Explicitly free temporary vector list and gc.collect after loading

On PyPy, gc.collect() helps release memory back to the OS after the
temporary list of 1.4M vectors is replaced by the numpy matrix.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: vthorsteinsson

vectors/simserver.py

@@ -63,6 +63,7 @@
 
 from __future__ import annotations
 
+import gc
 import json
 import time
 import sys
@@ -141,14 +142,21 @@ def _load_topics(self) -> None:
         dims = self._corpus.dimensions
         if vectors:
             self._matrix = np.array(vectors, dtype=np.float32)
+            # Free the temporary list before computing norms
+            del vectors
+            gc.collect()
             # Precompute squared norms for cosine similarity
             self._norms_sq = np.einsum("ij,ij->i", self._matrix, self._matrix)
         else:
+            del vectors
             self._matrix = np.empty((0, dims), dtype=np.float32)
             self._norms_sq = np.empty((0,), dtype=np.float32)
         self._ids = ids
         self._id_to_index = {aid: idx for idx, aid in enumerate(ids)}
 
+        # Release any remaining temporary memory back to the OS
+        gc.collect()
+
         print(
             "Loading of {0} topic vectors completed in {1:.2f} seconds".format(
                 len(ids), t1 - t0