Remove unportable use of anonymous unions from reorderbuffer.h.

In b89e151054a I had assumed it was ok to use anonymous unions as
struct members, but while a longstanding extension in many compilers,
it's only been standardized in C11.

To fix, remove one of the anonymous unions which tried to hide some
implementation specific enum values and give the other a name. The
latter unfortunately requires changes in output plugins, but since the
feature has only been added a few days ago...

Andres Freund

diff --git a/contrib/test_decoding/test_decoding.c b/contrib/test_decoding/test_decoding.c
index ea463fb2e7cda44c203cdba60bc7a4c1d90661b3..e356c7ca67522ac1cb4c8f2c8751a91401f67049 100644 (file)
--- a/contrib/test_decoding/test_decoding.c
+++ b/contrib/test_decoding/test_decoding.c
@@ -358,43 +358,45 @@ pg_decode_change(LogicalDecodingContext *ctx, ReorderBufferTXN *txn,
    {
        case REORDER_BUFFER_CHANGE_INSERT:
            appendStringInfoString(ctx->out, " INSERT:");
-           if (change->tp.newtuple == NULL)
+           if (change->data.tp.newtuple == NULL)
                appendStringInfoString(ctx->out, " (no-tuple-data)");
            else
                tuple_to_stringinfo(ctx->out, tupdesc,
-                                   &change->tp.newtuple->tuple,
+                                   &change->data.tp.newtuple->tuple,
                                    false);
            break;
        case REORDER_BUFFER_CHANGE_UPDATE:
            appendStringInfoString(ctx->out, " UPDATE:");
-           if (change->tp.oldtuple != NULL)
+           if (change->data.tp.oldtuple != NULL)
            {
                appendStringInfoString(ctx->out, " old-key:");
                tuple_to_stringinfo(ctx->out, tupdesc,
-                                   &change->tp.oldtuple->tuple,
+                                   &change->data.tp.oldtuple->tuple,
                                    true);
                appendStringInfoString(ctx->out, " new-tuple:");
            }
 
-           if (change->tp.newtuple == NULL)
+           if (change->data.tp.newtuple == NULL)
                appendStringInfoString(ctx->out, " (no-tuple-data)");
            else
                tuple_to_stringinfo(ctx->out, tupdesc,
-                                   &change->tp.newtuple->tuple,
+                                   &change->data.tp.newtuple->tuple,
                                    false);
            break;
        case REORDER_BUFFER_CHANGE_DELETE:
            appendStringInfoString(ctx->out, " DELETE:");
 
            /* if there was no PK, we only know that a delete happened */
-           if (change->tp.oldtuple == NULL)
+           if (change->data.tp.oldtuple == NULL)
                appendStringInfoString(ctx->out, " (no-tuple-data)");
            /* In DELETE, only the replica identity is present; display that */
            else
                tuple_to_stringinfo(ctx->out, tupdesc,
-                                   &change->tp.oldtuple->tuple,
+                                   &change->data.tp.oldtuple->tuple,
                                    true);
            break;
+       default:
+           Assert(false);
    }
 
    MemoryContextSwitchTo(old);

diff --git a/src/backend/replication/logical/decode.c b/src/backend/replication/logical/decode.c
index af3948e8a4a040eab138271663c71d402fb4048d..414cfa95586df3c4e69f45583b449192eb6ec6c7 100644 (file)
--- a/src/backend/replication/logical/decode.c
+++ b/src/backend/replication/logical/decode.c
@@ -586,17 +586,17 @@ DecodeInsert(LogicalDecodingContext *ctx, XLogRecordBuffer *buf)
 
    change = ReorderBufferGetChange(ctx->reorder);
    change->action = REORDER_BUFFER_CHANGE_INSERT;
-   memcpy(&change->tp.relnode, &xlrec->target.node, sizeof(RelFileNode));
+   memcpy(&change->data.tp.relnode, &xlrec->target.node, sizeof(RelFileNode));
 
    if (xlrec->flags & XLOG_HEAP_CONTAINS_NEW_TUPLE)
    {
        Assert(r->xl_len > (SizeOfHeapInsert + SizeOfHeapHeader));
 
-       change->tp.newtuple = ReorderBufferGetTupleBuf(ctx->reorder);
+       change->data.tp.newtuple = ReorderBufferGetTupleBuf(ctx->reorder);
 
        DecodeXLogTuple((char *) xlrec + SizeOfHeapInsert,
                        r->xl_len - SizeOfHeapInsert,
-                       change->tp.newtuple);
+                       change->data.tp.newtuple);
    }
 
    ReorderBufferQueueChange(ctx->reorder, r->xl_xid, buf->origptr, change);
@@ -626,7 +626,7 @@ DecodeUpdate(LogicalDecodingContext *ctx, XLogRecordBuffer *buf)
 
    change = ReorderBufferGetChange(ctx->reorder);
    change->action = REORDER_BUFFER_CHANGE_UPDATE;
-   memcpy(&change->tp.relnode, &xlrec->target.node, sizeof(RelFileNode));
+   memcpy(&change->data.tp.relnode, &xlrec->target.node, sizeof(RelFileNode));
 
    data = (char *) &xlhdr->header;
 
