Further improvements to c8f621c43.

Coverity and inspection for the issue addressed in fd45d16f found some
questionable code.

Specifically coverity noticed that the wrong length was added in
ReorderBufferSerializeChange() - without immediate negative consequences
as the variable isn't used afterwards.  During code-review and testing I
noticed that a bit of space was wasted when allocating tuple bufs in
several places.  Thirdly, the debug memset()s in
ReorderBufferGetTupleBuf() reduce the error checking valgrind can do.

Backpatch: 9.4, like c8f621c43.

diff --git a/src/backend/replication/logical/decode.c b/src/backend/replication/logical/decode.c
index 0f7ff1501be5bf602330124255fa9aec90559d35..fafbd5f0ec21c5e315081e220dd1a4dce1620697 100644 (file)
--- a/src/backend/replication/logical/decode.c
+++ b/src/backend/replication/logical/decode.c
@@ -625,7 +625,8 @@ DecodeInsert(LogicalDecodingContext *ctx, XLogRecordBuffer *buf)
 
        if (xlrec->flags & XLOG_HEAP_CONTAINS_NEW_TUPLE)
        {
-               Size            tuplelen = r->xl_len - SizeOfHeapInsert;
+               Size            datalen = r->xl_len - SizeOfHeapInsert;
+               Size            tuplelen = datalen - SizeOfHeapHeader;
 
                Assert(r->xl_len > (SizeOfHeapInsert + SizeOfHeapHeader));
 
@@ -633,7 +634,7 @@ DecodeInsert(LogicalDecodingContext *ctx, XLogRecordBuffer *buf)
                        ReorderBufferGetTupleBuf(ctx->reorder, tuplelen);
 
                DecodeXLogTuple((char *) xlrec + SizeOfHeapInsert,
-                                               tuplelen, change->data.tp.newtuple);
+                                               datalen, change->data.tp.newtuple);
        }
 
        change->data.tp.clear_toast_afterwards = true;
@@ -670,6 +671,7 @@ DecodeUpdate(LogicalDecodingContext *ctx, XLogRecordBuffer *buf)
 
        if (xlrec->flags & XLOG_HEAP_CONTAINS_NEW_TUPLE)
        {
+               Size            datalen;
                Size            tuplelen;
                xl_heap_header_len xlhdr;
 
@@ -678,12 +680,13 @@ DecodeUpdate(LogicalDecodingContext *ctx, XLogRecordBuffer *buf)
                memcpy(&xlhdr, data, sizeof(xlhdr));
                data += offsetof(xl_heap_header_len, header);
 
-               tuplelen = xlhdr.t_len + SizeOfHeapHeader;
+               datalen = xlhdr.t_len + SizeOfHeapHeader;
+               tuplelen = xlhdr.t_len;
 
                change->data.tp.newtuple =
                        ReorderBufferGetTupleBuf(ctx->reorder, tuplelen);
 
-               DecodeXLogTuple(data, tuplelen, change->data.tp.newtuple);
+               DecodeXLogTuple(data, datalen, change->data.tp.newtuple);
                /* skip over the rest of the tuple header */
                data += SizeOfHeapHeader;
                /* skip over the tuple data */
@@ -692,18 +695,20 @@ DecodeUpdate(LogicalDecodingContext *ctx, XLogRecordBuffer *buf)
 
        if (xlrec->flags & XLOG_HEAP_CONTAINS_OLD)
        {
+               Size            datalen;
                Size            tuplelen;
                xl_heap_header_len xlhdr;
 
                memcpy(&xlhdr, data, sizeof(xlhdr));
                data += offsetof(xl_heap_header_len, header);
 
-               tuplelen = xlhdr.t_len + SizeOfHeapHeader;
+               datalen = xlhdr.t_len + SizeOfHeapHeader;
+               tuplelen = xlhdr.t_len;
 
                change->data.tp.oldtuple =
                        ReorderBufferGetTupleBuf(ctx->reorder, tuplelen);
 
-               DecodeXLogTuple(data, tuplelen, change->data.tp.oldtuple);
+               DecodeXLogTuple(data, datalen, change->data.tp.oldtuple);
 #ifdef NOT_USED
                data += SizeOfHeapHeader;
                data += xlhdr.t_len;
@@ -741,15 +746,16 @@ DecodeDelete(LogicalDecodingContext *ctx, XLogRecordBuffer *buf)
        /* old primary key stored */
        if (xlrec->flags & XLOG_HEAP_CONTAINS_OLD)
        {
-               Size            len = r->xl_len - SizeOfHeapDelete;
+               Size            datalen = r->xl_len - SizeOfHeapDelete;
+               Size            tuplelen = datalen - SizeOfHeapHeader;
 
                Assert(r->xl_len > (SizeOfHeapDelete + SizeOfHeapHeader));
 
                change->data.tp.oldtuple =
-                       ReorderBufferGetTupleBuf(ctx->reorder, len);
+                       ReorderBufferGetTupleBuf(ctx->reorder, tuplelen);
 
                DecodeXLogTuple((char *) xlrec + SizeOfHeapDelete,
-                                               len, change->data.tp.oldtuple);
+                                               datalen, change->data.tp.oldtuple);
        }
 
        change->data.tp.clear_toast_afterwards = true;

diff --git a/src/backend/replication/logical/reorderbuffer.c b/src/backend/replication/logical/reorderbuffer.c
index 8eadb4bed180c96458564148700ec1edc6ab4c6f..1c8a554051627380a41fadbd81912e75f64c6d5e 100644 (file)
--- a/src/backend/replication/logical/reorderbuffer.c
+++ b/src/backend/replication/logical/reorderbuffer.c
@@ -469,12 +469,15 @@ ReorderBufferGetTupleBuf(ReorderBuffer *rb, Size tuple_len)
                rb->nr_cached_tuplebufs--;
                tuple = slist_container(ReorderBufferTupleBuf, node,
                                                                slist_pop_head_node(&rb->cached_tuplebufs));
+               Assert(tuple->alloc_tuple_size == MaxHeapTupleSize);
 #ifdef USE_ASSERT_CHECKING
                memset(&tuple->tuple, 0xa9, sizeof(HeapTupleData));
+               VALGRIND_MAKE_MEM_UNDEFINED(&tuple->tuple, sizeof(HeapTupleData));
 #endif
                tuple->tuple.t_data = ReorderBufferTupleBufData(tuple);
 #ifdef USE_ASSERT_CHECKING
                memset(tuple->tuple.t_data, 0xa8, tuple->alloc_tuple_size);
+               VALGRIND_MAKE_MEM_UNDEFINED(tuple->tuple.t_data, tuple->alloc_tuple_size);
 #endif
        }
        else