56 lines
1.7 KiB
Python
56 lines
1.7 KiB
Python
#!/usr/bin/env python3
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# -*- coding: utf-8 -*-
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"""服务端 PNG 渲染：通过 sharp 将 SVG 转为 PNG。"""
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import os
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import subprocess
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def _script_path():
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return os.path.join(os.path.dirname(__file__), "svg_to_png.js")
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def render_png_from_svg(svg_text, width, height, *, timeout_seconds=20):
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if not svg_text or not str(svg_text).strip():
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raise ValueError("SVG 内容为空")
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script = _script_path()
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if not os.path.isfile(script):
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raise FileNotFoundError(f"未找到 SVG 转 PNG 脚本: {script}")
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safe_width = max(1, min(4096, int(round(float(width or 0) or 0))))
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safe_height = max(1, min(4096, int(round(float(height or 0) or 0))))
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cmd = [
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"node",
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script,
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"--width",
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str(safe_width),
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"--height",
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str(safe_height),
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]
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try:
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completed = subprocess.run(
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cmd,
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input=str(svg_text).encode("utf-8"),
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stdout=subprocess.PIPE,
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stderr=subprocess.PIPE,
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timeout=timeout_seconds,
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check=False,
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)
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except FileNotFoundError as error:
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raise RuntimeError("未找到 node，请先安装 Node.js") from error
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if completed.returncode != 0:
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stderr = completed.stderr.decode("utf-8", errors="replace").strip()
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if "Cannot find module 'sharp'" in stderr:
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raise RuntimeError("缺少 sharp 依赖，请在项目根目录执行: npm install")
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raise RuntimeError(stderr or f"PNG 渲染失败，退出码: {completed.returncode}")
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png_bytes = completed.stdout
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if not png_bytes:
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raise RuntimeError("PNG 渲染失败，返回空内容")
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return png_bytes
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