[inets/httpc] Better handling of session db update failure

A failure to update the session database will now result
in an informative error message and a controlled (handler)
exit rather then an ugly crash.
Also debug functions to retrieve sessions info and
updated the info function with more info (sessions and
options).

OTP-10093

3 files changed, 135 insertions, 10 deletions

diff --git a/lib/inets/src/http_client/httpc.erl b/lib/inets/src/http_client/httpc.erl
index f4802fb96d..b6e7708353 100644
--- a/lib/inets/src/http_client/httpc.erl
+++ b/lib/inets/src/http_client/httpc.erl
@@ -39,6 +39,7 @@
 	 cookie_header/1, cookie_header/2, cookie_header/3, 
 	 which_cookies/0, which_cookies/1, 
 	 reset_cookies/0, reset_cookies/1, 
+	 which_sessions/0, which_sessions/1, 
 	 stream_next/1,
 	 default_profile/0, 
 	 profile_name/1, profile_name/2,
@@ -267,6 +268,7 @@ set_option(Key, Value, Profile) ->
 %%   Reason - term()
 %% Description: Retrieves the current options. 
 %%-------------------------------------------------------------------------
+
 get_options() ->
     record_info(fields, options).
 
@@ -373,8 +375,6 @@ cookie_header(Url, Opts, Profile)
 	    {error, {not_started, Profile}}
     end.
     
-    
-
 
 %%--------------------------------------------------------------------------
 %% which_cookies() -> [cookie()]
@@ -398,6 +398,28 @@ which_cookies(Profile) ->
 
 
 %%--------------------------------------------------------------------------
+%% which_sessions() -> {GoodSession, BadSessions, NonSessions}
+%% which_sessions(Profile) -> {GoodSession, BadSessions, NonSessions}
+%%               
+%% Description: Debug function, dumping the sessions database, sorted 
+%%              into three groups (Good-, Bad- and Non-sessions).
+%%-------------------------------------------------------------------------
+which_sessions() ->
+    which_sessions(default_profile()).
+
+which_sessions(Profile) ->
+    ?hcrt("which sessions", [{profile, Profile}]),
+    try 
+	begin
+	    httpc_manager:which_sessions(profile_name(Profile))
+	end
+    catch 
+	exit:{noproc, _} ->
+	    {[], [], []}
+    end.
+
+
+%%--------------------------------------------------------------------------
 %% info() -> list()
 %% info(Profile) -> list()
 %%               
diff --git a/lib/inets/src/http_client/httpc_handler.erl b/lib/inets/src/http_client/httpc_handler.erl
index b8c34bd99b..6fe05dec80 100644
--- a/lib/inets/src/http_client/httpc_handler.erl
+++ b/lib/inets/src/http_client/httpc_handler.erl
@@ -1713,7 +1713,32 @@ update_session(ProfileName, #session{id = SessionId} = Session, Pos, Value) ->
     catch
 	error:undef -> % This could happen during code upgrade
 	    Session2 = erlang:setelement(Pos, Session, Value),
-	    insert_session(Session2, ProfileName)
+	    insert_session(Session2, ProfileName);
+	  T:E ->
+            error_logger:error_msg("Failed updating session: "
+                                   "~n   ProfileName: ~p"
+                                   "~n   SessionId:   ~p"
+                                   "~n   Pos:         ~p"
+                                   "~n   Value:       ~p"
+                                   "~nwhen"
+                                   "~n   Session (db) info: ~p"
+                                   "~n   Session (db):      ~p"
+                                   "~n   Session (record):  ~p"
+                                   "~n   T: ~p"
+                                   "~n   E: ~p", 
+                                   [ProfileName, SessionId, Pos, Value, 
+                                    (catch httpc_manager:which_session_info(ProfileName)), 
+                                    Session, 
+                                    (catch httpc_manager:lookup_session(ProfileName, SessionId)), 
+                                    T, E]),
+            exit({failed_updating_session, 
+                  [{profile,    ProfileName}, 
+                   {session_id, SessionId}, 
+                   {pos,        Pos}, 
+                   {value,      Value}, 
+                   {etype,      T}, 
+                   {error,      E}, 
+                   {stacktrace, erlang:get_stacktrace()}]})	    
     end.
 
 
diff --git a/lib/inets/src/http_client/httpc_manager.erl b/lib/inets/src/http_client/httpc_manager.erl
index 771968e169..3612b331e7 100644
--- a/lib/inets/src/http_client/httpc_manager.erl
+++ b/lib/inets/src/http_client/httpc_manager.erl
@@ -34,8 +34,11 @@
 	 retry_request/2, 
 	 redirect_request/2,
 	 insert_session/2, 
+	 lookup_session/2, 
 	 update_session/4, 
 	 delete_session/2, 
+	 which_sessions/1, 
+	 which_session_info/1, 
 	 set_options/2, 
 	 get_options/2, 
 	 store_cookies/3,
@@ -187,13 +190,28 @@ insert_session(Session, ProfileName) ->
 
