121 lines
3.8 KiB
Python
121 lines
3.8 KiB
Python
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"""
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模板缓存引擎。解决 QgsProject 单例问题。
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流程：
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1. 首次请求：project.read() 加载模板（慢，仅一次）
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2. 加载后 project.write() 保存到临时文件
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3. 后续同模板请求：从临时文件恢复（快，连接复用）
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4. 手动恢复文本/过滤/缩放（毫秒级）
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"""
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import os
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import time
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import tempfile
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from qgis.core import QgsProject, QgsRectangle
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from app.config.paths import get_logger
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logger = get_logger("qgis.cache")
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class TemplateCache:
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def __init__(self):
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self._cache: dict[str, dict] = {}
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def is_loaded(self, template_path: str) -> bool:
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return template_path in self._cache
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def load_template(self, template_path: str, layout_name: str = "A4") -> None:
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"""首次加载模板"""
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start = time.time()
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project = QgsProject.instance()
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logger.info(f"首次加载: {os.path.basename(template_path)}")
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project.read(template_path)
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logger.info(f"project.read() 耗时: {time.time() - start:.1f}s")
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# 保存到临时文件
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tmp_file = tempfile.NamedTemporaryFile(
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suffix=".qgz", delete=False,
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dir=os.path.dirname(template_path),
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)
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tmp_path = tmp_file.name
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tmp_file.close()
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t_save = time.time()
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project.write(tmp_path)
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logger.info(f"项目保存耗时: {time.time() - t_save:.1f}s")
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# 记录初始状态
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texts = {}
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extent = None
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layout = project.layoutManager().layoutByName(layout_name)
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if layout:
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for item_id in ["mapTitle", "mapTime", "mapUnit", "info"]:
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item = layout.itemById(item_id)
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if item:
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texts[item_id] = item.text()
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map_item = layout.itemById("Map")
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if map_item:
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extent = QgsRectangle(map_item.extent())
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self._cache[template_path] = {
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"file": tmp_path,
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"texts": texts,
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"extent": extent,
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"layout": layout_name,
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}
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logger.info(f"模板加载完成，总耗时: {time.time() - start:.1f}s")
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def restore_template(self, template_path: str) -> tuple:
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"""从缓存恢复模板"""
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cached = self._cache.get(template_path)
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if not cached:
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raise RuntimeError(f"模板未缓存: {template_path}")
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start = time.time()
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project = QgsProject.instance()
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logger.info(f"恢复模板: {os.path.basename(template_path)}")
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project.read(cached["file"])
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logger.info(f"project.read() 耗时: {time.time() - start:.1f}s")
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return project, cached["texts"], cached["extent"]
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def reset_project_state(self, project: QgsProject, texts: dict, extent) -> None:
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"""重置项目到干净状态"""
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start = time.time()
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for layer in project.mapLayers().values():
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if layer.subsetString():
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layer.setSubsetString("")
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# 获取 layout 名称（从缓存中）
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layout_name = "A4"
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for cached in self._cache.values():
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layout_name = cached.get("layout", "A4")
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break
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layout = project.layoutManager().layoutByName(layout_name)
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if layout:
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for item_id, text in texts.items():
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item = layout.itemById(item_id)
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if item:
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item.setText(text)
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if extent:
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map_item = layout.itemById("Map")
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if map_item:
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map_item.zoomToExtent(extent)
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logger.info(f"状态重置耗时: {time.time() - start:.3f}s")
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def cleanup(self) -> None:
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"""清理所有临时文件"""
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for cached in self._cache.values():
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try:
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os.remove(cached["file"])
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except OSError:
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pass
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self._cache.clear()
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logger.info("已清理所有缓存")
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