[Jnode-svn-commits] SF.net SVN: jnode:[5925] trunk/fs/src/fs/org/jnode/fs/ext2

[<ga...@us...>]

Revision: 5925
          http://jnode.svn.sourceforge.net/jnode/?rev=5925&view=rev
Author:   galatnm
Date:     2012-08-10 07:26:22 +0000 (Fri, 10 Aug 2012)
Log Message:
-----------
Further support for ext4 extents and bug fixes

Modified Paths:
--------------
    trunk/fs/src/fs/org/jnode/fs/ext2/ExtentHeader.java
    trunk/fs/src/fs/org/jnode/fs/ext2/ExtentIndex.java
    trunk/fs/src/fs/org/jnode/fs/ext2/INode.java

Modified: trunk/fs/src/fs/org/jnode/fs/ext2/ExtentHeader.java
===================================================================
--- trunk/fs/src/fs/org/jnode/fs/ext2/ExtentHeader.java	2012-08-10 07:23:31 UTC (rev 5924)
+++ trunk/fs/src/fs/org/jnode/fs/ext2/ExtentHeader.java	2012-08-10 07:26:22 UTC (rev 5925)
@@ -103,33 +103,74 @@
         return extentEntries;
     }
 
-    public long getBlockNumber(long index) {
+    public long getBlockNumber(Ext2FileSystem fs, long index) throws IOException {
         if (getDepth() > 0) {
-            ExtentIndex[] indexes = getIndexEntries();
+            ExtentIndex extentIndex = binarySearchIndexes(index, getIndexEntries());
+            byte[] indexData = fs.getBlock(extentIndex.getLeafLow());
 
-            throw new UnsupportedOperationException();
+            ExtentHeader indexHeader = new ExtentHeader(indexData);
+            return indexHeader.getBlockNumber(fs, index);
         }
         else {
-            Extent[] extents = getExtentEntries();
+            Extent extent = binarySearchExtents(index, getExtentEntries());
+            return index - extent.getBlockIndex() + extent.getStartLow();
+        }
+    }
 
-            int lowIndex = 0;
-            int highIndex = extents.length - 1;
-            Extent extent = null;
+    /**
+     * Performs a binary search in the extent indexes.
+     *
+     * @param index the index of the block to match.
+     * @param indexes the indexes to search in.
+     * @return the matching index.
+     */
+    private ExtentIndex binarySearchIndexes(long index, ExtentIndex[] indexes)
+    {
+        int lowIndex = 0;
+        int highIndex = indexes.length - 1;
+        ExtentIndex extentIndex = null;
 
-            while (lowIndex <= highIndex) {
-                int middle = lowIndex + (highIndex - lowIndex) / 2;
-                extent = extents[middle];
+        while (lowIndex <= highIndex) {
+            int middle = lowIndex + (highIndex - lowIndex) / 2;
+            extentIndex = indexes[middle];
 
-                if (index < extent.getBlockIndex()) {
-                    highIndex = middle - 1;
-                }
-                else {
-                    lowIndex = middle + 1;
-                }
+            if (index < extentIndex.getBlockIndex()) {
+                highIndex = middle - 1;
             }
+            else {
+                lowIndex = middle + 1;
+            }
+        }
 
-            return index - extent.getBlockIndex() + extent.getStartLow();
+        return indexes[Math.max(0, lowIndex - 1)];
+    }
+
+    /**
+     * Performs a binary search in the extents.
+     *
+     * @param index the index of the block to match.
+     * @param extents the extents to search in.
+     * @return the matching extent.
+     */
+    private Extent binarySearchExtents(long index, Extent[] extents)
+    {
+        int lowIndex = 0;
+        int highIndex = extents.length - 1;
+        Extent extent = null;
+
+        while (lowIndex <= highIndex) {
+            int middle = lowIndex + (highIndex - lowIndex) / 2;
+            extent = extents[middle];
+
+            if (index < extent.getBlockIndex()) {
+                highIndex = middle - 1;
+            }
+            else {
+                lowIndex = middle + 1;
+            }
         }
+
+        return extents[Math.max(0, lowIndex - 1)];
     }
 
     @Override

Modified: trunk/fs/src/fs/org/jnode/fs/ext2/ExtentIndex.java
===================================================================
--- trunk/fs/src/fs/org/jnode/fs/ext2/ExtentIndex.java	2012-08-10 07:23:31 UTC (rev 5924)
+++ trunk/fs/src/fs/org/jnode/fs/ext2/ExtentIndex.java	2012-08-10 07:26:22 UTC (rev 5925)
@@ -24,6 +24,11 @@
     public ExtentIndex(byte[] data) {
         this.data = new byte[EXTENT_INDEX_LENGTH];
         System.arraycopy(data, 0, this.data, 0, EXTENT_INDEX_LENGTH);
+
+        // Safety check
+        if (getLeafHigh() != 0) {
+            throw new UnsupportedOperationException("Extent indexes that use the high bits aren't supported yet");
+        }
     }
 
     public long getBlockIndex() {
@@ -37,4 +42,10 @@
     public int getLeafHigh() {
         return Ext2Utils.get16(data, 8);
     }
+
+    @Override
+    public String toString() {
+        return String.format("ExtentIndex: blockindex:%d leaf(low:%d high:%d)", getBlockIndex(), getLeafLow(),
+                             getLeafHigh());
+    }
 }

Modified: trunk/fs/src/fs/org/jnode/fs/ext2/INode.java
===================================================================
--- trunk/fs/src/fs/org/jnode/fs/ext2/INode.java	2012-08-10 07:23:31 UTC (rev 5924)
+++ trunk/fs/src/fs/org/jnode/fs/ext2/INode.java	2012-08-10 07:26:22 UTC (rev 5925)
@@ -300,7 +300,7 @@
                 extentHeader = new ExtentHeader(getINodeBlockData());
             }
 
-            return extentHeader.getBlockNumber(i);
+            return extentHeader.getBlockNumber(fs, i);
         }
         else {
             return getDataBlockNrIndirect(i);

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