irc_web/.svn/pristine/b4/b459405b6453f15b53193ef8d11...

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import * as cornerstone from 'cornerstone-core'
const taskPool = [] // 请求池
let numRequest = 0 // 正在执行数量
const maxRequest = 2 // 可配置
let taskTimer // 轮询的定时器
const cachedTask = {} // 存放的任务数据
// 预加载池的添加
function addTaskIntoPool(task) {
return new Promise((resolve, reject) => {
taskPool.forEach(task=>{
task.priority = task.priority
})
const cache = cachedTask[task.key]
const callback = (executeRes) => {
if (executeRes.success) {
resolve(executeRes.res)
} else {
reject(executeRes.err)
}
}
const priority = task.priority || 0;
if (cache) {
cache.priority = priority
task.callback =callback
} else {
task.callback =callback
cachedTask[task.key] = task
taskPool.push(task)
}
})
}
// 执行下载
function executeTask() {
if (taskPool.length > 0) {
const executeRequest = maxRequest - numRequest
if (executeRequest > 0) {
for (let i = 0; i < executeRequest; i++) {
sortTaskPool()
const task = taskPool.shift()
if (!task) {
return
}
numRequest++
task.execute().then((res) => {
numRequest--
task.callback({ success: true, res })
executeTask()
}, (err) => {
numRequest--
task.callback({ success: true, res })
delete cachedTask[task.key]
executeTask()
})
}
}
} else {
startTaskTimer()
}
}
function sortTaskPool() {
if (taskPool.length > 0) {
taskPool.sort((a, b) => b.priority-a.priority )
}
}
// 轮询检查请求池中是否有请求需要执行
function startTaskTimer() {
taskTimer = setInterval(() => {
if (taskPool.length > 0) {
stopTaskTimer()
executeTask()
}
}, 500)
}
// 停止轮询
function stopTaskTimer() {
clearInterval(taskTimer)
taskTimer = null
}
function loadAndCacheImagePlus(imageId,seriesId, priority) {
return new Promise((resolve, reject) => {
// if(!taskTimer){
// startTaskTimer()
// }
const imageLoadObject = cornerstone.imageCache.getImageLoadObject(imageId)
if (imageLoadObject) {
imageLoadObject.promise.then((image) => {
resolve(image)
}, (err) => {
reject(err)
})
} else {
const imageTask = buildImageRequestTask(imageId,seriesId, { priority })
addTaskIntoPool(imageTask).then((res) => {
resolve(res)
}).catch(e => {
reject(e)
})
}
})
}
function removeTask(seriesId){
stopTaskTimer()
if (taskPool.length > 0) {
for(var i =taskPool.length-1; i>=0;i--){
if(taskPool[i] && taskPool[i].seriesId === seriesId){
taskPool.splice(i,1)
}
}
}
startTaskTimer()
}
function buildImageRequestTask(imageId,seriesId, config = {}) {
return {
key: imageId,
seriesId:seriesId,
...config,
execute: () => {
return cornerstone.loadAndCacheImage(imageId)
}
};
}
export default {
addTaskIntoPool,
executeTask,
startTaskTimer,
stopTaskTimer,
loadAndCacheImagePlus,
removeTask
}