255 lines
8.6 KiB
Python
255 lines
8.6 KiB
Python
"""Playwright 页面抓取工具。
|
||
|
||
对外仅暴露两个动作：
|
||
- open_page(url, wait_ms): 打开页面，返回 page_id
|
||
- query(page_id, selector): 选中节点并提取文字、图片 URL 与属性
|
||
|
||
实现上内部常驻一个 Browser；每次 open_page 创建独立 BrowserContext 和 Page，
|
||
query 完成后自动释放对应资源。
|
||
"""
|
||
|
||
from __future__ import annotations
|
||
|
||
import asyncio
|
||
import threading
|
||
import uuid
|
||
from dataclasses import dataclass
|
||
|
||
from playwright.async_api import Browser, BrowserContext, Page, async_playwright
|
||
|
||
|
||
@dataclass
|
||
class NodeSnapshot:
|
||
"""页面节点快照。"""
|
||
|
||
tag: str
|
||
text: str
|
||
image_urls: list[str]
|
||
attrs: dict[str, str]
|
||
|
||
|
||
@dataclass
|
||
class _PageSession:
|
||
context: BrowserContext
|
||
page: Page
|
||
|
||
|
||
class _BrowserRuntime:
|
||
"""在后台事件循环中管理 Playwright 生命周期。"""
|
||
|
||
def __init__(self) -> None:
|
||
self._thread: threading.Thread | None = None
|
||
self._loop: asyncio.AbstractEventLoop | None = None
|
||
self._ready = threading.Event()
|
||
self._lock = threading.RLock()
|
||
self._playwright = None
|
||
self._browser: Browser | None = None
|
||
self._pages: dict[str, _PageSession] = {}
|
||
|
||
def _thread_main(self) -> None:
|
||
loop = asyncio.new_event_loop()
|
||
asyncio.set_event_loop(loop)
|
||
self._loop = loop
|
||
self._ready.set()
|
||
loop.run_forever()
|
||
|
||
pending = asyncio.all_tasks(loop)
|
||
for task in pending:
|
||
task.cancel()
|
||
|
||
if pending:
|
||
loop.run_until_complete(asyncio.gather(*pending, return_exceptions=True))
|
||
|
||
if self._browser is not None:
|
||
loop.run_until_complete(self._browser.close())
|
||
self._browser = None
|
||
|
||
if self._playwright is not None:
|
||
loop.run_until_complete(self._playwright.stop())
|
||
self._playwright = None
|
||
|
||
loop.run_until_complete(loop.shutdown_asyncgens())
|
||
loop.close()
|
||
|
||
def _ensure_thread(self) -> None:
|
||
with self._lock:
|
||
if self._thread and self._thread.is_alive():
|
||
return
|
||
|
||
self._thread = threading.Thread(
|
||
target=self._thread_main,
|
||
name="offerpie-playwright",
|
||
daemon=True,
|
||
)
|
||
self._thread.start()
|
||
self._ready.wait()
|
||
|
||
def _run(self, coro):
|
||
self._ensure_thread()
|
||
assert self._loop is not None
|
||
future = asyncio.run_coroutine_threadsafe(coro, self._loop)
|
||
return future.result()
|
||
|
||
async def _ensure_browser(self) -> Browser:
|
||
if self._browser is not None:
|
||
return self._browser
|
||
|
||
if self._playwright is None:
|
||
self._playwright = await async_playwright().start()
|
||
|
||
self._browser = await self._playwright.chromium.launch(headless=True)
|
||
return self._browser
|
||
|
||
async def _open_page(self, url: str, wait_ms: int) -> str:
|
||
browser = await self._ensure_browser()
|
||
context = await browser.new_context()
|
||
page = await context.new_page()
|
||
await page.goto(url, wait_until="domcontentloaded", timeout=30000)
|
||
if wait_ms > 0:
|
||
await page.wait_for_timeout(wait_ms)
|
||
|
||
page_id = uuid.uuid4().hex
|
||
self._pages[page_id] = _PageSession(context=context, page=page)
|
||
return page_id
|
||
|
||
async def _query(self, page_id: str, selector: str) -> list[NodeSnapshot]:
|
||
session = self._pages.get(page_id)
|
||
