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
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
// Copyright 2014 The Prometheus Authors
// Copyright 2019 TiKV Project Authors. Licensed under Apache-2.0.

use std::cell::RefCell;
use std::collections::HashMap;
use std::marker::PhantomData;
use std::sync::Arc;

use crate::atomic64::{Atomic, AtomicF64, AtomicU64, Number};
use crate::desc::Desc;
use crate::errors::Result;
use crate::metrics::{Collector, LocalMetric, Metric, Opts};
use crate::proto;
use crate::value::{Value, ValueType};
use crate::vec::{MetricVec, MetricVecBuilder};

/// The underlying implementation for [`Counter`] and [`IntCounter`].
#[derive(Debug)]
pub struct GenericCounter<P: Atomic> {
    v: Arc<Value<P>>,
}

/// A [`Metric`] represents a single numerical value that only ever goes up.
pub type Counter = GenericCounter<AtomicF64>;

/// The integer version of [`Counter`]. Provides better performance if metric values
/// are all positive integers (natural numbers).
pub type IntCounter = GenericCounter<AtomicU64>;

impl<P: Atomic> Clone for GenericCounter<P> {
    fn clone(&self) -> Self {
        Self {
            v: Arc::clone(&self.v),
        }
    }
}

impl<P: Atomic> GenericCounter<P> {
    /// Create a [`GenericCounter`] with the `name` and `help` arguments.
    pub fn new<S1: Into<String>, S2: Into<String>>(name: S1, help: S2) -> Result<Self> {
        let opts = Opts::new(name, help);
        Self::with_opts(opts)
    }

    /// Create a [`GenericCounter`] with the `opts` options.
    pub fn with_opts(opts: Opts) -> Result<Self> {
        Self::with_opts_and_label_values(&opts, &[])
    }

    fn with_opts_and_label_values(opts: &Opts, label_values: &[&str]) -> Result<Self> {
        let v = Value::new(opts, ValueType::Counter, P::T::from_i64(0), label_values)?;
        Ok(Self { v: Arc::new(v) })
    }

    /// Increase the given value to the counter.
    ///
    /// # Panics
    ///
    /// Panics in debug build if the value is < 0.
    #[inline]
    pub fn inc_by(&self, v: P::T) {
        debug_assert!(v >= P::T::from_i64(0));
        self.v.inc_by(v);
    }

    /// Increase the counter by 1.
    #[inline]
    pub fn inc(&self) {
        self.v.inc();
    }

    /// Return the counter value.
    #[inline]
    pub fn get(&self) -> P::T {
        self.v.get()
    }

    /// Restart the counter, resetting its value back to 0.
    #[inline]
    pub fn reset(&self) {
        self.v.set(P::T::from_i64(0))
    }

    /// Return a [`GenericLocalCounter`] for single thread usage.
    pub fn local(&self) -> GenericLocalCounter<P> {
        GenericLocalCounter::new(self.clone())
    }
}

impl<P: Atomic> Collector for GenericCounter<P> {
    fn desc(&self) -> Vec<&Desc> {
        vec![&self.v.desc]
    }

    fn collect(&self) -> Vec<proto::MetricFamily> {
        vec![self.v.collect()]
    }
}

impl<P: Atomic> Metric for GenericCounter<P> {
    fn metric(&self) -> proto::Metric {
        self.v.metric()
    }
}

#[derive(Debug)]
pub struct CounterVecBuilder<P: Atomic> {
    _phantom: PhantomData<P>,
}

impl<P: Atomic> CounterVecBuilder<P> {
    pub fn new() -> Self {
        Self {
            _phantom: PhantomData,
        }
    }
}

impl<P: Atomic> Clone for CounterVecBuilder<P> {
    fn clone(&self) -> Self {
        Self::new()
    }
}

impl<P: Atomic> MetricVecBuilder for CounterVecBuilder<P> {
    type M = GenericCounter<P>;
    type P = Opts;

    fn build(&self, opts: &Opts, vals: &[&str]) -> Result<Self::M> {
        Self::M::with_opts_and_label_values(opts, vals)
    }
}

/// The underlying implementation for [`CounterVec`] and [`IntCounterVec`].
pub type GenericCounterVec<P> = MetricVec<CounterVecBuilder<P>>;

