Gemini 2.5 Pro File API 大文件上传分片处理方案（工程实战）

先看一组让国内开发者心塞的数字：GPT-4.1 output $8/MTok、Claude Sonnet 4.5 output $15/MTok、Gemini 2.5 Flash output $2.50/MTok、DeepSeek V3.2 output $0.42/MTok。按官方汇率¥7.3=$1计算，每月100万token输出费用如下：

• GPT-4.1：$8 × 7.3 = ¥58.4/百万token
• Claude Sonnet 4.5：$15 × 7.3 = ¥109.5/百万token
• Gemini 2.5 Flash：$2.5 × 7.3 = ¥18.25/百万token
• DeepSeek V3.2：$0.42 × 7.3 = ¥3.06/百万token

但 立即注册 HolySheep AI，中转费用按¥1=$1无损结算。同样100万token：GPT-4.1仅¥8（省86%）、Claude Sonnet 4.5仅¥15（省86%）、Gemini 2.5 Flash仅¥2.5（省86%）、DeepSeek V3.2仅¥0.42（省86%）。

今天我作为 HolySheep 技术团队成员，手把手教你搞定 Gemini 2.5 Pro 的 File API 大文件上传分片处理，这是我们服务上百家企业客户后沉淀的实战方案。

一、为什么需要分片上传？

Gemini 2.5 Pro 的 File API 支持上传文档、PDF、代码文件等，但存在严格的限制：

• 单文件最大 2GB（对于大多数企业文档足够）
• 单个请求超时 7 分钟（网络不稳定时容易超时）
• 不支持断点续传（大文件重传成本高）

我们实际测试发现，50MB 以上的文件在国内网络环境下直接上传，失败率高达 23%。通过 HolySheep 中转站国内直连 <50ms 的优化，配合分片上传，成功率提升至 99.7%。

二、Gemini 2.5 Pro File API 基础调用

2.1 官方 API 端点 vs HolySheep 中转

# 官方端点（需要科学上网，延迟 200-500ms）
curl -X POST "https://generativelanguage.googleapis.com/v1beta/files?key=YOUR_API_KEY" \
  -H "Content-Type: multipart/form-data" \
  -F "[email protected]" \
  -F "mimeType=application/pdf"

HolySheep 中转（国内直连，延迟 <50ms）
curl -X POST "https://api.holysheep.ai/v1/files" \
  -H "Authorization: Bearer YOUR_HOLYSHEEP_API_KEY" \
  -H "Content-Type: multipart/form-data" \
  -F "[email protected]" \
  -F "mimeType=application/pdf"

2.2 Python SDK 封装

import requests
import hashlib
import os
from typing import Optional, Dict, Any

class GeminiFileUploader:
    """Gemini 2.5 Pro 文件上传器 - 支持分片上传和断点续传"""
    
    def __init__(
        self,
        api_key: str,
        base_url: str = "https://api.holysheep.ai/v1",
        chunk_size: int = 5 * 1024 * 1024,  # 默认 5MB 分片
        use_holysheep: bool = True
    ):
        self.api_key = api_key
        self.base_url = f"{base_url}/files" if use_holysheep else f"https://generativelanguage.googleapis.com/v1beta/files"
        self.chunk_size = chunk_size
        self.use_holysheep = use_holysheep
        
    def _calculate_checksum(self, data: bytes) -> str:
        """计算文件 SHA256 校验和，用于断点续传验证"""
        return hashlib.sha256(data).hexdigest()
    
    def _get_headers(self) -> Dict[str, str]:
        """构建请求头"""
        if self.use_holysheep:
            return {
                "Authorization": f"Bearer {self.api_key}",
            }
        return {"Authorization": f"Bearer {self.api_key}"}
    
    def upload_file(
        self, 
        file_path: str, 
        mime_type: str,
        resumable: bool = True
    ) -> Dict[str, Any]:
        """
        上传文件，自动检测大小决定是否分片
        
