-
Notifications
You must be signed in to change notification settings - Fork 3
/
telemetria.ex
385 lines (309 loc) · 11.2 KB
/
telemetria.ex
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
defmodule Telemetria do
@moduledoc """
`Telemetría` is the opinionated wrapper for [`:telemetry`](https://hexdocs.pm/telemetry)
providing handy macros to attach telemetry events to any function, private function,
anonymous functions (on per-clause basis) and just random set of expressions.
`Telemetría` exports three macros:
- `deft/2` which is wrapping `Kernel.def/2`
- `defpt/2` which is wrapping `Kernel.defp/2`
- `t/2` which is wrapping the expression passed as the first parameter
and adds the options passed as a keyword to the second parameter to the
context of the respective telemetry event
`Telemetría` allows compile-time telemetry events definition and provides
a compiler that is responsible for incremental builds and updates of the list of
events telemetry is aware about.
## Using module attribute
Besides the functions listed above, one might attach `Telemetría` to the function
by annotating it with `@telemetria` module attribute.
There are several options to pass to this attribute:
- **`true`** — attach the `telemetry` to the function
- **`if: boolean()`** — compile-time condition
- **`if: (result -> boolean())`** — runtime condition
- **`level: Logger,level()`** — specify a min logger level to attach telemetry
- **`group: atom()`** — the configured group to manage event throttling,
see `:throttle` setting in `Telemetria.Options`
## Advantages
`Telemetría` takes care about managing events in the target application,
makes it a single-letter change to turn a function into a function wrapped
with telemetry call, measuring the execution time out of the box.
It also allows to easily convert expressions to be be telemetry-aware.
Besides that, `telemetry: false` flag allows to purge the calls in compile-time
resulting in zero overhead (useful for benchmark, or like.)
## Example
You need to include the compiler in `mix.exs`:
```elixir
defmodule MyApp.MixProject do
def project do
[
# ...
compilers: [:telemetria | Mix.compilers()],
# ...
]
end
# ...
end
```
In the modules you want to add telemetry to, you should `require Telemetria` (or,
preferably, `import Telemetria` to make it available without FQN.) Once imported,
the macros are available and tracked by the compiler.
```elixir
defmodule MyMod do
import Telemetria
defpt pi, do: 3.14
deft answer, do: 42 - pi()
def inner do
short_result = t(42 * 42)
result =
t do
# long calculations
:ok
end
end
end
```
## Use in releases
`:telemetria` compiler keeps track of the events in the compiler manifest file
to support incremental builds. Also it spits out `config/.telemetria.config.json`
config for convenience. It might be used in in the release configuration as shown below.
```elixir
releases: [
configured: [
# ...,
config_providers: [{Telemetria.ConfigProvider, "/etc/telemetria.json"}]
]
]
```
## Options
#{NimbleOptions.docs(Telemetria.Options.schema())}
"""
alias Telemetria.Mix.Events
@doc false
defmacro __using__(opts) do
initial_ast =
case Keyword.get(opts, :action, :none) do
:require -> quote(location: :keep, generated: true, do: require(Telemetria))
:import -> quote(location: :keep, generated: true, do: import(Telemetria))
:none -> :ok
unknown -> IO.puts("Ignored unknown value for :action option: " <> inspect(unknown))
end
quote location: :keep, generated: true do
unquote(initial_ast)
Module.register_attribute(__MODULE__, :telemetria, accumulate: false)
Module.register_attribute(__MODULE__, :telemetria_hooks, accumulate: true)
@on_definition Telemetria.Hooks
@before_compile Telemetria.Hooks
end
end
@doc "Declares a function with a telemetry attached, measuring execution time"
defmacro deft(call, expr) do
expr = telemetry_wrap(expr, call, __CALLER__)
quote location: :keep, generated: true do
Kernel.def(unquote(call), unquote(expr))
end
end
@doc "Declares a private function with a telemetry attached, measuring execution time"
defmacro defpt(call, expr) do
expr = telemetry_wrap(expr, call, __CALLER__)
quote location: :keep, generated: true do
Kernel.defp(unquote(call), unquote(expr))
end
end
@doc "Attaches telemetry to anonymous function (per clause,) or to expression(s)"
defmacro t(ast, opts \\ [])
defmacro t({:fn, meta, clauses}, opts) do
clauses =
for {:->, meta, [args, clause]} <- clauses do
{:->, meta,
[
args,
do_t(clause, Keyword.merge([arguments: extract_guards(args)], opts), __CALLER__)
]}
end
{:fn, meta, clauses}
end
defmacro t(ast, opts), do: do_t(ast, opts, __CALLER__)
@compile {:inline, enabled?: 0, enabled?: 1}
@spec enabled?(opts :: keyword()) :: boolean()
defp enabled?(opts \\ []),
do: Keyword.get(opts, :enabled, Application.get_env(:telemetria, :enabled, true))
@compile {:inline, do_t: 3}
@spec do_t(ast, keyword(), Macro.Env.t()) :: ast
when ast: {atom(), keyword(), tuple() | list()}
