staticvoidReorderBufferSerializeChange(ReorderBuffer*rb, ReorderBufferTXN*txn,
intfd, ReorderBufferChange*change)
{
ReorderBufferDiskChange*ondisk;
Sizesz=sizeof(ReorderBufferDiskChange);
ReorderBufferSerializeReserve(rb, sz);
ondisk= (ReorderBufferDiskChange*) rb->outbuf;
memcpy(&ondisk->change, change, sizeof(ReorderBufferChange));
switch (change->action)
 {
/* fall through these, they're all similar enough */caseREORDER_BUFFER_CHANGE_INSERT:
caseREORDER_BUFFER_CHANGE_UPDATE:
caseREORDER_BUFFER_CHANGE_DELETE:
caseREORDER_BUFFER_CHANGE_INTERNAL_SPEC_INSERT:
   {
char*data;
ReorderBufferTupleBuf*oldtup,
*newtup;
Sizeoldlen=0;
Sizenewlen=0;
oldtup=change->data.tp.oldtuple;
newtup=change->data.tp.newtuple;
if (oldtup)
    {
sz+=sizeof(HeapTupleData);
oldlen=oldtup->tuple.t_len;
sz+=oldlen;
    }
if (newtup)
    {
sz+=sizeof(HeapTupleData);
newlen=newtup->tuple.t_len;
sz+=newlen;
    }
/* make sure we have enough space */ReorderBufferSerializeReserve(rb, sz);
data= ((char*) rb->outbuf) +sizeof(ReorderBufferDiskChange);
/* might have been reallocated above */ondisk= (ReorderBufferDiskChange*) rb->outbuf;
if (oldlen)
    {
memcpy(data, &oldtup->tuple, sizeof(HeapTupleData));
data+=sizeof(HeapTupleData);
memcpy(data, oldtup->tuple.t_data, oldlen);
data+=oldlen;
    }
if (newlen)
    {
memcpy(data, &newtup->tuple, sizeof(HeapTupleData));
data+=sizeof(HeapTupleData);
memcpy(data, newtup->tuple.t_data, newlen);
data+=newlen;
    }
break;
   }
caseREORDER_BUFFER_CHANGE_MESSAGE:
   {
char*data;
Sizeprefix_size=strlen(change->data.msg.prefix) +1;
sz+=prefix_size+change->data.msg.message_size+sizeof(Size) +sizeof(Size);
ReorderBufferSerializeReserve(rb, sz);
data= ((char*) rb->outbuf) +sizeof(ReorderBufferDiskChange);
/* might have been reallocated above */ondisk= (ReorderBufferDiskChange*) rb->outbuf;
/* write the prefix including the size */memcpy(data, &prefix_size, sizeof(Size));
data+=sizeof(Size);
memcpy(data, change->data.msg.prefix,
prefix_size);
data+=prefix_size;
/* write the message including the size */memcpy(data, &change->data.msg.message_size, sizeof(Size));
data+=sizeof(Size);
memcpy(data, change->data.msg.message,
change->data.msg.message_size);
data+=change->data.msg.message_size;
break;
   }
caseREORDER_BUFFER_CHANGE_INTERNAL_SNAPSHOT:
   {
Snapshotsnap;
char*data;
snap=change->data.snapshot;
sz+=sizeof(SnapshotData) +sizeof(TransactionId) *snap->xcnt+sizeof(TransactionId) *snap->subxcnt;
/* make sure we have enough space */ReorderBufferSerializeReserve(rb, sz);
data= ((char*) rb->outbuf) +sizeof(ReorderBufferDiskChange);
/* might have been reallocated above */ondisk= (ReorderBufferDiskChange*) rb->outbuf;
memcpy(data, snap, sizeof(SnapshotData));
data+=sizeof(SnapshotData);
if (snap->xcnt)
    {
memcpy(data, snap->xip,
sizeof(TransactionId) *snap->xcnt);
data+=sizeof(TransactionId) *snap->xcnt;
    }
if (snap->subxcnt)
    {
memcpy(data, snap->subxip,
sizeof(TransactionId) *snap->subxcnt);
data+=sizeof(TransactionId) *snap->subxcnt;
    }
break;
   }
caseREORDER_BUFFER_CHANGE_TRUNCATE:
   {
Sizesize;
char*data;
/* account for the OIDs of truncated relations */size=sizeof(Oid) *change->data.truncate.nrelids;
sz+=size;
/* make sure we have enough space */ReorderBufferSerializeReserve(rb, sz);
data= ((char*) rb->outbuf) +sizeof(ReorderBufferDiskChange);
/* might have been reallocated above */ondisk= (ReorderBufferDiskChange*) rb->outbuf;
memcpy(data, change->data.truncate.relids, size);
data+=size;
break;
   }
caseREORDER_BUFFER_CHANGE_INTERNAL_SPEC_CONFIRM:
caseREORDER_BUFFER_CHANGE_INTERNAL_SPEC_ABORT:
caseREORDER_BUFFER_CHANGE_INTERNAL_COMMAND_ID:
caseREORDER_BUFFER_CHANGE_INTERNAL_TUPLECID:
/* ReorderBufferChange contains everything important */break;
 }
ondisk->size=sz;
errno=0;
pgstat_report_wait_start(WAIT_EVENT_REORDER_BUFFER_WRITE);
if (write(fd, rb->outbuf, ondisk->size) !=ondisk->size)
 {
intsave_errno=errno;
CloseTransientFile(fd);
/* if write didn't set errno, assume problem is no disk space */errno=save_errno?save_errno : ENOSPC;
ereport(ERROR,
    (errcode_for_file_access(),
errmsg("could not write to data file for XID %u: %m",
txn->xid)));
 }
pgstat_report_wait_end();
/** Keep the transaction's final_lsn up to date with each change we send to* disk, so that ReorderBufferRestoreCleanup works correctly.  (We used to* only do this on commit and abort records, but that doesn't work if a* system crash leaves a transaction without its abort record).** Make sure not to move it backwards.*/if (txn->final_lsn<change->lsn)
txn->final_lsn=change->lsn;
Assert(ondisk->change.action==change->action);