Drop file continously from cache as we read it.

1 files changed, 16 insertions, 7 deletions

diff --git a/vespajlib/src/main/java/com/yahoo/io/NativeIO.java b/vespajlib/src/main/java/com/yahoo/io/NativeIO.java
index f69bdb4e3dd..109b7ff7943 100644
--- a/vespajlib/src/main/java/com/yahoo/io/NativeIO.java
+++ b/vespajlib/src/main/java/com/yahoo/io/NativeIO.java
@@ -54,19 +54,28 @@ public class NativeIO {
     }
 
     /**
-     * Will hint the OS that this is will not be accessed again and should hence be dropped from the buffer cache.
+     * Will hint the OS that data read so far will not be accessed again and should hence be dropped from the buffer cache.
      * @param fd The file descriptor to drop from buffer cache.
      */
-    public void dropFileFromCache(FileDescriptor fd) {
-        try {
-            fd.sync();
-        } catch (SyncFailedException e) {
-            logger.warning("Sync failed while dropping cache: " + e.getMessage());
+    public void dropPartialFileFromCache(FileDescriptor fd, long offset, long len, boolean sync) {
+        if (sync) {
+            try {
+                fd.sync();
+            } catch (SyncFailedException e) {
+                logger.warning("Sync failed while dropping cache: " + e.getMessage());
+            }
         }
         if (initialized) {
-            posix_fadvise(getNativeFD(fd), 0, 0, POSIX_FADV_DONTNEED);
+            posix_fadvise(getNativeFD(fd), offset, len, POSIX_FADV_DONTNEED);
         }
     }
+    /**
+     * Will hint the OS that this is will not be accessed again and should hence be dropped from the buffer cache.
+     * @param fd The file descriptor to drop from buffer cache.
+     */
+    public void dropFileFromCache(FileDescriptor fd) {
+        dropPartialFileFromCache(fd, 0, 0, true);
+    }
 
     /**
      * Will hint the OS that this is will not be accessed again and should hence be dropped from the buffer cache.