Merge pull request #39 from stepio/feature/metrics

Feature/metrics

pom.xml

@@ -11,7 +11,7 @@
     </parent>
     <groupId>io.github.stepio.coffee-boots</groupId>
     <artifactId>coffee-boots</artifactId>
-    <version>2.0.1-SNAPSHOT</version>
+    <version>2.1.0-SNAPSHOT</version>
     <inceptionYear>2018</inceptionYear>
 
     <name>Coffee Boots</name>
@@ -66,16 +66,19 @@
         <dependency>
             <groupId>com.github.ben-manes.caffeine</groupId>
             <artifactId>caffeine</artifactId>
-            <optional>true</optional>
         </dependency>
         <dependency>
             <groupId>org.springframework</groupId>
             <artifactId>spring-context-support</artifactId>
-            <optional>true</optional>
         </dependency>
         <dependency>
             <groupId>org.springframework.boot</groupId>
-            <artifactId>spring-boot-autoconfigure</artifactId>
+            <artifactId>spring-boot-actuator-autoconfigure</artifactId>
+            <optional>true</optional>
+        </dependency>
+        <dependency>
+            <groupId>io.micrometer</groupId>
+            <artifactId>micrometer-core</artifactId>
             <optional>true</optional>
         </dependency>
         <dependency>

src/main/java/io/github/stepio/cache/CacheCustomizer.java

@@ -0,0 +1,19 @@
+package io.github.stepio.cache;
+
+import org.springframework.cache.Cache;
+
+/**
+ * Allows additional post-processing for newly created {@link Cache} instances.
+ *
+ * @author Igor Stepanov
+ */
+public interface CacheCustomizer {
+
+    /**
+     * Invoked upon creating a {@link Cache} instance.
+     * @param name the name of the cache
+     * @param cache recently created Cache instance
+     * @see io.github.stepio.cache.caffeine.MultiConfigurationCacheManager#createCaffeineCache(String)
+     */
+    void onCreate(String name, Cache cache);
+}

src/main/java/io/github/stepio/cache/caffeine/CaffeineSpecSpringAutoConfiguration.java → src/main/java/io/github/stepio/cache/caffeine/CaffeineSpecAutoConfiguration.java

@@ -17,27 +17,28 @@
 package io.github.stepio.cache.caffeine;
 
 import com.github.benmanes.caffeine.cache.Caffeine;
-import org.springframework.boot.autoconfigure.AutoConfigureBefore;
+import org.springframework.boot.autoconfigure.AutoConfigureAfter;
 import org.springframework.boot.autoconfigure.cache.CacheAutoConfiguration;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
-import org.springframework.cache.CacheManager;
+import org.springframework.cache.caffeine.CaffeineCacheManager;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Primary;
 
 /**
  * AutoConfiguration to create all the necessary beans.
  *
  * @author Igor Stepanov
  */
 @Configuration
-@ConditionalOnClass({CacheManager.class, Caffeine.class})
+@ConditionalOnClass({CaffeineCacheManager.class, Caffeine.class})
 @ConditionalOnMissingBean(
-        value = {CacheManager.class},
-        name = {"cacheResolver"}
+        value = {MultiConfigurationCacheManager.class},
+        name = {"multiCaffeineManager"}
 )
-@AutoConfigureBefore({CacheAutoConfiguration.class})
-public class CaffeineSpecSpringAutoConfiguration {
+@AutoConfigureAfter(CacheAutoConfiguration.class)
+public class CaffeineSpecAutoConfiguration {
 
     /**
      * Create CaffeineSupplier bean if it's not available in the context.
@@ -55,8 +56,9 @@ public CaffeineSupplier caffeineSupplier() {
      * @return the MultiConfigurationCacheManager instance
      */
     @Bean
+    @Primary
     @ConditionalOnMissingBean
-    public MultiConfigurationCacheManager cacheManager(CaffeineSupplier caffeineSupplier) {
+    public MultiConfigurationCacheManager multiCaffeineManager(CaffeineSupplier caffeineSupplier) {
         MultiConfigurationCacheManager cacheManager = new MultiConfigurationCacheManager();
         cacheManager.setCacheBuilderSupplier(caffeineSupplier);
         return cacheManager;

src/main/java/io/github/stepio/cache/caffeine/MultiConfigurationCacheManager.java

@@ -19,8 +19,10 @@
 import com.github.benmanes.caffeine.cache.Cache;
 import com.github.benmanes.caffeine.cache.Caffeine;
 import com.github.benmanes.caffeine.cache.CaffeineSpec;
+import io.github.stepio.cache.CacheCustomizer;
 import org.springframework.cache.caffeine.CaffeineCacheManager;
 
+import java.util.List;
 import java.util.function.Function;
 
