Merge pull request #7 from prometheus/refactor/pointers/only-on-mutation

Pointers to references for non-mutation calls.

metrics/accumulating_bucket.go

@@ -59,7 +59,7 @@ func (b *AccumulatingBucket) Add(value float64) {
 	heap.Push(&b.elements, &v)
 }
 
-func (b *AccumulatingBucket) String() string {
+func (b AccumulatingBucket) String() string {
 	b.mutex.RLock()
 	defer b.mutex.RUnlock()
 
@@ -76,7 +76,7 @@ func (b *AccumulatingBucket) String() string {
 	return buffer.String()
 }
 
-func (b *AccumulatingBucket) ValueForIndex(index int) float64 {
+func (b AccumulatingBucket) ValueForIndex(index int) float64 {
 	b.mutex.RLock()
 	defer b.mutex.RUnlock()
 
@@ -102,7 +102,7 @@ func (b *AccumulatingBucket) ValueForIndex(index int) float64 {
 	return sortedElements[targetIndex]
 }
 
-func (b *AccumulatingBucket) Observations() int {
+func (b AccumulatingBucket) Observations() int {
 	b.mutex.RLock()
 	defer b.mutex.RUnlock()
 

metrics/counter.go

@@ -74,7 +74,7 @@ func (metric *counter) ResetAll() {
 	}
 }
 
-func (metric *counter) String() string {
+func (metric counter) String() string {
 	formatString := "[Counter %s]"
 
 	metric.mutex.RLock()
@@ -133,7 +133,7 @@ func (metric *counter) Decrement(labels map[string]string) float64 {
 	return metric.DecrementBy(labels, 1)
 }
 
-func (metric *counter) AsMarshallable() map[string]interface{} {
+func (metric counter) AsMarshallable() map[string]interface{} {
 	metric.mutex.RLock()
 	defer metric.mutex.RUnlock()
 

metrics/gauge.go

@@ -39,7 +39,7 @@ type gauge struct {
 	values map[string]*gaugeVector
 }
 
-func (metric *gauge) String() string {
+func (metric gauge) String() string {
 	formatString := "[Gauge %s]"
 
 	metric.mutex.RLock()
@@ -82,7 +82,7 @@ func (metric *gauge) ResetAll() {
 	}
 }
 
-func (metric *gauge) AsMarshallable() map[string]interface{} {
+func (metric gauge) AsMarshallable() map[string]interface{} {
 	metric.mutex.RLock()
 	defer metric.mutex.RUnlock()
 

metrics/histogram.go

@@ -125,7 +125,7 @@ func (h *histogram) Add(labels map[string]string, value float64) {
 	histogram.buckets[lastIndex].Add(value)
 }
 
-func (h *histogram) String() string {
+func (h histogram) String() string {
 	h.mutex.RLock()
 	defer h.mutex.RUnlock()
 
@@ -160,7 +160,7 @@ func prospectiveIndexForPercentile(percentile float64, totalObservations int) in
 }
 
 // Determine the next bucket element when interim bucket intervals may be empty.
-func (h *histogram) nextNonEmptyBucketElement(signature string, currentIndex, bucketCount int, observationsByBucket []int) (*Bucket, int) {
+func (h histogram) nextNonEmptyBucketElement(signature string, currentIndex, bucketCount int, observationsByBucket []int) (*Bucket, int) {
 	for i := currentIndex; i < bucketCount; i++ {
 		if observationsByBucket[i] == 0 {
 			continue
@@ -179,7 +179,7 @@ func (h *histogram) nextNonEmptyBucketElement(signature string, currentIndex, bu
 // longer contained by the bucket, the index of the last item is returned.  This
 // may occur if the underlying bucket catalogs values and employs an eviction
 // strategy.
-func (h *histogram) bucketForPercentile(signature string, percentile float64) (*Bucket, int) {
+func (h histogram) bucketForPercentile(signature string, percentile float64) (*Bucket, int) {
 	bucketCount := len(h.bucketStarts)
 
 	// This captures the quantity of samples in a given bucket's range.
@@ -232,7 +232,7 @@ func (h *histogram) bucketForPercentile(signature string, percentile float64) (*
 // Return the histogram's estimate of the value for a given percentile of
 // collected samples.  The requested percentile is expected to be a real
 // value within (0, 1.0].
-func (h *histogram) percentile(signature string, percentile float64) float64 {
+func (h histogram) percentile(signature string, percentile float64) float64 {
 	bucket, index := h.bucketForPercentile(signature, percentile)
 
 	return (*bucket).ValueForIndex(index)
@@ -242,7 +242,7 @@ func formatFloat(value float64) string {
 	return strconv.FormatFloat(value, floatFormat, floatPrecision, floatBitCount)
 }
 
-func (h *histogram) AsMarshallable() map[string]interface{} {
+func (h histogram) AsMarshallable() map[string]interface{} {
 	h.mutex.RLock()
 	defer h.mutex.RUnlock()
 

metrics/tallying_bucket.go

@@ -88,7 +88,7 @@ func (b *TallyingBucket) Add(value float64) {
 	b.largestObserved = math.Max(value, b.largestObserved)
 }
 
-func (b *TallyingBucket) String() string {
+func (b TallyingBucket) String() string {
 	b.mutex.RLock()
 	defer b.mutex.RUnlock()
 
@@ -101,14 +101,14 @@ func (b *TallyingBucket) String() string {
 	return fmt.Sprintf("[TallyingBucket (%f, %f); %d items]", b.smallestObserved, b.largestObserved, observations)
 }
 
-func (b *TallyingBucket) Observations() int {
+func (b TallyingBucket) Observations() int {
 	b.mutex.RLock()
 	defer b.mutex.RUnlock()
 
 	return b.observations
 }
 
-func (b *TallyingBucket) ValueForIndex(index int) float64 {
+func (b TallyingBucket) ValueForIndex(index int) float64 {
 	b.mutex.RLock()
 	defer b.mutex.RUnlock()