Add in flexible rollout strategy

Author: elpete

lib/murmur-1.0.0.jar

@@ -0,0 +1,83 @@
+component implements="IStrategy" singleton {
+
+    property name="murmur3" inject="java:com.sangupta.murmur.Murmur3";
+
+    public boolean function isEnabled(
+        required struct parameters,
+        required struct context
+    ) {
+        param arguments.parameters.stickiness = "default";
+        var stickinessId = resolveStickiness( arguments.parameters.stickiness, arguments.context );
+        if ( !len( stickinessId ) ) {
+            return false;
+        }
+        param arguments.parameters.rollout = 100;
+        var percentage = getPercentage( arguments.parameters.rollout );
+        param arguments.parameters.groupId = "";
+        var norm = getNormalizedNumber( stickinessId, arguments.parameters.groupId )
+        return norm <= percentage;
+    }
+
+    private string function resolveStickiness( required string stickinessKey, required struct context ) {
+        switch ( arguments.stickinessKey ) {
+            case "userId":
+                return arguments.context.userId;
+            case "sessionId":
+                return arguments.context.sessionId
+            case "random":
+                return randRange( 1, 100 );
+            case "default":
+            default:
+                if ( arguments.context.keyExists( "userId" ) && len( arguments.context.userId ) ) {
+                    return arguments.context.userId;
+                }
+                if ( arguments.context.keyExists( "sessionId" ) && len( arguments.context.sessionId ) ) {
+                    return arguments.context.sessionId;
+                }
+                return randRange( 1, 100 );
+        }
+    }
+
+    /**
+     * Takes a numeric string value and converts it to a integer between 0 and 100.
+     *
+     * returns 0 if the string is not numeric.
+     *
+     * @param percentage - A numeric string value
+     * @return a integer between 0 and 100
+     */
+    private numeric function getPercentage( required any percentage ) {
+        return clamp( 0, isNumeric( arguments.percentage ) ? arguments.percentage : 0, 100 );
+    }
+
+    private numeric function clamp( required numeric low, required numeric actual, required numeric high ) {
+        if ( arguments.actual < arguments.low ) {
+            return arguments.low;
+        }
+        if ( arguments.actual > arguments.high ) {
+            return arguments.high;
+        }
+        return arguments.actual;
+    }
+
+    private numeric function getNormalizedNumber( required string identifier, required string groupId, numeric normalizer = 100 ) {
+        var value = getStringBytes( "#arguments.groupId#:#arguments.identifier#" );
+        var hash = calculateHash( value );
+        return normalizeHash( hash, normalizer );
+    }
+
+    private array function getStringBytes( required string identifier ) {
+        return createObject( "java", "java.lang.String" ).init( arguments.identifier ).getBytes();
+    }
+
+    private any function calculateHash( required array bytes ) {
+        var hash = variables.murmur3.hash_x86_32( arguments.bytes, len( arguments.bytes ), 0 );
+        return createObject( "java", "java.math.BigInteger" ).valueOf( hash );
+    }
+
+    private numeric function normalizeHash( required any hash, required numeric normalizer ) {
+        var normalizerBigInt = createObject( "java", "java.math.BigInteger" ).init( normalizer )
+        return arguments.hash.remainder( normalizerBigInt ) + 1;
+    }
+
+}

models/strategies/FlexibleRolloutStrategy.cfc

@@ -16,6 +16,14 @@ component {
     this.mappings[ "/coldbox" ] = testsPath & "resources/app/coldbox";
     this.mappings[ "/testbox" ] = rootPath & "/testbox";
 
+    this.javaSettings = {
+		loadPaths = [
+            expandPath( "../lib" )
+        ],
+		loadColdFusionClassPath = true,
+		reloadOnChange = false
+	};
+
     function onRequestStart() {
         setting requestTimeout="180";
         structDelete( application, "cbController" );

tests/Application.cfc

@@ -0,0 +1,94 @@
+component extends="tests.resources.ModuleIntegrationSpec" {
+
+    property name="cache" inject="cachebox:default";
+
+    function beforeAll() {
+        super.beforeAll();
+        variables.strategy = getInstance( "FlexibleRolloutStrategy@unleashsdk" );
+    }
+
+    function run() {
+        describe( "FlexibleRolloutStrategy", function() {
+            it( "always is enabled for 100 percent rollouts", function() {
+                var result = variables.strategy.isEnabled(
+                    parameters = {
+                        "rollout": "100",
+                        "stickiness": "default",
+                        "groupId": "Feature.flexibleRollout.100"
+                    },
+                    context = {}
+                );
+                expect( result ).toBeTrue();
+            } );
+
+            it( "never is enabled for 0 percent rollouts", function() {
+                var result = variables.strategy.isEnabled(
+                    parameters = {
+                        "rollout": "0",
+                        "stickiness": "default",
+                        "groupId": "Feature.flexibleRollout.0"
+                    },
+                    context = {
+                        "sessionId": "147",
+                        "userId": "12"
+                    }
+                );
+                expect( result ).toBeFalse();
+            } );
+
+            it( "should be enabled for userId=174 in rollout of 10", function() {
+                var result = variables.strategy.isEnabled(
+                    parameters = {
+                        "rollout": "10",
+                        "stickiness": "default",
+                        "groupId": "Feature.flexibleRollout.10"
+                    },
+                    context = getTestContext( {
+                        "userId": "174"
+                    } )
+                );
+                expect( result ).toBeTrue();
+            } );
+
+            it( "should be disabled for userId=499 in rollout of 10", function() {
+                var result = variables.strategy.isEnabled(
+                    parameters = {
+                        "rollout": "10",
+                        "stickiness": "default",
+                        "groupId": "Feature.flexibleRollout.10"
+                    },
+                    context = getTestContext( {
+                        "userId": "499"
+                    } )
+                );
+                expect( result ).toBeFalse();
+            } );
+
+            it( "should be disabled for sessionId=25 for a userId specific version", function() {
+                var result = variables.strategy.isEnabled(
+                    parameters = {
+                        "rollout": "55",
+                        "stickiness": "userId",
+                        "groupId": "Feature.flexibleRollout.userId.55"
+                    },
+                    context = getTestContext( {
+                        "sessionId": "25"
+                    } )
+                );
+                expect( result ).toBeFalse();
+            } );
+        } );
+    }
+
+    function getTestContext( struct overrides = {} ) {
+        structAppend( arguments.overrides, {
+            "appName": "unleashsdk-tests",
+            "environment": "testing",
+            "userId": "",
+            "sessionId": "",
+            "remoteAddress": CGI.REMOTE_ADDR
+        }, false );
+        return arguments.overrides;
+    }
+
+}