationTime if item can be found.

Get

Get(k string) (any, bool)

Return item.V, isFound. If item has expired or isDeleted is true, will not be found.

UnsafeGet

UnsafeGet(k string) (any, bool)

Return item.V, isExist. It will also return data that has expired and isDeleted is true.

GetWithExpiration

GetWithExpiration(k string) (any, time.Time, bool)

Return item.V, item.ExpirationTime, isFound.

GetCreateTime

GetCreateTime(k string) (time.Time, bool)

Return item.CreateTime, isFound.

GetUpdateTime

GetUpdateTime(k string) (time.Time, bool)

Return item.UpdateTime, isFound.

Increment

Increment(k string, n int64) error

For int, item.V + n.

IncrementFloat

IncrementFloat(k string, n float64) error

For float, item.V + n.

Decrement

Decrement(k string, n int64) error

For int, item.V - n.

DecrementFloat

DecrementFloat(k string, n float64) error

For float, item.V - n.

ItemCount

ItemCount() (count int)

Return count(item).

RunJanitor

RunJanitor(jt janitorType)

If you set CleanupInterval or SavingInterval, you do not need to call it explicitly. Of course, you can use this method to start a custom Janitor after mounting the Cache instance. Note that jt is a janitorType and needs to reference the Janitor constant(Cleanup or Saving).

StopJanitor

StopJanitor(jt janitorType)

If you set CleanupInterval or SavingInterval, you do not need to call it explicitly. Of course, you can use this method to stop a custom Janitor after mounting the Cache instance. Note that jt is a janitorType and needs to reference the Janitor constant(Cleanup or Saving).

OnExited

OnExited(f func(), isSave bool)

Supports configuring the actions you want to do when the program exits or crashes. And also supports choosing whether to export the data in the cache after your actions.

OnEvicted

OnEvicted(f func(key string, value any))

Supports configuring the actions you want to do after Delete || UnsafeDelete || c.clean().

CacheSize

CacheSize() int

Return cache memory size.

GetShardMap

GetShardMap(key string) *SharedMap

Return key's SharedMap. It is not recommended to directly operate SharedMap.

Items

Items() map[string]Item

Exports all data in the cache for data persistence or data migration.

ItemsInit

ItemsInit(items map[string]Item)

Writes the data exported by the c.Items() into the cache.

Flush

Flush()

Clear all data in the cache.

NewFrom

NewFrom(config Config, items map[string]Item) *Cache

Encapsulates the New and c.ItemInit(). You can also use them separately. Note that the items parameter needs to be generated in advance using the c.Items(). It is not recommended to pass custom items directly, as this may cause unknown errors.

New

New(config Config) *Cache

Create Cache with Config

Author

-ErQi-Full Stack Developer-ErQi22577

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