Merge pull request yegor256#187 from carlosmiranda/186

yegor256#187: pull request yegor256#186 Cached retrieval of CloudWatch stats
carlosmiranda · Jul 2, 2014 · 5ce592b · 5ce592b
2 parents b8d3a86 + ee865f5
commit 5ce592b
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Showing 2 changed files with 35 additions and 10 deletions.
diff --git a/s3auth-hosts/src/main/java/com/s3auth/hosts/DefaultHost.java b/s3auth-hosts/src/main/java/com/s3auth/hosts/DefaultHost.java
@@ -108,6 +108,11 @@ public AmazonCloudWatchClient get() {
      */
     private final transient Htpasswd htpasswd;
 
+    /**
+     * Holder of host stats.
+     */
+    private final transient Stats statistics;
+
     /**
      * Amazon Cloudwatch Client.
      */
@@ -136,6 +141,7 @@ public AmazonCloudWatchClient get() {
         this.bucket = bckt;
         this.htpasswd = new Htpasswd(this);
         this.cloudwatch = cwatch;
+        this.statistics = new HostStats(this.bucket.bucket());
     }
 
     @Override
@@ -254,7 +260,7 @@ public String syslog() {
 
     @Override
     public Stats stats() {
-        return new HostStats();
+        return this.statistics;
     }
 
     /**
@@ -348,15 +354,23 @@ public String toString() {
 
     /**
      * Stats for this domain.
-     *
-     * @todo #173 We should be caching the results of this method for a short
-     *  period somehow, or at least prevent unnecessary repeated requests to
-     *  Amazon CloudWatch API. This is so that we can improve performance and
-     *  reduce access costs.
      */
     @Loggable(Loggable.DEBUG)
+    @EqualsAndHashCode(of = "bucket")
     private final class HostStats implements Stats {
+        /**
+         * The S3 bucket.
+         */
+        private final transient String bucket;
+        /**
+         * Public ctor.
+         * @param bckt The name of the bucket
+         */
+        public HostStats(final String bckt) {
+            this.bucket = bckt;
+        }
         @Override
+        @Cacheable(lifetime = Tv.THIRTY, unit = TimeUnit.MINUTES)
         public long bytesTransferred() {
             final Date now = new Date();
             final List<Datapoint> datapoints =
@@ -368,7 +382,7 @@ public long bytesTransferred() {
                         .withDimensions(
                             new Dimension()
                                 .withName("Bucket")
-                                .withValue(DefaultHost.this.bucket.bucket())
+                                .withValue(this.bucket)
                         )
                         .withUnit(StandardUnit.Bytes)
                         .withPeriod((int) TimeUnit.DAYS.toSeconds(Tv.SEVEN))

diff --git a/s3auth-hosts/src/test/java/com/s3auth/hosts/DefaultHostTest.java b/s3auth-hosts/src/test/java/com/s3auth/hosts/DefaultHostTest.java
@@ -289,10 +289,10 @@ public void showsVersionListingForIndexHtml() throws Exception {
     }
 
     /**
-     * DefaultHost can retrieve Cloudwatch stats.
+     * DefaultHost can retrieve Cloudwatch stats and cache the results.
      */
     @Test
-    public void retrievesCloudWatchStats() {
+    public void retrievesAndCachesCloudWatchStats() {
         final long sum = 10;
         final CloudWatch cloudwatch = this.cloudWatch();
         final GetMetricStatisticsResult result = new GetMetricStatisticsResult()
@@ -304,7 +304,18 @@ public void retrievesCloudWatchStats() {
                 new BucketMocker().mock(),
                 cloudwatch
             ).stats().bytesTransferred(),
-            Matchers.is(sum)
+            Matchers.allOf(
+                Matchers.is(sum),
+                Matchers.is(
+                    new DefaultHost(
+                        new BucketMocker().mock(),
+                        cloudwatch
+                    ).stats().bytesTransferred()
+                )
+            )
+        );
+        Mockito.verify(cloudwatch.get(), Mockito.times(1)).getMetricStatistics(
+            Mockito.any(GetMetricStatisticsRequest.class)
         );
     }