 
 %%--------------------------------------------------------------------
+%% Function: lookup_session(SessionId, ProfileName) -> _
+%%      SessionId - term()
+%%      ProfileName - atom()
+%%
+%% Description: Looks up a session record in the httpc manager
+%% table <ProfileName>__session_db. 
+%%--------------------------------------------------------------------
+
+lookup_session(SessionId, ProfileName) ->
+    SessionDbName = session_db_name(ProfileName), 
+    ?hcrt("lookup session", [{session_id, SessionId}, {profile, ProfileName}]),
+    ets:lookup(SessionDbName, SessionId).
+
+
+%%--------------------------------------------------------------------
 %% Function: update_session(ProfileName, SessionId, Pos, Value) -> _
 %%	Session - #session{}
 %%      ProfileName - atom()
 %%
 %% Description: Update, only one field (Pos) of the session record
 %%              identified by the SessionId, the session information 
-%%              of the httpc manager table <ProfileName>_session_db. 
+%%              of the httpc manager table <ProfileName>__session_db. 
 %%              Intended to be called by the httpc request handler process.
 %%--------------------------------------------------------------------
 
@@ -208,12 +226,12 @@ update_session(ProfileName, SessionId, Pos, Value) ->
 
 
 %%--------------------------------------------------------------------
-%% Function: delete_session(SessionId, ProfileName) -> _
+%% Function: delete_session(SessionId, ProfileName) -> void()
 %%	SessionId -  {{Host, Port}, HandlerPid}
 %%      ProfileName - atom()
 %% 
 %% Description: Deletes session information from the httpc manager
-%% table httpc_manager_session_db_<Profile>. Intended to be called by
+%% table <ProfileName>__session_db. Intended to be called by
 %% the httpc request handler process.
 %%--------------------------------------------------------------------
 
@@ -224,6 +242,57 @@ delete_session(SessionId, ProfileName) ->
 
 
 %%--------------------------------------------------------------------
+%% Function: which sessions(ProfileName) -> SessionsInfo
+%%      ProfileName - atom()
+%%      SessionsInfo - {GoodSessions, BadSessions, NonSessions}
+%%      GoodSessions - [#session{}]
+%%      BadSessions  - [tuple()]
+%%      NonSessions  - [term()]
+%%
+%% Description: Produces a list of all sessions in the session db.
+%% Used for debugging and since that is the intent, there is some
+%% checking and transforming done, which produces the results.
+%%--------------------------------------------------------------------
+
+which_sessions(ProfileName) ->
+    ?hcrt("which_sessions", [{profile, ProfileName}]),
+    SessionDbName = session_db_name(ProfileName), 
+    which_sessions2(SessionDbName).
+
+which_sessions2(SessionDbName) ->
+    Sessions     = which_sessions_order(ets:tab2list(SessionDbName)),
+    GoodSessions = [GoodSession || {good_session, GoodSession} <- Sessions],
+    BadSessions  = [BadSession  || {bad_session,  BadSession}  <- Sessions],
+    NonSessions  = [NonSession  || {non_session,  NonSession}  <- Sessions],
+    {lists:keysort(#session.id, GoodSessions), 
+     lists:keysort(#session.id, BadSessions), 
+     lists:sort(NonSessions)}.
+
+which_sessions_order([]) ->
+    [];
+which_sessions_order([Session|Sessions]) when is_record(Session, session) ->
+    [{good_session, Session} | which_sessions_order(Sessions)];
+which_sessions_order([BadSession|Sessions]) 
+  when is_tuple(BadSession) andalso 
+       (element(1, BadSession) =:= session) ->
+    [{bad_session, BadSession} | which_sessions_order(Sessions)];
+which_sessions_order([NonSession|Sessions]) ->
+    [{non_session, NonSession} | which_sessions_order(Sessions)].
+
+
+%%--------------------------------------------------------------------
+%% Function: which session_info(ProfileName) -> list()
+%%
+%% Description: Produces a ets table info list of the sessions table
+%%--------------------------------------------------------------------
+
+which_session_info(ProfileName) ->
+    SessionDbName = session_db_name(ProfileName), 
+    ?hcrt("which_session_info", [{profile, ProfileName}]),
+    ets:info(SessionDbName).
+
+
+%%--------------------------------------------------------------------
 %% Function: set_options(Options, ProfileName) -> ok
 %%
 %%	Options = [Option]
@@ -449,8 +518,8 @@ handle_call({which_cookies, Url, Options}, _,
 
 handle_call({get_options, OptionItems}, _, #state{options = Options} = State) ->
     ?hcrv("get options", [{option_items, OptionItems}]),
-    Reply = [{OptionItem, get_option(OptionItem, Options)} || OptionItem <- 
-								  OptionItems], 
+    Reply = [{OptionItem, get_option(OptionItem, Options)} || 
+		OptionItem <- OptionItems], 
     {reply, Reply, State};
 
 handle_call(info, _, State) ->
@@ -665,10 +734,19 @@ update_session_table(SessionDB, Key, Transform) ->
 %%--------------------------------------------------------------------
 
 get_manager_info(#state{handler_db = HDB, 
-			cookie_db  = CDB} = _State) ->
+			session_db = SDB, 
+			cookie_db  = CDB, 
+			options    = Options} = _State) ->
     HandlerInfo = get_handler_info(HDB),
+    SessionInfo = which_sessions2(SDB), 
+    OptionsInfo = 
+	[{Item, get_option(Item, Options)} || 
+	    Item <- record_info(fields, options)], 
     CookieInfo  = httpc_cookie:which_cookies(CDB),
-    [{handlers, HandlerInfo}, {cookies, CookieInfo}].
+    [{handlers, HandlerInfo}, 
+     {sessions, SessionInfo}, 
+     {options,  OptionsInfo}, 
+     {cookies,  CookieInfo}].
 
 sort_handlers(Unsorted) ->
     sort_handlers2(lists:keysort(1, Unsorted)).