Improving sampling rate support

src/IllimaniProfiler-Tests/IllAbstractProfilerTest.class.st

@@ -57,7 +57,7 @@ IllAbstractProfilerTest >> testSamplingRate [
 	| allocatedByteSrings |
 
 	profiler
-		samplingRate: 33;
+		samplingRate: 33 / 100;
 		profileOn: [ 100 timesRepeat: [ ByteString new ] ].
 
 	allocatedByteSrings := (profiler objectAllocations select:
@@ -69,13 +69,30 @@ IllAbstractProfilerTest >> testSamplingRate [
 	self assert: (allocatedByteSrings >= 33) & (allocatedByteSrings < 40)
 ]
 
+{ #category : 'tests' }
+IllAbstractProfilerTest >> testSamplingRate1in1000 [
+
+	| allocatedByteSrings |
+
+	profiler
+		samplingRate: 1/1000;
+		profileOn: [ 1000 timesRepeat: [ ByteString new ] ].
+
+	allocatedByteSrings := (profiler objectAllocations select:
+		[ :e | e allocatedObjectClass = ByteString ]) size.
+
+	"We are cheking in this range becase the profiler makes some allocations that are
+	necessary for the profiler to work, like Durations objects."
+	self assert: (allocatedByteSrings >= 1) & (allocatedByteSrings < 4)
+]
+
 { #category : 'tests' }
 IllAbstractProfilerTest >> testSamplingRateOtherPercentage [
 
 	| allocatedByteSrings |
 
 	profiler
-		samplingRate: 75;
+		samplingRate: 75 / 100;
 		profileOn: [ 100 timesRepeat: [ ByteString new ] ].
 
 	allocatedByteSrings := (profiler objectAllocations select:
@@ -91,17 +108,17 @@ IllAbstractProfilerTest >> testSamplingRateOtherPercentage [
 IllAbstractProfilerTest >> testSamplingRateVariable [
 
 	"By default, do not sample"
-	self assert: profiler samplingRate equals: 100.
+	self assert: profiler samplingRate equals: 1.
 
 	"Sample at 20%"
-	profiler samplingRate: 20.
-	self assert: profiler samplingRate equals: 20.
+	profiler samplingRate: 20 / 100.
+	self assert: profiler samplingRate equals: (20 / 100).
 
 	"Sample at 75%"
-	profiler samplingRate: 75.
-	self assert: profiler samplingRate equals: 75.
+	profiler samplingRate: 75 / 100.
+	self assert: profiler samplingRate equals: (75 / 100).
 
-	"Do not sample. The same as sampling 100%".
-	profiler samplingRate: 100.
-	self assert: profiler samplingRate equals: 100.
+	"Do not sample. The same as sampling 100%"
+	profiler samplingRate: 1.
+	self assert: profiler samplingRate equals: 1.
 ]

src/IllimaniProfiler-Tests/IllAllocationRateProfilerTest.class.st

@@ -18,7 +18,7 @@ IllAllocationRateProfilerTest >> testSamplingRate [
 	| allocatedByteSrings |
 
 	profiler
-		samplingRate: 33;
+		samplingRate: 33 / 100;
 		profileOn: [ 100 timesRepeat: [ ByteString new ] ].
 
 	"We don't have the classes on this profiler"
@@ -30,13 +30,29 @@ IllAllocationRateProfilerTest >> testSamplingRate [
 	self assert: (allocatedByteSrings >= 33) & (allocatedByteSrings < 40)
 ]
 
+{ #category : 'tests' }
+IllAllocationRateProfilerTest >> testSamplingRate1in1000 [
+
+	| allocatedByteSrings |
+
+	profiler
+		samplingRate: 1/1000;
+		profileOn: [ 1000 timesRepeat: [ ByteString new ] ].
+
+	allocatedByteSrings := profiler objectAllocations size.
+
+	"We are cheking in this range becase the profiler makes some allocations that are
+	necessary for the profiler to work, like Durations objects."
+	self assert: (allocatedByteSrings >= 1) & (allocatedByteSrings < 4)
+]
+
 { #category : 'tests' }
 IllAllocationRateProfilerTest >> testSamplingRateOtherPercentage [
 
 	| allocatedByteSrings |
 
 	profiler
-		samplingRate: 75;
+		samplingRate: 75 / 100;
 		profileOn: [ 100 timesRepeat: [ ByteString new ] ].
 
 	"We don't have the class on this profiler"

src/IllimaniProfiler/IllAbstractProfiler.class.st

@@ -81,7 +81,7 @@ IllAbstractProfiler >> initialize [
 		yourself.
 	self initializeMethodProxies: handler.
 	samplingCounter := 0.
-	samplingRate := 100.
+	samplingRate := 1.
 	gcActivityMonitor := NullGCActivityMonitor new
 ]
 
@@ -174,15 +174,15 @@ IllAbstractProfiler >> profiledCode [
 { #category : 'profiling' }
 IllAbstractProfiler >> registerAllocation: anObject [
 
-	samplingRate = 100 ifTrue: [
+	samplingRate = 1 ifTrue: [
 		"Sampling 100% capture all"
 		self internalRegisterAllocation: anObject.
 		^ self ].
 
 	samplingCounter := samplingCounter + 1.
-	samplingCounter > 100 ifTrue: [ samplingCounter := 1 ].
+	samplingCounter > samplingRate denominator ifTrue: [ samplingCounter := 1 ].
 
-	samplingCounter <= samplingRate
+	samplingCounter <= samplingRate numerator
 		ifTrue: [ self internalRegisterAllocation: anObject ]
 		ifFalse: [ ^ self ]
 ]
@@ -269,11 +269,11 @@ IllAbstractProfiler >> samplingRate [
 ]
 
 { #category : 'api' }
-IllAbstractProfiler >> samplingRate: anInteger [
-	"The anInteger needs to be an integer number between 1 and 100. This number represents the
-	sampling rate *percentage*"
+IllAbstractProfiler >> samplingRate: aFraction [
+	"I expect my argument to be a fraction. For example 4 / 5. That will mean that I will
+	register 4 out of 5 allocations."
 
-	samplingRate := anInteger
+	samplingRate := aFraction
 ]
 
 { #category : 'profiling' }