@@ -634,11 +634,11 @@ DecodeUpdate(LogicalDecodingContext *ctx, XLogRecordBuffer *buf)
    {
        Assert(r->xl_len > (SizeOfHeapUpdate + SizeOfHeapHeaderLen));
 
-       change->tp.newtuple = ReorderBufferGetTupleBuf(ctx->reorder);
+       change->data.tp.newtuple = ReorderBufferGetTupleBuf(ctx->reorder);
 
        DecodeXLogTuple(data,
                        xlhdr->t_len + SizeOfHeapHeader,
-                       change->tp.newtuple);
+                       change->data.tp.newtuple);
        /* skip over the rest of the tuple header */
        data += SizeOfHeapHeader;
        /* skip over the tuple data */
@@ -648,10 +648,10 @@ DecodeUpdate(LogicalDecodingContext *ctx, XLogRecordBuffer *buf)
    if (xlrec->flags & XLOG_HEAP_CONTAINS_OLD)
    {
        xlhdr = (xl_heap_header_len *) data;
-       change->tp.oldtuple = ReorderBufferGetTupleBuf(ctx->reorder);
+       change->data.tp.oldtuple = ReorderBufferGetTupleBuf(ctx->reorder);
        DecodeXLogTuple((char *) &xlhdr->header,
                        xlhdr->t_len + SizeOfHeapHeader,
-                       change->tp.oldtuple);
+                       change->data.tp.oldtuple);
        data = (char *) &xlhdr->header;
        data += SizeOfHeapHeader;
        data += xlhdr->t_len;
@@ -681,18 +681,18 @@ DecodeDelete(LogicalDecodingContext *ctx, XLogRecordBuffer *buf)
    change = ReorderBufferGetChange(ctx->reorder);
    change->action = REORDER_BUFFER_CHANGE_DELETE;
 
-   memcpy(&change->tp.relnode, &xlrec->target.node, sizeof(RelFileNode));
+   memcpy(&change->data.tp.relnode, &xlrec->target.node, sizeof(RelFileNode));
 
    /* old primary key stored */
    if (xlrec->flags & XLOG_HEAP_CONTAINS_OLD)
    {
        Assert(r->xl_len > (SizeOfHeapDelete + SizeOfHeapHeader));
 
-       change->tp.oldtuple = ReorderBufferGetTupleBuf(ctx->reorder);
+       change->data.tp.oldtuple = ReorderBufferGetTupleBuf(ctx->reorder);
 
        DecodeXLogTuple((char *) xlrec + SizeOfHeapDelete,
                        r->xl_len - SizeOfHeapDelete,
-                       change->tp.oldtuple);
+                       change->data.tp.oldtuple);
    }
    ReorderBufferQueueChange(ctx->reorder, r->xl_xid, buf->origptr, change);
 }
@@ -735,7 +735,7 @@ DecodeMultiInsert(LogicalDecodingContext *ctx, XLogRecordBuffer *buf)
 
        change = ReorderBufferGetChange(ctx->reorder);
        change->action = REORDER_BUFFER_CHANGE_INSERT;
-       memcpy(&change->tp.relnode, &xlrec->node, sizeof(RelFileNode));
+       memcpy(&change->data.tp.relnode, &xlrec->node, sizeof(RelFileNode));
 
        /*
         * CONTAINS_NEW_TUPLE will always be set currently as multi_insert
@@ -746,9 +746,9 @@ DecodeMultiInsert(LogicalDecodingContext *ctx, XLogRecordBuffer *buf)
         */
        if (xlrec->flags & XLOG_HEAP_CONTAINS_NEW_TUPLE)
        {
-           change->tp.newtuple = ReorderBufferGetTupleBuf(ctx->reorder);
+           change->data.tp.newtuple = ReorderBufferGetTupleBuf(ctx->reorder);
 
-           tuple = change->tp.newtuple;
+           tuple = change->data.tp.newtuple;
 
            /* not a disk based tuple */
            ItemPointerSetInvalid(&tuple->tuple.t_self);

diff --git a/src/backend/replication/logical/reorderbuffer.c b/src/backend/replication/logical/reorderbuffer.c
index ad560345b40ff8dda94522a2fdf91c3aa77f6532..4493930eda0a40df78979ead57ed3d7dd98c330e 100644 (file)
--- a/src/backend/replication/logical/reorderbuffer.c
+++ b/src/backend/replication/logical/reorderbuffer.c
@@ -80,26 +80,6 @@
 #include "utils/relfilenodemap.h"
 #include "utils/tqual.h"
 
