README
¶
counters
A GoLang implementation of counters.
It provides an object: counters.CounterBox and Counter, Min and Max implementation.
Installation:
$ go get -u github.com/orian/counters
The example usages:
import "github.com/orian/counters"
//... some code
cb := counters.NewCounterBox()
c := cb.GetCounter("ex")
c.Increment()
c.IncrementBy(6)
c.Value() // returns 7
cb.GetCounter("ex").Value() // Returns 7
For convenience there is also an http.HandleFunc provided which prints values of counters.
One may use subpackage globals if want to use a global counters.
import "github.com/orian/counters/global"
//... some code
c := global.GetCounter("ex")
c.Increment()
c.IncrementBy(6)
c.Value() // returns 7
global.GetCounter("ex").Value() // Returns 7
The library and all objects are thread safe.
Print into log or stdout on SIGINT
Please check the example/example.go to see how the interrupt can be handled in a nice way.
Performance and benchmarks
The library has two benchmarks. It's blazingly fast. One should cache counters which are used often. Every time the counter is requested, it's necessary to look up in map for a counter, this slows down the lib by a factor of 4.
$ go test --bench=. .
PASS
BenchmarkCounters 1000000 1287 ns/op
BenchmarkCountersCached 5000000 252 ns/op
ok github.com/orian/counters 2.822s
Documentation
¶
Overview ¶
Package counters provides a simple counter, max and min functionalities. All counters are kept in CounterBox. Library is thread safe.
Index ¶
- func InitCountersOnSignal(logger TrivialLogger, box Counters)
- func LogCountersEvery(logger TrivialLogger, box Counters, d time.Duration)
- type Counter
- type CounterBox
- func (c *CounterBox) CreateHTTPHandler() http.HandlerFunc
- func (c *CounterBox) Get(name string) Counter
- func (c *CounterBox) GetCounter(name string) Counter
- func (c *CounterBox) GetMax(name string) MaxMinValue
- func (c *CounterBox) GetMin(name string) MaxMinValue
- func (c *CounterBox) Max(name string) MaxMinValue
- func (c *CounterBox) Min(name string) MaxMinValue
- func (c *CounterBox) Names() []string
- func (c *CounterBox) Prefix() string
- func (c *CounterBox) String() string
- func (c *CounterBox) WithPrefix(name string) Counters
- func (c *CounterBox) WriteTo(w io.Writer) (int64, error)
- type Counters
- type MaxMinValue
- type TrivialLogger
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func InitCountersOnSignal ¶
func InitCountersOnSignal(logger TrivialLogger, box Counters)
InitCountersOnSignal impl
func LogCountersEvery ¶
func LogCountersEvery(logger TrivialLogger, box Counters, d time.Duration)
LogCountersEvery impl
Types ¶
type Counter ¶
type Counter interface {
// Increment increases counter by one.
Increment() int64
// IncrementBy increases counter by a given number.
IncrementBy(num int) int64
// Decrement decreases counter by one.
Decrement() int64
// DecrementBy decreases counter by a given number.
DecrementBy(num int) int64
// Set sets a specific value.
Set(num int)
// Name returns a name of counter.
Name() string
// Value returns a current value of counter.
Value() int64
}
Counter is an interface for integer increase only counter.
type CounterBox ¶
type CounterBox struct {
// contains filtered or unexported fields
}
CounterBox is a main type, it keeps references to all counters requested from it.
func NewCounterBox ¶
func NewCounterBox() *CounterBox
NewCounterBox creates a new object to keep all counters.
func (*CounterBox) CreateHTTPHandler ¶
func (c *CounterBox) CreateHTTPHandler() http.HandlerFunc
CreateHTTPHandler creates a simple handler printing values of all counters.
func (*CounterBox) GetCounter ¶
func (c *CounterBox) GetCounter(name string) Counter
GetCounter returns a counter of given name, if doesn't exist than create.
func (*CounterBox) GetMax ¶
func (c *CounterBox) GetMax(name string) MaxMinValue
GetMax returns a maxima counter of given name, if doesn't exist than create.
func (*CounterBox) GetMin ¶
func (c *CounterBox) GetMin(name string) MaxMinValue
GetMin returns a minima counter of given name, if doesn't exist than create.
func (*CounterBox) String ¶
func (c *CounterBox) String() string
func (*CounterBox) WithPrefix ¶
func (c *CounterBox) WithPrefix(name string) Counters
WithPrefix impl
type Counters ¶
type Counters interface {
Get(string) Counter
Min(string) MaxMinValue
Max(string) MaxMinValue
WithPrefix(string) Counters
GetCounter(string) Counter
GetMin(string) MaxMinValue
GetMax(string) MaxMinValue
WriteTo(w io.Writer) (int64, error)
Prefix() string
String() string
}
Counters interface
type MaxMinValue ¶
type MaxMinValue interface {
// Set allows to update value if necessary.
Set(int)
// Name returns a name of counter.
Name() string
// Value returns a current value.
Value() int64
}
MaxMinValue is an interface for minima and maxima counters.
type TrivialLogger ¶
type TrivialLogger interface {
Print(...interface{})
}
TrivialLogger logger interface
Source Files
Directories