[verified] refresh OpenVINO NPU reranker prototype

openvino-reranker-npu/server.py

@@ -16,6 +16,7 @@ import argparse
 import json
 import math
 import os
+import socket
 import sys
 import threading
 import time
@@ -251,6 +252,27 @@ def normalize_documents(value: Any, max_documents: int) -> list[dict[str, Any]]:
     return docs
 
 
+def parse_top_k(value: Any, document_count: int) -> int:
+    """Validate top_k/top_n before inference so schema errors return HTTP 400."""
+    if value is None:
+        return document_count
+    if isinstance(value, bool) or not isinstance(value, int):
+        raise ValueError("top_k/top_n must be a positive integer")
+    if value < 1:
+        raise ValueError("top_k/top_n must be a positive integer")
+    return min(value, document_count)
+
+
+def assert_port_available(host: str, port: int) -> None:
+    """Fail fast on listener conflicts before compiling the OpenVINO model."""
+    with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as sock:
+        sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+        try:
+            sock.bind((host, port))
+        except OSError as exc:
+            raise RuntimeError(f"cannot bind {host}:{port}; listener conflict or invalid bind: {exc}") from exc
+
+
 class Handler(BaseHTTPRequestHandler):
     server_version = "OpenVINOReranker/0.1"
 
@@ -293,6 +315,7 @@ class Handler(BaseHTTPRequestHandler):
                 raise ValueError("query is required")
             top_k = payload.get("top_k", payload.get("top_n"))
             documents = normalize_documents(payload.get("documents"), self.max_documents)
+            top_k = parse_top_k(top_k, len(documents))
             return_documents = bool(payload.get("return_documents", True))
             response = self.svc.rerank(query.strip(), documents, top_k=top_k, return_documents=return_documents)
             self.write_json(response)
@@ -342,6 +365,7 @@ def main() -> int:
     parser.add_argument("--skip-startup-smoke", action="store_true", default=os.environ.get("OPENVINO_RERANKER_SKIP_STARTUP_SMOKE", "").lower() in {"1", "true", "yes"})
     args = parser.parse_args()
 
+    assert_port_available(args.host, args.port)
     service = RerankerService(
         Path(args.model_dir).expanduser(),
         args.model,