[JGIT PATCH 2/5 v2] Add copy(InputStream) to TemporaryBuffer

From: Shawn O. Pearce <spearce@spearce.org>
Date: Dec 11, 2008, 16:53 UTC
Message-ID: <20081211165345.GG32487@spearce.org>
In-Reply-To: <20081211155218.GF32487@spearce.org>

In some places we may find ourselves with an InputStream we need to copy into a TemporaryBuffer, so we can flatten out the entire stream to a single byte[]. Putting the copy loop here is more useful then duplicating it in application level code.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
---
  "Shawn O. Pearce" <spearce@spearce.org> wrote:
  > Robin Rosenberg <robin.rosenberg@dewire.com> wrote:
  > > torsdag 11 december 2008 05:58:39 skrev Shawn O. Pearce:
  > > > +		final byte[] b = new byte[2048];
  > >
  > > Why not 8192 here too?
  > 
  > Blargh, you're right.  Actually what I should do is look to see
  > if blocks != null, in which case I should alloc a block and read
  > directly into it.  That would avoid one copy of the data.

  And now we do that...

diff --git a/org.spearce.jgit/src/org/spearce/jgit/util/TemporaryBuffer.java b/org.spearce.jgit/src/org/spearce/jgit/util/TemporaryBuffer.java
index b1ffd6e..761f359 100644
--- a/org.spearce.jgit/src/org/spearce/jgit/util/TemporaryBuffer.java
+++ b/org.spearce.jgit/src/org/spearce/jgit/util/TemporaryBuffer.java
@@ -42,6 +42,7 @@
 import java.io.FileInputStream;
 import java.io.FileOutputStream;
 import java.io.IOException;
+import java.io.InputStream;
 import java.io.OutputStream;
 import java.util.ArrayList;
 
@@ -135,6 +136,39 @@ public void write(final byte[] b, int off, int len) throws IOException {
 			diskOut.write(b, off, len);
 	}
 
+	/**
+	 * Copy all bytes remaining on the input stream into this buffer.
+	 * 
+	 * @param in
+	 *            the stream to read from, until EOF is reached.
+	 * @throws IOException
+	 *             an error occurred reading from the input stream, or while
+	 *             writing to a local temporary file.
+	 */
+	public void copy(final InputStream in) throws IOException {
+		if (blocks != null) {
+			for (;;) {
+				Block s = last();
+				if (s.isFull()) {
+					if (reachedInCoreLimit())
+						break;
+					s = new Block();
+					blocks.add(s);
+				}
+
+				final int n = in.read(s.buffer, s.count, Block.SZ - s.count);
+				if (n < 1)
+					return;
+				s.count += n;
+			}
+		}
+
+		final byte[] tmp = new byte[Block.SZ];
+		int n;
+		while ((n = in.read(tmp)) > 0)
+			diskOut.write(tmp, 0, n);
+	}
+
 	private Block last() {
 		return blocks.get(blocks.size() - 1);
 	}

-- 
1.6.1.rc2.306.ge5d5e


-- 
Shawn.