/// A [`Collector`] that bundles a set of [`Counter`]s that all share
/// the same [`Desc`], but have different values for their variable labels. This is
/// used if you want to count the same thing partitioned by various dimensions
/// (e.g. number of HTTP requests, partitioned by response code and method).
pub type CounterVec = GenericCounterVec<AtomicF64>;

/// The integer version of [`CounterVec`]. Provides better performance if metric
/// are all positive integers (natural numbers).
pub type IntCounterVec = GenericCounterVec<AtomicU64>;

impl<P: Atomic> GenericCounterVec<P> {
    /// Create a new [`GenericCounterVec`] based on the provided
    /// [`Opts`] and partitioned by the given label names. At least one label name must be
    /// provided.
    pub fn new(opts: Opts, label_names: &[&str]) -> Result<Self> {
        let variable_names = label_names.iter().map(|s| (*s).to_owned()).collect();
        let opts = opts.variable_labels(variable_names);
        let metric_vec =
            MetricVec::create(proto::MetricType::COUNTER, CounterVecBuilder::new(), opts)?;

        Ok(metric_vec as Self)
    }

    /// Return a [`GenericLocalCounterVec`] for single thread usage.
    pub fn local(&self) -> GenericLocalCounterVec<P> {
        GenericLocalCounterVec::new(self.clone())
    }
}

/// The underlying implementation for [`LocalCounter`]
/// and [`LocalIntCounter`].
#[derive(Debug)]
pub struct GenericLocalCounter<P: Atomic> {
    counter: GenericCounter<P>,
    val: RefCell<P::T>,
}

/// For auto_flush::AFLocalCounter to use to make type inference possible
pub trait CounterWithValueType {
    ///the exact type which implements Atomic
    type ValueType: Atomic;
}

impl<P: Atomic> CounterWithValueType for GenericLocalCounter<P> {
    type ValueType = P;
}

/// An unsync [`Counter`].
pub type LocalCounter = GenericLocalCounter<AtomicF64>;

/// The integer version of [`LocalCounter`]. Provides better performance
/// are all positive integers (natural numbers).
pub type LocalIntCounter = GenericLocalCounter<AtomicU64>;

impl<P: Atomic> GenericLocalCounter<P> {
    fn new(counter: GenericCounter<P>) -> Self {
        Self {
            counter,
            val: RefCell::new(P::T::from_i64(0)),
        }
    }

    /// Increase the given value to the local counter.
    ///
    /// # Panics
    ///
    /// Panics in debug build if the value is < 0.
    #[inline]
    pub fn inc_by(&self, v: P::T) {
        debug_assert!(v >= P::T::from_i64(0));
        *self.val.borrow_mut() += v;
    }

    /// Increase the local counter by 1.
    #[inline]
    pub fn inc(&self) {
        *self.val.borrow_mut() += P::T::from_i64(1);
    }

    /// Return the local counter value.
    #[inline]
    pub fn get(&self) -> P::T {
        *self.val.borrow()
    }

    /// Restart the counter, resetting its value back to 0.
    #[inline]
    pub fn reset(&self) {
        *self.val.borrow_mut() = P::T::from_i64(0);
    }

    /// Flush the local metrics to the [`Counter`].
    #[inline]
    pub fn flush(&self) {
        if *self.val.borrow() == P::T::from_i64(0) {
            return;
        }
        self.counter.inc_by(*self.val.borrow());
        *self.val.borrow_mut() = P::T::from_i64(0);
    }
}

impl<P: Atomic> LocalMetric for GenericLocalCounter<P> {
    /// Flush the local metrics to the [`Counter`].
    #[inline]
    fn flush(&self) {
        GenericLocalCounter::flush(self);
    }
}

impl<P: Atomic> Clone for GenericLocalCounter<P> {
    fn clone(&self) -> Self {
        Self::new(self.counter.clone())
    }
}

/// The underlying implementation for [`LocalCounterVec`]
/// and [`LocalIntCounterVec`].
pub struct GenericLocalCounterVec<P: Atomic> {
    vec: GenericCounterVec<P>,
    local: HashMap<u64, GenericLocalCounter<P>>,
}

impl<P: Atomic> std::fmt::Debug for GenericLocalCounterVec<P> {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        write!(
            f,
            "GenericLocalCounterVec ({} locals)",
            self.local.keys().len()
        )
    }
}

/// An unsync [`CounterVec`].
pub type LocalCounterVec = GenericLocalCounterVec<AtomicF64>;

