文件下载器

apps/efka/src/efka_downloader.erl

@@ -12,15 +12,14 @@
 -behaviour(gen_server).
 
 %% API
--export([start_link/2, download/1]).
+-export([start_link/0, download/3]).
 -export([test/0]).
 
 %% gen_server callbacks
 -export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3]).
 
 -record(state, {
-    url :: string(),
+
-    target_file :: string()
 }).
 
 %%%===================================================================
@@ -28,26 +27,28 @@
 %%%===================================================================
 
 test() ->
-    {ok, Pid} = start_link("https://codeload.github.com/genadyo/LivePhotoDemo/zip/refs/heads/master", "/tmp/test.tar"),
+    {ok, Pid} = start_link(),
-    Ref = download(Pid),
+    Url = "https://codeload.github.com/genadyo/LivePhotoDemo/zip/refs/heads/master",
+    TargetDir = "/tmp/",
+    Ref = download(Pid, Url, TargetDir),
     receive
         {download_response, Ref, Info} ->
             lager:debug("info is: ~p", [Info])
     end,
     ok.
 
--spec download(Pid :: pid()) -> reference().
+-spec download(Pid :: pid(), Url :: string(), TargetDir :: string()) -> reference().
-download(Pid) when is_pid(Pid) ->
+download(Pid, Url, TargetDir) when is_pid(Pid), is_list(Url), is_list(TargetDir) ->
     Ref = make_ref(),
     ReceiverPid = self(),
-    gen_server:cast(Pid, {download, ReceiverPid, Ref}),
+    gen_server:cast(Pid, {download, ReceiverPid, Ref, Url, TargetDir}),
     Ref.
 
 %% @doc Spawns the server and registers the local name (unique)
--spec(start_link(Url :: string(), TargetFile :: string()) ->
+-spec(start_link() ->
     {ok, Pid :: pid()} | ignore | {error, Reason :: term()}).
-start_link(Url, TargetFile) when is_list(Url), is_list(TargetFile) ->
+start_link() ->
-    gen_server:start_link(?MODULE, [Url, TargetFile], []).
+    gen_server:start_link(?MODULE, [], []).
 
 %%%===================================================================
 %%% gen_server callbacks
@@ -58,8 +59,8 @@ start_link(Url, TargetFile) when is_list(Url), is_list(TargetFile) ->
 -spec(init(Args :: term()) ->
     {ok, State :: #state{}} | {ok, State :: #state{}, timeout() | hibernate} |
     {stop, Reason :: term()} | ignore).
-init([Url, TargetFile]) ->
+init([]) ->
-    {ok, #state{url = Url, target_file = TargetFile}}.
+    {ok, #state{}}.
 
 %% @private
 %% @doc Handling call messages
@@ -80,11 +81,16 @@ handle_call(_Request, _From, State = #state{}) ->
     {noreply, NewState :: #state{}} |
     {noreply, NewState :: #state{}, timeout() | hibernate} |
     {stop, Reason :: term(), NewState :: #state{}}).
-handle_cast({download, ReceiverPid, Ref}, State = #state{url = Url, target_file = TargetFile}) ->
+handle_cast({download, ReceiverPid, Ref, Url, TargetDir}, State = #state{}) ->
-    case hackney:get(Url, [], <<>>, [async]) of
+    SSLOpts = {ssl_options, [
+        % 完全禁用证书验证
+        {verify, verify_none}
+    ]},
+
+    TargetFile = get_filename_from_url(Url),
+    case hackney:request(get, Url, [], <<>>, [async, {stream_to, self()}, {pool, false}, SSLOpts]) of
         {ok, ClientRef} ->
-            {ok, File} = file:open(TargetFile, [write, binary]),
+            case receive_data(ClientRef, TargetDir, TargetFile) of
-            case receive_data(ClientRef, File) of
                 ok ->
                     ReceiverPid ! {download_response, Ref, ok};
                 {error, Reason} ->
@@ -126,23 +132,56 @@ code_change(_OldVsn, State = #state{}, _Extra) ->
 %%% Internal functions
 %%%===================================================================
 
-receive_data(ClientRef, File) ->
+%% 读取请求 ResponseLine
+receive_data(ClientRef, TargetDir, DefaultFile) when is_list(TargetDir), is_list(DefaultFile) ->
     receive
-        {hackney_response, ClientRef, {headers, _Headers}} ->
-            receive_data(ClientRef, File);
         {hackney_response, ClientRef, {status, 200, _Reason}} ->
-            receive_data(ClientRef, File);
+            receive_data0(ClientRef, TargetDir, DefaultFile);
         {hackney_response, ClientRef, {status, StatusCode, _Reason}} ->
-            lager:debug("call me here"),
+            {error, {http_status, StatusCode}}
-            {error, {http_status, StatusCode}};
+    end.
-        {hackney_response, ClientRef, Data} ->
+%% 处理头部信息, 解析可能的文件名
-            file:write(File, Data),
+receive_data0(ClientRef, TargetDir, DefaultFile) ->
-            receive_data(ClientRef, File);
+    receive
+        {hackney_response, ClientRef, {headers, Headers}} ->
+            TargetFilename = extra_filename(Headers, DefaultFile),
+            FullFilename = TargetDir ++ TargetFilename,
+            {ok, File} = file:open(FullFilename, [write, binary]),
+            receive_data1(ClientRef, File)
+    end.
+%% 接受文件数据
+receive_data1(ClientRef, File) ->
+    receive
+        {hackney_response, ClientRef, {error, Reason}} ->
+            ok = file:close(File),
+            {error, Reason};
         {hackney_response, ClientRef, done} ->
             ok = file:close(File),
             hackney:close(ClientRef),
             ok;
-        {hackney_response, ClientRef, {error, Reason}} ->
+        {hackney_response, ClientRef, Data} ->
-            ok = file:close(File),
+            file:write(File, Data),
-            {error, Reason}
+            receive_data1(ClientRef, File)
     end.
+
+-spec extra_filename(Headers :: list(), Default :: string()) -> Filename :: string().
+extra_filename(Headers, Default) when is_list(Headers), is_list(Default) ->
+    case lists:filter(fun({K, _}) -> string:lowercase(K) =:= <<"content-disposition">> end, Headers) of
+        [{_, <<"attachment; ", Rest/binary>>}|_] ->
+            Params0 = binary:split(Rest, <<";">>, [global]),
+            Params = lists:map(fun(P) -> list_to_tuple(binary:split(P, <<"=">>)) end, Params0),
+            case proplists:get_value(<<"filename">>, Params) of
+                undefined ->
+                    Default;
+                Filename ->
+                    binary_to_list(Filename)
+            end;
+        _ ->
+            Default
+    end.
+
+-spec get_filename_from_url(Url :: string()) -> string().
+get_filename_from_url(Url) when is_list(Url) ->
+    URIMap = uri_string:parse(Url),
+    Path = maps:get(path, URIMap),
+    filename:basename(Path).