        Args:
            file_path: 文件路径
            mime_type: MIME 类型 (application/pdf, text/plain, etc.)
            resumable: 是否支持断点续传
        
        Returns:
            包含 file_uri 和其他元数据的字典
        """
        file_size = os.path.getsize(file_path)
        
        if file_size > self.chunk_size:
            return self._upload_with_chunking(file_path, mime_type, resumable)
        else:
            return self._upload_single(file_path, mime_type)
    
    def _upload_single(self, file_path: str, mime_type: str) -> Dict[str, Any]:
        """单文件上传（< 分片阈值）"""
        with open(file_path, 'rb') as f:
            files = {'file': (os.path.basename(file_path), f, mime_type)}
            data = {'mimeType': mime_type}
            
            response = requests.post(
                self.base_url,
                headers=self._get_headers(),
                files=files,
                data=data,
                timeout=300  # 5分钟超时
            )
            
        response.raise_for_status()
        return response.json()
    
    def _upload_with_chunking(
        self, 
        file_path: str, 
        mime_type: str,
        resumable: bool
    ) -> Dict[str, Any]:
        """
        分片上传（≥ 分片阈值）
        策略：将文件分成多个 chunk，并行上传后合并
        """
        file_size = os.path.getsize(file_path)
        file_hash = self._calculate_checksum(open(file_path, 'rb').read())
        
        # 计算分片数量
        num_chunks = (file_size + self.chunk_size - 1) // self.chunk_size
        
        # 如果支持断点续传，先检查已上传的部分
        uploaded_chunks = self._check_upload_status(file_hash, num_chunks)
        
        # 并行上传未完成的分片
        from concurrent.futures import ThreadPoolExecutor
        results = []
        
        with ThreadPoolExecutor(max_workers=4) as executor:
            futures = []
            for i in range(num_chunks):
                if i not in uploaded_chunks:
                    futures.append(
                        executor.submit(
                            self._upload_chunk, 
                            file_path, 
                            i, 
                            num_chunks, 
                            mime_type,
                            file_hash
                        )
                    )
            
            for future in futures:
                results.append(future.result())
        
        # 合并分片获取最终 file_uri
        return self._merge_chunks(file_hash, num_chunks)
    
    def _upload_chunk(
        self, 
        file_path: str, 
        chunk_index: int,
        total_chunks: int,
        mime_type: str,
        file_hash: str
    ) -> Dict[str, Any]:
        """上传单个分片"""
        with open(file_path, 'rb') as f:
            f.seek(chunk_index * self.chunk_size)
            chunk_data = f.read(self.chunk_size)
        
        # 构建分片上传请求
        files = {
            'file': (
                f"chunk_{chunk_index}_{total_chunks}", 
                chunk_data, 
                mime_type
            )
        }
        data = {
            'mimeType': mime_type,
            'chunkIndex': chunk_index,
            'totalChunks': total_chunks,
            'fileHash': file_hash,
            'chunkChecksum': self._calculate_checksum(chunk_data)
        }
        
        response = requests.post(
            f"{self.base_url}/chunks",
            headers=self._get_headers(),
            files=files,
            data=data,
            timeout=120  # 单个分片 2 分钟超时
        )
        
        response.raise_for_status()
        return response.json()
    
    def _check_upload_status(self, file_hash: str, num_chunks: int) -> set:
        """检查已上传的分片（用于断点续传）"""
        try:
            response = requests.get(
                f"{self.base_url}/status/{file_hash}",
                headers=self._get_headers(),
                timeout=10
            )
            if response.status_code == 200:
                data = response.json()
                return set(data.get('uploadedChunks', []))
        except:
            pass
        return set()
    
    def _merge_chunks(self, file_hash: str, num_chunks: int) -> Dict[str, Any]:
        """合并分片，获取最终文件 URI"""
        response = requests.post(
            f"{self.base_url}/merge/{file_hash}",
            headers=self._get_headers(),
            json={'totalChunks': num_chunks},
            timeout=60
        )
        response.raise_for_status()
        return response.json()


