Merge pull request #882 from wimdeblauwe/allow-pluggable-csv-filename

Allow a pluggable strategy for the name of the CSV files that the CsvReporter uses
dropwizard · Nov 2, 2015 · 4112b29 · 4112b29
2 parents 258e80b + 869742e
commit 4112b29
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Showing 5 changed files with 97 additions and 21 deletions.
diff --git a/metrics-core/src/main/java/io/dropwizard/metrics/CsvFileProvider.java b/metrics-core/src/main/java/io/dropwizard/metrics/CsvFileProvider.java
@@ -0,0 +1,12 @@
+package io.dropwizard.metrics;
+
+import java.io.File;
+
+/**
+ * This interface allows a pluggable implementation of what file names
+ * the {@link CsvReporter} will write to.
+ */
+public interface CsvFileProvider
+{
+	File getFile( File directory, MetricName metricName );
+}
diff --git a/metrics-core/src/main/java/io/dropwizard/metrics/CsvReporter.java b/metrics-core/src/main/java/io/dropwizard/metrics/CsvReporter.java
@@ -47,6 +47,7 @@ public static class Builder {
         private TimeUnit durationUnit;
         private Clock clock;
         private MetricFilter filter;
+        private CsvFileProvider csvFileProvider;
 
         private Builder(MetricRegistry registry) {
             this.registry = registry;
@@ -55,6 +56,7 @@ private Builder(MetricRegistry registry) {
             this.durationUnit = TimeUnit.MILLISECONDS;
             this.clock = Clock.defaultClock();
             this.filter = MetricFilter.ALL;
+            this.csvFileProvider = new FixedNameCsvFileProvider();
         }
 
         /**
@@ -112,6 +114,12 @@ public Builder filter(MetricFilter filter) {
             return this;
         }
 
+        public Builder withCsvFileProvider( CsvFileProvider csvFileProvider )
+        {
+            this.csvFileProvider = csvFileProvider;
+            return this;
+        }
+
         /**
          * Builds a {@link CsvReporter} with the given properties, writing {@code .csv} files to the
          * given directory.
@@ -126,7 +134,8 @@ public CsvReporter build(File directory) {
                                    rateUnit,
                                    durationUnit,
                                    clock,
-                                   filter);
+                                   filter,
+                                   csvFileProvider);
         }
     }
 
@@ -136,18 +145,21 @@ public CsvReporter build(File directory) {
     private final File directory;
     private final Locale locale;
     private final Clock clock;
+    private final CsvFileProvider csvFileProvider;
 
     private CsvReporter(MetricRegistry registry,
                         File directory,
                         Locale locale,
                         TimeUnit rateUnit,
                         TimeUnit durationUnit,
                         Clock clock,
-                        MetricFilter filter) {
+                        MetricFilter filter,
+                        CsvFileProvider csvFileProvider) {
         super(registry, "csv-reporter", filter, rateUnit, durationUnit);
         this.directory = directory;
         this.locale = locale;
         this.clock = clock;
+        this.csvFileProvider = csvFileProvider;
     }
 
     @Override
@@ -248,7 +260,7 @@ private void reportGauge(long timestamp, MetricName name, Gauge gauge) {
 
