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authorHans Nilsson <[email protected]>2018-08-08 19:31:27 +0200
committerHans Nilsson <[email protected]>2018-08-13 12:27:51 +0200
commit6bd4fc6943112db14c0b71fac707cf3def22aa83 (patch)
tree79ab410518a057c6a0438399c2c133f680c89c40 /lib
parent52289cedff1f0fbbf87fedbda557c55348b4c712 (diff)
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ssh: Circular trace buffer primitives
Diffstat (limited to 'lib')
-rw-r--r--lib/ssh/src/ssh.hrl25
-rw-r--r--lib/ssh/src/ssh_dbg.erl108
2 files changed, 132 insertions, 1 deletions
diff --git a/lib/ssh/src/ssh.hrl b/lib/ssh/src/ssh.hrl
index 9631427749..01c44cb371 100644
--- a/lib/ssh/src/ssh.hrl
+++ b/lib/ssh/src/ssh.hrl
@@ -492,4 +492,29 @@
-define(wr_record(N), ?wr_record(N, [])).
+%% Circular trace buffer macros
+
+-record(circ_buf_entry,
+ {
+ module,
+ line,
+ function,
+ pid = self(),
+ value
+ }).
+
+-define(CIRC_BUF_IN(VALUE),
+ ssh_dbg:cbuf_in(
+ #circ_buf_entry{module = ?MODULE,
+ line = ?LINE,
+ function = {?FUNCTION_NAME,?FUNCTION_ARITY},
+ pid = self(),
+ value = (VALUE)
+ })
+ ).
+
+-define(CIRC_BUF_IN_ONCE(VALUE),
+ ((fun(V) -> ?CIRC_BUF_IN(V), V end)(VALUE))
+ ).
+
-endif. % SSH_HRL defined
diff --git a/lib/ssh/src/ssh_dbg.erl b/lib/ssh/src/ssh_dbg.erl
index b53c09b17d..3681e03cc2 100644
--- a/lib/ssh/src/ssh_dbg.erl
+++ b/lib/ssh/src/ssh_dbg.erl
@@ -54,7 +54,13 @@
start_tracer/0, start_tracer/1,
on/1, on/0,
off/1, off/0,
- go_on/0
+ go_on/0,
+ %% Circular buffer
+ cbuf_start/0, cbuf_start/1,
+ cbuf_stop_clear/0,
+ cbuf_in/1,
+ cbuf_list/0,
+ fmt_cbuf_items/0, fmt_cbuf_item/1
]).
-export([shrink_bin/1,
@@ -331,3 +337,103 @@ ts({_,_,Usec}=Now) when is_integer(Usec) ->
io_lib:format("~.2.0w:~.2.0w:~.2.0w.~.6.0w",[HH,MM,SS,Usec]);
ts(_) ->
"-".
+
+%%%================================================================
+-define(CIRC_BUF, circ_buf).
+
+cbuf_start() ->
+ cbuf_start(20).
+
+cbuf_start(CbufMaxLen) ->
+ put(?CIRC_BUF, {CbufMaxLen,queue:new()}),
+ ok.
+
+
+cbuf_stop_clear() ->
+ case erase(?CIRC_BUF) of
+ undefined ->
+ [];
+ {_CbufMaxLen,Queue} ->
+ queue:to_list(Queue)
+ end.
+
+
+cbuf_in(Value) ->
+ case get(?CIRC_BUF) of
+ undefined ->
+ disabled;
+ {CbufMaxLen,Queue} ->
+ UpdatedQueue =
+ try queue:head(Queue) of
+ {Value, TS0, Cnt0} ->
+ %% Same Value as last saved in the queue
+ queue:in_r({Value, TS0, Cnt0+1},
+ queue:drop(Queue)
+ );
+ _ ->
+ queue:in_r({Value, erlang:timestamp(), 1},
+ truncate_cbuf(Queue, CbufMaxLen)
+ )
+ catch
+ error:empty ->
+ queue:in_r({Value, erlang:timestamp(), 1}, Queue)
+ end,
+ put(?CIRC_BUF, {CbufMaxLen,UpdatedQueue}),
+ ok
+ end.
+
+
+cbuf_list() ->
+ case get(?CIRC_BUF) of
+ undefined ->
+ [];
+ {_CbufMaxLen,Queue} ->
+ queue:to_list(Queue)
+ end.
+
+
+truncate_cbuf(Q, CbufMaxLen) ->
+ case queue:len(Q) of
+ N when N>=CbufMaxLen ->
+ truncate_cbuf(element(2,queue:out_r(Q)), CbufMaxLen);
+ _ ->
+ Q
+ end.
+
+fmt_cbuf_items() ->
+ lists:flatten(
+ io_lib:format("Circular trace buffer. Latest item first.~n~s~n",
+ [case get(?CIRC_BUF) of
+ {Max,_} ->
+ L = cbuf_list(),
+ [io_lib:format("==== ~.*w: ~s~n",[num_digits(Max),N,fmt_cbuf_item(X)]) ||
+ {N,X} <- lists:zip(lists:seq(1,length(L)), L)
+ ];
+ _ ->
+ io_lib:format("Not started.~n",[])
+ end])).
+
+
+num_digits(0) -> 1;
+num_digits(N) when N>0 -> 1+trunc(math:log10(N)).
+
+
+fmt_cbuf_item({Value, TimeStamp, N}) ->
+ io_lib:format("~s~s~n~s~n",
+ [fmt_ts(TimeStamp),
+ [io_lib:format(" (Repeated ~p times)",[N]) || N>1],
+ fmt_value(Value)]).
+
+
+fmt_ts(TS = {_,_,Us}) ->
+ {{YY,MM,DD},{H,M,S}} = calendar:now_to_universal_time(TS),
+ io_lib:format("~w-~.2.0w-~.2.0w ~.2.0w:~.2.0w:~.2.0w.~.6.0w UTC",[YY,MM,DD,H,M,S,Us]).
+
+fmt_value(#circ_buf_entry{module = M,
+ line = L,
+ function = {F,A},
+ pid = Pid,
+ value = V}) ->
+ io_lib:format("~p:~p ~p/~p ~p~n~s",[M,L,F,A,Pid,fmt_value(V)]);
+fmt_value(Value) ->
+ io_lib:format("~p",[Value]).