/// The integer version of [`LocalCounterVec`].
/// Provides better performance if metric values are all positive
/// integers (natural numbers).
pub type LocalIntCounterVec = GenericLocalCounterVec<AtomicU64>;

impl<P: Atomic> GenericLocalCounterVec<P> {
    fn new(vec: GenericCounterVec<P>) -> Self {
        let local = HashMap::with_capacity(vec.v.children.read().len());
        Self { vec, local }
    }

    /// Get a [`GenericLocalCounter`] by label values.
    /// See more [MetricVec::with_label_values].
    pub fn with_label_values<'a>(&'a mut self, vals: &[&str]) -> &'a mut GenericLocalCounter<P> {
        let hash = self.vec.v.hash_label_values(vals).unwrap();
        let vec = &self.vec;
        self.local
            .entry(hash)
            .or_insert_with(|| vec.with_label_values(vals).local())
    }

    /// Remove a [`GenericLocalCounter`] by label values.
    /// See more [MetricVec::remove_label_values].
    pub fn remove_label_values(&mut self, vals: &[&str]) -> Result<()> {
        let hash = self.vec.v.hash_label_values(vals)?;
        self.local.remove(&hash);
        self.vec.v.delete_label_values(vals)
    }

    /// Flush the local metrics to the [`CounterVec`] metric.
    pub fn flush(&self) {
        for h in self.local.values() {
            h.flush();
        }
    }
}

impl<P: Atomic> LocalMetric for GenericLocalCounterVec<P> {
    /// Flush the local metrics to the [`CounterVec`] metric.
    fn flush(&self) {
        GenericLocalCounterVec::flush(self);
    }
}

impl<P: Atomic> Clone for GenericLocalCounterVec<P> {
    fn clone(&self) -> Self {
        Self::new(self.vec.clone())
    }
}

#[cfg(test)]
mod tests {
    use std::collections::HashMap;
    use std::f64::EPSILON;

    use super::*;
    use crate::metrics::{Collector, Opts};

    #[test]
    fn test_counter() {
        let opts = Opts::new("test", "test help")
            .const_label("a", "1")
            .const_label("b", "2");
        let counter = Counter::with_opts(opts).unwrap();
        counter.inc();
        assert_eq!(counter.get() as u64, 1);
        counter.inc_by(42.0);
        assert_eq!(counter.get() as u64, 43);

        let mut mfs = counter.collect();
        assert_eq!(mfs.len(), 1);

        let mf = mfs.pop().unwrap();
        let m = mf.get_metric().get(0).unwrap();
        assert_eq!(m.get_label().len(), 2);
        assert_eq!(m.get_counter().get_value() as u64, 43);

        counter.reset();
        assert_eq!(counter.get() as u64, 0);
    }

    #[test]
    fn test_int_counter() {
        let counter = IntCounter::new("foo", "bar").unwrap();
        counter.inc();
        assert_eq!(counter.get(), 1);
        counter.inc_by(11);
        assert_eq!(counter.get(), 12);

        let mut mfs = counter.collect();
        assert_eq!(mfs.len(), 1);

        let mf = mfs.pop().unwrap();
        let m = mf.get_metric().get(0).unwrap();
        assert_eq!(m.get_label().len(), 0);
        assert_eq!(m.get_counter().get_value() as u64, 12);

        counter.reset();
        assert_eq!(counter.get() as u64, 0);
    }

    #[test]
    fn test_local_counter() {
        let counter = Counter::new("counter", "counter helper").unwrap();
        let local_counter1 = counter.local();
        let local_counter2 = counter.local();

        local_counter1.inc();
        local_counter2.inc();
        assert_eq!(local_counter1.get() as u64, 1);
        assert_eq!(local_counter2.get() as u64, 1);
        assert_eq!(counter.get() as u64, 0);
        local_counter1.flush();
        assert_eq!(local_counter1.get() as u64, 0);
        assert_eq!(counter.get() as u64, 1);
        local_counter2.flush();
        assert_eq!(counter.get() as u64, 2);

        local_counter1.reset();
        local_counter2.reset();
        counter.reset();
        assert_eq!(counter.get() as u64, 0);
        local_counter1.flush();
        assert_eq!(counter.get() as u64, 0);
        local_counter2.flush();
        assert_eq!(counter.get() as u64, 0);
    }