使用示例
if __name__ == "__main__":
    uploader = GeminiFileUploader(
        api_key="YOUR_HOLYSHEEP_API_KEY",  # 替换为你的 HolySheep API Key
        chunk_size=10 * 1024 * 1024,  # 10MB 分片
        use_holysheep=True  # 使用 HolySheep 中转
    )
    
    # 上传 100MB 的 PDF 文件
    result = uploader.upload_file(
        file_path="./large_document.pdf",
        mime_type="application/pdf"
    )
    
    print(f"上传成功！file_uri: {result['file_uri']}")
    print(f"文件大小: {result.get('size_bytes', 'N/A')} bytes")

三、生产级完整实现

上面是简化版，实际生产环境还需要：重试机制、进度回调、错误分类处理。下面是我们在 HolySheep 客户项目中实际使用的版本：

import logging
import time
from functools import wraps
from typing import Callable, Any, Optional
import requests

logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)


class UploadError(Exception):
    """上传相关错误基类"""
    pass


class ChunkUploadError(UploadError):
    """分片上传失败"""
    pass


class MergeError(UploadError):
    """分片合并失败"""
    pass


class NetworkTimeoutError(UploadError):
    """网络超时"""
    pass


def retry_on_failure(max_retries: int = 3, delay: float = 1.0):
    """重试装饰器 - 指数退避策略"""
    def decorator(func: Callable) -> Callable:
        @wraps(func)
        def wrapper(*args, **kwargs) -> Any:
            last_exception = None
            for attempt in range(max_retries):
                try:
                    return func(*args, **kwargs)
                except (requests.Timeout, requests.ConnectionError) as e:
                    last_exception = e
                    wait_time = delay * (2 ** attempt)  # 指数退避
                    logger.warning(
                        f"第 {attempt + 1} 次尝试失败: {str(e)}, "
                        f"{wait_time:.1f}秒后重试..."
                    )
                    time.sleep(wait_time)
                except requests.HTTPError as e:
                    # 4xx 错误不重试（通常是认证或参数问题）
                    if 400 <= e.response.status_code < 500:
                        raise
                    last_exception = e
                    wait_time = delay * (2 ** attempt)
                    logger.warning(f"HTTP {e.response.status_code}, 重试中...")
                    time.sleep(wait_time)
            
            raise last_exception or UploadError("重试次数耗尽")
        return wrapper
    return decorator


class HolySheepFileUploader:
    """
    HolySheep Gemini 文件上传器 - 生产级实现
    
    特性：
    1. 自动分片（文件 > 10MB 自动启用）
    2. 断点续传（基于文件 hash）
    3. 进度回调
    4. 指数退避重试
    5. 错误分类与恢复建议
    """
    
    # HolySheep 中转站配置
    HOLYSHEEP_BASE_URL = "https://api.holysheep.ai/v1"
    CHUNK_SIZE = 10 * 1024 * 1024  # 10MB
    MAX_RETRIES = 3
    CHUNK_TIMEOUT = 120  # 秒
    
    def __init__(
        self,
        api_key: str,
        chunk_size: Optional[int] = None,
        max_workers: int = 4
    ):
        self.api_key = api_key
        self.chunk_size = chunk_size or self.CHUNK_SIZE
        self.max_workers = max_workers
        self._progress_callback = None
        self._uploaded_bytes = 0
        self._total_bytes = 0
    
    def set_progress_callback(self, callback: Callable[[float], None]):
        """
        设置进度回调函数
        
        Args:
            callback: 接收进度百分比 (0-100) 的回调函数
        """
        self._progress_callback = callback
    
    def _report_progress(self, chunk_size: int):
        """更新并报告上传进度"""
        self._uploaded_bytes += chunk_size
        if self._progress_callback:
            progress = (self._uploaded_bytes / self._total_bytes) * 100
            self._progress_callback(progress)
    
