added automatic channel closure for failed locks. (suggest this class becomes a singl...

[vamsas.git] / src / org / vamsas / client / simpleclient / FileWatcher.java

diff --git a/src/org/vamsas/client/simpleclient/FileWatcher.java b/src/org/vamsas/client/simpleclient/FileWatcher.java
index 84a5e0a..bc9f705 100644 (file)
--- a/src/org/vamsas/client/simpleclient/FileWatcher.java
+++ b/src/org/vamsas/client/simpleclient/FileWatcher.java
@@ -16,7 +16,7 @@ public class FileWatcher {
   private File subject = null;
 
   private long lastStat[];
-
+  boolean waslocked=false;
   boolean exists = false;
 
   /**
@@ -33,12 +33,13 @@ public class FileWatcher {
       if (tl.isLocked()) {
         tl.release();
         return false;
-      } else {
-        return true;
       }
+      tl.release();
+      return true;
     }
     return false;
   }
+  
   private long[] getStat(File subject) {
     return new long[] { subject.lastModified(), subject.length() };
   }
@@ -47,32 +48,57 @@ public class FileWatcher {
       return false;
     return true;
   }
+  /**
+   * Detect changes in file state and release of any
+   * lock in place during change.
+   * @return true if file state has changed
+   */
   private boolean check() {
     if (subject != null) {
       if (!subject.exists()) {
         if (exists) {
-          exists = false;
-          return true;
+          if (!waslocked) {
+            // !checkLock()) {
+          
+            exists = false;
+            // waslocked=false;
+            return true;
+          }
         }
+        // locked - state change registered after lock is released
         return false;
       } else {
-        
         long[] newStat = getStat(subject); // subject.lastModified();
-        if (exists && ((compStat(lastStat, newStat) || checkLock()))) {
+        if (!checkLock()) {
+          // file is free to access, return state change
+          if (!exists || !compStat(lastStat, newStat)) {
+            waslocked=false;
+            exists=true;
+            lastStat=newStat;
+            return true;
+          }
+          // no change
+          return false;
+        } else {
+          waslocked=true;
           return false;
         }
-        lastStat = newStat;
-        exists = true;
-        return true;
       }
     }
     return false;
   }
-
+  public void setState() {
+    if (subject!=null) {
+      lastStat = getStat(subject);
+      exists = subject.exists();
+      waslocked = checkLock();
+    }
+  }
+  
   public FileWatcher(File subject) {
     // TODO Auto-generated constructor stub
     this.subject = subject;
-    check();
+    setState();
   }
 
   public boolean hasChanged() {