Add 'p4' (Perforce) as a dependency type

This calls the 'p4' command-line tool to checkout and sync Perforce
trees. It involves significantly more special code in Rebar than
using 'git p4', but it eliminates the indirection of
Rebar->Git->Python->Perforce

rebar.config.sample

@@ -155,7 +155,7 @@
 %% name as an atom, eg. mochiweb, a name and a version (from the .app file), or
 %% an application name, a version and the SCM details on how to fetch it (SCM
 %% type, location and revision).
-%% Rebar currently supports git, hg, bzr, svn, rsync, and fossil.
+%% Rebar currently supports git, hg, bzr, svn, rsync, fossil, and p4.
 {deps, [app_name,
         {rebar, "1.0.*"},
         {rebar, ".*",
@@ -188,7 +188,8 @@
         {app_name, ".*", {svn, "svn://svn.example.org/url"}},
         {app_name, ".*", {bzr, "https://www.example.org/url", "Rev"}},
         {app_name, ".*", {fossil, "https://www.example.org/url"}},
-        {app_name, ".*", {fossil, "https://www.example.org/url", "Vsn"}}]}.
+        {app_name, ".*", {fossil, "https://www.example.org/url", "Vsn"}},
+        {app_name, ".*", {p4, "//depot/subdir/app_dir"}}]}.
 
 %% == Subdirectories ==
 

src/rebar_deps.erl

@@ -277,7 +277,8 @@ info_help(Description) ->
           {app_name, ".*", {svn, "svn://svn.example.org/url"}},
           {app_name, ".*", {bzr, "https://www.example.org/url", "Rev"}},
           {app_name, ".*", {fossil, "https://www.example.org/url"}},
-          {app_name, ".*", {fossil, "https://www.example.org/url", "Vsn"}}]}
+          {app_name, ".*", {fossil, "https://www.example.org/url", "Vsn"}},
+          {app_name, ".*", {p4, "//depot/subdir/app_dir"}}]}
        ]).
 
 %% Added because of trans deps,
@@ -507,6 +508,40 @@ use_source(Config, Dep, Count) ->
             use_source(Config, Dep#dep { dir = TargetDir }, Count-1)
     end.
 
+-record(p4_settings, {
+          client=undefined,
+          transport="tcp4:perforce:1666",
+          username,
+          password
+         }).
+init_p4_settings(Basename) ->
+    #p4_settings{client =
+                     case inet:gethostname() of
+                         {ok,HostName} ->
+                             HostName ++ "-"
+                                 ++ os:getenv("USER") ++ "-"
+                                 ++ Basename
+                                 ++ "-Rebar-automated-download"
+                     end}.
+
+download_source(AppDir, {p4, Url}) ->
+    download_source(AppDir, {p4, Url, "#head"});
+download_source(AppDir, {p4, Url, Rev}) ->
+    download_source(AppDir, {p4, Url, Rev, init_p4_settings(filename:basename(AppDir))});
+download_source(AppDir, {p4, Url, _Rev, Settings}) ->
+    ok = filelib:ensure_dir(AppDir),
+    rebar_utils:sh_send("p4 client -i",
+                   ?FMT("Client: ~s~n"
+                        ++"Description: generated by Rebar~n"
+                        ++"Root: ~s~n"
+                        ++"View:~n"
+                        ++"  ~s/...  //~s/...~n",
+                        [Settings#p4_settings.client,
+                         AppDir,
+                         Url,
+                         Settings#p4_settings.client]),
+                       []),
+    rebar_utils:sh(?FMT("p4 -c ~s sync -f", [Settings#p4_settings.client]), []);
 download_source(AppDir, {hg, Url, Rev}) ->
     ok = filelib:ensure_dir(AppDir),
     rebar_utils:sh(?FMT("hg clone -U ~s ~s", [Url, filename:basename(AppDir)]),
@@ -573,6 +608,8 @@ update_source(Config, Dep) ->
             Dep
     end.
 