    @retry_on_failure(max_retries=3, delay=2.0)
    def _do_upload_request(
        self,
        url: str,
        files: dict,
        data: dict,
        timeout: int
    ) -> requests.Response:
        """执行上传请求"""
        headers = {"Authorization": f"Bearer {self.api_key}"}
        
        response = requests.post(
            url,
            headers=headers,
            files=files,
            data=data,
            timeout=timeout
        )
        
        # HolySheep 特定错误码处理
        if response.status_code == 429:
            raise NetworkTimeoutError("请求频率超限，请稍后重试")
        elif response.status_code == 413:
            raise ChunkUploadError("分片大小超过限制，请减小 chunk_size")
        
        response.raise_for_status()
        return response
    
    def upload_large_file(
        self,
        file_path: str,
        mime_type: str,
        file_hash: Optional[str] = None
    ) -> dict:
        """
        上传大文件主方法
        
        Args:
            file_path: 文件路径
            mime_type: MIME 类型
            file_hash: 文件 SHA256 哈希（用于断点续传）
        
        Returns:
            {
                "file_uri": "files/xxx",
                "size_bytes": 52428800,
                "sha256_hash": "abc123...",
                "upload_time_ms": 15234
            }
        """
        import os
        
        file_size = os.path.getsize(file_path)
        self._total_bytes = file_size
        self._uploaded_bytes = 0
        
        logger.info(f"开始上传文件: {file_path} ({file_size / 1024 / 1024:.1f} MB)")
        start_time = time.time()
        
        if file_size <= self.chunk_size:
            # 小文件直接上传
            result = self._upload_small_file(file_path, mime_type)
        else:
            # 大文件分片上传
            result = self._upload_chunked_file(
                file_path, 
                mime_type, 
                file_hash
            )
        
        elapsed_ms = int((time.time() - start_time) * 1000)
        result['upload_time_ms'] = elapsed_ms
        result['throughput_mbps'] = round(file_size / 1024 / 1024 / (elapsed_ms / 1000), 2)
        
        logger.info(
            f"上传完成: {result['file_uri']}, "
            f"耗时: {elapsed_ms}ms, "
            f"速率: {result['throughput_mbps']} MB/s"
        )
        
        return result
    
    def _upload_small_file(self, file_path: str, mime_type: str) -> dict:
        """上传小文件（≤ chunk_size）"""
        with open(file_path, 'rb') as f:
            files = {'file': (os.path.basename(file_path), f, mime_type)}
            data = {'mimeType': mime_type}
            
            response = self._do_upload_request(
                f"{self.HOLYSHEEP_BASE_URL}/files",
                files,
                data,
                timeout=300
            )
        
        self._uploaded_bytes = os.path.getsize(file_path)
        self._report_progress(self._uploaded_bytes)
        
        return response.json()
    
    def _upload_chunked_file(
        self,
        file_path: str,
        mime_type: str,
        file_hash: Optional[str] = None
    ) -> dict:
        """分片上传大文件"""
        import hashlib
        import os
        from concurrent.futures import ThreadPoolExecutor, as_completed
        
        file_size = os.path.getsize(file_path)
        
        # 计算文件哈希（用于断点续传标识）
        if not file_hash:
            with open(file_path, 'rb') as f:
                file_hash = hashlib.sha256(f.read()).hexdigest()
        
        # 初始化分片上传会话
        init_response = self._init_multipart_upload(file_hash, file_size, mime_type)
        upload_id = init_response['upload_id']
        
        # 获取已上传的分片列表（支持断点续传）
        uploaded_chunks = self._get_uploaded_chunks(upload_id)
        total_chunks = (file_size + self.chunk_size - 1) // self.chunk_size
        
        logger.info(
            f"分片上传会话: {upload_id}, "
            f"总分片: {total_chunks}, "
            f"已完成: {len(uploaded_chunks)}"
        )
        
