fix: clear batch on flush failure and tune LMDB for low memory

When add_assets() throws during batch flush, batch.clear() was never
reached causing an infinite retry loop where every subsequent file
triggers another failed flush of the growing batch. Wrap both mid-loop
and final flush in try/except/finally to always clear the batch.

Tune LMDB for single-process server: meminit=False skips memset on
buffer alloc, max_readers=4 and max_spare_txns=1 reduce overhead.

Author: titusz

iscc_search/cli/add.py

@@ -187,11 +187,17 @@ def parse_and_index_files(files, index, index_name, batch_size=100, verbose=Fals
                 # Flush batch when full
                 if len(batch) >= batch_size:
                     batch_count += 1
-                    progress.update(parse_task, description=f"Indexing batch {batch_count} ({len(batch)} assets)...")
+                    flush_size = len(batch)
+                    progress.update(parse_task, description=f"Indexing batch {batch_count} ({flush_size} assets)...")
 
-                    results = index.add_assets(index_name, batch)
-                    all_results.extend(results)
-                    batch.clear()
+                    try:
+                        results = index.add_assets(index_name, batch)
+                        all_results.extend(results)
+                    except Exception as flush_err:
+                        errors.append(f"Batch {batch_count} ({flush_size} assets): {flush_err}")
+                        logger.error(f"Batch {batch_count} failed: {flush_err}")
+                    finally:
+                        batch.clear()
                     progress.update(parse_task, description="Parsing files...")
 
             except Exception as e:
@@ -205,11 +211,17 @@ def parse_and_index_files(files, index, index_name, batch_size=100, verbose=Fals
         # Flush remaining assets
         if batch:
             batch_count += 1
-            progress.update(parse_task, description=f"Indexing batch {batch_count} ({len(batch)} assets)...")
+            flush_size = len(batch)
+            progress.update(parse_task, description=f"Indexing batch {batch_count} ({flush_size} assets)...")
 
-            results = index.add_assets(index_name, batch)
-            all_results.extend(results)
-            batch.clear()
+            try:
+                results = index.add_assets(index_name, batch)
+                all_results.extend(results)
+            except Exception as flush_err:
+                errors.append(f"Batch {batch_count} ({flush_size} assets): {flush_err}")
+                logger.error(f"Batch {batch_count} failed: {flush_err}")
+            finally:
+                batch.clear()
 
     return all_results, errors
 

iscc_search/indexes/usearch/index.py

@@ -62,10 +62,10 @@ class UsearchIndex:
         "create": True,
         "readahead": False,
         "writemap": False,
-        "meminit": True,
+        "meminit": False,
         "map_async": False,
-        "max_readers": 126,
-        "max_spare_txns": 16,
+        "max_readers": 4,
+        "max_spare_txns": 1,
         "lock": True,
     }