38 lines
1.1 KiB
Erlang
38 lines
1.1 KiB
Erlang
-module(afile_server).
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-compile([debug_info]).
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-export([start/1, loop/1]).
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start(Dir) ->
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spawn(afile_server, loop, [Dir]).
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%% Three significant points to observer about this code:
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%%
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%% + Who to reply to: all the received messages contain
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%% the variable Client - the PID of the sender.
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%% + Use of self(): the PID of the server.
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%% + Pattern matching to select the message.
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loop(Dir) ->
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receive
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{Client, list_dir} ->
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Client ! {self(), file:list_dir(Dir)};
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{Client, {get_file, File}} ->
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Full = filename:join(Dir, File),
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Client ! {self(), file:read_file(Full)};
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{Client, {put_file, File, Contents}} ->
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Full = filename:join(Dir, File),
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Client ! {self(), file:write_file(Full, Contents)},
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{Client, ping} ->
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Client ! {self(), pong};
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{Client, _} ->
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Client ! {self(), unrecognised_message};
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{_} ->
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io:format("unhandled message")
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end,
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loop(Dir).
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%% Notes:
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%% + function names are always lowercased
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%% + universal receiver: receive X -> X end.
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%% + erlang: use processes to structure the solutions to our problems.
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%% + *ATOMS*ARE*LOWER*CASED*
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