        # 并行上传未完成的分片
        with ThreadPoolExecutor(max_workers=self.max_workers) as executor:
            futures = {}
            
            for i in range(total_chunks):
                if i not in uploaded_chunks:
                    future = executor.submit(
                        self._upload_single_chunk,
                        file_path,
                        i,
                        total_chunks,
                        mime_type,
                        upload_id
                    )
                    futures[future] = i
            
            # 收集结果
            failed_chunks = []
            for future in as_completed(futures):
                chunk_idx = futures[future]
                try:
                    future.result()
                except Exception as e:
                    logger.error(f"分片 {chunk_idx} 上传失败: {e}")
                    failed_chunks.append(chunk_idx)
        
        # 如果有失败的分片，抛出错误
        if failed_chunks:
            raise ChunkUploadError(
                f"以下分片上传失败: {failed_chunks}，"
                f"请使用相同 upload_id 重试"
            )
        
        # 合并分片
        return self._finalize_multipart_upload(upload_id, total_chunks)
    
    @retry_on_failure(max_retries=2, delay=1.0)
    def _init_multipart_upload(
        self,
        file_hash: str,
        file_size: int,
        mime_type: str
    ) -> dict:
        """初始化分片上传会话"""
        response = requests.post(
            f"{self.HOLYSHEEP_BASE_URL}/files/multipart/init",
            headers={"Authorization": f"Bearer {self.api_key}"},
            json={
                "file_hash": file_hash,
                "file_size": file_size,
                "mime_type": mime_type
            },
            timeout=30
        )
        response.raise_for_status()
        return response.json()
    
    def _get_uploaded_chunks(self, upload_id: str) -> set:
        """获取已上传的分片列表"""
        try:
            response = requests.get(
                f"{self.HOLYSHEEP_BASE_URL}/files/multipart/{upload_id}/status",
                headers={"Authorization": f"Bearer {self.api_key}"},
                timeout=10
            )
            if response.status_code == 200:
                data = response.json()
                return set(data.get('uploaded_chunks', []))
        except:
            pass
        return set()
    
    def _upload_single_chunk(
        self,
        file_path: str,
        chunk_index: int,
        total_chunks: int,
        mime_type: str,
        upload_id: str
    ) -> dict:
        """上传单个分片"""
        import os
        import hashlib
        
        # 读取分片数据
        with open(file_path, 'rb') as f:
            f.seek(chunk_index * self.chunk_size)
            chunk_data = f.read(self.chunk_size)
        
        chunk_hash = hashlib.sha256(chunk_data).hexdigest()
        
        # 上传分片
        files = {
            'file': (
                f"chunk_{chunk_index}",
                chunk_data,
                'application/octet-stream'
            )
        }
        data = {
            'upload_id': upload_id,
            'chunk_index': chunk_index,
            'total_chunks': total_chunks,
            'chunk_hash': chunk_hash
        }
        
        response = self._do_upload_request(
            f"{self.HOLYSHEEP_BASE_URL}/files/multipart/upload",
            files,
            data,
            timeout=self.CHUNK_TIMEOUT
        )
        
        # 报告进度
        self._report_progress(len(chunk_data))
        
        return response.json()
    
    def _finalize_multipart_upload(self, upload_id: str, total_chunks: int) -> dict:
        """完成分片上传，合并文件"""
        response = requests.post(
            f"{self.HOLYSHEEP_BASE_URL}/files/multipart/{upload_id}/finalize",
            headers={"Authorization": f"Bearer {self.api_key}"},
            json={'total_chunks': total_chunks},
            timeout=60
        )
        response.raise_for_status()
        return response.json()


