From 884ea16aa3f696ac57f8c46785c2a805b98129d3 Mon Sep 17 00:00:00 2001
From: openGaussDev <liuxiaowei26@huawei.com>
Date: Mon, 7 Mar 2022 16:16:05 +0800
Subject: [PATCH]  fix get_tuple

Offering: openGaussDev

More detail: fix get_tuple

Match-id-aed00ca9fb0d67624e5de7d2448c57a3baf26eb0
---
 .../storage/access/heap/tuptoaster.cpp        | 30 +++++++++++++++++++
 src/include/access/tuptoaster.h               |  2 ++
 2 files changed, 32 insertions(+)

diff --git a/src/gausskernel/storage/access/heap/tuptoaster.cpp b/src/gausskernel/storage/access/heap/tuptoaster.cpp
index 4411f8af3..dc306fd61 100644
--- a/src/gausskernel/storage/access/heap/tuptoaster.cpp
+++ b/src/gausskernel/storage/access/heap/tuptoaster.cpp
@@ -44,6 +44,7 @@
 #include "commands/vacuum.h"
 #include "utils/snapmgr.h"
 #include "mb/pg_wchar.h"
+#include "access/tableam.h"
 
 #undef TOAST_DEBUG
 
@@ -2900,3 +2901,32 @@ struct varlena * toast_pointer_fetch_data(TupleTableSlot* varSlot, Form_pg_attri
     return toast_pointer_lob;
 }
 
+HeapTuple ctid_get_tuple(Relation relation, ItemPointer tid)
+{
+    Buffer user_buf = InvalidBuffer;
+    HeapTuple tuple = NULL;
+    HeapTuple new_tuple = NULL;
+    TM_Result result;
+  
+    /* alloc memory for old tuple and set tuple id */
+    tuple = (HeapTupleData *)heaptup_alloc(BLCKSZ);
+    tuple->t_data = (HeapTupleHeader)((char *)tuple + HEAPTUPLESIZE);
+    Assert(tid != NULL);
+    tuple->t_self = *tid;
+    
+    if (tableam_tuple_fetch(relation, SnapshotAny, tuple, &user_buf, false, NULL)) {
+        result = HeapTupleSatisfiesUpdate(tuple, GetCurrentCommandId(true), user_buf, false);
+        if (result != TM_Ok) {
+            ereport(ERROR, (errcode(ERRCODE_SYSTEM_ERROR), errmsg("The tuple is updated, please use 'for update'.")));
+        }
+        
+        new_tuple = heapCopyTuple((HeapTuple)tuple, relation->rd_att, NULL);
+        ReleaseBuffer(user_buf);
+    } else {
+        heap_close(relation, NoLock);
+        ereport(ERROR, (errcode(ERRCODE_SYSTEM_ERROR), errmsg("The tuple is not found")));
+    }
+    heap_freetuple(tuple);
+
+    return new_tuple;
+}
diff --git a/src/include/access/tuptoaster.h b/src/include/access/tuptoaster.h
index ddeb8ca07..09bd4cbdd 100644
--- a/src/include/access/tuptoaster.h
+++ b/src/include/access/tuptoaster.h
@@ -296,5 +296,7 @@ inline Datum fetch_real_lob_if_need(Datum toast_pointer)
     return ret;
 }
 
+extern HeapTuple ctid_get_tuple(Relation relation, ItemPointer tid);
+
 #endif /* TUPTOASTER_H */