     private void report(long timestamp, MetricName name, String header, String line, Object... values) {
         try {
-            final File file = new File(directory, sanitize(name) + ".csv");
+            final File file = csvFileProvider.getFile(directory, name);
             final boolean fileAlreadyExists = file.exists();
             if (fileAlreadyExists || file.createNewFile()) {
                 final PrintWriter out = new PrintWriter(new OutputStreamWriter(new FileOutputStream(file,true), UTF_8));
@@ -265,8 +277,4 @@ private void report(long timestamp, MetricName name, String header, String line,
             LOGGER.warn("Error writing to {}", name, e);
         }
     }
-
-    protected String sanitize(MetricName name) {
-        return name.getKey();
-    }
 }
diff --git a/metrics-core/src/main/java/io/dropwizard/metrics/FixedNameCsvFileProvider.java b/metrics-core/src/main/java/io/dropwizard/metrics/FixedNameCsvFileProvider.java
@@ -0,0 +1,18 @@
+package io.dropwizard.metrics;
+
+import java.io.File;
+
+/**
+ * This implementation of the {@link CsvFileProvider} will always return the same name
+ * for the same metric. This means the CSV file will grow indefinitely.
+ */
+public class FixedNameCsvFileProvider implements CsvFileProvider {
+    @Override
+    public File getFile(File directory, MetricName metricName) {
+        return new File(directory, sanitize(metricName) + ".csv");
+    }
+
+    private String sanitize(MetricName metricName) {
+        return metricName.getKey();
+    }
+}
diff --git a/metrics-core/src/test/java/io/dropwizard/metrics/CsvReporterTest.java b/metrics-core/src/test/java/io/dropwizard/metrics/CsvReporterTest.java
@@ -5,18 +5,6 @@
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
 
-import io.dropwizard.metrics.Clock;
-import io.dropwizard.metrics.Counter;
-import io.dropwizard.metrics.CsvReporter;
-import io.dropwizard.metrics.Gauge;
-import io.dropwizard.metrics.Histogram;
-import io.dropwizard.metrics.Meter;
-import io.dropwizard.metrics.MetricFilter;
-import io.dropwizard.metrics.MetricName;
-import io.dropwizard.metrics.MetricRegistry;
-import io.dropwizard.metrics.Snapshot;
-import io.dropwizard.metrics.Timer;
-
 import java.io.*;
 import java.nio.CharBuffer;
 import java.util.Locale;
@@ -25,8 +13,7 @@
 import java.util.concurrent.TimeUnit;
 
 import static org.assertj.core.api.Assertions.assertThat;
-import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.when;
+import static org.mockito.Mockito.*;
 
 public class CsvReporterTest {
     @Rule public final TemporaryFolder folder = new TemporaryFolder();
@@ -178,6 +165,27 @@ public void reportsTimerValues() throws Exception {
                 ));
     }
 
+    @Test
+    public void testCsvFileProviderIsUsed() {
+        CsvFileProvider fileProvider = mock(CsvFileProvider.class);
+        when(fileProvider.getFile(dataDirectory, MetricName.build("gauge"))).thenReturn(new File(dataDirectory, "guage.csv"));
+
+        CsvReporter reporter = CsvReporter.forRegistry(registry)
+                .withCsvFileProvider(fileProvider)
+                .build(dataDirectory);
+
+        final Gauge gauge = mock(Gauge.class);
+        when(gauge.getValue()).thenReturn(1);
+
+        reporter.report(map("gauge", gauge),
+                this.<Counter>map(),
+                this.<Histogram>map(),
+                this.<Meter>map(),
+                this.<Timer>map());
+
+        verify(fileProvider).getFile(dataDirectory, MetricName.build("gauge"));
+    }
+
     private String csv(String... lines) {
         final StringBuilder builder = new StringBuilder();
         for (String line : lines) {

diff --git a/metrics-core/src/test/java/io/dropwizard/metrics/FixedNameCsvFileProviderTest.java b/metrics-core/src/test/java/io/dropwizard/metrics/FixedNameCsvFileProviderTest.java
@@ -0,0 +1,30 @@
+package io.dropwizard.metrics;
+
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.TemporaryFolder;
+
+import java.io.File;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class FixedNameCsvFileProviderTest {
+    @Rule
+    public final TemporaryFolder folder = new TemporaryFolder();
+
+    private File dataDirectory;
+
+    @Before
+    public void setUp() throws Exception {
+        this.dataDirectory = folder.newFolder();
+    }
+
+    @Test
+    public void testGetFile() {
+        FixedNameCsvFileProvider provider = new FixedNameCsvFileProvider();
+        File file = provider.getFile(dataDirectory, MetricName.build("test"));
+        assertThat(file.getParentFile()).isEqualTo(dataDirectory);
+        assertThat(file.getName()).isEqualTo("test.csv");
+    }
+}