add test back in to external_index, fix elog in CheckMem

src/hnsw/external_index.c

@@ -6,6 +6,7 @@
 #include <access/generic_xlog.h>  // GenericXLog
 #include <assert.h>
 #include <common/relpath.h>
+#include <miscadmin.h>
 #include <pg_config.h>       // BLCKSZ
 #include <storage/bufmgr.h>  // Buffer
 #include <utils/hsearch.h>
@@ -629,6 +630,12 @@ void *ldb_wal_index_node_retriever(void *ctxp, int id)
                 LockBuffer(buf, BUFFER_LOCK_UNLOCK);
             }
 
+            CheckMem(work_mem,
+                     NULL,
+                     NULL,
+                     0,
+                     "Pinned more tuples during node retrieval than will fir in work_mem, cosider increasing work_mem");
+
             cache_set_item(&ctx->node_cache, &id, nodepage->node);
 
             return nodepage->node;

src/hnsw/utils.c

@@ -55,18 +55,21 @@ usearch_label_t GetUsearchLabel(ItemPointer itemPtr)
 
 void CheckMem(int limit, Relation index, usearch_index_t uidx, uint32 n_nodes, char *msg)
 {
-    usearch_error_t    error;
-    double             M = ldb_HnswGetM(index);
-    double             mL = 1 / log(M);
-    usearch_metadata_t meta = usearch_metadata(uidx, &error);
-    // todo:: update sizeof(float) to correct vector size once #19 is merged
-    uint32 node_size = UsearchNodeBytes(&meta, meta.dimensions * sizeof(float), (int)round(mL + 1));
-    Size   pg_mem = MemoryContextMemAllocated(CurrentMemoryContext, true);
+    uint32 node_size = 0;
+    if(index != NULL) {
+        usearch_error_t    error;
+        double             M = ldb_HnswGetM(index);
+        double             mL = 1 / log(M);
+        usearch_metadata_t meta = usearch_metadata(uidx, &error);
+        // todo:: update sizeof(float) to correct vector size once #19 is merged
+        node_size = UsearchNodeBytes(&meta, meta.dimensions * sizeof(float), (int)round(mL + 1));
+    }
+    Size pg_mem = MemoryContextMemAllocated(CurrentMemoryContext, true);
 
     // The average number of layers for an element to be added in is mL+1 per section 4.2.2
     // Accuracy could maybe be improved by not rounding
     // This is a guess, but it's a reasonably good one
     if(pg_mem + node_size * n_nodes > (uint32)limit * 1024UL) {
-        elog(WARNING, msg);
+        elog(WARNING, "%s", msg);
     }
 }