defp do_t(ast, opts, caller) do
if enabled?(opts) do
{suffix, opts} = Keyword.pop(opts, :suffix)
ast
|> telemetry_wrap(List.wrap(suffix), caller, opts)
|> Keyword.get(:do, [])
else
ast
end
end
@doc false
@spec otp_app :: atom()
def otp_app do
Application.get_env(
:telemetria,
:otp_app,
case :application.get_application(self()) do
{:ok, otp_app} -> otp_app
_ -> :unknown
end
)
end
@doc false
@spec noop(any()) :: any()
def noop(arg), do: arg
@doc false
@spec yes(any()) :: true
def yes(_arg), do: true
@spec telemetry_prefix(
Macro.Env.t(),
{atom(), keyword(), tuple()} | nil | maybe_improper_list()
) :: [atom()]
def telemetry_prefix(%Macro.Env{module: mod, function: fun}, call) do
suffix =
case fun do
{f, _arity} -> [f]
_ -> []
end ++
case call do
[_ | _] = suffices -> suffices
{f, _, _} when is_atom(f) -> [f]
_ -> []
end
prefix =
case mod do
nil ->
[:module_scope]
mod when is_atom(mod) ->
mod |> Module.split() |> Enum.map(&(&1 |> Macro.underscore() |> String.to_atom()))
end
Enum.dedup(prefix ++ suffix)
end
@spec telemetry_wrap(ast, nil | ast | maybe_improper_list(), Macro.Env.t(), [
Telemetria.Hooks.option()
]) :: ast
when ast: keyword() | {atom(), keyword(), any()}
@doc false
def telemetry_wrap(expr, call, caller, context \\ [])
def telemetry_wrap(expr, {:when, _meta, [call, _guards]}, %Macro.Env{} = caller, context) do
telemetry_wrap(expr, call, caller, context)
end
def telemetry_wrap(expr, call, %Macro.Env{} = caller, context) do
find_name = fn
{{:_, _, _}, _} -> nil
{{_, _, na} = n, _} when na in [nil, []] -> n
{{:=, _, [{_, _, na} = n, _]}, _} when na in [nil, []] -> n
{{:=, _, [_, {_, _, na} = n]}, _} when na in [nil, []] -> n
{any, idx} -> {:=, [], [{:"arg_#{idx}", [], Elixir}, any]}
end
args =
case call do
{fun, meta, args} when is_atom(fun) and is_list(meta) and is_list(args) -> args
_ -> []
end
|> Enum.with_index()
|> Enum.map(find_name)
|> Enum.reject(&is_nil/1)
|> Enum.map(fn
{:=, _, [{name, _, _}, var]} -> {name, var}
{name, _, _} = var -> {name, var}
end)
if enabled?() do
{block, expr} =
if Keyword.keyword?(expr) do
Keyword.pop(expr, :do, [])
else
{expr, []}
end
event = telemetry_prefix(caller, call)
report(event, caller)
unless is_nil(caller.module),
do: Module.put_attribute(caller.module, :doc, {caller.line, telemetry: true})
caller = caller |> Map.take(~w|module function file line|a) |> Macro.escape()
fix_fun = fn
nil ->
&Telemetria.noop/1
{mod, fun} ->
Function.capture(mod, fun, 1)
f when is_function(f, 1) ->
f
weird ->
raise Telemetria.Error,
"transform must be a tuple `{mod, fun}` or a function capture, #{inspect(weird)} given"
end
group = get_in(context, [:options, :group])
args_transform =
context |> get_in([:options, :transform, :args]) |> fix_fun.() |> Macro.escape()
result_transform =
context |> get_in([:options, :transform, :result]) |> fix_fun.() |> Macro.escape()
{clause_args, context} = Keyword.pop(context, :arguments, [])
args = Keyword.merge(args, clause_args)
conditional = Macro.escape(context[:conditional] || (&Telemetria.yes/1))
block =
quote location: :keep, generated: true do
now = [
system: System.system_time(),
monotonic: System.monotonic_time(:microsecond),
utc: DateTime.utc_now()
]
result = unquote(block)
if unquote(conditional).(result) do
benchmark = System.monotonic_time(:microsecond) - now[:monotonic]
Telemetria.Throttler.execute(unquote(group), {
unquote(event),
%{
system_time: now,
consumed: benchmark
},
%{
env: unquote(caller),
result: unquote(result_transform).(result),
args: unquote(args_transform).(unquote(args)),
context: unquote(context)
}
})
end
result
end
Keyword.put(expr, :do, block)
else
expr
end
end
@warn_missing_compiler Application.compile_env(:telemetria, :warn_missing_compiler, false)
defp report(event, caller) do
if is_nil(GenServer.whereis(Events)) do
if @warn_missing_compiler do
Mix.shell().warning([
"Added event: #{inspect(event)} at #{caller.file}:#{caller.line}, ",
"but `Telemetria` config won’t be updated. `",
"Add `:telemetria` compiler to `compilers:` in your `mix.exs`!"
])
end
else
Events.put(:event, {caller.module, event})
end
end
defp variablize({:_, _, _}), do: {:_, :skipped}
defp variablize({:{}, _, elems}), do: {:tuple, Enum.map(elems, &variablize/1)}
defp variablize({:%{}, _, elems}), do: {:map, Enum.map(elems, &variablize/1)}
defp variablize({var, _, _} = val), do: {var, val}
defp extract_guards([]), do: []
defp extract_guards([_ | _] = list) do
list
|> Enum.map(&extract_guards/1)
|> Enum.map(fn
{:_, _, _} = underscore -> variablize(underscore)
{{op, _, _} = term, _guards} when op in [:{}, :%{}] -> variablize(term)
{{_, _, _} = val, _guards} -> variablize(val)
{_, _, _} = val -> variablize(val)
other -> {:unknown, inspect(other)}
end)
end
defp extract_guards({:when, _, [l, r]}), do: {l, extract_or_guards(r)}
defp extract_guards(other), do: {other, []}
defp extract_or_guards({:when, _, [l, r]}), do: [l | extract_or_guards(r)]
defp extract_or_guards(other), do: [other]
end