2026-04-29-21-51-19 - 全栈系统改造：FastAPI后端+SAM2+PostgreSQL+Redis+MinIO+前端Zustand重构

backend/minio_client.py

@@ -0,0 +1,127 @@
+"""MinIO client wrapper for object storage operations."""
+
+import io
+import logging
+from typing import Optional
+
+from minio import Minio
+from minio.error import S3Error
+
+from config import settings
+
+logger = logging.getLogger(__name__)
+
+BUCKET_NAME = "seg-media"
+
+_minio_client: Optional[Minio] = None
+
+
+def get_minio_client() -> Minio:
+    """Return a singleton MinIO client instance."""
+    global _minio_client
+    if _minio_client is None:
+        _minio_client = Minio(
+            settings.minio_endpoint,
+            access_key=settings.minio_access_key,
+            secret_key=settings.minio_secret_key,
+            secure=settings.minio_secure,
+        )
+    return _minio_client
+
+
+def ensure_bucket_exists() -> None:
+    """Create the bucket if it does not already exist."""
+    client = get_minio_client()
+    try:
+        if not client.bucket_exists(BUCKET_NAME):
+            client.make_bucket(BUCKET_NAME)
+            logger.info("Created MinIO bucket: %s", BUCKET_NAME)
+        else:
+            logger.info("MinIO bucket %s already exists", BUCKET_NAME)
+    except S3Error as exc:
+        logger.error("MinIO bucket check/creation failed: %s", exc)
+        raise
+
+
+def upload_file(
+    object_name: str,
+    data: bytes,
+    content_type: str = "application/octet-stream",
+    length: int = -1,
+) -> str:
+    """Upload bytes to MinIO and return the object name.
+
+    Args:
+        object_name: Destination path inside the bucket.
+        data: Raw bytes or a file-like object.
+        content_type: MIME type of the object.
+        length: Object size; -1 for unknown (uses chunked upload).
+
+    Returns:
+        The object name (same as input).
+    """
+    client = get_minio_client()
+    if isinstance(data, bytes):
+        data = io.BytesIO(data)
+        length = len(data.getvalue())
+
+    try:
+        client.put_object(
+            BUCKET_NAME,
+            object_name,
+            data,
+            length=length,
+            content_type=content_type,
+        )
+        logger.info("Uploaded to MinIO: %s", object_name)
+        return object_name
+    except S3Error as exc:
+        logger.error("MinIO upload failed: %s", exc)
+        raise
+
+
+from datetime import timedelta
+
+def get_presigned_url(
+    object_name: str,
+    expires: int = 3600,
+    method: str = "GET",
+) -> str:
+    """Generate a presigned URL for an object.
+
+    Args:
+        object_name: Path inside the bucket.
+        expires: Expiration time in seconds (default 1 hour).
+        method: HTTP method (GET or PUT).
+
+    Returns:
+        Presigned URL string.
+    """
+    client = get_minio_client()
+    try:
+        url = client.get_presigned_url(method, BUCKET_NAME, object_name, expires=timedelta(seconds=expires))
+        return url
+    except S3Error as exc:
+        logger.error("MinIO presigned URL failed: %s", exc)
+        raise
+
+
+def download_file(object_name: str) -> bytes:
+    """Download an object from MinIO and return its bytes.
+
+    Args:
+        object_name: Path inside the bucket.
+
+    Returns:
+        Raw bytes of the object.
+    """
+    client = get_minio_client()
+    try:
+        response = client.get_object(BUCKET_NAME, object_name)
+        data = response.read()
+        response.close()
+        response.release_conn()
+        return data
+    except S3Error as exc:
+        logger.error("MinIO download failed: %s", exc)
+        raise