-/*
- * For efficiency and simplicity reasons we want to keep Snapshots, CommandIds
- * and ComboCids in the same list with the user visible INSERT/UPDATE/DELETE
- * changes. We don't want to leak those internal values to external users
- * though (they would just use switch()...default:) because that would make it
- * harder to add to new user visible values.
- *
- * This needs to be synchronized with ReorderBufferChangeType! Adjust the
- * StaticAssertExpr's in ReorderBufferAllocate if you add anything!
- */
-typedef enum
-{
-   REORDER_BUFFER_CHANGE_INTERNAL_INSERT,
-   REORDER_BUFFER_CHANGE_INTERNAL_UPDATE,
-   REORDER_BUFFER_CHANGE_INTERNAL_DELETE,
-   REORDER_BUFFER_CHANGE_INTERNAL_SNAPSHOT,
-   REORDER_BUFFER_CHANGE_INTERNAL_COMMAND_ID,
-   REORDER_BUFFER_CHANGE_INTERNAL_TUPLECID
-} ReorderBufferChangeTypeInternal;
-
 /* entry for a hash table we use to map from xid to our transaction state */
 typedef struct ReorderBufferTXNByIdEnt
 {
@@ -255,10 +235,6 @@ ReorderBufferAllocate(void)
    HASHCTL     hash_ctl;
    MemoryContext new_ctx;
 
-   StaticAssertExpr((int) REORDER_BUFFER_CHANGE_INTERNAL_INSERT == (int) REORDER_BUFFER_CHANGE_INSERT, "out of sync enums");
-   StaticAssertExpr((int) REORDER_BUFFER_CHANGE_INTERNAL_UPDATE == (int) REORDER_BUFFER_CHANGE_UPDATE, "out of sync enums");
-   StaticAssertExpr((int) REORDER_BUFFER_CHANGE_INTERNAL_DELETE == (int) REORDER_BUFFER_CHANGE_DELETE, "out of sync enums");
-
    /* allocate memory in own context, to have better accountability */
    new_ctx = AllocSetContextCreate(CurrentMemoryContext,
                                    "ReorderBuffer",
@@ -427,28 +403,28 @@ void
 ReorderBufferReturnChange(ReorderBuffer *rb, ReorderBufferChange *change)
 {
    /* free contained data */
-   switch ((ReorderBufferChangeTypeInternal) change->action_internal)
+   switch (change->action)
    {
-       case REORDER_BUFFER_CHANGE_INTERNAL_INSERT:
-       case REORDER_BUFFER_CHANGE_INTERNAL_UPDATE:
-       case REORDER_BUFFER_CHANGE_INTERNAL_DELETE:
-           if (change->tp.newtuple)
+       case REORDER_BUFFER_CHANGE_INSERT:
+       case REORDER_BUFFER_CHANGE_UPDATE:
+       case REORDER_BUFFER_CHANGE_DELETE:
+           if (change->data.tp.newtuple)
            {
-               ReorderBufferReturnTupleBuf(rb, change->tp.newtuple);
-               change->tp.newtuple = NULL;
+               ReorderBufferReturnTupleBuf(rb, change->data.tp.newtuple);
+               change->data.tp.newtuple = NULL;
            }
 
-           if (change->tp.oldtuple)
+           if (change->data.tp.oldtuple)
            {
-               ReorderBufferReturnTupleBuf(rb, change->tp.oldtuple);
-               change->tp.oldtuple = NULL;
+               ReorderBufferReturnTupleBuf(rb, change->data.tp.oldtuple);
+               change->data.tp.oldtuple = NULL;
            }
            break;
        case REORDER_BUFFER_CHANGE_INTERNAL_SNAPSHOT:
-           if (change->snapshot)
+           if (change->data.snapshot)
            {
-               ReorderBufferFreeSnap(rb, change->snapshot);
-               change->snapshot = NULL;
+               ReorderBufferFreeSnap(rb, change->data.snapshot);
+               change->data.snapshot = NULL;
            }
            break;
        case REORDER_BUFFER_CHANGE_INTERNAL_COMMAND_ID:
@@ -1086,7 +1062,7 @@ ReorderBufferCleanupTXN(ReorderBuffer *rb, ReorderBufferTXN *txn)
        ReorderBufferChange *change;
 
        change = dlist_container(ReorderBufferChange, node, iter.cur);
-       Assert(change->action_internal == REORDER_BUFFER_CHANGE_INTERNAL_TUPLECID);
+       Assert(change->action == REORDER_BUFFER_CHANGE_INTERNAL_TUPLECID);
        ReorderBufferReturnChange(rb, change);
    }
 
@@ -1161,14 +1137,14 @@ ReorderBufferBuildTupleCidHash(ReorderBuffer *rb, ReorderBufferTXN *txn)
 
        change = dlist_container(ReorderBufferChange, node, iter.cur);
 
-       Assert(change->action_internal == REORDER_BUFFER_CHANGE_INTERNAL_TUPLECID);
+       Assert(change->action == REORDER_BUFFER_CHANGE_INTERNAL_TUPLECID);
 
        /* be careful about padding */
        memset(&key, 0, sizeof(ReorderBufferTupleCidKey));
 
-       key.relnode = change->tuplecid.node;
+       key.relnode = change->data.tuplecid.node;
 
