fix: use http.client for LLM streaming (bypass 64KB buffer)

ai_answers.py

@@ -1,6 +1,10 @@
-import json, os, logging, base64, time, hashlib, codecs, re
+import json, os, logging, base64, time, hashlib, codecs, re, http.client, ssl
 from urllib.parse import urlparse
 from searx import network
+try:
+    from searx.network import get_network
+except ImportError:
+    get_network = None  # Graceful fallback for test/demo environments
 from flask import Response, request, abort, jsonify
 from searx.plugins import Plugin, PluginInfo
 from searx.result_types import EngineResults
@@ -10,6 +14,30 @@ from markupsafe import Markup
 logger = logging.getLogger(__name__)
 
 TOKEN_EXPIRY_SEC = 3600
+STREAM_CHUNK_SIZE = 128
+STREAM_TIMEOUT_SEC = 60
+
+def _get_streaming_connection(url: str):
+    parsed = urlparse(url)
+    host = parsed.hostname
+    port = parsed.port or (443 if parsed.scheme == 'https' else 80)
+    path = parsed.path + ('?' + parsed.query if parsed.query else '')
+    
+    verify_ssl = True
+    if get_network is not None:
+        try:
+            net = get_network()
+            verify_ssl = getattr(net, 'verify', True)
+        except Exception:
+            pass
+    
+    if parsed.scheme == 'https':
+        ctx = ssl.create_default_context() if verify_ssl else ssl._create_unverified_context()
+        conn = http.client.HTTPSConnection(host, port, timeout=STREAM_TIMEOUT_SEC, context=ctx)
+    else:
+        conn = http.client.HTTPConnection(host, port, timeout=STREAM_TIMEOUT_SEC)
+    
+    return conn, path
 
 
 
@@ -731,22 +759,23 @@ class SXNGPlugin(Plugin):
                 else:
                     url = f"{self.endpoint_url}?key={self.api_key}"
 
+                conn = None
                 try:
-                    payload = {"contents": [{"parts": [{"text": prompt}]}], "generationConfig": {"maxOutputTokens": self.max_tokens, "temperature": self.temperature, "stopSequences": ["</answer>"]}}
-                    headers = {"Content-Type": "application/json"}
-                    res, chunk_gen = network.stream('POST', url, json=payload, headers=headers, timeout=60)
+                    conn, path = _get_streaming_connection(url)
+                    payload = json.dumps({"contents": [{"parts": [{"text": prompt}]}], "generationConfig": {"maxOutputTokens": self.max_tokens, "temperature": self.temperature, "stopSequences": ["</answer>"]}})
+                    conn.request("POST", path, body=payload, headers={"Content-Type": "application/json"})
+                    res = conn.getresponse()
                     
-                    if res.status_code != 200:
-                        for _ in chunk_gen: pass  # Drain to prevent resource leak
-                        logger.error(f"{PLUGIN_NAME}: Gemini API {res.status_code}")
+                    if res.status != 200:
+                        logger.error(f"{PLUGIN_NAME}: Gemini API {res.status}")
                         return
 
                     decoder = json.JSONDecoder()
                     buffer = ""
-                    utf8_decoder = codecs.getincrementaldecoder("utf-8")(errors='replace')
-                    for chunk in chunk_gen:
-                        if not chunk: continue
-                        buffer += utf8_decoder.decode(chunk, final=False)
+                    while True:
+                        chunk = res.read(STREAM_CHUNK_SIZE)
+                        if not chunk: break
+                        buffer += chunk.decode('utf-8', errors='replace')
                         while buffer:
                             buffer = buffer.lstrip()
                             if not buffer: break
@@ -765,17 +794,21 @@ class SXNGPlugin(Plugin):
                             except json.JSONDecodeError: break
                 except Exception as e:
                     logger.error(f"{PLUGIN_NAME}: Gemini stream error: {e}")
+                finally:
+                    if conn: conn.close()
 
             def stream_openai_compatible():
+                conn = None
                 try:
-                    payload = {
+                    conn, path = _get_streaming_connection(self.endpoint_url)
+                    payload = json.dumps({
                         "model": self.model,
                         "messages": [{"role": "user", "content": prompt}],
                         "stream": True,
                         "max_tokens": self.max_tokens,
                         "temperature": self.temperature,
                         "stop": ["</answer>"]
-                    }
+                    })
                     headers = {
                         "Content-Type": "application/json",
                         "HTTP-Referer": "https://github.com/searxng/searxng",
@@ -785,17 +818,18 @@ class SXNGPlugin(Plugin):
                         headers['api-key'] = self.api_key
                     else:
                         headers['Authorization'] = f"Bearer {self.api_key}"
-                    res, chunk_gen = network.stream('POST', self.endpoint_url, json=payload, headers=headers, timeout=60)
+                    conn.request("POST", path, body=payload, headers=headers)
+                    res = conn.getresponse()
 
-                    if res.status_code != 200:
-                        for _ in chunk_gen: pass
-                        logger.error(f"{PLUGIN_NAME}: {self.provider} API {res.status_code}")
+                    if res.status != 200:
+                        logger.error(f"{PLUGIN_NAME}: {self.provider} API {res.status}")
                         return
 
                     decoder = json.JSONDecoder()
                     buffer = b""
-                    for chunk in chunk_gen:
-                        if not chunk: continue
+                    while True:
+                        chunk = res.read(STREAM_CHUNK_SIZE)
+                        if not chunk: break
                         buffer += chunk
                         while b"\n" in buffer:
                             line_bytes, buffer = buffer.split(b"\n", 1)
@@ -811,13 +845,16 @@ class SXNGPlugin(Plugin):
                                     pass
                 except Exception as e:
                     logger.error(f"{PLUGIN_NAME}: {self.provider} stream error: {e}")
+                finally:
+                    if conn: conn.close()
 
             generator = stream_gemini if self.is_gemini else stream_openai_compatible
             return Response(generator(), mimetype='text/event-stream', headers={
                 'X-Accel-Buffering': 'no',
                 'Cache-Control': 'no-cache, no-store',
                 'Connection': 'keep-alive',
-                'Content-Encoding': 'identity'
+                'Transfer-Encoding': 'chunked',
+                'Content-Encoding': 'identity',
             })
         return True