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Last active November 7, 2016 16:21
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获取 B 站右上角所有小图的 JS 代码 -> https://maicong.me/t/202
((url, delay) => {
let starTime = new Date().getTime();
let xhr = new XMLHttpRequest();
let times = [];
let style = document.createElement('style');
style.textContent = 'body { display: flex; flex-wrap: wrap; } div { text-align: center; padding: 0.5rem; margin: 1rem; border: 1px solid #ddd; }';
document.head.appendChild(style);
document.body.innerHTML = '';
xhr.open('GET', url, true);
xhr.onload = event => {
if (xhr.status >= 200 && xhr.status < 400) {
console.debug(`资源已加载,耗时 ${new Date().getTime() - starTime} ms,开始获取...`);
(loadImg = (i, srcs) => {
(promise = (src, title, timeStamp) => new Promise(resolve => {
let img = new Image();
let div = document.createElement('div');
let p = document.createElement('p');
p.textContent = title;
img.src = src;
img.alt = title;
img.onload = newEvent => {
setTimeout(() => {
let usedTime = newEvent.timeStamp - timeStamp;
usedTime = Math.floor(i > 0 ? usedTime - delay : usedTime);
times.push(usedTime);
console.info(`第 ${i + 1} 张获取成功,耗时 ${usedTime} ms`, img.src);
div.appendChild(img);
div.appendChild(p);
document.body.appendChild(div);
resolve(newEvent.timeStamp);
}, delay);
};
img.onerror = err => {
console.warn(`第 ${i + 1} 张获取失败`, img.src);
resolve(err.timeStamp);
};
}).then(timeStamp => {
if (i === srcs.length - 1) {
let min = Math.min.apply(null, times);
let max = Math.max.apply(null, times);
let avg = (times.reduce((p, c) => Number(p) + Number(c)) / times.length).toFixed(0);
console.debug(`图片下载完毕,最快用时 ${min} ms,最慢用时 ${max} ms,平均用时 ${avg} ms`);
} else {
i += 1;
promise(srcs[i].icon, srcs[i].title, timeStamp);
}
}))(srcs[i].icon, srcs[i].title, event.timeStamp);
})(0, (JSON.parse(xhr.responseText)).fix);
}
};
xhr.send();
})('http://www.bilibili.com/index/index-icon.json', 100);
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