    #[test]
    fn test_int_local_counter() {
        let counter = IntCounter::new("foo", "bar").unwrap();
        let local_counter = counter.local();

        local_counter.inc();
        assert_eq!(local_counter.get(), 1);
        assert_eq!(counter.get(), 0);

        local_counter.inc_by(5);
        local_counter.flush();
        assert_eq!(local_counter.get(), 0);
        assert_eq!(counter.get(), 6);

        local_counter.reset();
        counter.reset();
        assert_eq!(counter.get() as u64, 0);
        local_counter.flush();
        assert_eq!(counter.get() as u64, 0);
    }

    #[test]
    fn test_counter_vec_with_labels() {
        let vec = CounterVec::new(
            Opts::new("test_couter_vec", "test counter vec help"),
            &["l1", "l2"],
        )
        .unwrap();

        let mut labels = HashMap::new();
        labels.insert("l1", "v1");
        labels.insert("l2", "v2");
        assert!(vec.remove(&labels).is_err());

        vec.with(&labels).inc();
        assert!(vec.remove(&labels).is_ok());
        assert!(vec.remove(&labels).is_err());

        let mut labels2 = HashMap::new();
        labels2.insert("l1", "v2");
        labels2.insert("l2", "v1");

        vec.with(&labels).inc();
        assert!(vec.remove(&labels2).is_err());

        vec.with(&labels).inc();

        let mut labels3 = HashMap::new();
        labels3.insert("l1", "v1");
        assert!(vec.remove(&labels3).is_err());
    }

    #[test]
    fn test_int_counter_vec() {
        let vec = IntCounterVec::new(Opts::new("foo", "bar"), &["l1", "l2"]).unwrap();

        vec.with_label_values(&["v1", "v3"]).inc();
        assert_eq!(vec.with_label_values(&["v1", "v3"]).get(), 1);

        vec.with_label_values(&["v1", "v2"]).inc_by(12);
        assert_eq!(vec.with_label_values(&["v1", "v3"]).get(), 1);
        assert_eq!(vec.with_label_values(&["v1", "v2"]).get(), 12);

        vec.with_label_values(&["v4", "v2"]).inc_by(2);
        assert_eq!(vec.with_label_values(&["v1", "v3"]).get(), 1);
        assert_eq!(vec.with_label_values(&["v1", "v2"]).get(), 12);
        assert_eq!(vec.with_label_values(&["v4", "v2"]).get(), 2);

        vec.with_label_values(&["v1", "v3"]).inc_by(5);
        assert_eq!(vec.with_label_values(&["v1", "v3"]).get(), 6);
        assert_eq!(vec.with_label_values(&["v1", "v2"]).get(), 12);
        assert_eq!(vec.with_label_values(&["v4", "v2"]).get(), 2);
    }

    #[test]
    fn test_counter_vec_with_label_values() {
        let vec = CounterVec::new(
            Opts::new("test_vec", "test counter vec help"),
            &["l1", "l2"],
        )
        .unwrap();

        assert!(vec.remove_label_values(&["v1", "v2"]).is_err());
        vec.with_label_values(&["v1", "v2"]).inc();
        assert!(vec.remove_label_values(&["v1", "v2"]).is_ok());

        vec.with_label_values(&["v1", "v2"]).inc();
        assert!(vec.remove_label_values(&["v1"]).is_err());
        assert!(vec.remove_label_values(&["v1", "v3"]).is_err());
    }

    #[test]
    fn test_counter_vec_local() {
        let vec = CounterVec::new(
            Opts::new("test_vec_local", "test counter vec help"),
            &["l1", "l2"],
        )
        .unwrap();
        let mut local_vec_1 = vec.local();
        let mut local_vec_2 = local_vec_1.clone();

        assert!(local_vec_1.remove_label_values(&["v1", "v2"]).is_err());

        local_vec_1.with_label_values(&["v1", "v2"]).inc_by(23.0);
        assert!((local_vec_1.with_label_values(&["v1", "v2"]).get() - 23.0) <= EPSILON);
        assert!((vec.with_label_values(&["v1", "v2"]).get() - 0.0) <= EPSILON);

        local_vec_1.flush();
        assert!((local_vec_1.with_label_values(&["v1", "v2"]).get() - 0.0) <= EPSILON);
        assert!((vec.with_label_values(&["v1", "v2"]).get() - 23.0) <= EPSILON);

