Fix for jboss-logging#139.

ext/src/main/java/org/jboss/logmanager/ext/handlers/PeriodicRotatingFileHandler.java

@@ -19,17 +19,19 @@
 
 package org.jboss.logmanager.ext.handlers;
 
+import org.jboss.logmanager.ExtLogRecord;
+import org.jboss.logmanager.handlers.FileHandler;
+
 import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
 import java.text.SimpleDateFormat;
-import java.util.Calendar;
-import java.util.Date;
-import java.util.TimeZone;
+import java.util.*;
 import java.util.logging.ErrorManager;
-
-import org.jboss.logmanager.ExtLogRecord;
-import org.jboss.logmanager.handlers.FileHandler;
+import java.util.regex.Pattern;
+import java.util.stream.Collectors;
 
 /**
  * A file handler which rotates the log at a preset time interval.  The interval is determined by the content of the
@@ -43,6 +45,8 @@ public class PeriodicRotatingFileHandler extends FileHandler {
     private long nextRollover = Long.MAX_VALUE;
     private TimeZone timeZone = TimeZone.getDefault();
     private SuffixRotator suffixRotator = SuffixRotator.EMPTY;
+    private long pruneSize = Long.MIN_VALUE;
+
 
     /**
      * Construct a new instance with no formatter and no output file.
@@ -198,9 +202,57 @@ private void rollOver() {
             suffixRotator.rotate(getErrorManager(), file.toPath(), nextSuffix);
             // start new file
             setFile(file);
+
+            if (pruneSize > 0) {
+                pruneFiles(file);
+            }
+
         } catch (IOException e) {
             reportError("Unable to rotate log file", e, ErrorManager.OPEN_FAILURE);
         }
+
+    }
+
+    private void pruneFiles(File baseFile) throws IOException {
+
+        String baseName = baseFile.getName();
+        Path parent = baseFile.toPath().getParent();
+        String suffixPattern = this.getSuffixRotator().getDatePattern();
+
+        Pattern namePattern = Pattern.compile("^" + Pattern.quote(baseName) + ".*$");
+
+        /*
+         * Pruneable files are files in the current file's directory that are:
+         *
+         * a) regular (not symlinks, dirs, or hidden)
+         * b) not the current log
+         * c) match the current file syntax
+         * d) at a max depth of 1 (files in nested dirs aren't considered)
+         */
+        List<File> pruneables = Files
+            .find(parent, 1, (p, a) ->
+                a.isRegularFile() &&
+                    !p.getFileName().toString().equals(baseName) &&
+                    namePattern.matcher(p.getFileName().toString()).matches()
+            )
+            .map(Path::toFile)
+            .filter(File::canWrite)
+            .collect(Collectors.toList());
+        long total = pruneables.stream().mapToLong(File::length).sum();
+        if (total > pruneSize) {
+            // sort files in ascending chronological order
+            pruneables.sort(Comparator.comparingLong(File::lastModified));
+
+            for (int i = 0, size = pruneables.size(); i < size && total > pruneSize; i++) {
+                long fsize = pruneables.get(i).length();
+                try {
+                    Files.deleteIfExists(pruneables.get(i).toPath());
+                } catch (IOException ex) {
+                    reportError("Unable to prune log file", ex, ErrorManager.GENERIC_FAILURE);
+                }
+                total -= fsize;
+            }
+        }
     }
 
     private void calcNextRollover(final long fromTime) {
@@ -293,6 +345,14 @@ public void setTimeZone(final TimeZone timeZone) {
         this.timeZone = timeZone;
     }
 
+    public long getPruneSize() {
+        return pruneSize;
+    }
+
+    public void setPruneSize(long pruneSize) {
+        this.pruneSize = pruneSize;
+    }
+
     private static <T extends Comparable<? super T>> T min(T a, T b) {
         return a.compareTo(b) <= 0 ? a : b;
     }