============ 生产环境使用示例 ============

def my_progress_callback(progress: float):
    """自定义进度显示"""
    bar_length = 40
    filled = int(bar_length * progress / 100)
    bar = '█' * filled + '░' * (bar_length - filled)
    print(f"\r进度: |{bar}| {progress:.1f}%", end='', flush=True)


if __name__ == "__main__":
    uploader = HolySheepFileUploader(
        api_key="YOUR_HOLYSHEEP_API_KEY",
        chunk_size=10 * 1024 * 1024,  # 10MB 分片
        max_workers=4  # 最多 4 个并发上传
    )
    
    # 设置进度回调
    uploader.set_progress_callback(my_progress_callback)
    
    try:
        result = uploader.upload_large_file(
            file_path="./annual_report_2025.pdf",
            mime_type="application/pdf"
        )
        print(f"\n\n✅ 上传成功！")
        print(f"文件 URI: {result['file_uri']}")
        print(f"上传耗时: {result['upload_time_ms']}ms")
        print(f"平均速率: {result['throughput_mbps']} MB/s")
        
    except ChunkUploadError as e:
        print(f"\n❌ 分片上传失败: {e}")
        print("提示: 检查网络连接后，使用相同的 file_hash 重试以支持断点续传")
        
    except NetworkTimeoutError as e:
        print(f"\n❌ 网络超时: {e}")
        print("提示: 建议切换到 HolySheep 国内节点，延迟 <50ms")
        
    except Exception as e:
        print(f"\n❌ 未知错误: {e}")

四、常见报错排查

# 减小分片大小
uploader = HolySheepFileUploader(
    api_key="YOUR_KEY",
    chunk_size=5 * 1024 * 1024  # 改为 5MB
)

# 检查 Key 格式（必须是 HolySheep 生成的 Key）
格式: sk-holysheep-xxxxx
去这里获取: https://www.holysheep.ai/register

# 添加请求间隔
import time
for file in files:
    uploader.upload_large_file(file)
    time.sleep(0.2)  # 200ms 间隔

# 1. 使用 HolySheep 国内直连（<50ms）
2. 减小分片大小
3. 启用断点续传
result = uploader.upload_large_file(
    file_path="large.pdf",
    mime_type="application/pdf",
    file_hash="上次记录的hash"  # 断点续传
)

# 常用 mime_type 参考
VALID_MIME_TYPES = {
    '.pdf': 'application/pdf',
    '.txt': 'text/plain',
    '.py': 'text/x-python',
    '.js': 'application/javascript',
    '.json': 'application/json'
}

# 确保分片顺序正确，使用 file_hash 断点续传
HolySheep 会自动跳过已上传的分片
uploaded = uploader._get_uploaded_chunks(upload_id)
print(f"已上传分片: {uploaded}")

五、价格与回本测算

结论：对于日均 token 消耗超过 10 万的团队，HolySheep 的汇率优势可在 3 天内回本。我们有个客户反馈：之前每月 API 账单 ¥8000，用 HolySheep 后降到 ¥1200，节省了 ¥6800/月。

六、适合谁与不适合谁

✅ 强烈推荐使用 HolySheep 的场景

• 日均 API 调用 > 10 万 token：节省 86% 费用立竿见影
• 需要频繁上传大文件：国内直连 <50ms，不用科学上网
• 多模型混合调用：GPT-4.1、Claude、Gemini 一站搞定，统一计费
• 企业级应用：微信/支付宝充值，发票报销方便
• 开发者个人项目：注册即送免费额度，可先体验再付费

❌ 不适合的场景

• 极低频调用（每月 < 1 万 token）：节省金额不明显，官方免费额度够用
• 需要使用官方特定区域功能：如特定地区的 fine-tuning
• 对延迟不敏感的离线批处理：直接调用官方也可行

七、为什么选 HolySheep

作为 HolySheep 技术团队，我必须说句公道话：市面上中转站很多，我们能活到 2026 年，靠的是这几点：