-       ItemPointerCopy(&change->tuplecid.tid,
+       ItemPointerCopy(&change->data.tuplecid.tid,
                        &key.tid);
 
        ent = (ReorderBufferTupleCidEnt *)
@@ -1178,22 +1154,22 @@ ReorderBufferBuildTupleCidHash(ReorderBuffer *rb, ReorderBufferTXN *txn)
                        &found);
        if (!found)
        {
-           ent->cmin = change->tuplecid.cmin;
-           ent->cmax = change->tuplecid.cmax;
-           ent->combocid = change->tuplecid.combocid;
+           ent->cmin = change->data.tuplecid.cmin;
+           ent->cmax = change->data.tuplecid.cmax;
+           ent->combocid = change->data.tuplecid.combocid;
        }
        else
        {
-           Assert(ent->cmin == change->tuplecid.cmin);
+           Assert(ent->cmin == change->data.tuplecid.cmin);
            Assert(ent->cmax == InvalidCommandId ||
-                  ent->cmax == change->tuplecid.cmax);
+                  ent->cmax == change->data.tuplecid.cmax);
 
            /*
             * if the tuple got valid in this transaction and now got deleted
             * we already have a valid cmin stored. The cmax will be
             * InvalidCommandId though.
             */
-           ent->cmax = change->tuplecid.cmax;
+           ent->cmax = change->data.tuplecid.cmax;
        }
    }
 }
@@ -1367,33 +1343,33 @@ ReorderBufferCommit(ReorderBuffer *rb, TransactionId xid,
            Relation    relation = NULL;
            Oid         reloid;
 
-           switch ((ReorderBufferChangeTypeInternal) change->action_internal)
+           switch (change->action)
            {
-               case REORDER_BUFFER_CHANGE_INTERNAL_INSERT:
-               case REORDER_BUFFER_CHANGE_INTERNAL_UPDATE:
-               case REORDER_BUFFER_CHANGE_INTERNAL_DELETE:
+               case REORDER_BUFFER_CHANGE_INSERT:
+               case REORDER_BUFFER_CHANGE_UPDATE:
+               case REORDER_BUFFER_CHANGE_DELETE:
                    Assert(snapshot_now);
 
-                   reloid = RelidByRelfilenode(change->tp.relnode.spcNode,
-                                               change->tp.relnode.relNode);
+                   reloid = RelidByRelfilenode(change->data.tp.relnode.spcNode,
+                                               change->data.tp.relnode.relNode);
 
                    /*
                     * Catalog tuple without data, emitted while catalog was
                     * in the process of being rewritten.
                     */
                    if (reloid == InvalidOid &&
-                       change->tp.newtuple == NULL &&
-                       change->tp.oldtuple == NULL)
+                       change->data.tp.newtuple == NULL &&
+                       change->data.tp.oldtuple == NULL)
                        continue;
                    else if (reloid == InvalidOid)
                        elog(ERROR, "could not lookup relation %s",
-                            relpathperm(change->tp.relnode, MAIN_FORKNUM));
+                            relpathperm(change->data.tp.relnode, MAIN_FORKNUM));
 
                    relation = RelationIdGetRelation(reloid);
 
                    if (relation == NULL)
                        elog(ERROR, "could open relation descriptor %s",
-                            relpathperm(change->tp.relnode, MAIN_FORKNUM));
+                            relpathperm(change->data.tp.relnode, MAIN_FORKNUM));
 
                    if (RelationIsLogicallyLogged(relation))
                    {
@@ -1440,7 +1416,7 @@ ReorderBufferCommit(ReorderBuffer *rb, TransactionId xid,
                    {
                        ReorderBufferFreeSnap(rb, snapshot_now);
                        snapshot_now =
-                           ReorderBufferCopySnap(rb, change->snapshot,
+                           ReorderBufferCopySnap(rb, change->data.snapshot,
                                                  txn, command_id);
                    }
                    /*
@@ -1448,15 +1424,15 @@ ReorderBufferCommit(ReorderBuffer *rb, TransactionId xid,
                     * free. We could introduce refcounting for that, but for
                     * now this seems infrequent enough not to care.
                     */
-                   else if (change->snapshot->copied)
+                   else if (change->data.snapshot->copied)
                    {
                        snapshot_now =
-                           ReorderBufferCopySnap(rb, change->snapshot,
+                           ReorderBufferCopySnap(rb, change->data.snapshot,
                                                  txn, command_id);
                    }
                    else
                    {
-                       snapshot_now = change->snapshot;
+                       snapshot_now = change->data.snapshot;
                    }
 
 
@@ -1465,11 +1441,11 @@ ReorderBufferCommit(ReorderBuffer *rb, TransactionId xid,
                    break;
 
                case REORDER_BUFFER_CHANGE_INTERNAL_COMMAND_ID:
-                   Assert(change->command_id != InvalidCommandId);
+                   Assert(change->data.command_id != InvalidCommandId);
 
-                   if (command_id < change->command_id)
+                   if (command_id < change->data.command_id)
                    {
-                       command_id = change->command_id;
+                       command_id = change->data.command_id;
 