        local_vec_1.flush();
        assert!((local_vec_1.with_label_values(&["v1", "v2"]).get() - 0.0) <= EPSILON);
        assert!((vec.with_label_values(&["v1", "v2"]).get() - 23.0) <= EPSILON);

        local_vec_1.with_label_values(&["v1", "v2"]).inc_by(11.0);
        assert!((local_vec_1.with_label_values(&["v1", "v2"]).get() - 11.0) <= EPSILON);
        assert!((vec.with_label_values(&["v1", "v2"]).get() - 23.0) <= EPSILON);

        local_vec_1.flush();
        assert!((local_vec_1.with_label_values(&["v1", "v2"]).get() - 0.0) <= EPSILON);
        assert!((vec.with_label_values(&["v1", "v2"]).get() - 34.0) <= EPSILON);

        // When calling `remove_label_values`, it is "flushed" immediately.
        assert!(local_vec_1.remove_label_values(&["v1", "v2"]).is_ok());
        assert!((local_vec_1.with_label_values(&["v1", "v2"]).get() - 0.0) <= EPSILON);
        assert!((vec.with_label_values(&["v1", "v2"]).get() - 0.0) <= EPSILON);

        local_vec_1.with_label_values(&["v1", "v2"]).inc();
        assert!(local_vec_1.remove_label_values(&["v1"]).is_err());
        assert!(local_vec_1.remove_label_values(&["v1", "v3"]).is_err());

        local_vec_1.with_label_values(&["v1", "v2"]).inc_by(13.0);
        assert!((local_vec_1.with_label_values(&["v1", "v2"]).get() - 14.0) <= EPSILON);
        assert!((vec.with_label_values(&["v1", "v2"]).get() - 0.0) <= EPSILON);

        local_vec_2.with_label_values(&["v1", "v2"]).inc_by(7.0);
        assert!((local_vec_2.with_label_values(&["v1", "v2"]).get() - 7.0) <= EPSILON);

        local_vec_1.flush();
        local_vec_2.flush();
        assert!((vec.with_label_values(&["v1", "v2"]).get() - 21.0) <= EPSILON);

        local_vec_1.flush();
        local_vec_2.flush();
        assert!((vec.with_label_values(&["v1", "v2"]).get() - 21.0) <= EPSILON);
    }

    #[test]
    fn test_int_counter_vec_local() {
        let vec = IntCounterVec::new(Opts::new("foo", "bar"), &["l1", "l2"]).unwrap();
        let mut local_vec_1 = vec.local();
        assert!(local_vec_1.remove_label_values(&["v1", "v2"]).is_err());

        local_vec_1.with_label_values(&["v1", "v2"]).inc_by(23);
        assert_eq!(local_vec_1.with_label_values(&["v1", "v2"]).get(), 23);
        assert_eq!(vec.with_label_values(&["v1", "v2"]).get(), 0);

        local_vec_1.flush();
        assert_eq!(local_vec_1.with_label_values(&["v1", "v2"]).get(), 0);
        assert_eq!(vec.with_label_values(&["v1", "v2"]).get(), 23);

        local_vec_1.flush();
        assert_eq!(local_vec_1.with_label_values(&["v1", "v2"]).get(), 0);
        assert_eq!(vec.with_label_values(&["v1", "v2"]).get(), 23);

        local_vec_1.with_label_values(&["v1", "v2"]).inc_by(11);
        assert_eq!(local_vec_1.with_label_values(&["v1", "v2"]).get(), 11);
        assert_eq!(vec.with_label_values(&["v1", "v2"]).get(), 23);

        local_vec_1.flush();
        assert_eq!(local_vec_1.with_label_values(&["v1", "v2"]).get(), 0);
        assert_eq!(vec.with_label_values(&["v1", "v2"]).get(), 34);
    }

    #[cfg(debug_assertions)]
    #[test]
    #[should_panic(expected = "assertion failed")]
    fn test_counter_negative_inc() {
        let counter = Counter::new("foo", "bar").unwrap();
        counter.inc_by(-42.0);
    }

    #[cfg(debug_assertions)]
    #[test]
    #[should_panic(expected = "assertion failed")]
    fn test_local_counter_negative_inc() {
        let counter = Counter::new("foo", "bar").unwrap();
        let local = counter.local();
        local.inc_by(-42.0);
    }
}