download_files.py

#!/usr/bin/env python3
"""
下载MC-MED数据集所有文件
1. 读取file_list.txt中的文件列表
2. 并行下载每个文件，支持断点续传
3. 记录下载失败的文件以便重试
"""

# ============== 可修改参数 ==============
NUM_WORKERS = 8  # 并行下载线程数
# ========================================

import os
import subprocess
import configparser
import time
from pathlib import Path
from concurrent.futures import ThreadPoolExecutor, as_completed
import threading

# 线程安全的锁
completed_lock = threading.Lock()
failed_lock = threading.Lock()
progress_lock = threading.Lock()

# 全局计数器
progress_counter = {'done': 0, 'total': 0, 'start_time': 0}


def format_time(seconds):
    """格式化时间为可读字符串"""
    if seconds < 60:
        return f"{seconds:.0f}秒"
    elif seconds < 3600:
        minutes = seconds // 60
        secs = seconds % 60
        return f"{minutes:.0f}分{secs:.0f}秒"
    else:
        hours = seconds // 3600
        minutes = (seconds % 3600) // 60
        return f"{hours:.0f}时{minutes:.0f}分"


def load_config(config_path='config.ini'):
    """加载配置文件"""
    config = configparser.ConfigParser()
    config.read(config_path)
    return {
        'username': config.get('credentials', 'username'),
        'password': config.get('credentials', 'password'),
        'base_url': config.get('settings', 'base_url').rstrip('/'),
        'output_dir': config.get('settings', 'output_dir')
    }


def download_file(url, output_path, username, password):
    """
    下载单个文件
    返回: True成功, False失败
    """
    # 确保目录存在
    os.makedirs(os.path.dirname(output_path), exist_ok=True)
    
    cmd = [
        'wget',
        '--user', username,
        '--password', password,
        '-c',  # 断点续传
        '-q',  # 静默模式
        '-O', output_path,
        url
    ]
    
    try:
        result = subprocess.run(cmd, timeout=300, capture_output=True)  # 5分钟超时
        return result.returncode == 0
    except subprocess.TimeoutExpired:
        return False
    except Exception as e:
        return False


def download_task(file_path, base_url, output_dir, username, password):
    """
    单个下载任务，供线程池调用
    返回: (file_path, success)
    """
    url = f"{base_url}/{file_path}"
    output_path = os.path.join(output_dir, file_path)
    
    success = download_file(url, output_path, username, password)
    
    # 更新进度
    with progress_lock:
        progress_counter['done'] += 1
        done = progress_counter['done']
        total = progress_counter['total']
        start_time = progress_counter['start_time']
        
        # 每100个文件或完成时打印进度
        if done % 100 == 0 or done == total:
            elapsed = time.time() - start_time
            speed = done / elapsed if elapsed > 0 else 0
            remaining = total - done
            eta = remaining / speed if speed > 0 else 0
            
            percent = done * 100 // total
            speed_str = f"{speed:.1f} 文件/秒"
            eta_str = format_time(eta)
            elapsed_str = format_time(elapsed)
            
            print(f"[进度] {done}/{total} ({percent}%) | 速度: {speed_str} | 已用: {elapsed_str} | 剩余: {eta_str}")
    
    return (file_path, success)


def load_file_list(file_list_path='file_list.txt'):
    """加载文件列表"""
    if not os.path.exists(file_list_path):
        return []
    with open(file_list_path, 'r') as f:
        return [line.strip() for line in f if line.strip()]


def load_completed(completed_path='completed.txt'):
    """加载已完成的文件列表"""
    if not os.path.exists(completed_path):
        return set()
    with open(completed_path, 'r') as f:
        return set(line.strip() for line in f if line.strip())


def main():
    # 加载配置
    config = load_config()
    base_url = config['base_url']
    username = config['username']
    password = config['password']
    output_dir = config['output_dir']
    
    print("=" * 60)
    print("MC-MED 数据下载工具 (并行版)")
    print("=" * 60)
    
    # 加载文件列表
    print("[信息] 正在加载文件列表...")
    file_list = load_file_list()
    if not file_list:
        print("[错误] file_list.txt 不存在或为空，请先运行 get_file_list.py")
        return
    
    # 加载已完成列表（用于断点续传）
    print("[信息] 正在加载已完成列表...")
    completed = load_completed()
    
    # 过滤掉已完成的
    pending = [f for f in file_list if f not in completed]
    
    print(f"[信息] 总文件数: {len(file_list)}")
    print(f"[信息] 已完成: {len(completed)}")
    print(f"[信息] 待下载: {len(pending)}")
    print(f"[信息] 并行线程数: {NUM_WORKERS}")
    print(f"[信息] 输出目录: {output_dir}")
    print("=" * 60)
    
    if not pending:
        print("[完成] 所有文件已下载完成！")
        return
    
    # 记录结果
    completed_files = []
    failed_files = []
    
    start_time = time.time()
    
    # 设置进度计数器
    progress_counter['total'] = len(pending)
    progress_counter['done'] = 0
    progress_counter['start_time'] = start_time
    
    # 使用线程池并行下载
    print(f"[开始] 启动 {NUM_WORKERS} 个下载线程...")
    
    with ThreadPoolExecutor(max_workers=NUM_WORKERS) as executor:
        # 提交所有任务
        futures = {
            executor.submit(download_task, file_path, base_url, output_dir, username, password): file_path
            for file_path in pending
        }
        
        # 处理完成的任务
        for future in as_completed(futures):
            file_path, success = future.result()
            
            if success:
                completed_files.append(file_path)
                # 立即记录完成（线程安全）
                with completed_lock:
                    with open('completed.txt', 'a') as f:
                        f.write(file_path + '\n')
            else:
                failed_files.append(file_path)
    
    elapsed_time = time.time() - start_time
    
    print("=" * 60)
    print(f"[完成] 本次下载完成")
    print(f"[完成] 耗时: {elapsed_time:.1f} 秒")
    print(f"[完成] 成功: {len(completed_files)}")
    print(f"[完成] 失败: {len(failed_files)}")
    
    if len(completed_files) > 0:
        avg_speed = len(completed_files) / elapsed_time
        print(f"[完成] 平均速度: {avg_speed:.1f} 文件/秒")
    
    # 保存失败列表
    if failed_files:
        with open('failed_files.txt', 'w') as f:
            for file_path in failed_files:
                f.write(file_path + '\n')
        print(f"[信息] 失败列表已保存到: failed_files.txt")
        print("[提示] 重新运行此脚本可自动重试未完成的文件")
    
    print("=" * 60)


if __name__ == '__main__':
    main()