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package metrics
import (
"time"
)
func InMicroseconds(d time.Duration) float64 {
return float64(d.Nanoseconds() / time.Microsecond.Nanoseconds())
}
type (
Counter func(...string)
Adder func(float64, ...string)
Watcher func(float64, ...string)
)
// Int adds the value of `x`; convenience func for adding integers.
func (a Adder) Int(x int, s ...string) {
a(float64(x), s...)
}
// Since records an observation of time.Now().Sub(t) in microseconds
func (w Watcher) Since(t time.Time, s ...string) {
w(InMicroseconds(time.Now().Sub(t)), s...)
}
// Harness funcs execute the given func and record metrics concerning the execution. The error
// returned from the harness is the same error returned from the execution of the func param.
type Harness func(func() error, ...string) error
// NewHarness generates and returns an execution harness that records metrics. `counts` and `errors`
// are required; `timed` and `clock` must either both be nil, or both be non-nil.
func NewHarness(counts, errors Counter, timed Watcher, clock func() time.Time) Harness {
var harness Harness
if timed != nil && clock != nil {
harness = func(f func() error, labels ...string) error {
counts(labels...)
var (
t = clock()
err = f()
)
timed.Since(t, labels...)
if err != nil {
errors(labels...)
}
return err
}
} else {
harness = func(f func() error, labels ...string) error {
counts(labels...)
err := f()
if err != nil {
errors(labels...)
}
return err
}
}
return harness
}
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