go-pulse/vendor/github.com/rcrowley/go-metrics/counter.go
Péter Szilágyi 289b30715d Godeps, vendor: convert dependency management to trash (#3198)
This commit converts the dependency management from Godeps to the vendor
folder, also switching the tool from godep to trash. Since the upstream tool
lacks a few features proposed via a few PRs, until those PRs are merged in
(if), use github.com/karalabe/trash.

You can update dependencies via trash --update.

All dependencies have been updated to their latest version.

Parts of the build system are reworked to drop old notions of Godeps and
invocation of the go vet command so that it doesn't run against the vendor
folder, as that will just blow up during vetting.

The conversion drops OpenCL (and hence GPU mining support) from ethash and our
codebase. The short reasoning is that there's noone to maintain and having
opencl libs in our deps messes up builds as go install ./... tries to build
them, failing with unsatisfied link errors for the C OpenCL deps.

golang.org/x/net/context is not vendored in. We expect it to be fetched by the
user (i.e. using go get). To keep ci.go builds reproducible the package is
"vendored" in build/_vendor.
2016-10-28 19:05:01 +02:00

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())
}