Clean up representation of flags in struct ReorderBufferTXN

This simplifies addition of further flags.

Author: Nikhil Sontakke
Discussion: https://postgr.es/m/CAMGcDxeViP+R-OL7QhzUV9eKCVjURobuY1Zijik4Ay_Ddwo4Cg@mail.gmail.com

src/backend/replication/logical/reorderbuffer.c

@@ -740,7 +740,7 @@ AssertTXNLsnOrder(ReorderBuffer *rb)
 			Assert(prev_first_lsn < cur_txn->first_lsn);
 
 		/* known-as-subtxn txns must not be listed */
-		Assert(!cur_txn->is_known_as_subxact);
+		Assert(!rbtxn_is_known_subxact(cur_txn));
 
 		prev_first_lsn = cur_txn->first_lsn;
 	}
@@ -760,7 +760,7 @@ AssertTXNLsnOrder(ReorderBuffer *rb)
 			Assert(prev_base_snap_lsn < cur_txn->base_snapshot_lsn);
 
 		/* known-as-subtxn txns must not be listed */
-		Assert(!cur_txn->is_known_as_subxact);
+		Assert(!rbtxn_is_known_subxact(cur_txn));
 
 		prev_base_snap_lsn = cur_txn->base_snapshot_lsn;
 	}
@@ -783,7 +783,7 @@ ReorderBufferGetOldestTXN(ReorderBuffer *rb)
 
 	txn = dlist_head_element(ReorderBufferTXN, node, &rb->toplevel_by_lsn);
 
-	Assert(!txn->is_known_as_subxact);
+	Assert(!rbtxn_is_known_subxact(txn));
 	Assert(txn->first_lsn != InvalidXLogRecPtr);
 	return txn;
 }
@@ -843,7 +843,7 @@ ReorderBufferAssignChild(ReorderBuffer *rb, TransactionId xid,
 
 	if (!new_sub)
 	{
-		if (subtxn->is_known_as_subxact)
+		if (rbtxn_is_known_subxact(subtxn))
 		{
 			/* already associated, nothing to do */
 			return;
@@ -859,7 +859,7 @@ ReorderBufferAssignChild(ReorderBuffer *rb, TransactionId xid,
 		}
 	}
 
-	subtxn->is_known_as_subxact = true;
+	subtxn->txn_flags |= RBTXN_IS_SUBXACT;
 	subtxn->toplevel_xid = xid;
 	Assert(subtxn->nsubtxns == 0);
 
@@ -1080,7 +1080,7 @@ ReorderBufferIterTXNInit(ReorderBuffer *rb, ReorderBufferTXN *txn,
 	{
 		ReorderBufferChange *cur_change;
 
-		if (txn->serialized)
+		if (rbtxn_is_serialized(txn))
 		{
 			/* serialize remaining changes */
 			ReorderBufferSerializeTXN(rb, txn);
@@ -1109,7 +1109,7 @@ ReorderBufferIterTXNInit(ReorderBuffer *rb, ReorderBufferTXN *txn,
 		{
 			ReorderBufferChange *cur_change;
 
-			if (cur_txn->serialized)
+			if (rbtxn_is_serialized(cur_txn))
 			{
 				/* serialize remaining changes */
 				ReorderBufferSerializeTXN(rb, cur_txn);
@@ -1273,7 +1273,7 @@ ReorderBufferCleanupTXN(ReorderBuffer *rb, ReorderBufferTXN *txn)
 		 * they originally were happening inside another subtxn, so we won't
 		 * ever recurse more than one level deep here.
 		 */
-		Assert(subtxn->is_known_as_subxact);
+		Assert(rbtxn_is_known_subxact(subtxn));
 		Assert(subtxn->nsubtxns == 0);
 
 		ReorderBufferCleanupTXN(rb, subtxn);
@@ -1321,7 +1321,7 @@ ReorderBufferCleanupTXN(ReorderBuffer *rb, ReorderBufferTXN *txn)
 	/*
 	 * Remove TXN from its containing list.
 	 *
-	 * Note: if txn->is_known_as_subxact, we are deleting the TXN from its
+	 * Note: if txn is known as subxact, we are deleting the TXN from its
 	 * parent's list of known subxacts; this leaves the parent's nsubxacts
 	 * count too high, but we don't care.  Otherwise, we are deleting the TXN
 	 * from the LSN-ordered list of toplevel TXNs.
@@ -1336,7 +1336,7 @@ ReorderBufferCleanupTXN(ReorderBuffer *rb, ReorderBufferTXN *txn)
 	Assert(found);
 
 	/* remove entries spilled to disk */
-	if (txn->serialized)
+	if (rbtxn_is_serialized(txn))
 		ReorderBufferRestoreCleanup(rb, txn);
 
 	/* deallocate */
@@ -1353,7 +1353,7 @@ ReorderBufferBuildTupleCidHash(ReorderBuffer *rb, ReorderBufferTXN *txn)
 	dlist_iter	iter;
 	HASHCTL		hash_ctl;
 
