113 lines
2.5 KiB
Go
113 lines
2.5 KiB
Go
|
package metrics
|
||
|
|
|
||
|
|
import "sync/atomic"
|
||
|
|
|
||
|
|
// Counters hold an int64 value that can be incremented and decremented.
|
||
|
|
type Counter interface {
|
||
|
|
Clear()
|
||
|
|
Count() int64
|
||
|
|
Dec(int64)
|
||
|
|
Inc(int64)
|
||
|
|
Snapshot() Counter
|
||
|
|
}
|
||
|
|
|
||
|
|
// GetOrRegisterCounter returns an existing Counter or constructs and registers
|
||
|
|
// a new StandardCounter.
|
||
|
|
func GetOrRegisterCounter(name string, r Registry) Counter {
|
||
|
|
if nil == r {
|
||
|
|
r = DefaultRegistry
|
||
|
|
}
|
||
|
|
return r.GetOrRegister(name, NewCounter).(Counter)
|
||
|
|
}
|
||
|
|
|
||
|
|
// NewCounter constructs a new StandardCounter.
|
||
|
|
func NewCounter() Counter {
|
||
|
|
if UseNilMetrics {
|
||
|
|
return NilCounter{}
|
||
|
|
}
|
||
|
|
return &StandardCounter{0}
|
||
|
|
}
|
||
|
|
|
||
|
|
// NewRegisteredCounter constructs and registers a new StandardCounter.
|
||
|
|
func NewRegisteredCounter(name string, r Registry) Counter {
|
||
|
|
c := NewCounter()
|
||
|
|
if nil == r {
|
||
|
|
r = DefaultRegistry
|
||
|
|
}
|
||
|
|
r.Register(name, c)
|
||
|
|
return c
|
||
|
|
}
|
||
|
|
|
||
|
|
// CounterSnapshot is a read-only copy of another Counter.
|
||
|
|
type CounterSnapshot int64
|
||
|
|
|
||
|
|
// Clear panics.
|
||
|
|
func (CounterSnapshot) Clear() {
|
||
|
|
panic("Clear called on a CounterSnapshot")
|
||
|
|
}
|
||
|
|
|
||
|
|
// Count returns the count at the time the snapshot was taken.
|
||
|
|
func (c CounterSnapshot) Count() int64 { return int64(c) }
|
||
|
|
|
||
|
|
// Dec panics.
|
||
|
|
func (CounterSnapshot) Dec(int64) {
|
||
|
|
panic("Dec called on a CounterSnapshot")
|
||
|
|
}
|
||
|
|
|
||
|
|
// Inc panics.
|
||
|
|
func (CounterSnapshot) Inc(int64) {
|
||
|
|
panic("Inc called on a CounterSnapshot")
|
||
|
|
}
|
||
|
|
|
||
|
|
// Snapshot returns the snapshot.
|
||
|
|
func (c CounterSnapshot) Snapshot() Counter { return c }
|
||
|
|
|
||
|
|
// NilCounter is a no-op Counter.
|
||
|
|
type NilCounter struct{}
|
||
|
|
|
||
|
|
// Clear is a no-op.
|
||
|
|
func (NilCounter) Clear() {}
|
||
|
|
|
||
|
|
// Count is a no-op.
|
||
|
|
func (NilCounter) Count() int64 { return 0 }
|
||
|
|
|
||
|
|
// Dec is a no-op.
|
||
|
|
func (NilCounter) Dec(i int64) {}
|
||
|
|
|
||
|
|
// Inc is a no-op.
|
||
|
|
func (NilCounter) Inc(i int64) {}
|
||
|
|
|
||
|
|
// Snapshot is a no-op.
|
||
|
|
func (NilCounter) Snapshot() Counter { return NilCounter{} }
|
||
|
|
|
||
|
|
// StandardCounter is the standard implementation of a Counter and uses the
|
||
|
|
// sync/atomic package to manage a single int64 value.
|
||
|
|
type StandardCounter struct {
|
||
|
|
count int64
|
||
|
|
}
|
||
|
|
|
||
|
|
// Clear sets the counter to zero.
|
||
|
|
func (c *StandardCounter) Clear() {
|
||
|
|
atomic.StoreInt64(&c.count, 0)
|
||
|
|
}
|
||
|
|
|
||
|
|
// Count returns the current count.
|
||
|
|
func (c *StandardCounter) Count() int64 {
|
||
|
|
return atomic.LoadInt64(&c.count)
|
||
|
|
}
|
||
|
|
|
||
|
|
// Dec decrements the counter by the given amount.
|
||
|
|
func (c *StandardCounter) Dec(i int64) {
|
||
|
|
atomic.AddInt64(&c.count, -i)
|
||
|
|
}
|
||
|
|
|
||
|
|
// Inc increments the counter by the given amount.
|
||
|
|
func (c *StandardCounter) Inc(i int64) {
|
||
|
|
atomic.AddInt64(&c.count, i)
|
||
|
|
}
|
||
|
|
|
||
|
|
// Snapshot returns a read-only copy of the counter.
|
||
|
|
func (c *StandardCounter) Snapshot() Counter {
|
||
|
|
return CounterSnapshot(c.Count())
|
||
|
|
}
|