From 12f635aa04c4a5c60307b3696c0f63f5f205989a Mon Sep 17 00:00:00 2001
From: Konstantin Knizhnik <knizhnik@neon.tech>
Date: Thu, 24 Oct 2024 17:09:38 +0300
Subject: [PATCH] Fix warnings

---
 pgxn/neon/file_cache.c |  1 -
 pgxn/neon/file_cache.h | 64 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 64 insertions(+), 1 deletion(-)
 create mode 100644 pgxn/neon/file_cache.h

diff --git a/pgxn/neon/file_cache.c b/pgxn/neon/file_cache.c
index fc46872c0a..d124ce59ba 100644
--- a/pgxn/neon/file_cache.c
+++ b/pgxn/neon/file_cache.c
@@ -688,7 +688,6 @@ lfc_load_pages(void)
 	uint32 entry_offset;
 	uint32 hash;
 	int    shard_no;
-	size_t i;
 	FileCacheStateEntry* fs = lfc_state;
 	size_t max_entries = lfc_state_size;
 
diff --git a/pgxn/neon/file_cache.h b/pgxn/neon/file_cache.h
new file mode 100644
index 0000000000..65985eb54d
--- /dev/null
+++ b/pgxn/neon/file_cache.h
@@ -0,0 +1,64 @@
+/*-------------------------------------------------------------------------
+ *
+ * file_cache.h
+ *
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef file_cache_h
+#define file_cache_h
+
+#include "neon_pgversioncompat.h"
+
+/* Local file storage allocation chunk.
+ * Should be power of two. Using larger than page chunks can
+ * 1. Reduce hash-map memory footprint: 8TB database contains billion pages
+ *    and size of hash entry is 40 bytes, so we need 40Gb just for hash map.
+ *    1Mb chunks can reduce hash map size to 320Mb.
+ * 2. Improve access locality, subsequent pages will be allocated together improving seqscan speed
+ */
+#define BLOCKS_PER_CHUNK	128 /* 1Mb chunk */
+#define CHUNK_BITMAP_SIZE   ((BLOCKS_PER_CHUNK + 31) / 32)
+
+typedef struct
+{
+	BufferTag	key;
+	uint32		bitmap[CHUNK_BITMAP_SIZE];
+} FileCacheEntryDesc;
+
+PGDLLEXPORT void LfcPrewarmMain(Datum main_arg);
+
+extern void lfc_writev(NRelFileInfo rinfo, ForkNumber forkNum,
+					   BlockNumber blkno, const void *const *buffers,
+					   BlockNumber nblocks);
+/* returns number of blocks read, with one bit set in *read for each  */
+extern int lfc_readv_select(NRelFileInfo rinfo, ForkNumber forkNum,
+							BlockNumber blkno, void **buffers,
+							BlockNumber nblocks, bits8 *mask);
+
+extern bool lfc_cache_contains(NRelFileInfo rinfo, ForkNumber forkNum,
+							   BlockNumber blkno);
+extern int lfc_cache_containsv(NRelFileInfo rinfo, ForkNumber forkNum,
+							   BlockNumber blkno, int nblocks, bits8 *bitmap);
+extern void lfc_evict(NRelFileInfo rinfo, ForkNumber forkNum, BlockNumber blkno);
+extern void lfc_init(void);
+
+static inline bool
+lfc_read(NRelFileInfo rinfo, ForkNumber forkNum, BlockNumber blkno,
+		 void *buffer)
+{
+	bits8		rv = 0;
+	return lfc_readv_select(rinfo, forkNum, blkno, &buffer, 1, &rv) == 1;
+}
+
+static inline void
+lfc_write(NRelFileInfo rinfo, ForkNumber forkNum, BlockNumber blkno,
+		  const void *buffer)
+{
+	return lfc_writev(rinfo, forkNum, blkno, &buffer, 1);
+}
+
+#endif