Replace gratuitous memmove() with memcpy()

The index access methods all had similar code that copied the
passed-in scan keys to local storage.  They all used memmove() for
that, which is not wrong, but it seems confusing not to use memcpy()
when that would work.  Presumably, this was all once copied from
ancient code and never adjusted.

Discussion: https://www.postgresql.org/message-id/flat/f8c739d9-f48d-4187-b214-df3391ba41ab@eisentraut.org

6 files changed, 8 insertions, 22 deletions

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index 94a8bd07017..60853a0f6ad 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -956,8 +956,7 @@ brinrescan(IndexScanDesc scan, ScanKey scankey, int nscankeys,
 	 */
 
 	if (scankey && scan->numberOfKeys > 0)
-		memmove(scan->keyData, scankey,
-				scan->numberOfKeys * sizeof(ScanKeyData));
+		memcpy(scan->keyData, scankey, scan->numberOfKeys * sizeof(ScanKeyData));
 }
 
 /*
diff --git a/src/backend/access/gin/ginscan.c b/src/backend/access/gin/ginscan.c
index af24d38544e..f2fd62afbbf 100644
--- a/src/backend/access/gin/ginscan.c
+++ b/src/backend/access/gin/ginscan.c
@@ -447,10 +447,7 @@ ginrescan(IndexScanDesc scan, ScanKey scankey, int nscankeys,
 	ginFreeScanKeys(so);
 
 	if (scankey && scan->numberOfKeys > 0)
-	{
-		memmove(scan->keyData, scankey,
-				scan->numberOfKeys * sizeof(ScanKeyData));
-	}
+		memcpy(scan->keyData, scankey, scan->numberOfKeys * sizeof(ScanKeyData));
 }
 
 
diff --git a/src/backend/access/gist/gistscan.c b/src/backend/access/gist/gistscan.c
index e05801e2f5b..de472e16373 100644
--- a/src/backend/access/gist/gistscan.c
+++ b/src/backend/access/gist/gistscan.c
@@ -233,8 +233,7 @@ gistrescan(IndexScanDesc scan, ScanKey key, int nkeys,
 				fn_extras[i] = scan->keyData[i].sk_func.fn_extra;
 		}
 
-		memmove(scan->keyData, key,
-				scan->numberOfKeys * sizeof(ScanKeyData));
+		memcpy(scan->keyData, key, scan->numberOfKeys * sizeof(ScanKeyData));
 
 		/*
 		 * Modify the scan key so that the Consistent method is called for all
@@ -289,8 +288,7 @@ gistrescan(IndexScanDesc scan, ScanKey key, int nkeys,
 				fn_extras[i] = scan->orderByData[i].sk_func.fn_extra;
 		}
 
-		memmove(scan->orderByData, orderbys,
-				scan->numberOfOrderBys * sizeof(ScanKeyData));
+		memcpy(scan->orderByData, orderbys, scan->numberOfOrderBys * sizeof(ScanKeyData));
 
 		so->orderByTypes = (Oid *) palloc(scan->numberOfOrderBys * sizeof(Oid));
 
diff --git a/src/backend/access/hash/hash.c b/src/backend/access/hash/hash.c
index a783b9b4e25..5ce36093943 100644
--- a/src/backend/access/hash/hash.c
+++ b/src/backend/access/hash/hash.c
@@ -415,11 +415,7 @@ hashrescan(IndexScanDesc scan, ScanKey scankey, int nscankeys,
 
 	/* Update scan key, if a new one is given */
 	if (scankey && scan->numberOfKeys > 0)
-	{
-		memmove(scan->keyData,
-				scankey,
-				scan->numberOfKeys * sizeof(ScanKeyData));
-	}
+		memcpy(scan->keyData, scankey, scan->numberOfKeys * sizeof(ScanKeyData));
 
 	so->hashso_buc_populated = false;
 	so->hashso_buc_split = false;
diff --git a/src/backend/access/nbtree/nbtree.c b/src/backend/access/nbtree/nbtree.c
index 8cfaab949be..6d090f8739b 100644
--- a/src/backend/access/nbtree/nbtree.c
+++ b/src/backend/access/nbtree/nbtree.c
@@ -404,9 +404,7 @@ btrescan(IndexScanDesc scan, ScanKey scankey, int nscankeys,
 	 * Reset the scan keys
 	 */
 	if (scankey && scan->numberOfKeys > 0)
-		memmove(scan->keyData,
-				scankey,
-				scan->numberOfKeys * sizeof(ScanKeyData));
+		memcpy(scan->keyData, scankey, scan->numberOfKeys * sizeof(ScanKeyData));
 	so->numberOfKeys = 0;		/* until _bt_preprocess_keys sets it */
 	so->numArrayKeys = 0;		/* ditto */
 }
diff --git a/src/backend/access/spgist/spgscan.c b/src/backend/access/spgist/spgscan.c
index 03293a7816e..3017861859f 100644
--- a/src/backend/access/spgist/spgscan.c
+++ b/src/backend/access/spgist/spgscan.c
@@ -384,16 +384,14 @@ spgrescan(IndexScanDesc scan, ScanKey scankey, int nscankeys,
 
 	/* copy scankeys into local storage */
 	if (scankey && scan->numberOfKeys > 0)
-		memmove(scan->keyData, scankey,
-				scan->numberOfKeys * sizeof(ScanKeyData));
+		memcpy(scan->keyData, scankey, scan->numberOfKeys * sizeof(ScanKeyData));
 
 	/* initialize order-by data if needed */
 	if (orderbys && scan->numberOfOrderBys > 0)
 	{
 		int			i;
 
-		memmove(scan->orderByData, orderbys,
-				scan->numberOfOrderBys * sizeof(ScanKeyData));
+		memcpy(scan->orderByData, orderbys, scan->numberOfOrderBys * sizeof(ScanKeyData));
 
 		for (i = 0; i < scan->numberOfOrderBys; i++)
 		{