Merge pull request #1237 from AndreyPolovodov/fix/time-based-cache-save-during-indexing

Problem
Saving cache every 10 files causes extremely slow indexing on large projects because save_all_caches() is an expensive operation. On a large project it gets triggered thousands of times during indexing, making the whole process take hours instead of minutes.

Fix
Switch from a file-count-based trigger (every 10 files) to a time-based trigger (every 30 seconds). This keeps cache saves infrequent enough to not hurt performance, while still preserving progress regularly in case indexing is interrupted.

src/serena/cli.py

@@ -5,6 +5,7 @@ import os
 import shutil
 import subprocess
 import sys
+import time
 from collections.abc import Iterator, Sequence
 from logging import Logger
 from pathlib import Path
@@ -705,6 +706,7 @@ class ProjectCommands(AutoRegisteringGroup):
             collected_exceptions: list[Exception] = []
             files_failed = []
             language_file_counts: dict[Language, int] = collections.defaultdict(lambda: 0)
+            last_save_time = time.monotonic()
             for i, f in enumerate(tqdm(files, desc="Indexing")):
                 try:
                     ls = ls_mgr.get_language_server(f)
@@ -714,8 +716,10 @@ class ProjectCommands(AutoRegisteringGroup):
                     log.error(f"Failed to index {f}, continuing.")
                     collected_exceptions.append(e)
                     files_failed.append(f)
-                if (i + 1) % 10 == 0:
+                now = time.monotonic()
+                if now - last_save_time >= 30:
                     ls_mgr.save_all_caches()
+                    last_save_time = now
             reported_language_file_counts = {k.value: v for k, v in language_file_counts.items()}
             click.echo(f"Indexed files per language: {dict_string(reported_language_file_counts, brackets=None)}")
             ls_mgr.save_all_caches()