src/beam_stats_state.erl

   1 -module(beam_stats_state).
   2
   3 -include("include/beam_stats.hrl").
   4
   5 -export_type(
   6     [ t/0
   7     ]).
   8
   9 -export(
  10     [ new/0
  11     , update/1
  12     , export/1
  13     ]).
  14
  15 -record(?MODULE,
  16     { timestamp             :: erlang:timestamp()
  17     , node_id               :: atom()
  18     , memory                :: [{atom(), non_neg_integer()}]
  19
  20     , previous_io_bytes_in  :: non_neg_integer()
  21     , previous_io_bytes_out :: non_neg_integer()
  22     , current_io_bytes_in   :: non_neg_integer()
  23     , current_io_bytes_out  :: non_neg_integer()
  24
  25     , previous_context_switches :: non_neg_integer()
  26     ,  current_context_switches :: non_neg_integer()
  27     }).
  28
  29 -define(T, #?MODULE).
  30
  31 -opaque t() ::
  32     ?T{}.
  33
  34 -spec new() ->
  35     t().
  36 new() ->
  37     { {input  , CurrentIOBytesIn}
  38     , {output , CurrentIOBytesOut}
  39     } = erlang:statistics(io),
  40     {CurrentContextSwitches, 0} = erlang:statistics(context_switches),
  41     ?T
  42     { timestamp             = os:timestamp()
  43     , node_id               = erlang:node()
  44     , memory                = erlang:memory()
  45     , previous_io_bytes_in  = 0
  46     , previous_io_bytes_out = 0
  47     , current_io_bytes_in   = CurrentIOBytesIn
  48     , current_io_bytes_out  = CurrentIOBytesOut
  49     , previous_context_switches = 0
  50     ,  current_context_switches = CurrentContextSwitches
  51     }.
  52
  53 -spec update(t()) ->
  54     t().
  55 update(?T
  56     { previous_io_bytes_in  = PreviousIOBytesIn
  57     , previous_io_bytes_out = PreviousIOBytesOut
  58     , previous_context_switches = PreviousContextSwitches
  59     }
  60 ) ->
  61     { {input  , CurrentIOBytesIn}
  62     , {output , CurrentIOBytesOut}
  63     } = erlang:statistics(io),
  64     {CurrentContextSwitches, 0} = erlang:statistics(context_switches),
  65     ?T
  66     { timestamp             = os:timestamp()
  67     , node_id               = erlang:node()
  68     , memory                = erlang:memory()
  69     , previous_io_bytes_in  = PreviousIOBytesIn
  70     , previous_io_bytes_out = PreviousIOBytesOut
  71     , current_io_bytes_in   = CurrentIOBytesIn
  72     , current_io_bytes_out  = CurrentIOBytesOut
  73     , previous_context_switches = PreviousContextSwitches
  74     ,  current_context_switches = CurrentContextSwitches
  75     }.
  76
  77 -spec export(t()) ->
  78     beam_stats:t().
  79 export(
  80     ?T
  81     { timestamp             = Timestamp
  82     , node_id               = NodeID
  83     , memory                = Memory
  84     , previous_io_bytes_in  = PreviousIOBytesIn
  85     , previous_io_bytes_out = PreviousIOBytesOut
  86     , current_io_bytes_in   = CurrentIOBytesIn
  87     , current_io_bytes_out  = CurrentIOBytesOut
  88     , previous_context_switches = PreviousContextSwitches
  89     ,  current_context_switches = CurrentContextSwitches
  90     }
  91 ) ->
  92     #beam_stats
  93     { timestamp    = Timestamp
  94     , node_id      = NodeID
  95     , memory       = Memory
  96     , io_bytes_in  = CurrentIOBytesIn  - PreviousIOBytesIn
  97     , io_bytes_out = CurrentIOBytesOut - PreviousIOBytesOut
  98     , context_switches = CurrentContextSwitches - PreviousContextSwitches
  99     }.