                        if (!snapshot_now->copied)
                        {
@@ -1712,8 +1688,8 @@ ReorderBufferAddSnapshot(ReorderBuffer *rb, TransactionId xid,
 {
    ReorderBufferChange *change = ReorderBufferGetChange(rb);
 
-   change->snapshot = snap;
-   change->action_internal = REORDER_BUFFER_CHANGE_INTERNAL_SNAPSHOT;
+   change->data.snapshot = snap;
+   change->action = REORDER_BUFFER_CHANGE_INTERNAL_SNAPSHOT;
 
    ReorderBufferQueueChange(rb, xid, lsn, change);
 }
@@ -1752,8 +1728,8 @@ ReorderBufferAddNewCommandId(ReorderBuffer *rb, TransactionId xid,
 {
    ReorderBufferChange *change = ReorderBufferGetChange(rb);
 
-   change->command_id = cid;
-   change->action_internal = REORDER_BUFFER_CHANGE_INTERNAL_COMMAND_ID;
+   change->data.command_id = cid;
+   change->action = REORDER_BUFFER_CHANGE_INTERNAL_COMMAND_ID;
 
    ReorderBufferQueueChange(rb, xid, lsn, change);
 }
@@ -1773,13 +1749,13 @@ ReorderBufferAddNewTupleCids(ReorderBuffer *rb, TransactionId xid,
 
    txn = ReorderBufferTXNByXid(rb, xid, true, NULL, lsn, true);
 
-   change->tuplecid.node = node;
-   change->tuplecid.tid = tid;
-   change->tuplecid.cmin = cmin;
-   change->tuplecid.cmax = cmax;
-   change->tuplecid.combocid = combocid;
+   change->data.tuplecid.node = node;
+   change->data.tuplecid.tid = tid;
+   change->data.tuplecid.cmin = cmin;
+   change->data.tuplecid.cmax = cmax;
+   change->data.tuplecid.combocid = combocid;
    change->lsn = lsn;
-   change->action_internal = REORDER_BUFFER_CHANGE_INTERNAL_TUPLECID;
+   change->action = REORDER_BUFFER_CHANGE_INTERNAL_TUPLECID;
 
    dlist_push_tail(&txn->tuplecids, &change->node);
    txn->ntuplecids++;
@@ -2017,26 +1993,30 @@ ReorderBufferSerializeChange(ReorderBuffer *rb, ReorderBufferTXN *txn,
    ondisk = (ReorderBufferDiskChange *) rb->outbuf;
    memcpy(&ondisk->change, change, sizeof(ReorderBufferChange));
 
-   switch ((ReorderBufferChangeTypeInternal) change->action_internal)
+   switch (change->action)
    {
-       case REORDER_BUFFER_CHANGE_INTERNAL_INSERT:
+       case REORDER_BUFFER_CHANGE_INSERT:
            /* fall through */
-       case REORDER_BUFFER_CHANGE_INTERNAL_UPDATE:
+       case REORDER_BUFFER_CHANGE_UPDATE:
            /* fall through */
-       case REORDER_BUFFER_CHANGE_INTERNAL_DELETE:
+       case REORDER_BUFFER_CHANGE_DELETE:
            {
                char       *data;
+               ReorderBufferTupleBuf *oldtup, *newtup;
                Size        oldlen = 0;
                Size        newlen = 0;
 
-               if (change->tp.oldtuple)
+               oldtup = change->data.tp.oldtuple;
+               newtup = change->data.tp.newtuple;
+
+               if (oldtup)
                    oldlen = offsetof(ReorderBufferTupleBuf, data)
-                       + change->tp.oldtuple->tuple.t_len
+                       + oldtup->tuple.t_len
                        - offsetof(HeapTupleHeaderData, t_bits);
 
-               if (change->tp.newtuple)
+               if (newtup)
                    newlen = offsetof(ReorderBufferTupleBuf, data)
-                       + change->tp.newtuple->tuple.t_len
+                       + newtup->tuple.t_len
                        - offsetof(HeapTupleHeaderData, t_bits);
 
                sz += oldlen;
@@ -2051,26 +2031,27 @@ ReorderBufferSerializeChange(ReorderBuffer *rb, ReorderBufferTXN *txn,
 
                if (oldlen)
                {
-                   memcpy(data, change->tp.oldtuple, oldlen);
+                   memcpy(data, oldtup, oldlen);
                    data += oldlen;
-                   Assert(&change->tp.oldtuple->header == change->tp.oldtuple->tuple.t_data);
                }
 
                if (newlen)
                {
-                   memcpy(data, change->tp.newtuple, newlen);
+                   memcpy(data, newtup, newlen);
                    data += newlen;
-                   Assert(&change->tp.newtuple->header == change->tp.newtuple->tuple.t_data);
                }
                break;
            }
        case REORDER_BUFFER_CHANGE_INTERNAL_SNAPSHOT:
            {
+               Snapshot    snap;
                char       *data;
 
+               snap = change->data.snapshot;
+
                sz += sizeof(SnapshotData) +
-                   sizeof(TransactionId) * change->snapshot->xcnt +
-                   sizeof(TransactionId) * change->snapshot->subxcnt
+                   sizeof(TransactionId) * snap->xcnt +
+                   sizeof(TransactionId) * snap->subxcnt
                    ;
 
