v1-0001-WIP-increase-glibc-buffering-for-pg_restore-custo.patch

From 56559e95fabbc498d7127db45992336f10a6cd93 Mon Sep 17 00:00:00 2001
From: Dimitrios Apostolou <jimis@qt.io>
Date: Tue, 21 Oct 2025 15:55:47 +0200
Subject: [PATCH v1] WIP: increase glibc buffering for pg_restore custom format

---
 src/bin/pg_dump/pg_backup_custom.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/bin/pg_dump/pg_backup_custom.c b/src/bin/pg_dump/pg_backup_custom.c
index f7c3af56304..79ffac315b5 100644
--- a/src/bin/pg_dump/pg_backup_custom.c
+++ b/src/bin/pg_dump/pg_backup_custom.c
@@ -160,18 +160,22 @@ InitArchiveFmt_Custom(ArchiveHandle *AH)
 		ctx->hasSeek = checkSeek(AH->FH);
 	}
 	else
 	{
 		if (AH->fSpec && strcmp(AH->fSpec, "") != 0)
 		{
 			AH->FH = fopen(AH->fSpec, PG_BINARY_R);
 			if (!AH->FH)
 				pg_fatal("could not open input file \"%s\": %m", AH->fSpec);
+			void *buf = pg_malloc(1024*1024);
+			int ret = setvbuf(AH->FH, buf, _IOFBF, 1024*1024);
+			if (ret != 0)
+				pg_fatal("setvbuf failed: %m");
 		}
 		else
 		{
 			AH->FH = stdin;
 			if (!AH->FH)
 				pg_fatal("could not open input file: %m");
 		}
 
 		ctx->hasSeek = checkSeek(AH->FH);
@@ -808,18 +812,23 @@ _ReopenArchive(ArchiveHandle *AH)
 		pg_fatal("could not close archive file: %m");
 #endif
 
 	AH->FH = fopen(AH->fSpec, PG_BINARY_R);
 	if (!AH->FH)
 		pg_fatal("could not open input file \"%s\": %m", AH->fSpec);
 
 	if (fseeko(AH->FH, tpos, SEEK_SET) != 0)
 		pg_fatal("could not set seek position in archive file: %m");
+
+	void *buf = pg_malloc(1024*1024);
+	int ret = setvbuf(AH->FH, buf, _IOFBF, 1024*1024);
+	if (ret != 0)
+		pg_fatal("setvbuf failed: %m");
 }
 
 /*
  * Prepare for parallel restore.
  *
  * The main thing that needs to happen here is to fill in TABLE DATA and BLOBS
  * TOC entries' dataLength fields with appropriate values to guide the
  * ordering of restore jobs.  The source of said data is format-dependent,
  * as is the exact meaning of the values.
-- 
2.51.0