+update_source1(AppDir, Args) when element(1, Args) =:= p4 ->
+    download_source(AppDir, Args);
 update_source1(AppDir, {git, Url}) ->
     update_source1(AppDir, {git, Url, {branch, "HEAD"}});
 update_source1(AppDir, {git, Url, ""}) ->
@@ -696,7 +733,7 @@ source_engine_avail(Source) ->
 
 source_engine_avail(Name, Source)
   when Name == hg; Name == git; Name == svn; Name == bzr; Name == rsync;
-       Name == fossil ->
+       Name == fossil; Name == p4 ->
     case vcs_client_vsn(Name) >= required_vcs_client_vsn(Name) of
         true ->
             true;
@@ -717,6 +754,7 @@ vcs_client_vsn(Path, VsnArg, VsnRegex) ->
             false
     end.
 
+required_vcs_client_vsn(p4)     -> {2013, 1};
 required_vcs_client_vsn(hg)     -> {1, 1};
 required_vcs_client_vsn(git)    -> {1, 5};
 required_vcs_client_vsn(bzr)    -> {2, 0};
@@ -724,6 +762,9 @@ required_vcs_client_vsn(svn)    -> {1, 6};
 required_vcs_client_vsn(rsync)  -> {2, 0};
 required_vcs_client_vsn(fossil) -> {1, 0}.
 
+vcs_client_vsn(p4) ->
+    vcs_client_vsn(rebar_utils:find_executable("p4"), " -V",
+                   "Rev\\. .*/(\\d+)\\.(\\d)/");
 vcs_client_vsn(hg) ->
     vcs_client_vsn(rebar_utils:find_executable("hg"), " --version",
                    "version (\\d+).(\\d+)");
@@ -743,6 +784,8 @@ vcs_client_vsn(fossil) ->
     vcs_client_vsn(rebar_utils:find_executable("fossil"), " version",
                    "version (\\d+).(\\d+)").
 
+has_vcs_dir(p4, _) ->
+    true;
 has_vcs_dir(git, Dir) ->
     filelib:is_dir(filename:join(Dir, ".git"));
 has_vcs_dir(hg, Dir) ->
@@ -760,6 +803,8 @@ has_vcs_dir(_, _) ->
 print_source(#dep{app=App, source=Source}) ->
     ?CONSOLE("~s~n", [format_source(App, Source)]).
 
+format_source(App, {p4, Url}) ->
+    format_source(App, {p4, Url, "#head"});
 format_source(App, {git, Url}) ->
     ?FMT("~p BRANCH ~s ~s", [App, "HEAD", Url]);
 format_source(App, {git, Url, ""}) ->

src/rebar_utils.erl

@@ -31,6 +31,7 @@
          get_arch/0,
          wordsize/0,
          sh/2,
+         sh_send/3,
          find_files/2, find_files/3,
          now_str/0,
          ensure_dir/1,
@@ -87,6 +88,24 @@ wordsize() ->
             integer_to_list(8 * erlang:system_info(wordsize))
     end.
 
+sh_send(Command0, String, Options0) ->
+    ?INFO("sh_send info:\n\tcwd: ~p\n\tcmd: ~s < ~s\n", [get_cwd(), Command0, String]),
+    ?DEBUG("\topts: ~p\n", [Options0]),
+
+    DefaultOptions = [use_stdout, abort_on_error],
+    Options = [expand_sh_flag(V)
+               || V <- proplists:compact(Options0 ++ DefaultOptions)],
+
+    Command = patch_on_windows(Command0, proplists:get_value(env, Options, [])),
+    PortSettings = proplists:get_all_values(port_settings, Options) ++
+        [exit_status, {line, 16384}, use_stdio, stderr_to_stdout, hide],
+    Port = open_port({spawn, Command}, PortSettings),
+
+    %% allow us to send some data to the shell command's STDIN
+    %% Erlang doesn't let us get any reply after sending an EOF, though...
+    Port ! {self(), {command, String}},
+    port_close(Port).
+
 %%
 %% Options = [Option] -- defaults to [use_stdout, abort_on_error]
 %% Option = ErrorOption | OutputOption | {cd, string()} | {env, Env}
@@ -478,6 +497,7 @@ vcs_vsn_1(Vcs, Dir) ->
     end.
 
 vcs_vsn_cmd(git)    -> "git describe --always --tags";
+vcs_vsn_cmd(p4)     -> "echo #head";
 vcs_vsn_cmd(hg)     -> "hg identify -i";
 vcs_vsn_cmd(bzr)    -> "bzr revno";
 vcs_vsn_cmd(svn)    -> "svnversion";