 /**
@@ -31,7 +33,8 @@
  */
 public class MultiConfigurationCacheManager extends CaffeineCacheManager {
 
-    private Function<String, Caffeine<Object, Object>> cacheBuilderSupplier;
+    protected Function<String, Caffeine<Object, Object>> cacheBuilderSupplier;
+    protected List<CacheCustomizer> customizers;
 
     /**
      * Set the {@link Function} to produce {@link Caffeine} for building each individual {@link Cache} instance.
@@ -43,12 +46,29 @@ public void setCacheBuilderSupplier(Function<String, Caffeine<Object, Object>> s
         this.cacheBuilderSupplier = supplier;
     }
 
+    /**
+     * Set list of {@link CacheCustomizer} instances to be invoked upon creation of each Cache instance.
+     * @param customizers list of CacheCustomizer instances to be invoked
+     * @see CacheCustomizer#onCreate(String, org.springframework.cache.Cache)
+     */
+    public void setCustomizers(List<CacheCustomizer> customizers) {
+        this.customizers = customizers;
+    }
+
     /**
      * Accessor for the underlying {@link Caffeine} producer.
      * @return exact implementation of function for instantiating the Cache with the specified name
      */
     public Function<String, Caffeine<Object, Object>> getCacheBuilderSupplier() {
-        return cacheBuilderSupplier;
+        return this.cacheBuilderSupplier;
+    }
+
+    protected org.springframework.cache.Cache createCaffeineCache(String name) {
+        org.springframework.cache.Cache cache = super.createCaffeineCache(name);
+        if (this.customizers != null) {
+            this.customizers.forEach(customizer -> customizer.onCreate(name, cache));
+        }
+        return cache;
     }
 
     /**

src/main/java/io/github/stepio/cache/metrics/CaffeineMetricsAutoConfiguration.java

@@ -0,0 +1,32 @@
+package io.github.stepio.cache.metrics;
+
+import io.github.stepio.cache.CacheCustomizer;
+import io.github.stepio.cache.caffeine.MultiConfigurationCacheManager;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.actuate.metrics.cache.CacheMetricsRegistrar;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
+import org.springframework.context.annotation.Configuration;
+
+import java.util.Collections;
+
+/**
+ * Binds {@link CacheMetricsRegistrar} to {@link MultiConfigurationCacheManager}.
+ * Allows configuring metrics for dynamic caches.
+ *
+ * @author Igor Stepanov
+ */
+@Configuration
+@ConditionalOnClass({CacheMetricsRegistrar.class})
+public class CaffeineMetricsAutoConfiguration {
+
+    /**
+     * Binds {@link CacheMetricsRegistrar} to {@link MultiConfigurationCacheManager} using {@link CacheCustomizer}.
+     * @param cacheManager instance of MultiConfigurationCacheManager bean
+     * @param metricsRegistrar instance of CacheMetricsRegistrar bean
+     */
+    @Autowired
+    public void bind(MultiConfigurationCacheManager cacheManager, CacheMetricsRegistrar metricsRegistrar) {
+        CacheCustomizer customizer = new MetricsRegistrarProxy(metricsRegistrar);
+        cacheManager.setCustomizers(Collections.singletonList(customizer));
+    }
+}

src/main/java/io/github/stepio/cache/metrics/MetricsRegistrarProxy.java

@@ -0,0 +1,24 @@
+package io.github.stepio.cache.metrics;
+
+import io.github.stepio.cache.CacheCustomizer;
+import io.micrometer.core.instrument.Tag;
+import org.springframework.boot.actuate.metrics.cache.CacheMetricsRegistrar;
+import org.springframework.cache.Cache;
+
+/**
+ * Implementation of {@link CacheCustomizer}, which is used to bind newly created caches to metrics registry.
+ */
+public class MetricsRegistrarProxy implements CacheCustomizer {
+
+    private CacheMetricsRegistrar cacheMetricsRegistrar;
+
+    public MetricsRegistrarProxy(CacheMetricsRegistrar cacheMetricsRegistrar) {
+        this.cacheMetricsRegistrar = cacheMetricsRegistrar;
+    }
+
+    @Override
+    public void onCreate(String name, Cache cache) {
+        Tag cacheManagerTag = Tag.of("cacheManager", "multiCaffeineManager");
+        this.cacheMetricsRegistrar.bindCacheToRegistry(cache, cacheManagerTag);
+    }
+}

src/main/resources/META-INF/spring.factories

@@ -1,3 +1,4 @@
 # Auto Configure
 org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
-io.github.stepio.cache.caffeine.CaffeineSpecSpringAutoConfiguration
+io.github.stepio.cache.caffeine.CaffeineSpecAutoConfiguration,\
+io.github.stepio.cache.metrics.CaffeineMetricsAutoConfiguration