com.github.jchanghong.cache.CacheHelp.kt Maven / Gradle / Ivy

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package com.github.jchanghong.cache

import cn.hutool.cron.CronUtil
import com.github.jchanghong.log.kDebug
import java.util.concurrent.ConcurrentHashMap
import java.util.function.Supplier

/** 后台定时更新cache，如果提供了 supplier,只能用get put方法*/
class CronMap(val cron: String) : ConcurrentHashMap() {
    //    调度id map
    private val schedulerIdMap = ConcurrentHashMap()
    private val supplierMap = ConcurrentHashMap>()

    //    put 为false，不调度，一旦调用过get。就调度
    private val lateinitMap = ConcurrentHashMap()

    init {
        try {
            CronUtil.setMatchSecond(true)
            CronUtil.start()
        } catch (e: Throwable) {
        }
    }

    @Synchronized
    @JvmOverloads
    fun get2(key: K, supplier: Supplier? = null, cron: String? = null): V? {
        if (supplier != null) {
            supplierMap[key] = supplier
            lateinitMap[key] = true
            return getAndSchudulValue(supplier, key, cron)
        }
        return super.get(key)
    }

    private fun getAndSchudulValue(supplier: Supplier, key: K, cron: String? = null): V? {
        schedulerIdMap[key]?.let { CronUtil.remove(it) }
        val scheduleId = CronUtil.schedule(cron ?: this.cron, Runnable {
            if (lateinitMap[key] == true) {
                val value = supplier.get()
                this[key] = value
                kDebug("调度 已更新key  $key -> $value")
            }
        })
        schedulerIdMap[key] = scheduleId
        if (lateinitMap[key] == true) {
            val value = supplier.get()
            put(key, value)
            return value
        }
        return null
    }

    @Synchronized
    @JvmOverloads
    fun put2(key: K, supplier: Supplier, cron: String? = null): V? {
        supplierMap[key] = supplier
        if (!lateinitMap.containsKey(key)) {
            lateinitMap[key] = false
        }
        getAndSchudulValue(supplier, key, cron)
        return null
    }

    @Synchronized
    override fun get(key: K): V? {
        lateinitMap[key] = true
        val v = super.get(key)
        if (v == null && supplierMap.containsKey(key)) {
            val get = supplierMap[key]?.get()?.apply { put(key, this) }
            return get
        }
        return v
    }
}

object CacheHelp {
    /**
     * CronMap
     */
    fun  newCronMap(cron: String): CronMap {
        return CronMap(cron)
    }
}

fun main() {
    val cache = CacheHelp.newCronMap("1/5 * * * * ?")
    cache.put2("test", Supplier { "sasa" })
    println(cache.get("test"))
    println(cache.get("test"))
    Thread.sleep(2000)
    println(cache.get("test"))
    println(cache.get("test"))
}