⚡ Bolt: Use json.loads instead of deepcopy for memory caches

.jules/bolt.md

@@ -0,0 +1,3 @@
+## 2024-05-04 - Caching OS Page Memory Instead of Deepcopy
+**Learning:** Python `copy.deepcopy()` on parsed JSON dicts is often slower than storing the raw JSON string and calling `json.loads()` on demand when retrieving from the cache, because json string parsing via the C-extension is heavily optimized.
+**Action:** When caching JSON-serializable payloads in memory to avoid mutation bugs, save the object as a JSON string with `json.dumps()` in the cache, and retrieve it using `json.loads()` instead of relying on `copy.deepcopy()`.

intelligence/company/meridian_platform/status_surface.py

@@ -5,6 +5,7 @@
 
 import concurrent.futures
 import copy
+import json
 import datetime
 import os
 import threading
@@ -467,21 +468,21 @@ def observability_snapshot(org_id, *, record_alerts=True):
     with OBSERVABILITY_SNAPSHOT_CACHE_LOCK:
         cached_entry = OBSERVABILITY_SNAPSHOT_CACHE.get(cache_key)
         if not isinstance(cached_entry, dict):
-            cached_entry = {'fetched_at': 0.0, 'payload': None, 'refresh_future': None}
+            cached_entry = {'fetched_at': 0.0, 'payload': None, 'refresh_future': None, 'payload_json': None}
             OBSERVABILITY_SNAPSHOT_CACHE[cache_key] = cached_entry
         fetched_at = float(cached_entry.get('fetched_at') or 0.0)
-        payload = cached_entry.get('payload')
+        payload = json.loads(cached_entry.get('payload_json', '{}')) if cached_entry.get('payload_json') else None
         refresh_future = cached_entry.get('refresh_future')
         if (
             isinstance(payload, dict)
             and fetched_at > 0
             and (now - fetched_at) <= ttl_seconds
         ):
-            return copy.deepcopy(payload)
+            return payload
         if not isinstance(payload, dict):
             pass  # cold start — fall through to synchronous build below
         elif refresh_future and not refresh_future.done():
-            return copy.deepcopy(payload)
+            return payload
         else:
             if not (refresh_future and not refresh_future.done()):
                 refresh_future = OBSERVABILITY_SNAPSHOT_EXECUTOR.submit(
@@ -490,17 +491,17 @@ def observability_snapshot(org_id, *, record_alerts=True):
                     record_alerts=record_alerts,
                 )
                 cached_entry['refresh_future'] = refresh_future
-            return copy.deepcopy(payload)
+            return payload
 
     if not isinstance(payload, dict):
         snapshot = _build_observability_snapshot(org_id, record_alerts=record_alerts)
         with OBSERVABILITY_SNAPSHOT_CACHE_LOCK:
             cached_entry = OBSERVABILITY_SNAPSHOT_CACHE.get(cache_key)
             if not isinstance(cached_entry, dict):
-                cached_entry = {'fetched_at': 0.0, 'payload': None, 'refresh_future': None}
+                cached_entry = {'fetched_at': 0.0, 'payload': None, 'refresh_future': None, 'payload_json': None}
                 OBSERVABILITY_SNAPSHOT_CACHE[cache_key] = cached_entry
             cached_entry['fetched_at'] = time.time()
-            cached_entry['payload'] = copy.deepcopy(snapshot)
+            cached_entry['payload_json'] = json.dumps(snapshot)
             cached_entry['refresh_future'] = None
         return snapshot
     try:
@@ -600,10 +601,10 @@ def observability_snapshot(org_id, *, record_alerts=True):
     with OBSERVABILITY_SNAPSHOT_CACHE_LOCK:
         cached_entry = OBSERVABILITY_SNAPSHOT_CACHE.get(cache_key)
         if not isinstance(cached_entry, dict):
-            cached_entry = {'fetched_at': 0.0, 'payload': None, 'refresh_future': None}
+            cached_entry = {'fetched_at': 0.0, 'payload': None, 'refresh_future': None, 'payload_json': None}
             OBSERVABILITY_SNAPSHOT_CACHE[cache_key] = cached_entry
         cached_entry['fetched_at'] = time.time()
-        cached_entry['payload'] = copy.deepcopy(snapshot)
+        cached_entry['payload_json'] = json.dumps(snapshot)
         cached_entry['refresh_future'] = None
     return snapshot
 

intelligence/company/meridian_platform/workspace.py

@@ -156,6 +156,7 @@
 import base64
 import concurrent.futures
 import copy
+import json
 import datetime
 import hashlib
 import hmac
@@ -861,7 +862,7 @@ def _build_payload():
         with _public_kernel_proof_cache_lock:
             _public_kernel_proof_cache[cache_key] = {
                 'cached_at_epoch': time.time(),
-                'payload': copy.deepcopy(cached_payload),
+                'payload_json': json.dumps(cached_payload),
             }
             _public_kernel_proof_last_error.pop(cache_key, None)
         return cached_payload
@@ -887,7 +888,11 @@ def _ensure_refresh_in_flight():
             return future
 
     with _public_kernel_proof_cache_lock:
-        cache_entry = copy.deepcopy(_public_kernel_proof_cache.get(cache_key))
+        cache_entry_raw = _public_kernel_proof_cache.get(cache_key)
+        if cache_entry_raw:
+            cache_entry = {'cached_at_epoch': cache_entry_raw.get('cached_at_epoch'), 'payload': json.loads(cache_entry_raw.get('payload_json')) if cache_entry_raw.get('payload_json') else None}
+        else:
+            cache_entry = None
         last_error = _public_kernel_proof_last_error.get(cache_key)
 
     if cache_entry:
@@ -929,7 +934,7 @@ def _ensure_refresh_in_flight():
                     base_url=normalized_base,
                     run_reference_proofs=False,
                 )
-                fallback_payload = copy.deepcopy(fast_payload)
+                fallback_payload = json.loads(json.dumps(fast_payload))
                 fallback_payload['status'] = 'degraded'
                 fallback_payload['degraded_reason'] = 'public_bundle_build_in_progress_fast_fallback'
                 cache_meta = dict(fallback_payload.get('cache') or {})