                /* make sure we have enough space */
@@ -2079,21 +2060,21 @@ ReorderBufferSerializeChange(ReorderBuffer *rb, ReorderBufferTXN *txn,
                /* might have been reallocated above */
                ondisk = (ReorderBufferDiskChange *) rb->outbuf;
 
-               memcpy(data, change->snapshot, sizeof(SnapshotData));
+               memcpy(data, snap, sizeof(SnapshotData));
                data += sizeof(SnapshotData);
 
-               if (change->snapshot->xcnt)
+               if (snap->xcnt)
                {
-                   memcpy(data, change->snapshot->xip,
-                          sizeof(TransactionId) + change->snapshot->xcnt);
-                   data += sizeof(TransactionId) + change->snapshot->xcnt;
+                   memcpy(data, snap->xip,
+                          sizeof(TransactionId) + snap->xcnt);
+                   data += sizeof(TransactionId) + snap->xcnt;
                }
 
-               if (change->snapshot->subxcnt)
+               if (snap->subxcnt)
                {
-                   memcpy(data, change->snapshot->subxip,
-                          sizeof(TransactionId) + change->snapshot->subxcnt);
-                   data += sizeof(TransactionId) + change->snapshot->subxcnt;
+                   memcpy(data, snap->subxip,
+                          sizeof(TransactionId) + snap->subxcnt);
+                   data += sizeof(TransactionId) + snap->subxcnt;
                }
                break;
            }
@@ -2116,7 +2097,7 @@ ReorderBufferSerializeChange(ReorderBuffer *rb, ReorderBufferTXN *txn,
                        txn->xid)));
    }
 
-   Assert(ondisk->change.action_internal == change->action_internal);
+   Assert(ondisk->change.action == change->action);
 }
 
 /*
@@ -2271,56 +2252,60 @@ ReorderBufferRestoreChange(ReorderBuffer *rb, ReorderBufferTXN *txn,
    data += sizeof(ReorderBufferDiskChange);
 
    /* restore individual stuff */
-   switch ((ReorderBufferChangeTypeInternal) change->action_internal)
+   switch (change->action)
    {
-       case REORDER_BUFFER_CHANGE_INTERNAL_INSERT:
+       case REORDER_BUFFER_CHANGE_INSERT:
            /* fall through */
-       case REORDER_BUFFER_CHANGE_INTERNAL_UPDATE:
+       case REORDER_BUFFER_CHANGE_UPDATE:
            /* fall through */
-       case REORDER_BUFFER_CHANGE_INTERNAL_DELETE:
-           if (change->tp.newtuple)
+       case REORDER_BUFFER_CHANGE_DELETE:
+           if (change->data.tp.newtuple)
            {
                Size        len = offsetof(ReorderBufferTupleBuf, data)
                +((ReorderBufferTupleBuf *) data)->tuple.t_len
                - offsetof(HeapTupleHeaderData, t_bits);
 
-               change->tp.newtuple = ReorderBufferGetTupleBuf(rb);
-               memcpy(change->tp.newtuple, data, len);
-               change->tp.newtuple->tuple.t_data = &change->tp.newtuple->header;
-
+               change->data.tp.newtuple = ReorderBufferGetTupleBuf(rb);
+               memcpy(change->data.tp.newtuple, data, len);
+               change->data.tp.newtuple->tuple.t_data =
+                   &change->data.tp.newtuple->header;
                data += len;
            }
 
-           if (change->tp.oldtuple)
+           if (change->data.tp.oldtuple)
            {
                Size        len = offsetof(ReorderBufferTupleBuf, data)
                +((ReorderBufferTupleBuf *) data)->tuple.t_len
                - offsetof(HeapTupleHeaderData, t_bits);
 
