report duration for file history cache updates

Author: Vladimir Kotal

opengrok-indexer/src/main/java/org/opengrok/indexer/history/FileHistoryCache.java

@@ -60,6 +60,7 @@
 import org.opengrok.indexer.logger.LoggerFactory;
 import org.opengrok.indexer.util.ForbiddenSymlinkException;
 import org.opengrok.indexer.util.IOUtils;
+import org.opengrok.indexer.util.Statistics;
 import org.opengrok.indexer.util.TandemPath;
 
 /**
@@ -90,7 +91,7 @@ public boolean isHistoryIndexDone() {
     }
 
     /**
-     * Generate history for single file.
+     * Generate history cache for single file or directory.
      * @param filename name of the file
      * @param historyEntries list of HistoryEntry objects forming the (incremental) history of the file
      * @param repository repository object in which the file belongs
@@ -102,6 +103,8 @@ private void doFileHistory(String filename, List<HistoryEntry> historyEntries,
             Repository repository, File srcFile, File root, boolean renamed)
             throws HistoryException {
 
+        Statistics statRepoHist = new Statistics();
+
         File file = new File(root, filename);
         // Only store directory history for the top-level directory.
         if (file.isDirectory() && !filename.equals(repository.getDirectoryName())) {
@@ -138,6 +141,10 @@ private void doFileHistory(String filename, List<HistoryEntry> historyEntries,
         }
 
         storeFile(hist, file, repository, !renamed);
+
+        statRepoHist.report(LOGGER, Level.FINER,
+                String.format("Done storing history cache for '%s'", filename),
+                "filehistorycache.history");
     }
 
     private boolean isRenamedFile(String filename, Repository repository, History history)

opengrok-indexer/src/main/java/org/opengrok/indexer/util/Statistics.java

@@ -31,6 +31,10 @@
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
+/**
+ * This class is handy for logging messages (and updating metrics)
+ * about duration of a task.
+ */
 public class Statistics {
 
     private final Instant startTime;
@@ -55,11 +59,13 @@ public void report(Logger logger, Level logLevel, String msg) {
     }
 
     /**
-     * Log a message and trigger statsd message along with how much time it took since the constructor was called.
+     * Log a message along with how much time it took since the constructor was called.
+     * If there is a metrics registry, it will update the timer specified by the meter name.
      * @param logger logger instance
      * @param logLevel log level
      * @param msg message string
      * @param meterName name of the meter
+     * @see Metrics#getRegistry()
      */
     public void report(Logger logger, Level logLevel, String msg, String meterName) {
         Duration duration = Duration.between(startTime, Instant.now());
@@ -76,6 +82,7 @@ public void report(Logger logger, Level logLevel, String msg, String meterName)
 
     /**
      * log a message along with how much time it took since the constructor was called.
+     * If there is a metrics registry, it will update the timer specified by the meter name.
      * The log level is {@code INFO}.
      * @param logger logger instance
      * @param msg message string