From 3088c08bcb23e8f0dbd991974d381af8a4e3b10c Mon Sep 17 00:00:00 2001
From: Siraaj Khandkar <siraaj@khandkar.net>
Date: Thu, 17 Sep 2015 11:26:22 -0400
Subject: [PATCH] Define process ancestry as its own data type.

---
 include/beam_stats_process.hrl          |  4 +-
 include/beam_stats_process_ancestry.hrl |  5 ++
 src/beam_stats_process.erl              | 64 +++++++++----------------
 3 files changed, 28 insertions(+), 45 deletions(-)
 create mode 100644 include/beam_stats_process_ancestry.hrl

diff --git a/include/beam_stats_process.hrl b/include/beam_stats_process.hrl
index 65dc860..7d2d951 100644
--- a/include/beam_stats_process.hrl
+++ b/include/beam_stats_process.hrl
@@ -1,9 +1,7 @@
 -record(beam_stats_process,
     { pid               ::               pid()
     , registered_name   :: hope_option:t(atom())
-    , raw_initial_call  ::               mfa()
-    , otp_initial_call  :: hope_option:t(mfa())
-    , otp_ancestors     ::               [{name, atom()} | {call, mfa()}]
+    , ancestry          ::               beam_stats_process:ancestry()
     , status            ::               beam_stats_process:status()
     , memory            ::               non_neg_integer()
     , total_heap_size   ::               non_neg_integer()
diff --git a/include/beam_stats_process_ancestry.hrl b/include/beam_stats_process_ancestry.hrl
new file mode 100644
index 0000000..45ae9e4
--- /dev/null
+++ b/include/beam_stats_process_ancestry.hrl
@@ -0,0 +1,5 @@
+-record(beam_stats_process_ancestry,
+    { raw_initial_call  ::               mfa()
+    , otp_initial_call  :: hope_option:t(mfa())
+    , otp_ancestors     ::               [{name, atom()} | {call, mfa()}]
+    }).
diff --git a/src/beam_stats_process.erl b/src/beam_stats_process.erl
index 9b2ae8a..ab6d1c2 100644
--- a/src/beam_stats_process.erl
+++ b/src/beam_stats_process.erl
@@ -1,17 +1,18 @@
 -module(beam_stats_process).
 
+-include("include/beam_stats_process_ancestry.hrl").
 -include("include/beam_stats_process.hrl").
 
 -export_type(
     [ t/0
     , status/0
-    , ancestor/0
+    , ancestry/0
     , best_known_origin/0
     ]).
 
 -export(
     [ of_pid/1
-    , best_known_origin/1
+    , get_best_known_origin/1
     , print/1
     ]).
 
@@ -24,15 +25,12 @@
     | waiting
     .
 
--type ancestor() ::
-      {otp_ancestors    , [pid() | atom()]}
-    | {otp_initial_call , mfa()}
-    | {raw_initial_call , mfa()}
-    .
+-type ancestry() ::
+    #beam_stats_process_ancestry{}.
 
 -type best_known_origin() ::
       {registered_name , atom()}
-    | {ancestry        , [ancestor()]}
+    | {ancestry        , ancestry()}
     .
 
 -define(T, #?MODULE).
@@ -48,12 +46,16 @@
     t().
 of_pid(Pid) ->
     Dict = pid_info_exn(Pid, dictionary),
+    Ancestry =
+        #beam_stats_process_ancestry
+        { raw_initial_call  = pid_info_exn(Pid, initial_call)
+        , otp_initial_call  = hope_kv_list:get(Dict, '$initial_call')
+        , otp_ancestors     = hope_kv_list:get(Dict, '$ancestors')
+        },
     ?T
     { pid               = Pid
     , registered_name   = pid_info_opt(Pid, registered_name)
-    , raw_initial_call  = pid_info_exn(Pid, initial_call)
-    , otp_initial_call  = hope_kv_list:get(Dict, '$initial_call')
-    , otp_ancestors     = hope_kv_list:get(Dict, '$ancestors')
+    , ancestry          = Ancestry
     , status            = pid_info_exn(Pid, status)
     , memory            = pid_info_exn(Pid, memory)
     , total_heap_size   = pid_info_exn(Pid, total_heap_size)
@@ -67,9 +69,11 @@ print(
     ?T
     { pid               = Pid
     , registered_name   = RegisteredNameOpt
-    , raw_initial_call  = InitialCallRaw
-    , otp_initial_call  = InitialCallOTPOpt
-    , otp_ancestors     = AncestorsOpt
+    , ancestry          = #beam_stats_process_ancestry
+        { raw_initial_call  = InitialCallRaw
+        , otp_initial_call  = InitialCallOTPOpt
+        , otp_ancestors     = AncestorsOpt
+        }
     , status            = Status
     , memory            = Memory
     , total_heap_size   = TotalHeapSize
@@ -77,7 +81,7 @@ print(
     , message_queue_len = MsgQueueLen
     }=T
 ) ->
-    BestKnownOrigin = best_known_origin(T),
+    BestKnownOrigin = get_best_known_origin(T),
     io:format("--------------------------------------------------~n"),
     io:format(
         "Pid               : ~p~n"
@@ -138,33 +142,9 @@ pid_info_opt(Pid, Key) ->
 
 -define(TAG(Tag), fun (X) -> {Tag, X} end).
 
--spec best_known_origin(t()) ->
+-spec get_best_known_origin(t()) ->
     best_known_origin().
-best_known_origin(?T{registered_name={some, RegisteredName}}) ->
+get_best_known_origin(?T{registered_name={some, RegisteredName}}) ->
     {registered_name, RegisteredName};
-best_known_origin(
-    ?T
-    { pid               = _Pid
-    , registered_name   = none
-    , raw_initial_call  = InitCallRaw
-    , otp_initial_call  = InitCallOTPOpt1
-    , otp_ancestors     = AncestorsOpt1
-    , status            = _Status
-    , memory            = _Memory
-    , total_heap_size   = _TotalHeapSize
-    , stack_size        = _StackSize
-    , message_queue_len = _MsgQueueLen
-    }
-) ->
-    ToSingleton       = fun (X) -> [X] end,
-    InitCallOTPOpt2   = hope_option:map(InitCallOTPOpt1, ?TAG(otp_initial_call)),
-    AncestorsOpt2     = hope_option:map(AncestorsOpt1  , ?TAG(otp_ancestors)),
-    InitCallOTPOpt3   = hope_option:map(InitCallOTPOpt2, ToSingleton),
-    AncestorsOpt3     = hope_option:map(AncestorsOpt2  , ToSingleton),
-    MaybeInitCallOTP  = hope_option:get(InitCallOTPOpt3, []),
-    MaybeAncestors    = hope_option:get(AncestorsOpt3  , []),
-    Ancestry =
-        [{raw_initial_call, InitCallRaw}] ++
-        MaybeInitCallOTP ++
-        MaybeAncestors,
+get_best_known_origin(?T{registered_name=none, ancestry=Ancestry}) ->
     {ancestry, Ancestry}.
-- 
2.20.1