Replace TypenameGetTypid with custom TypenameGetTypidAllNsp funct…

…ion.

After release of Postgres 17, search_path is restricted to (pg_catalog, pg_temp)
for maintenance operations [ref: postgres/postgres@2af07e2]
So when pgvector was installed in public schema and we will try to get
the oid for vector type using `TypenameGetTypid("vector")` it would return `InvalidOid`
By this change the function `TypenameGetTypidAllNsp` will iterate over all available
namespaces and search for the type in syscache returning the oid if found.

lantern_hnsw/src/hnsw.c

@@ -452,7 +452,7 @@ HnswColumnType GetColumnTypeFromOid(Oid oid)
 
     if(oid == FLOAT4ARRAYOID) {
         return REAL_ARRAY;
-    } else if(oid == TypenameGetTypid("vector")) {
+    } else if(oid == TypenameGetTypidAllNsp("vector")) {
         return VECTOR;
     } else if(oid == INT4ARRAYOID) {
         return INT_ARRAY;

lantern_hnsw/src/hnsw/utils.c

@@ -2,14 +2,18 @@
 
 #include "utils.h"
 
+#include <access/heapam.h>
 #include <assert.h>
+#include <catalog/pg_namespace.h>
 #include <catalog/pg_type_d.h>
 #include <executor/spi.h>
 #include <math.h>
 #include <miscadmin.h>
 #include <regex.h>
 #include <string.h>
 #include <utils/builtins.h>
+#include <utils/rel.h>
+#include <utils/syscache.h>
 
 #if PG_VERSION_NUM >= 130000
 #include <utils/memutils.h>
@@ -271,3 +275,41 @@ usearch_metric_kind_t GetMetricKindFromStr(char *metric_kind_str)
 
     elog(ERROR, "Unsupported metric kind: %s . Should be one of (l2sq, cos, hamming)", metric_kind_str);
 }
+
+/*
+ * We are not using existing TypenameGetTypid because after Postgres 17
+ * The maintenance operations have restricted search_path for namepsaces (pg_catalog, pg_temp)
+ * Thus if the type will be installed in public schema, it will not be able to find the type
+ * Here we will iterate over all available namespaces and try to find the specified type on each namepsace
+ */
+Oid TypenameGetTypidAllNsp(char *typname)
+{
+    Relation      nsp_rel;
+    TableScanDesc scan;
+    HeapTuple     tuple;
+    Oid           typid = InvalidOid;
+
+    // Open pg_namespace relation
+    nsp_rel = table_open(NamespaceRelationId, AccessShareLock);
+
+    // Begin a scan on pg_namespace
+    scan = table_beginscan_catalog(nsp_rel, 0, NULL);
+
+    // Loop through all tuples in pg_namespace
+    while((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL) {
+        Form_pg_namespace nsp_form = (Form_pg_namespace)GETSTRUCT(tuple);
+
+        typid
+            = GetSysCacheOid2(TYPENAMENSP, Anum_pg_type_oid, PointerGetDatum(typname), ObjectIdGetDatum(nsp_form->oid));
+
+        if(OidIsValid(typid)) {
+            break;
+        }
+    }
+
+    // End scan and close relation
+    table_endscan(scan);
+    table_close(nsp_rel, AccessShareLock);
+
+    return typid;
+}

lantern_hnsw/src/hnsw/utils.h

@@ -17,6 +17,7 @@ void                  CheckExtensionVersions();
 uint32                EstimateRowCount(Relation heap);
 int32                 GetColumnAttributeNumber(Relation rel, const char *columnName);
 usearch_metric_kind_t GetMetricKindFromStr(char *metric_kind_str);
+Oid                   TypenameGetTypidAllNsp(char *typname);
 
 // hoping to throw the error via an assertion, if those are on, before elog(ERROR)-ing as a last resort
 // We prefer Assert() because this function is used in contexts where the stack contains non-POD types