purge existing panic operations (#284)

* purge existing panic operations in core/stat module

Co-authored-by: louyuting <[email protected]>

Author: binbin0325

core/stat/base/atomic_window_wrap_array_test.go

@@ -39,7 +39,9 @@ func Test_atomicBucketWrapArray_elementOffset(t *testing.T) {
 		t.Run(tt.name, func(t *testing.T) {
 			now := uint64(1596199310000)
 			aa := NewAtomicBucketWrapArrayWithTime(tt.args.len, tt.args.bucketLengthInMs, now, tt.args.bg)
-			if got := uintptr(aa.elementOffset(tt.args.idx)) - uintptr(aa.base); got != tt.want {
+			offset, ok := aa.elementOffset(tt.args.idx)
+			assert.True(t, ok)
+			if got := uintptr(offset) - uintptr(aa.base); got != tt.want {
 				t.Errorf("AtomicBucketWrapArray.elementOffset() = %v, want %v \n", got, tt.want)
 			}
 		})

core/stat/base/bucket_leap_array.go

@@ -1,7 +1,6 @@
 package base
 
 import (
-	"fmt"
 	"sync/atomic"
 
 	"github.com/alibaba/sentinel-golang/core/base"
@@ -30,10 +29,9 @@ func (bla *BucketLeapArray) ResetBucketTo(bw *BucketWrap, startTime uint64) *Buc
 
 // sampleCount is the number of slots
 // intervalInMs is the time length of sliding window
+// sampleCount and intervalInMs must be positive and intervalInMs%sampleCount == 0,
+// the validation must be done before call NewBucketLeapArray
 func NewBucketLeapArray(sampleCount uint32, intervalInMs uint32) *BucketLeapArray {
-	if intervalInMs%sampleCount != 0 {
-		panic(fmt.Sprintf("Invalid parameters, intervalInMs is %d, sampleCount is %d.", intervalInMs, sampleCount))
-	}
 	bucketLengthInMs := intervalInMs / sampleCount
 	ret := &BucketLeapArray{
 		data: LeapArray{

core/stat/base/leap_array.go

@@ -7,6 +7,7 @@ import (
 	"unsafe"
 
 	"github.com/alibaba/sentinel-golang/core/base"
+	"github.com/alibaba/sentinel-golang/logging"
 	"github.com/alibaba/sentinel-golang/util"
 	"github.com/pkg/errors"
 )
@@ -93,25 +94,34 @@ func NewAtomicBucketWrapArray(len int, bucketLengthInMs uint32, generator Bucket
 	return NewAtomicBucketWrapArrayWithTime(len, bucketLengthInMs, util.CurrentTimeMillis(), generator)
 }
 
-func (aa *AtomicBucketWrapArray) elementOffset(idx int) unsafe.Pointer {
+func (aa *AtomicBucketWrapArray) elementOffset(idx int) (unsafe.Pointer, bool) {
 	if idx >= aa.length || idx < 0 {
-		panic(fmt.Sprintf("The index (%d) is out of bounds, length is %d.", idx, aa.length))
+		logging.Error(errors.New("array index out of bounds"),
+			"array index out of bounds in AtomicBucketWrapArray.elementOffset()",
+			"idx", idx, "arrayLength", aa.length)
+		return nil, false
 	}
 	basePtr := aa.base
-	return unsafe.Pointer(uintptr(basePtr) + uintptr(idx*PtrSize))
+	return unsafe.Pointer(uintptr(basePtr) + uintptr(idx*PtrSize)), true
 }
 
 func (aa *AtomicBucketWrapArray) get(idx int) *BucketWrap {
 	// aa.elementOffset(idx) return the secondary pointer of BucketWrap, which is the pointer to the aa.data[idx]
 	// then convert to (*unsafe.Pointer)
-	return (*BucketWrap)(atomic.LoadPointer((*unsafe.Pointer)(aa.elementOffset(idx))))
+	if offset, ok := aa.elementOffset(idx); ok {
+		return (*BucketWrap)(atomic.LoadPointer((*unsafe.Pointer)(offset)))
+	}
+	return nil
 }
 
 func (aa *AtomicBucketWrapArray) compareAndSet(idx int, except, update *BucketWrap) bool {
 	// aa.elementOffset(idx) return the secondary pointer of BucketWrap, which is the pointer to the aa.data[idx]
 	// then convert to (*unsafe.Pointer)
 	// update secondary pointer
-	return atomic.CompareAndSwapPointer((*unsafe.Pointer)(aa.elementOffset(idx)), unsafe.Pointer(except), unsafe.Pointer(update))
+	if offset, ok := aa.elementOffset(idx); ok {
+		return atomic.CompareAndSwapPointer((*unsafe.Pointer)(offset), unsafe.Pointer(except), unsafe.Pointer(update))
+	}
+	return false
 }
 
 // The BucketWrap leap array,

core/stat/base/metric_bucket.go

@@ -1,10 +1,11 @@
 package base
 
 import (
-	"fmt"
 	"sync/atomic"
 
 	"github.com/alibaba/sentinel-golang/core/base"
+	"github.com/alibaba/sentinel-golang/logging"
+	"github.com/pkg/errors"
 )
 
 // MetricBucket represents the entity to record metrics per minimum time unit (i.e. the bucket time span).
@@ -25,7 +26,8 @@ func NewMetricBucket() *MetricBucket {
 // Add statistic count for the given metric event.
 func (mb *MetricBucket) Add(event base.MetricEvent, count int64) {
 	if event >= base.MetricEventTotal || event < 0 {
-		panic(fmt.Sprintf("Unknown metric event: %v", event))
+		logging.Error(errors.Errorf("Unknown metric event: %v", event), "")
+		return
 	}
 	if event == base.MetricEventRt {
 		mb.AddRt(count)
@@ -41,7 +43,8 @@ func (mb *MetricBucket) addCount(event base.MetricEvent, count int64) {
 // Get current statistic count of the given metric event.
 func (mb *MetricBucket) Get(event base.MetricEvent) int64 {
 	if event >= base.MetricEventTotal || event < 0 {
-		panic(fmt.Sprintf("Unknown metric event: %v", event))
+		logging.Error(errors.Errorf("Unknown metric event: %v", event), "")
+		return 0
 	}
 	return atomic.LoadInt64(&mb.counter[event])
 }