%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 2005-2018. All Rights Reserved.
%%
%% Licensed under the Apache License, Version 2.0 (the "License");
%% you may not use this file except in compliance with the License.
%% You may obtain a copy of the License at
%%
%% http://www.apache.org/licenses/LICENSE-2.0
%%
%% Unless required by applicable law or agreed to in writing, software
%% distributed under the License is distributed on an "AS IS" BASIS,
%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
%% See the License for the specific language governing permissions and
%% limitations under the License.
%%
%% %CopyrightEnd%
%%
%%
%% Description: This module impements a temporary process that
%% performes progress reporting during file transfer calling a user
%% defined callback function. Its life span is as long as the ftp connection
%% processes that spawned it lives. The purpose of this process is to
%% shild the ftp connection process from errors and time consuming operations
%% in the user defined callback function.
-module(ftp_progress).
%% Internal API
-export([start_link/1, report/2, stop/1]).
%% Spawn export
-export([init/1]).
-include_lib("kernel/include/file.hrl").
-record(progress, {
file :: string() | 'undefined',
cb_module :: module(),
cb_function :: atom(),
init_progress_term :: term(),
current_progress_term :: term()
}).
%%%=========================================================================
%%% Internal application API
%%%=========================================================================
%%--------------------------------------------------------------------------
%% start_link(Options) -> ignore | pid()
%% Options = ignore | {CBModule, CBFunction, InitProgressTerm}
%%
%% Description: Starts the progress report process unless progress reporting
%% should not be performed.
%%--------------------------------------------------------------------------
-type options() :: 'ignore' | {module(), atom(), term()}.
-spec start_link(options()) -> 'ignore' | pid().
start_link(ignore) ->
ignore;
start_link(Options) ->
spawn_link(?MODULE, init, [Options]).
%%--------------------------------------------------------------------------
%% report_progress(Pid, Report) -> ok
%% Pid = pid()
%% Report = {local_file, File} | {remote_file, File} |
%% {transfer_size, Size}
%% Size = integer()
%%
%% Description: Reports progress to the reporting process that calls the
%% user defined callback function.
%%--------------------------------------------------------------------------
-type report() :: {'local_file', string()} | {'remote_file', string()}
| {'transfer_size', non_neg_integer()}.
-spec report(pid(), report()) -> 'ok'.
report(Pid, Report) ->
Pid ! {progress_report, Report},
ok.
%%--------------------------------------------------------------------------
%% stop(Pid) -> ok
%% Pid = pid()
%%
%% Description:
%%--------------------------------------------------------------------------
-spec stop(pid()) -> 'ok'.
stop(Pid) ->
Pid ! stop,
ok.
%%%=========================================================================
%%% Internal functions
%%%=========================================================================
init(Options) ->
loop(progress(Options)).
loop(Progress) ->
receive
{progress_report, Report} ->
NewProgress = report_progress(Report, Progress),
loop(NewProgress);
stop ->
ok
end.
progress({CBModule, CBFunction, InitProgressTerm}) when is_atom(CBModule),
is_atom(CBFunction) ->
#progress{cb_module = CBModule,
cb_function = CBFunction,
init_progress_term = InitProgressTerm,
current_progress_term = InitProgressTerm}.
report_progress({local_file, File}, Progress) ->
{ok, FileInfo} = file:read_file_info(File),
report_progress({file_size, FileInfo#file_info.size},
Progress#progress{file = File});
report_progress({remote_file, File}, Progress) ->
report_progress({file_size, unknown}, Progress#progress{file = File});
report_progress(Size, #progress{file = File,
cb_module = CBModule,
cb_function = CBFunction,
current_progress_term = Term,
init_progress_term = InitTerm} = Progress) ->
NewProgressTerm = CBModule:CBFunction(Term, File, Size),
case Size of
{transfer_size, 0} ->
%% Transfer is compleat reset initial values
Progress#progress{current_progress_term = InitTerm,
file = undefined};
_ ->
Progress#progress{current_progress_term = NewProgressTerm}
end.
