Move constants to priority package and readme , docs update (#14)

* update readme

* update readme and docs

* more updates

* move constants to priority package

* more readme and docs

README.md

@@ -5,8 +5,8 @@
 
 ## About
 
-concurrency-limiter is a minimalistic package that allows you to limit the number of concurrent goroutines accessing a resource with support for
-timeouts and priority of goroutines.
+concurrency-limiter allows you to limit the number of goroutines accessing a resource with support for
+timeouts and dynamic priority of goroutines.
 
 ## Examples
 
@@ -36,7 +36,7 @@ number of concurrent goroutines is greater than the limit specified.
 
 ```go
     nl := priority.NewLimiter(3)
-    nl.Wait(constants.High)
+    nl.Wait(priority.High)
     Execute......
     nl.Finish()
 ```
@@ -48,7 +48,7 @@ given the maximum preference because it is of high priority. In the case of tie
 
 ```go
     nl := priority.NewLimiter(3).WithDynamicPriority(5)
-    nl.Wait(constants.Low)
+    nl.Wait(priority.Low)
     Execute......
     nl.Finish()
 ```

priority/priorityRateLimiter.go

@@ -5,10 +5,20 @@ import (
 	"sync"
 	"time"
 
-	"github.com/vivek-ng/concurrency-limiter/constants"
 	"github.com/vivek-ng/concurrency-limiter/queue"
 )
 
+// PriorityValue defines the priority values of goroutines.
+// Greater priority value means higher priority
+type PriorityValue int
+
+const (
+	Low        PriorityValue = 1
+	Medium     PriorityValue = 2
+	MediumHigh PriorityValue = 3
+	High       PriorityValue = 4
+)
+
 // limit: max number of concurrent goroutines that can access aresource
 //
 // count: current number of goroutines accessing a resource
@@ -59,13 +69,13 @@ func (p *PriorityLimiter) WithTimeout(timeout int) *PriorityLimiter {
 // Wait method waits if the number of concurrent requests is more than the limit specified.
 // If the priority of two goroutines are same , the FIFO order is followed.
 // Greater priority value means higher priority.
-// priority must be one fo the values specified by constants.PriorityValue
+// priority must be one fo the values specified by PriorityValue
 //
 // Low = 1
 // Medium = 2
 // MediumHigh = 3
 // High = 4
-func (p *PriorityLimiter) Wait(priority constants.PriorityValue) {
+func (p *PriorityLimiter) Wait(priority PriorityValue) {
 	ok, w := p.proceed(priority)
 	if ok {
 		return
@@ -83,7 +93,7 @@ func (p *PriorityLimiter) Wait(priority constants.PriorityValue) {
 				return
 			case <-ticker.C:
 				p.mu.Lock()
-				if w.Priority < int(constants.High) {
+				if w.Priority < int(High) {
 					currentPriority := w.Priority
 					p.waitList.Update(w, currentPriority+1)
 				}
@@ -105,7 +115,7 @@ func (p *PriorityLimiter) Wait(priority constants.PriorityValue) {
 // proceed will return true if the number of concurrent requests is less than the limit else it
 // will add the goroutine to the priority queue and will return a channel. This channel is used by goutines to
 // check for signal when they are granted access to use the resource.
-func (p *PriorityLimiter) proceed(priority constants.PriorityValue) (bool, *queue.Item) {
+func (p *PriorityLimiter) proceed(priority PriorityValue) (bool, *queue.Item) {
 	p.mu.Lock()
 	defer p.mu.Unlock()
 

priority/priorityRateLimiter_test.go

@@ -6,7 +6,6 @@ import (
 	"time"
 
 	"github.com/stretchr/testify/assert"
-	"github.com/vivek-ng/concurrency-limiter/constants"
 	"github.com/vivek-ng/concurrency-limiter/queue"
 )
 
@@ -18,7 +17,7 @@ func TestPriorityLimiter(t *testing.T) {
 	for i := 0; i < 5; i++ {
 		go func(pr int) {
 			defer wg.Done()
-			nl.Wait(constants.PriorityValue(pr))
+			nl.Wait(PriorityValue(pr))
 		}(i)
 	}
 	time.Sleep(200 * time.Millisecond)
@@ -55,8 +54,8 @@ func TestDynamicPriority(t *testing.T) {
 	pVal = nl.waitList.Top()
 	pValItem = pVal.(queue.Item)
 	expectedVal2 := pValItem.Priority
-	assert.GreaterOrEqual(t, expectedVal1, int(constants.High))
-	assert.GreaterOrEqual(t, expectedVal2, int(constants.High))
+	assert.GreaterOrEqual(t, expectedVal1, int(High))
+	assert.GreaterOrEqual(t, expectedVal2, int(High))
 }
 
 func TestPriorityLimiter_Timeout(t *testing.T) {