fix for a OOM in MapView that can cause unavailability of

- seed list
- bookmarks
during very low memory configuration

git-svn-id: https://svn.berlios.de/svnroot/repos/yacy/trunk@6529 6c8d7289-2bf4-0310-a012-ef5d649a1542

source/net/yacy/kelondro/blob/MapView.java

@@ -116,11 +116,12 @@ public class MapView {
         return bb.toString();
     }
 
-    private static Map<String, String> bytes2map(byte[] b) throws IOException {
+    private static Map<String, String> bytes2map(byte[] b) throws IOException, RowSpaceExceededException {
         final BufferedReader br = new BufferedReader(new InputStreamReader(new ByteArrayInputStream(b)));
         final Map<String, String> map = new HashMap<String, String>();
         String line;
         int pos;
+        try {
         while ((line = br.readLine()) != null) { // very slow readLine????
             line = line.trim();
             if (line.equals("# EOF")) return map;
@@ -129,6 +130,9 @@ public class MapView {
             if (pos < 0) continue;
             map.put(line.substring(0, pos), line.substring(pos + 1));
         }
+        } catch (OutOfMemoryError e) {
+            throw new RowSpaceExceededException(0, "readLine probably uses too much RAM", e);
+        }
         return map;
     }
     
@@ -229,7 +233,11 @@ public class MapView {
                 // read object
                 final byte[] b = blob.get(keyb);
                 if (b == null) return null;
+                try {
                     map = bytes2map(b);
+                } catch (RowSpaceExceededException e) {
+                    throw new IOException(e.getMessage());
+                }
         
                 // write map to cache
                 cache.put(key, map);
@@ -245,7 +253,11 @@ public class MapView {
                 b = blob.get(keyb);
             }
             if (b == null) return null;
+            try {
                 return bytes2map(b);
+            } catch (RowSpaceExceededException e) {
+                throw new IOException(e.getMessage());
+            }
         }
     }
 

source/net/yacy/kelondro/index/RowSpaceExceededException.java

@@ -45,6 +45,14 @@ public class RowSpaceExceededException extends Exception {
         this.forUsage = forUsage;
     }
 
+    public RowSpaceExceededException(long neededRAM, String forUsage, Throwable t) {
+        super(Long.toString(neededRAM) + " bytes needed for " + forUsage + ": " + MemoryControl.available() + " free at " + (new Date()).toString(), t);
+        this.time = System.currentTimeMillis();
+        this.availableRAM = MemoryControl.available();
+        this.neededRAM = neededRAM;
+        this.forUsage = forUsage;
+    }
+
     public String getUsage() {
         return forUsage;
     }