compress previous log file on startup (#16674)

1 files changed, 10 insertions, 2 deletions

diff --git a/jdisc_http_service/src/main/java/com/yahoo/container/logging/LogFileHandler.java b/jdisc_http_service/src/main/java/com/yahoo/container/logging/LogFileHandler.java
index 3e257813b5e..0f2a9e42eb8 100644
--- a/jdisc_http_service/src/main/java/com/yahoo/container/logging/LogFileHandler.java
+++ b/jdisc_http_service/src/main/java/com/yahoo/container/logging/LogFileHandler.java
@@ -366,6 +366,7 @@ class LogFileHandler <LOGTYPE> {
                 throw new RuntimeException("Couldn't open log file '" + fileName + "'", e);
             }
 
+            if(oldFileName == null) oldFileName = getOldFileNameFromSymlink(); // To compress previous file, if so configured
             createSymlinkToCurrentFile();
 
             nextRotationTime = 0; //figure it out later (lazy evaluation)
@@ -465,6 +466,15 @@ class LogFileHandler <LOGTYPE> {
             }
         }
 
+        private String getOldFileNameFromSymlink() {
+            if(symlinkName == null) return null;
+            try {
+                return Paths.get(fileName).resolveSibling(symlinkName).toRealPath().toString();
+            } catch (IOException e) {
+                return null;
+            }
+        }
+
         private static final long lengthOfDayMillis = 24 * 60 * 60 * 1000;
         private static long timeOfDayMillis(long time) {
             return time % lengthOfDayMillis;
@@ -475,8 +485,6 @@ class LogFileHandler <LOGTYPE> {
     private static class Operation<LOGTYPE> {
         enum Type {log, flush, close, rotate}
 
-        ;
-
         final Type type;
 
         final Optional<LOGTYPE> log;