rsync - Apr 2009 - [Code study]append_mode definitions

Dear List,
Can anyone help to explain definitions of variable "append_mode"?

I have found this variable is changed in many places, and quite
confused.


option.c #line549~550
>   {"append-verify",    0,  POPT_ARG_VAL,    &append_mode, 2,
0, 0 },
>   {"no-append",        0,  POPT_ARG_VAL,    &append_mode, 0,
0, 0 },
#line1183~1188
> case OPT_APPEND:
> if (am_server)
> append_mode++;
> else
> append_mode = 1;
> break;
batch.c #line153~156
> if (tweaked_append)
> append_mode = 1;
> else if (tweaked_append_verify)
> append_mode = 2;
compat.c #line191~192
> if (append_mode == 1)
> append_mode = 2;
generate.c #line2102,2127
> append_mode = -append_mode;

receive.c #line503,513
> append_mode = -append_mode;
send.c #line248,254
> append_mode = -append_mode;
-- 
Daniel

On Mon, Apr 27, 2009 at 10:33:02AM +0800, Daniel.Li
wrote:
> Can anyone help to explain definitions of variable "append_mode"?
There are two different type of appending (see the man page) depending
on how new rsync is and how much of the file should be checksummed.  The
option is also disabled if a file is being fixed during a redo event.

..wayne..