[#1] mclock: Add assert package

Signed-off-by: Dmitrii Stepanov <d.stepanov@yadro.com>

internal/assert/cond.go

@@ -0,0 +1,9 @@
+package assert
+
+import "strings"
+
+func Cond(cond bool, details ...string) {
+	if !cond {
+		panic(strings.Join(details, " "))
+	}
+}

scheduling/mclock.go

@@ -7,6 +7,8 @@ import (
 	"math"
 	"sync"
 	"time"
+
+	"git.frostfs.info/TrueCloudLab/frostfs-qos/internal/assert"
 )
 
 const (
@@ -172,9 +174,7 @@ func (q *MClock) dropRequest(req *request) {
 
 	select {
 	case <-req.scheduled:
-		if q.inProgress == 0 {
-			panic("invalid requests count")
-		}
+		assert.Cond(q.inProgress > 0, "invalid requests count")
 		q.inProgress--
 	default:
 	}
@@ -199,9 +199,7 @@ func (q *MClock) pushRequest(tag string) (*request, ReleaseFunc, error) {
 		return nil, nil, ErrMClockSchedulerUnknownTag
 	}
 	prev, ok := q.previous[tag]
-	if !ok {
-		panic("undefined previous: " + tag)
-	}
+	assert.Cond(ok, "undefined previous:", tag)
 
 	if q.idleTimeout >= 0 && now-prev.ts > q.idleTimeout { // was inactive for q.idleTimeout
 		q.adjustTags(now, tag)
@@ -321,9 +319,7 @@ func (q *MClock) scheduleByLimitAndWeight(now float64) {
 		q.removeFromQueues(next.r)
 
 		tagInfo, ok := q.tagInfo[next.r.tag]
-		if !ok {
-			panic("unknown tag: " + next.r.tag) // must be checked on top level
-		}
+		assert.Cond(ok, "unknown tag:", next.r.tag)
 		if tagInfo.ReservedIOPS != nil && hadReservation {
 			var updated bool
 			for _, i := range q.reservationQueue.items {
@@ -390,24 +386,14 @@ func (q *MClock) requestCompleted() {
 		return
 	}
 
-	if q.inProgress == 0 {
-		panic("invalid requests count")
-	}
+	assert.Cond(q.inProgress > 0, "invalid requests count")
 	q.inProgress--
 	q.scheduleRequestUnsafe()
 }
 
 func assertIndexInvalid(r *request) {
-	if r.limitIdx != invalidIndex {
-		panic("limitIdx is not -1")
-	}
-	if r.sharesIdx != invalidIndex {
-		panic("sharesIdx is not -1")
-	}
-	if r.reservationIdx != invalidIndex {
-		panic("reservationIdx is not -1")
-	}
-	if r.readyIdx != invalidIndex {
-		panic("readyIdx is not -1")
-	}
+	assert.Cond(r.limitIdx == invalidIndex, "limitIdx is not -1")
+	assert.Cond(r.sharesIdx == invalidIndex, "sharesIdx is not -1")
+	assert.Cond(r.reservationIdx == invalidIndex, "reservationIdx is not -1")
+	assert.Cond(r.readyIdx == invalidIndex, "readyIdx is not -1")
 }