Add debug output in GitRekt.WireProtocol.Service

apps/gitrekt/lib/gitrekt/wire_protocol/service.ex

@@ -5,6 +5,8 @@ defmodule GitRekt.WireProtocol.Service do
   See `GitRekt.WireProtocol.UploadPack` and `GitRekt.WireProtocol.ReceivePack` for more details.
   """
 
+  alias GitRekt.Git
+
   import GitRekt.WireProtocol, only: [encode: 1, decode: 1]
 
   @callback run(struct) :: {struct, [term]}
@@ -15,16 +17,32 @@ defmodule GitRekt.WireProtocol.Service do
   """
   @spec new(Git.repo, binary) :: struct
   def new(repo, executable) do
-    struct(exec_mod(executable), repo: repo)
+    struct(exec_impl(executable), repo: repo)
   end
 
   @doc """
   Transist the `service` struct to the next state by parsing the given `data`.
   """
   @spec next(struct, binary) :: {struct, iolist}
   def next(service, data) do
+    IO.puts "incoming data via #{inspect service}:"
+    debug = if byte_size(data) > 1024, do: binary_part(data, 0, 1024), else: data
+    IO.binwrite debug
+    IO.puts ""
+
+    resp = exec_orig(service.__struct__, Git.repository_get_path(service.repo), data)
+    IO.puts "orig response (#{byte_size(resp)}):"
+    debug = if byte_size(resp) > 1024, do: binary_part(resp, 0, 1024), else: resp
+    IO.binwrite debug
+    IO.puts ""
+
     lines = Enum.to_list(decode(data))
-    flush(read_all(service, lines))
+    {service, resp} = flush(read_all(service, lines))
+    IO.puts "impl response (#{IO.iodata_length(resp)}):"
+    debug = if IO.iodata_length(resp) > 1024, do: binary_part(IO.iodata_to_binary(resp), 0, 1024), else: resp
+    IO.binwrite debug
+    IO.puts ""
+    {service, resp}
   end
 
   @doc """
@@ -48,13 +66,35 @@ defmodule GitRekt.WireProtocol.Service do
   # Helpers
   #
 
-  defp exec_mod("git-upload-pack"),  do: GitRekt.WireProtocol.UploadPack
-  defp exec_mod("git-receive-pack"), do: GitRekt.WireProtocol.ReceivePack
+  defp exec_impl("git-upload-pack"),  do: GitRekt.WireProtocol.UploadPack
+  defp exec_impl("git-receive-pack"), do: GitRekt.WireProtocol.ReceivePack
+
+  defp exec_orig(GitRekt.WireProtocol.UploadPack, repo_path, request) do
+    exec_port("git-upload-pack", repo_path, request)
+  end
+
+  defp exec_orig(GitRekt.WireProtocol.ReceivePack, repo_path, request) do
+    exec_port("git-receive-pack", repo_path, request)
+  end
+
+  defp exec_port(service, repo_path, request) do
+    port = Port.open({:spawn, "#{service} --stateless-rpc #{repo_path}"}, [:binary, :exit_status])
+    if Port.command(port, request), do: capture_port_output(port)
+  end
 
   defp read_all(service, lines) do
     case apply(service.__struct__, :next, [service, lines]) do
       {handle, []} -> handle
       {handle, lines} -> read_all(handle, lines)
     end
   end
+
+  defp capture_port_output(port, buffer \\ "") do
+    receive do
+      {^port, {:data, data}} ->
+        capture_port_output(port, buffer <> data)
+      {^port, {:exit_status, 0}} ->
+        buffer
+    end
+  end
 end