-	if (!txn->has_catalog_changes || dlist_is_empty(&txn->tuplecids))
+	if (!rbtxn_has_catalog_changes(txn) || dlist_is_empty(&txn->tuplecids))
 		return;
 
 	memset(&hash_ctl, 0, sizeof(hash_ctl));
@@ -1981,7 +1981,7 @@ ReorderBufferAbortOld(ReorderBuffer *rb, TransactionId oldestRunningXid)
 			 * final_lsn to that of their last change; this causes
 			 * ReorderBufferRestoreCleanup to do the right thing.
 			 */
-			if (txn->serialized && txn->final_lsn == 0)
+			if (rbtxn_is_serialized(txn) && txn->final_lsn == 0)
 			{
 				ReorderBufferChange *last =
 				dlist_tail_element(ReorderBufferChange, node, &txn->changes);
@@ -2129,7 +2129,7 @@ ReorderBufferSetBaseSnapshot(ReorderBuffer *rb, TransactionId xid,
 	 * operate on its top-level transaction instead.
 	 */
 	txn = ReorderBufferTXNByXid(rb, xid, true, &is_new, lsn, true);
-	if (txn->is_known_as_subxact)
+	if (rbtxn_is_known_subxact(txn))
 		txn = ReorderBufferTXNByXid(rb, txn->toplevel_xid, false,
 									NULL, InvalidXLogRecPtr, false);
 	Assert(txn->base_snapshot == NULL);
@@ -2276,7 +2276,7 @@ ReorderBufferXidSetCatalogChanges(ReorderBuffer *rb, TransactionId xid,
 
 	txn = ReorderBufferTXNByXid(rb, xid, true, NULL, lsn, true);
 
-	txn->has_catalog_changes = true;
+	txn->txn_flags |= RBTXN_HAS_CATALOG_CHANGES;
 }
 
 /*
@@ -2293,7 +2293,7 @@ ReorderBufferXidHasCatalogChanges(ReorderBuffer *rb, TransactionId xid)
 	if (txn == NULL)
 		return false;
 
-	return txn->has_catalog_changes;
+	return rbtxn_has_catalog_changes(txn);
 }
 
 /*
@@ -2313,7 +2313,7 @@ ReorderBufferXidHasBaseSnapshot(ReorderBuffer *rb, TransactionId xid)
 		return false;
 
 	/* a known subtxn? operate on top-level txn instead */
-	if (txn->is_known_as_subxact)
+	if (rbtxn_is_known_subxact(txn))
 		txn = ReorderBufferTXNByXid(rb, txn->toplevel_xid, false,
 									NULL, InvalidXLogRecPtr, false);
 
@@ -2500,13 +2500,13 @@ ReorderBufferSerializeTXN(ReorderBuffer *rb, ReorderBufferTXN *txn)
 	rb->spillCount += 1;
 	rb->spillBytes += size;
 
-	/* Don't consider already serialized transaction. */
-	rb->spillTxns += txn->serialized ? 0 : 1;
+	/* Don't consider already serialized transactions. */
+	rb->spillTxns += rbtxn_is_serialized(txn) ? 0 : 1;
 
 	Assert(spilled == txn->nentries_mem);
 	Assert(dlist_is_empty(&txn->changes));
 	txn->nentries_mem = 0;
-	txn->serialized = true;
+	txn->txn_flags |= RBTXN_IS_SERIALIZED;
 
 	if (fd != -1)
 		CloseTransientFile(fd);

src/include/replication/reorderbuffer.h

@@ -158,18 +158,38 @@ typedef struct ReorderBufferChange
 	dlist_node	node;
 } ReorderBufferChange;
 
+/* ReorderBufferTXN txn_flags */
+#define RBTXN_HAS_CATALOG_CHANGES 0x0001
+#define RBTXN_IS_SUBXACT          0x0002
+#define RBTXN_IS_SERIALIZED       0x0004
+
+/* Does the transaction have catalog changes? */
+#define rbtxn_has_catalog_changes(txn) \
+( \
+	 ((txn)->txn_flags & RBTXN_HAS_CATALOG_CHANGES) != 0 \
+)
+
+/* Is the transaction known as a subxact? */
+#define rbtxn_is_known_subxact(txn) \
+( \
+	((txn)->txn_flags & RBTXN_IS_SUBXACT) != 0 \
+)
+
+/* Has this transaction been spilled to disk? */
+#define rbtxn_is_serialized(txn) \
+( \
+	((txn)->txn_flags & RBTXN_IS_SERIALIZED) != 0 \
+)
+
 typedef struct ReorderBufferTXN
 {
-	/*
-	 * The transactions transaction id, can be a toplevel or sub xid.
-	 */
-	TransactionId xid;
+	/* See above */
+	bits32		txn_flags;
 
-	/* did the TX have catalog changes */
-	bool		has_catalog_changes;
+	/* The transaction's transaction id, can be a toplevel or sub xid. */
+	TransactionId xid;
 
-	/* Do we know this is a subxact?  Xid of top-level txn if so */
-	bool		is_known_as_subxact;
+	/* Xid of top-level transaction, if known */
 	TransactionId toplevel_xid;
 
 	/*
@@ -237,15 +257,6 @@ typedef struct ReorderBufferTXN
 	 */
 	uint64		nentries_mem;
 
-	/*
-	 * Has this transaction been spilled to disk?  It's not always possible to
-	 * deduce that fact by comparing nentries with nentries_mem, because e.g.
-	 * subtransactions of a large transaction might get serialized together
-	 * with the parent - if they're restored to memory they'd have
-	 * nentries_mem == nentries.
-	 */
-	bool		serialized;
-
 	/*
 	 * List of ReorderBufferChange structs, including new Snapshots and new
 	 * CommandIds
@@ -298,7 +309,6 @@ typedef struct ReorderBufferTXN
 	 * Size of this transaction (changes currently in memory, in bytes).
 	 */
 	Size		size;
-
 } ReorderBufferTXN;
 
 /* so we can define the callbacks used inside struct ReorderBuffer itself */