viewer: stream artifacts, skip unchanged live refresh, debounce search

viewer.py

@@ -7,6 +7,7 @@ import json
 import os
 import pathlib
 import re
+import shutil
 import threading
 import time
 import urllib.parse
@@ -102,13 +103,19 @@ function select(i){selected=i;
  jsonBox.textContent=JSON.stringify(e,null,2);
  if(e.evidence&&e.evidence.sha256)loadPayload(e.evidence.sha256);
  else{payloadBytes=null;art.innerHTML='<h2>Payload</h2><pre>no payload in this event</pre>';}}
+let lastBytes=-1,lastKey='';
 async function load(){
  const p=new URLSearchParams({q:document.getElementById('q').value,event:document.getElementById('event').value,
    peer:document.getElementById('peer').value,payload:document.getElementById('payload').checked?'1':'0',
    hide:document.getElementById('hide').checked?'1':'0',
    size:document.getElementById('size').value,page:page});
+ const key=p.toString();
  const r=await fetch('/api/events?'+p);const d=await r.json();
- current=d.events;lastScanned=d.scanned;lastHidden=d.hidden;hasMore=d.has_more;render(current);
+ lastScanned=d.scanned;lastHidden=d.hidden;hasMore=d.has_more;
+ // Skip re-render when nothing changed on the live page (cheap 3s refresh).
+ if(page===0 && d.journal_bytes===lastBytes && key===lastKey){return;}
+ lastBytes=d.journal_bytes;lastKey=key;
+ current=d.events;render(current);
  document.getElementById('page').textContent='page '+(page+1);
  document.getElementById('prev').disabled=page<=0;
  document.getElementById('next').disabled=!hasMore;}
@@ -117,6 +124,7 @@ document.getElementById('reload').onclick=reset;
 document.getElementById('prev').onclick=()=>{if(page>0){page--;load();}};
 document.getElementById('next').onclick=()=>{if(hasMore){page++;load();}};
 document.getElementById('q').addEventListener('keydown',e=>{if(e.key==='Enter')reset();});
+let qTimer;document.getElementById('q').addEventListener('input',()=>{clearTimeout(qTimer);qTimer=setTimeout(reset,300);});
 document.getElementById('peer').addEventListener('keydown',e=>{if(e.key==='Enter')reset();});
 document.getElementById('event').onchange=reset;
 document.getElementById('payload').onchange=reset;
@@ -236,20 +244,37 @@ class Handler(http.server.BaseHTTPRequestHandler):
                 if len(rows) >= need:
                     break
         page_rows = rows[page * size:(page + 1) * size]
+        try:
+            stat = self.server.journal.stat()
+            journal_bytes, journal_mtime = stat.st_size, int(stat.st_mtime)
+        except OSError:
+            journal_bytes, journal_mtime = 0, 0
         body = json.dumps({'events': page_rows, 'scanned': scanned, 'page': page, 'size': size,
                            'has_more': len(rows) >= need, 'hidden': len(hidden),
-                           'hidden_ips': sorted(hidden)}, ensure_ascii=True).encode()
+                           'hidden_ips': sorted(hidden), 'journal_bytes': journal_bytes,
+                           'journal_mtime': journal_mtime}, ensure_ascii=True).encode()
         self.send(200, body, 'application/json', (('Content-Disposition', 'inline'),))
 
+    def send_stream(self, path, download_name=None):
+        # Stream large payloads without loading them into memory.
+        self.send_response(200)
+        self.send_header('Content-Type', 'application/octet-stream')
+        self.send_header('Content-Length', str(path.stat().st_size))
+        self.send_header('X-Content-Type-Options', 'nosniff')
+        self.send_header('Cache-Control', 'no-store')
+        if download_name:
+            self.send_header('Content-Disposition', f'attachment; filename="{download_name}"')
+        self.end_headers()
+        if self.command != 'HEAD':
+            with path.open('rb') as stream:
+                shutil.copyfileobj(stream, self.wfile, length=1 << 20)
+
     def artifact(self, sha, query):
         path = artifact_path(self.server.artifacts, sha)
         if path is None:
             return self.send(404, b'not found', 'text/plain; charset=utf-8')
-        data = path.read_bytes()
+        download = None if self.one(query, 'inline', '0') == '1' else f'{sha}.bin'
-        if self.one(query, 'inline', '0') == '1':
+        self.send_stream(path, download)
-            return self.send(200, data, 'application/octet-stream')
-        self.send(200, data, 'application/octet-stream',
-                  (('Content-Disposition', f'attachment; filename="{sha}.bin"'),))
 
 
 def main():