congsh
5c028d7952
包含 FastAPI 后端、React 前端、队列/OCR/标签/待办等完整功能。 Co-authored-by: Cursor <cursoragent@cursor.com>
49 lines
1.5 KiB
Python
49 lines
1.5 KiB
Python
"""生成并缓存缩略图。"""
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from __future__ import annotations
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import hashlib
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from pathlib import Path
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from PIL import Image
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from app.core.config import settings
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from app.core.path_utils import path_to_storage
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SUPPORTED_EXTS = {".png", ".jpg", ".jpeg", ".webp", ".gif", ".bmp", ".tif", ".tiff"}
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def is_supported(path: Path) -> bool:
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"""是否为我们支持的图片格式。"""
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return path.suffix.lower() in SUPPORTED_EXTS
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def generate_thumbnail(image_path: Path, max_side: int | None = None) -> Path:
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"""生成 webp 缩略图，落到缓存目录。返回缓存路径。"""
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max_side = max_side or settings.thumb_size
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# 用文件路径 + mtime 哈希作为缓存键，源文件变化会自动生成新缩略图
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stat = image_path.stat()
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key = hashlib.md5(
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f"{path_to_storage(image_path)}|{stat.st_mtime_ns}|{max_side}".encode("utf-8")
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).hexdigest()
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out = settings.thumb_dir / f"{key}.webp"
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if out.exists():
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return out
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with Image.open(image_path) as img:
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img = img.convert("RGB")
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img.thumbnail((max_side, max_side), Image.LANCZOS)
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img.save(out, format="WEBP", quality=80)
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return out
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def file_hash(image_path: Path, chunk: int = 1024 * 1024) -> str:
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"""计算文件 sha256，用作去重键。"""
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h = hashlib.sha256()
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with open(image_path, "rb") as f:
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while True:
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data = f.read(chunk)
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if not data:
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break
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h.update(data)
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return h.hexdigest()
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