最近折腾esp32，想要在自己的小站上安装Arduino-cli环境，根据【此教程】一步步安装下来

但是发现安装esp32的库下载得巨慢

于是研究了一下下载原理

https://raw.githubusercontent.com/espressif/arduino-esp32/gh-pages/package_esp32_index.json

我们平时的步骤是把上面的链接丢进配置文件的additional_urls里，然后运行这行命令来安装esp的库

arduino-cli core install esp32:esp32

但是这样在没有魔法的情况下下载得会很慢

其实他要下载的东西就是json里的库包和工具包，也就是下图的platforms和tools

platforms直接下载里面的url就行，tools下的每项都有不同架构的包，下载对应系统架构的包即可

知道要下载的东西后，就可以把这个json下载下来，然后再用python解析下载了，下完了再全部放到安装目录的.arduino15/staging/packages下

我的下载的python脚本如下，使用的话要把json放到py文件的同目录，并调整下载目录和架构即可

import json
import requests
from concurrent.futures import ThreadPoolExecutor
from urllib.parse import urlparse
import os
import threading
from tqdm import tqdm
import time

download_dir = "Download"
json_dir = "package_esp32_index.json"
arrch = "x86_64-pc-linux-gnu"
proxy = {
    "http": "http://127.0.0.1:7890",
    "https": "http://127.0.0.1:7890"
}

# 定义下载函数
def download_file(url, filename, proxy=None):
    try:
        start_time = time.time()
        response = requests.get(url, proxies=proxy, stream=True)
        total_size = int(response.headers.get('content-length', 0))

        with open(filename, 'wb') as f, tqdm(
                desc=filename,
                total=total_size,
                unit='B',
                unit_scale=True,
                unit_divisor=1024,
                ) as pbar:
            for data in response.iter_content(chunk_size=1024):
                f.write(data)
                pbar.update(len(data))

        end_time = time.time()
        download_time = end_time - start_time
        download_speed = total_size / download_time if download_time > 0 else 0
        print(f"{filename} 下载完成，用时: {download_time:.2f}秒，平均速度: {download_speed:.2f}B/s")

    except Exception as e:
        print(f"下载 {filename} 时出现异常: {e}")

urls = []
sizes = []
with open(json_dir, 'r') as f:
    data = json.load(f)
    urls.append(data["packages"][0]["platforms"][0]["url"])
    sizes.append(data["packages"][0]["platforms"][0]["size"])
    for tool in data["packages"][0]["tools"]:
        for system in tool["systems"]:
            if system["host"] == arrch:
                urls.append(system["url"])
                sizes.append(system["size"])

os.makedirs("Download", exist_ok=True)


# 创建线程并启动下载
threads = []
for index, url in enumerate(urls):
    file_path = f"{download_dir}/{os.path.basename(url)}"
    if os.path.exists(file_path) and os.stat(file_path).st_size == int(sizes[index]):
        print(f"{file_path} exist, skip")
        continue
    filename = os.path.join(download_dir, os.path.basename(url))
    thread = threading.Thread(target=download_file, args=(url, filename, proxy))
    thread.start()
    threads.append(thread)

# 等待所有线程完成
for thread in threads:
    thread.join()

print("所有文件下载完成")