From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Fri, 2 Sep 2005 18:55:32 +0000 (+0000)
Subject: In copy_file, use a palloc'd buffer instead of just a local char array;
X-Git-Url: http://waps.l3s.uni-hannover.de/gitweb/?a=commitdiff_plain;h=faaf2b623fc57ec8d1d0e3146ae348ed49baccb4;p=users%2Fbernd%2Fpostgres.git

In copy_file, use a palloc'd buffer instead of just a local char array;
a local array isn't guaranteed to have any particular alignment, and
so it could slow down the data transfer.
---

diff --git a/src/port/copydir.c b/src/port/copydir.c
index 0392f0d43e..cc54be216b 100644
--- a/src/port/copydir.c
+++ b/src/port/copydir.c
@@ -88,11 +88,16 @@ copydir(char *fromdir, char *todir, bool recurse)
 static void
 copy_file(char *fromfile, char *tofile)
 {
-	char		buffer[8 * BLCKSZ];
+	char	   *buffer;
 	int			srcfd;
 	int			dstfd;
 	int			nbytes;
 
+	/* Use palloc to ensure we get a maxaligned buffer */
+#define COPY_BUF_SIZE (8 * BLCKSZ)
+
+	buffer = palloc(COPY_BUF_SIZE);
+
 	/*
 	 * Open the files
 	 */
@@ -114,7 +119,7 @@ copy_file(char *fromfile, char *tofile)
 	 */
 	for (;;)
 	{
-		nbytes = read(srcfd, buffer, sizeof(buffer));
+		nbytes = read(srcfd, buffer, COPY_BUF_SIZE);
 		if (nbytes < 0)
 			ereport(ERROR,
 					(errcode_for_file_access(),
@@ -147,4 +152,6 @@ copy_file(char *fromfile, char *tofile)
 				 errmsg("could not close file \"%s\": %m", tofile)));
 
 	close(srcfd);
+
+	pfree(buffer);
 }