-               change->tp.oldtuple = ReorderBufferGetTupleBuf(rb);
-               memcpy(change->tp.oldtuple, data, len);
-               change->tp.oldtuple->tuple.t_data = &change->tp.oldtuple->header;
+               change->data.tp.oldtuple = ReorderBufferGetTupleBuf(rb);
+               memcpy(change->data.tp.oldtuple, data, len);
+               change->data.tp.oldtuple->tuple.t_data =
+                   &change->data.tp.oldtuple->header;
                data += len;
            }
            break;
        case REORDER_BUFFER_CHANGE_INTERNAL_SNAPSHOT:
            {
-               Snapshot    oldsnap = (Snapshot) data;
-               Size        size = sizeof(SnapshotData) +
-               sizeof(TransactionId) * oldsnap->xcnt +
-               sizeof(TransactionId) * (oldsnap->subxcnt + 0)
-                          ;
-
-               Assert(change->snapshot != NULL);
-
-               change->snapshot = MemoryContextAllocZero(rb->context, size);
-
-               memcpy(change->snapshot, data, size);
-               change->snapshot->xip = (TransactionId *)
-                   (((char *) change->snapshot) + sizeof(SnapshotData));
-               change->snapshot->subxip =
-                   change->snapshot->xip + change->snapshot->xcnt + 0;
-               change->snapshot->copied = true;
+               Snapshot    oldsnap;
+               Snapshot    newsnap;
+               Size        size;
+
+               oldsnap = (Snapshot) data;
+
+               size = sizeof(SnapshotData) +
+                   sizeof(TransactionId) * oldsnap->xcnt +
+                   sizeof(TransactionId) * (oldsnap->subxcnt + 0);
+
+               change->data.snapshot = MemoryContextAllocZero(rb->context, size);
+
+               newsnap = change->data.snapshot;
+
+               memcpy(newsnap, data, size);
+               newsnap->xip = (TransactionId *)
+                   (((char *) newsnap) + sizeof(SnapshotData));
+               newsnap->subxip = newsnap->xip + newsnap->xcnt;
+               newsnap->copied = true;
                break;
            }
            /* the base struct contains all the data, easy peasy */
@@ -2464,6 +2449,7 @@ ReorderBufferToastAppendChunk(ReorderBuffer *rb, ReorderBufferTXN *txn,
                              Relation relation, ReorderBufferChange *change)
 {
    ReorderBufferToastEnt *ent;
+   ReorderBufferTupleBuf *newtup;
    bool        found;
    int32       chunksize;
    bool        isnull;
@@ -2477,9 +2463,10 @@ ReorderBufferToastAppendChunk(ReorderBuffer *rb, ReorderBufferTXN *txn,
 
    Assert(IsToastRelation(relation));
 
-   chunk_id = DatumGetObjectId(fastgetattr(&change->tp.newtuple->tuple, 1, desc, &isnull));
+   newtup = change->data.tp.newtuple;
+   chunk_id = DatumGetObjectId(fastgetattr(&newtup->tuple, 1, desc, &isnull));
    Assert(!isnull);
-   chunk_seq = DatumGetInt32(fastgetattr(&change->tp.newtuple->tuple, 2, desc, &isnull));
+   chunk_seq = DatumGetInt32(fastgetattr(&newtup->tuple, 2, desc, &isnull));
    Assert(!isnull);
 
    ent = (ReorderBufferToastEnt *)
@@ -2505,7 +2492,7 @@ ReorderBufferToastAppendChunk(ReorderBuffer *rb, ReorderBufferTXN *txn,
        elog(ERROR, "got sequence entry %d for toast chunk %u instead of seq %d",
             chunk_seq, chunk_id, ent->last_chunk_seq + 1);
 
-   chunk = DatumGetPointer(fastgetattr(&change->tp.newtuple->tuple, 3, desc, &isnull));
+   chunk = DatumGetPointer(fastgetattr(&newtup->tuple, 3, desc, &isnull));
    Assert(!isnull);
 
    /* calculate size so we can allocate the right size at once later */
@@ -2539,10 +2526,11 @@ ReorderBufferToastReplace(ReorderBuffer *rb, ReorderBufferTXN *txn,
    Datum      *attrs;
    bool       *isnull;
    bool       *free;
-   HeapTuple   newtup;
+   HeapTuple   tmphtup;
    Relation    toast_rel;
    TupleDesc   toast_desc;
    MemoryContext oldcontext;
+   ReorderBufferTupleBuf *newtup;
 
    /* no toast tuples changed */
    if (txn->toast_hash == NULL)
@@ -2551,7 +2539,7 @@ ReorderBufferToastReplace(ReorderBuffer *rb, ReorderBufferTXN *txn,
    oldcontext = MemoryContextSwitchTo(rb->context);
 
    /* we should only have toast tuples in an INSERT or UPDATE */
-   Assert(change->tp.newtuple);
+   Assert(change->data.tp.newtuple);
 
    desc = RelationGetDescr(relation);
 
@@ -2563,8 +2551,9 @@ ReorderBufferToastReplace(ReorderBuffer *rb, ReorderBufferTXN *txn,
    isnull = palloc0(sizeof(bool) * desc->natts);
    free = palloc0(sizeof(bool) * desc->natts);
 
-   heap_deform_tuple(&change->tp.newtuple->tuple, desc,
-                     attrs, isnull);
+   newtup = change->data.tp.newtuple;
+
+   heap_deform_tuple(&newtup->tuple, desc, attrs, isnull);
 
    for (natt = 0; natt < desc->natts; natt++)
    {
@@ -2628,10 +2617,14 @@ ReorderBufferToastReplace(ReorderBuffer *rb, ReorderBufferTXN *txn,
        dlist_foreach(it, &ent->chunks)
        {
            bool        isnull;
-           ReorderBufferTupleBuf *tup =
-           dlist_container(ReorderBufferChange, node, it.cur)->tp.newtuple;
-           Pointer     chunk =
-           DatumGetPointer(fastgetattr(&tup->tuple, 3, toast_desc, &isnull));
+           ReorderBufferChange *cchange;
+           ReorderBufferTupleBuf *ctup;
+           Pointer     chunk;
+
+           cchange = dlist_container(ReorderBufferChange, node, it.cur);
+           ctup = cchange->data.tp.newtuple;
+           chunk = DatumGetPointer(
+               fastgetattr(&ctup->tuple, 3, toast_desc, &isnull));
 
