[PATCH JGIT 1/2] Calculate CRC32 on Pack Index v2

["Daniel Cheng (aka SDiZ)" <j16sdiz+freenet@gmail.com>]

Signed-off-by: Daniel Cheng (aka SDiZ) <j16sdiz+freenet@gmail.com>
---
 .../src/org/spearce/jgit/lib/PackWriter.java       |    2 +
 .../spearce/jgit/util/CountingOutputStream.java    |   32 +++++++++++++++++++-
 2 files changed, 33 insertions(+), 1 deletions(-)

diff --git a/org.spearce.jgit/src/org/spearce/jgit/lib/PackWriter.java b/org.spearce.jgit/src/org/spearce/jgit/lib/PackWriter.java
index 601ce71..d8b50e6 100644
--- a/org.spearce.jgit/src/org/spearce/jgit/lib/PackWriter.java
+++ b/org.spearce.jgit/src/org/spearce/jgit/lib/PackWriter.java
@@ -687,11 +687,13 @@ public class PackWriter {
 
 		assert !otp.isWritten();
 
+		countingOut.resetCRC32();
 		otp.setOffset(countingOut.getCount());
 		if (otp.isDeltaRepresentation())
 			writeDeltaObject(otp);
 		else
 			writeWholeObject(otp);
+		otp.setCRC((int) countingOut.getCRC32());
 
 		writeMonitor.update(1);
 	}
diff --git a/org.spearce.jgit/src/org/spearce/jgit/util/CountingOutputStream.java b/org.spearce.jgit/src/org/spearce/jgit/util/CountingOutputStream.java
index b0b5f7d..b4ae915 100644
--- a/org.spearce.jgit/src/org/spearce/jgit/util/CountingOutputStream.java
+++ b/org.spearce.jgit/src/org/spearce/jgit/util/CountingOutputStream.java
@@ -40,12 +40,16 @@ package org.spearce.jgit.util;
 import java.io.FilterOutputStream;
 import java.io.IOException;
 import java.io.OutputStream;
+import java.util.zip.CRC32;
 
 /**
- * Counting output stream decoration. Counts bytes written to stream.
+ * Counting output stream decoration. Counts bytes written to stream and 
+ * calculate CRC32 checksum.
  */
 public class CountingOutputStream extends FilterOutputStream {
 	private long count;
+	
+	private CRC32 crc;
 
 	/**
 	 * Create counting stream being decorated to provided real output stream.
@@ -55,6 +59,7 @@ public class CountingOutputStream extends FilterOutputStream {
 	 */
 	public CountingOutputStream(OutputStream out) {
 		super(out);
+		crc = new CRC32();
 	}
 
 	@Override
@@ -79,10 +84,35 @@ public class CountingOutputStream extends FilterOutputStream {
 		return count;
 	}
 
+    /**
+     * Resets CRC-32 to initial value.
+     */
+	public void resetCRC32() {
+		crc.reset();
+	}
+
+    /**
+     * Returns CRC-32 value.
+     * @return CRC32
+     */
+	public long getCRC32() {
+		return crc.getValue();
+	}
+
+
 	/**
 	 * Reset counter to zero value.
 	 */
 	public void reset() {
 		count = 0;
+		crc.reset();
+	}
+	
+	/**
+	 * {@inheritDoc}
+	 */
+	public void close() throws IOException {
+		crc = null;
+		super.close();
 	}
 }
-- 
1.6.2