新增PDF生成并发设置

backend/app/api/routes/admin_certificates.py

@@ -10,7 +10,8 @@ from app.models import AdminUser, Certificate, CertificateAccessToken, Learner,
 from app.schemas.certificate import CertificateCreate, CertificateOut
 from app.services.certificate_number import build_certificate_no
 from app.services.logs import log_action
-from app.services.pdf import render_certificate_pdf
+from app.services.pdf import PdfGenerationBusy, render_certificate_pdf
+from app.services.system_settings import get_pdf_generation_concurrency_limit
 
 router = APIRouter()
 
@@ -143,7 +144,16 @@ def download_certificate(
     project = db.query(ProjectCourse).filter(ProjectCourse.code == certificate.project_code).first()
     if not learner or not token:
         raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="Certificate data is incomplete")
-    pdf_path = render_certificate_pdf(certificate, learner, project, token)
+    try:
+        pdf_path = render_certificate_pdf(
+            certificate,
+            learner,
+            project,
+            token,
+            concurrency_limit=get_pdf_generation_concurrency_limit(db),
+        )
+    except PdfGenerationBusy as exc:
+        raise HTTPException(status_code=status.HTTP_429_TOO_MANY_REQUESTS, detail=str(exc)) from exc
     db.commit()
     return FileResponse(pdf_path, media_type="application/pdf", filename=f"{certificate.certificate_no}.pdf")