            Assert(!isnull);
            Assert(!VARATT_IS_EXTERNAL(chunk));
@@ -2665,21 +2658,19 @@ ReorderBufferToastReplace(ReorderBuffer *rb, ReorderBufferTXN *txn,
     * passed to the output plugin. We can't directly heap_fill_tuple() into
     * the tuplebuf because attrs[] will point back into the current content.
     */
-   newtup = heap_form_tuple(desc, attrs, isnull);
-   Assert(change->tp.newtuple->tuple.t_len <= MaxHeapTupleSize);
-   Assert(&change->tp.newtuple->header == change->tp.newtuple->tuple.t_data);
+   tmphtup = heap_form_tuple(desc, attrs, isnull);
+   Assert(newtup->tuple.t_len <= MaxHeapTupleSize);
+   Assert(&newtup->header == newtup->tuple.t_data);
 
-   memcpy(change->tp.newtuple->tuple.t_data,
-          newtup->t_data,
-          newtup->t_len);
-   change->tp.newtuple->tuple.t_len = newtup->t_len;
+   memcpy(newtup->tuple.t_data, tmphtup->t_data, tmphtup->t_len);
+   newtup->tuple.t_len = tmphtup->t_len;
 
    /*
     * free resources we won't further need, more persistent stuff will be
     * free'd in ReorderBufferToastReset().
     */
    RelationClose(toast_rel);
-   pfree(newtup);
+   pfree(tmphtup);
    for (natt = 0; natt < desc->natts; natt++)
    {
        if (free[natt])

diff --git a/src/include/replication/reorderbuffer.h b/src/include/replication/reorderbuffer.h
index 01eabfb7be7306578f6c00e3ec3f7f9a03b4530c..04ff002990dbb5afbdd8fe2e8cf630beff785e54 100644 (file)
--- a/src/include/replication/reorderbuffer.h
+++ b/src/include/replication/reorderbuffer.h
@@ -32,12 +32,22 @@ typedef struct ReorderBufferTupleBuf
    char        data[MaxHeapTupleSize];
 } ReorderBufferTupleBuf;
 
-/* types of the change passed to a 'change' callback */
+/*
+ * Types of the change passed to a 'change' callback.
+ *
+ * For efficiency and simplicity reasons we want to keep Snapshots, CommandIds
+ * and ComboCids in the same list with the user visible INSERT/UPDATE/DELETE
+ * changes. Users of the decoding facilities will never see changes with
+ * *_INTERNAL_* actions.
+ */
 enum ReorderBufferChangeType
 {
    REORDER_BUFFER_CHANGE_INSERT,
    REORDER_BUFFER_CHANGE_UPDATE,
-   REORDER_BUFFER_CHANGE_DELETE
+   REORDER_BUFFER_CHANGE_DELETE,
+   REORDER_BUFFER_CHANGE_INTERNAL_SNAPSHOT,
+   REORDER_BUFFER_CHANGE_INTERNAL_COMMAND_ID,
+   REORDER_BUFFER_CHANGE_INTERNAL_TUPLECID
 };
 
 /*
@@ -51,13 +61,8 @@ typedef struct ReorderBufferChange
 {
    XLogRecPtr  lsn;
 
-   /* type of change */
-   union
-   {
-       enum ReorderBufferChangeType action;
-       /* do not leak internal enum values to the outside */
-       int         action_internal;
-   };
+   /* The type of change. */
+   enum ReorderBufferChangeType action;
 
    /*
     * Context data for the change, which part of the union is valid depends
@@ -65,7 +70,7 @@ typedef struct ReorderBufferChange
     */
    union
    {
-       /* old, new tuples when action == *_INSERT|UPDATE|DELETE */
+       /* Old, new tuples when action == *_INSERT|UPDATE|DELETE */
        struct
        {
            /* relation that has been changed */
@@ -76,13 +81,19 @@ typedef struct ReorderBufferChange
            ReorderBufferTupleBuf *newtuple;
        } tp;
 
-       /* new snapshot */
+       /* New snapshot, set when action == *_INTERNAL_SNAPSHOT */
        Snapshot    snapshot;
 
-       /* new command id for existing snapshot in a catalog changing tx */
+       /*
+        * New command id for existing snapshot in a catalog changing tx. Set
+        * when action == *_INTERNAL_COMMAND_ID.
+        */
        CommandId   command_id;
 
-       /* new cid mapping for catalog changing transaction */
+       /*
+        * New cid mapping for catalog changing transaction, set when action
+        * == *_INTERNAL_TUPLECID.
+        */
        struct
        {
            RelFileNode node;
@@ -91,7 +102,7 @@ typedef struct ReorderBufferChange
            CommandId   cmax;
            CommandId   combocid;
        }           tuplecid;
-   };
+   } data;
 
    /*
     * While in use this is how a change is linked into a transactions,