From f31323745f90aeb8f0b9bd0df4248363fc284bfe Mon Sep 17 00:00:00 2001
From: Shawn Pearce <spearce@spearce.org>
Date: Mon, 24 Nov 2014 20:05:34 -0800
Subject: [PATCH] DirCache: Buffer TREE extension to $GIT_DIR

Increase the in-memory buffer for the TREE extension to 5 MiB, and
overflow to $GIT_DIR instead of /tmp.  Using a larger buffer reduces
the chances a repository will overflow and need to spool the extension
to disk.  Using $GIT_DIR allows the TREE extension contents to have
the same file system protections as the final $GIT_DIR/index.

Wrap the entire thing in a try/finally to ensure the temp file is
deleted from disk after the block has finished using it. To avoid
dangling NFS files, LocalFile.destroy() does close the local file
before deleting it.

Change-Id: I8f871181a4689e3ebf0cdd4fd1769333cf7546c3
---
 .../DirCacheCGitCompatabilityTest.java        |  2 +-
 .../org/eclipse/jgit/dircache/DirCache.java   | 23 +++++++++++--------
 2 files changed, 15 insertions(+), 10 deletions(-)

diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/dircache/DirCacheCGitCompatabilityTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/dircache/DirCacheCGitCompatabilityTest.java
index 53d672d7f..7f58a1cbe 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/dircache/DirCacheCGitCompatabilityTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/dircache/DirCacheCGitCompatabilityTest.java
@@ -213,7 +213,7 @@ public void testReadWriteV3() throws Exception {
 		assertV3TreeEntry(9, "newfile.txt", false, true, dc);
 
 		final ByteArrayOutputStream bos = new ByteArrayOutputStream();
-		dc.writeTo(bos);
+		dc.writeTo(null, bos);
 		final byte[] indexBytes = bos.toByteArray();
 		final byte[] expectedBytes = IO.readFully(file);
 		assertArrayEquals(expectedBytes, indexBytes);
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/dircache/DirCache.java b/org.eclipse.jgit/src/org/eclipse/jgit/dircache/DirCache.java
index 645de2704..98a1c8ca4 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/dircache/DirCache.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/dircache/DirCache.java
@@ -607,7 +607,8 @@ public void write() throws IOException {
 		final LockFile tmp = myLock;
 		requireLocked(tmp);
 		try {
-			writeTo(new SafeBufferedOutputStream(tmp.getOutputStream()));
+			writeTo(liveFile.getParentFile(),
+					new SafeBufferedOutputStream(tmp.getOutputStream()));
 		} catch (IOException err) {
 			tmp.unlock();
 			throw err;
@@ -620,7 +621,7 @@ public void write() throws IOException {
 		}
 	}
 
-	void writeTo(final OutputStream os) throws IOException {
+	void writeTo(File dir, final OutputStream os) throws IOException {
 		final MessageDigest foot = Constants.newMessageDigest();
 		final DigestOutputStream dos = new DigestOutputStream(os, foot);
 
@@ -670,14 +671,18 @@ void writeTo(final OutputStream os) throws IOException {
 		}
 
 		if (writeTree) {
-			final TemporaryBuffer bb = new TemporaryBuffer.LocalFile();
-			tree.write(tmp, bb);
-			bb.close();
+			TemporaryBuffer bb = new TemporaryBuffer.LocalFile(dir, 5 << 20);
+			try {
+				tree.write(tmp, bb);
+				bb.close();
 
-			NB.encodeInt32(tmp, 0, EXT_TREE);
-			NB.encodeInt32(tmp, 4, (int) bb.length());
-			dos.write(tmp, 0, 8);
-			bb.writeTo(dos, null);
+				NB.encodeInt32(tmp, 0, EXT_TREE);
+				NB.encodeInt32(tmp, 4, (int) bb.length());
+				dos.write(tmp, 0, 8);
+				bb.writeTo(dos, null);
+			} finally {
+				bb.destroy();
+			}
 		}
 		writeIndexChecksum = foot.digest();
 		os.write(writeIndexChecksum);