if session is None:
|
||
raise KeyError(f"Unknown page_id: {page_id}")
|
||
|
||
try:
|
||
locator = session.page.locator(selector)
|
||
payload = await locator.evaluate_all(
|
||
r"""(elements) => elements.map((el) => {
|
||
const attrs = {};
|
||
for (const attr of Array.from(el.attributes || [])) {
|
||
attrs[attr.name] = attr.value;
|
||
}
|
||
|
||
const imageUrls = [];
|
||
const addImageUrl = (url) => {
|
||
if (!url) return;
|
||
try {
|
||
const absUrl = new URL(url, location.href).href;
|
||
if (
|
||
absUrl.startsWith('data:') ||
|
||
absUrl.startsWith('blob:') ||
|
||
absUrl === 'about:blank'
|
||
) {
|
||
return;
|
||
}
|
||
imageUrls.push(absUrl);
|
||
} catch {
|
||
if (
|
||
url.startsWith('data:') ||
|
||
url.startsWith('blob:') ||
|
||
url === 'about:blank'
|
||
) {
|
||
return;
|
||
}
|
||
imageUrls.push(url);
|
||
}
|
||
};
|
||
|
||
const resolveImageUrl = (img) => {
|
||
const candidates = [
|
||
img.getAttribute('data-src'),
|
||
img.getAttribute('data-original'),
|
||
img.getAttribute('data-croporisrc'),
|
||
img.currentSrc,
|
||
img.src,
|
||
img.getAttribute('src'),
|
||
];
|
||
|
||
const srcset = img.getAttribute('srcset');
|
||
if (srcset) {
|
||
for (const part of srcset.split(',')) {
|
||
const candidate = part.trim().split(/\s+/)[0];
|
||
candidates.push(candidate);
|
||
}
|
||
}
|
||
|
||
for (const candidate of candidates) {
|
||
if (!candidate) continue;
|
||
if (
|
||
candidate.startsWith('data:') ||
|
||
candidate.startsWith('blob:') ||
|
||
candidate === 'about:blank'
|
||
) {
|
||
continue;
|
||
}
|
||
try {
|
||
const absUrl = new URL(candidate, location.href).href;
|
||
if (
|
||
absUrl.startsWith('data:') ||
|
||
absUrl.startsWith('blob:') ||
|
||
absUrl === 'about:blank'
|
||
) {
|
||
continue;
|
||
}
|
||
return absUrl;
|
||
} catch {
|
||
return candidate;
|
||
}
|
||
}
|
||
|
||
return null;
|
||
};
|
||
|
||
if (el.tagName === 'IMG') {
|
||
addImageUrl(resolveImageUrl(el));
|
||
}
|
||
|
||
for (const img of Array.from(el.querySelectorAll('img'))) {
|
||
addImageUrl(resolveImageUrl(img));
|
||
}
|
||
|
||
const text = (el.innerText || el.textContent || '').trim();
|
||
|
||
return {
|
||
tag: (el.tagName || '').toLowerCase(),
|
||
text,
|
||
image_urls: Array.from(new Set(imageUrls)),
|
||
attrs,
|
||
};
|
||
})"""
|
||
)
|
||
return [
|
||
NodeSnapshot(
|
||
tag=item.get("tag", ""),
|
||
text=item.get("text", ""),
|
||
image_urls=list(item.get("image_urls", [])),
|
||
attrs=dict(item.get("attrs", {})),
|
||
)
|
||
for item in payload
|
||
]
|
||
finally:
|
||
await session.page.close()
|
||
await session.context.close()
|
||
self._pages.pop(page_id, None)
|
||
|
||
|
||
_runtime = _BrowserRuntime()
|
||
|
||
|
||
def open_page(url: str, wait_ms: int = 3000) -> str:
|
||
"""打开页面并返回 page_id。"""
|
||
return _runtime._run(_runtime._open_page(url, wait_ms))
|
||
|
||
|
||
def query(page_id: str, selector: str) -> list[NodeSnapshot]:
|
||
"""按选择器抓取节点，提取文本、图片 URL 与属性。"""
|
||
items = _runtime._run(_runtime._query(page_id, selector))
|
||
seen_urls: set[str] = set()
|
||
|
||
for item in items:
|
||
unique_urls: list[str] = []
|
||
for url in item.image_urls:
|
||
if url in seen_urls:
|
||
continue
|
||
seen_urls.add(url)
|
||
unique_urls.append(url)
|
||
item.image_urls = unique_urls
|
||
|
||
return items
|