Add the beginning backbone of the vertex am

Author: JoshInnis

Makefile

@@ -25,6 +25,7 @@ OBJS = src/backend/postgraph.o \
        src/backend/access/ivfflat/ivfscan.o \
        src/backend/access/ivfflat/ivfutils.o \
        src/backend/access/ivfflat/ivfvacuum.o \
+       src/backend/access/vertex_heap/vertex_heapam_handler.o \
        src/backend/catalog/ag_catalog.o \
        src/backend/catalog/ag_graph.o \
        src/backend/catalog/ag_label.o \

src/backend/access/vertex_heap/vertex_heapam_handler.c

@@ -0,0 +1,137 @@
+/*-------------------------------------------------------------------------
+ *
+ * vertex_heapam_handler.c
+ *	  vertex heap access method code
+ *
+ * Portions Copyright (c) 2025, PostGraphDB
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/access/vertex_heap/vertex_heapam_handler.c
+ *
+ *
+ * NOTES
+ *	  This files wires up the lower level heapam.c et al routines with the
+ *	  tableam abstraction.
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "access/genam.h"
+#include "access/heapam.h"
+#include "access/heaptoast.h"
+#include "access/multixact.h"
+#include "access/rewriteheap.h"
+#include "access/syncscan.h"
+#include "access/tableam.h"
+#include "access/tsmapi.h"
+#include "access/xact.h"
+#include "catalog/catalog.h"
+#include "catalog/index.h"
+#include "catalog/storage.h"
+#include "catalog/storage_xlog.h"
+#include "commands/progress.h"
+#include "executor/executor.h"
+#include "miscadmin.h"
+#include "pgstat.h"
+#include "storage/bufmgr.h"
+#include "storage/bufpage.h"
+#include "storage/lmgr.h"
+#include "storage/predicate.h"
+#include "storage/procarray.h"
+#include "storage/smgr.h"
+#include "utils/builtins.h"
+#include "utils/rel.h"
+
+
+/* ------------------------------------------------------------------------
+ * Slot related callbacks for vertex heap AM
+ * ------------------------------------------------------------------------
+ */
+
+static const TupleTableSlotOps *
+vertex_heapam_slot_callbacks(Relation relation)
+{
+	return &TTSOpsBufferHeapTuple;
+}
+
+
+/* ------------------------------------------------------------------------
+ * Definition of the heap table access method.
+ * ------------------------------------------------------------------------
+ */
+
+static const TableAmRoutine vertex_heapam_methods = {
+	.type = T_TableAmRoutine,
+
+	.slot_callbacks = vertex_heapam_slot_callbacks,
+
+	.scan_begin = NULL,
+	.scan_end = NULL,
+	.scan_rescan = NULL,
+	.scan_getnextslot = NULL,
+
+	.scan_set_tidrange = NULL,
+	.scan_getnextslot_tidrange = NULL,
+
+	.parallelscan_estimate = NULL,
+	.parallelscan_initialize = NULL,
+	.parallelscan_reinitialize = NULL,
+
+	.index_fetch_begin = NULL,
+	.index_fetch_reset = NULL,
+	.index_fetch_end = NULL,
+	.index_fetch_tuple = NULL,
+
+	.tuple_insert = NULL,
+	.tuple_insert_speculative = NULL,
+	.tuple_complete_speculative = NULL,
+	.multi_insert = NULL,
+	.tuple_delete = NULL,
+	.tuple_update = NULL,
+	.tuple_lock = NULL,
+
+	.tuple_fetch_row_version = NULL,
+	.tuple_get_latest_tid = NULL,
+	.tuple_tid_valid = NULL,
+	.tuple_satisfies_snapshot = NULL,
+	.index_delete_tuples = NULL,
+
+	.relation_set_new_filenode = NULL,
+	.relation_nontransactional_truncate = NULL,
+	.relation_copy_data = NULL,
+	.relation_copy_for_cluster = NULL,
+	.relation_vacuum = NULL,
+	.scan_analyze_next_block = NULL,
+	.scan_analyze_next_tuple = NULL,
+	.index_build_range_scan = NULL,
+	.index_validate_scan = NULL,
+
+	.relation_size = NULL,
+	.relation_needs_toast_table = NULL,
+	.relation_toast_am = NULL,
+	.relation_fetch_toast_slice = NULL,
+
+	.relation_estimate_size = NULL,
+
+	.scan_bitmap_next_block = NULL,
+	.scan_bitmap_next_tuple = NULL,
+	.scan_sample_next_block = NULL,
+	.scan_sample_next_tuple = NULL
+};
+
+
+const TableAmRoutine *
+GetVertexHeapamTableAmRoutine(void)
+{
+	return &vertex_heapam_methods;
+}
+
+Datum
+vertex_heap_tableam_handler(PG_FUNCTION_ARGS)
+{
+	PG_RETURN_POINTER(&vertex_heapam_methods);
+}