Create an input stream that transforms LF to CRLF

The transformation is the same as AutoCRLFOutputStream does, but
the direction is reversed. The tests are reused, but the implementation
derives somewhat from the EolCanonicalizingInputStream.

This stream will be used to compare blobs with LF line endings with
worktree data that has CRLF line endings.

Bug: 387501
Change-Id: I80d96e453e7f780dd464a89778de124cf35384e1
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

2 files changed, 273 insertions, 0 deletions

diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/util/io/AutoCRLFInputStreamTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/util/io/AutoCRLFInputStreamTest.java
new file mode 100644
index 0000000000..754c9fc435
--- /dev/null
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/util/io/AutoCRLFInputStreamTest.java
@@ -0,0 +1,122 @@
+/*
+ * Copyright (C) 2012, Robin Rosenberg
+ * and other copyright owners as documented in the project's IP log.
+ *
+ * This program and the accompanying materials are made available
+ * under the terms of the Eclipse Distribution License v1.0 which
+ * accompanies this distribution, is reproduced below, and is
+ * available at http://www.eclipse.org/org/documents/edl-v10.php
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above
+ *   copyright notice, this list of conditions and the following
+ *   disclaimer in the documentation and/or other materials provided
+ *   with the distribution.
+ *
+ * - Neither the name of the Eclipse Foundation, Inc. nor the
+ *   names of its contributors may be used to endorse or promote
+ *   products derived from this software without specific prior
+ *   written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+ * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package org.eclipse.jgit.util.io;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class AutoCRLFInputStreamTest {
+
+	@Test
+	public void test() throws IOException {
+		assertNoCrLf("", "");
+		assertNoCrLf("\r", "\r");
+		assertNoCrLf("\r\n", "\n");
+		assertNoCrLf("\r\n", "\r\n");
+		assertNoCrLf("\r\r", "\r\r");
+		assertNoCrLf("\r\n\r", "\n\r");
+		assertNoCrLf("\r\n\r\r", "\r\n\r\r");
+		assertNoCrLf("\r\n\r\n", "\r\n\r\n");
+		assertNoCrLf("\r\n\r\n\r", "\n\r\n\r");
+	}
+
+	private void assertNoCrLf(String string, String string2) throws IOException {
+		assertNoCrLfHelper(string, string2);
+		// \u00e5 = LATIN SMALL LETTER A WITH RING ABOVE
+		// the byte value is negative
+		assertNoCrLfHelper("\u00e5" + string, "\u00e5" + string2);
+		assertNoCrLfHelper("\u00e5" + string + "\u00e5", "\u00e5" + string2
+				+ "\u00e5");
+		assertNoCrLfHelper(string + "\u00e5", string2 + "\u00e5");
+	}
+
+	private void assertNoCrLfHelper(String expect, String input)
+			throws IOException {
+		byte[] inbytes = input.getBytes();
+		byte[] expectBytes = expect.getBytes();
+		for (int i = 0; i < 5; ++i) {
+			byte[] buf = new byte[i];
+			ByteArrayInputStream bis = new ByteArrayInputStream(inbytes);
+			InputStream in = new AutoCRLFInputStream(bis, true);
+			ByteArrayOutputStream out = new ByteArrayOutputStream();
+			if (i > 0) {
+				int n;
+				while ((n = in.read(buf)) >= 0) {
+					out.write(buf, 0, n);
+				}
+			} else {
+				int c;
+				while ((c = in.read()) != -1)
+					out.write(c);
+			}
+			out.flush();
+			in.close();
+			out.close();
+			byte[] actualBytes = out.toByteArray();
+			Assert.assertEquals("bufsize=" + i, encode(expectBytes),
+					encode(actualBytes));
+		}
+	}
+
+	String encode(byte[] in) {
+		StringBuilder str = new StringBuilder();
+		for (byte b : in) {
+			if (b < 32)
+				str.append(0xFF & b);
+			else {
+				str.append("'");
+				str.append((char) b);
+				str.append("'");
+			}
+			str.append(' ');
+		}
+		return str.toString();
+	}
+
+}
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/util/io/AutoCRLFInputStream.java b/org.eclipse.jgit/src/org/eclipse/jgit/util/io/AutoCRLFInputStream.java
new file mode 100644
index 0000000000..2a353a58b9
--- /dev/null
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/util/io/AutoCRLFInputStream.java
@@ -0,0 +1,151 @@
+/*
+ * Copyright (C) 2012, Robin Rosenberg
+ * Copyright (C) 2010, Marc Strapetz <marc.strapetz@syntevo.com>
+ * and other copyright owners as documented in the project's IP log.
+ *
+ * This program and the accompanying materials are made available
+ * under the terms of the Eclipse Distribution License v1.0 which
+ * accompanies this distribution, is reproduced below, and is
+ * available at http://www.eclipse.org/org/documents/edl-v10.php
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above
+ *   copyright notice, this list of conditions and the following
+ *   disclaimer in the documentation and/or other materials provided
+ *   with the distribution.
+ *
+ * - Neither the name of the Eclipse Foundation, Inc. nor the
+ *   names of its contributors may be used to endorse or promote
+ *   products derived from this software without specific prior
+ *   written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+ * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package org.eclipse.jgit.util.io;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+import org.eclipse.jgit.diff.RawText;
+
+/**
+ * An OutputStream that expands LF to CRLF.
+ *
+ * Existing CRLF are not expanded to CRCRLF, but retained as is.
+ *
+ * Optionally, a binary check on the first 8000 bytes is performed and in case
+ * of binary files, canonicalization is turned off (for the complete file).
+ */
+public class AutoCRLFInputStream extends InputStream {
+	private final byte[] single = new byte[1];
+
+	private final byte[] buf = new byte[8096];
+
+	private final InputStream in;
+
+	private int cnt;
+
+	private int ptr;
+
+	private boolean isBinary;
+
+	private boolean detectBinary;
+
+	private byte last;
+
+	/**
+	 * Creates a new InputStream, wrapping the specified stream
+	 *
+	 * @param in
+	 *            raw input stream
+	 * @param detectBinary
+	 *            whether binaries should be detected
+	 * @since 2.0
+	 */
+	public AutoCRLFInputStream(InputStream in, boolean detectBinary) {
+		this.in = in;
+		this.detectBinary = detectBinary;
+	}
+
+	@Override
+	public int read() throws IOException {
+		final int read = read(single, 0, 1);
+		return read == 1 ? single[0] & 0xff : -1;
+	}
+
+	@Override
+	public int read(byte[] bs, int off, int len) throws IOException {
+		if (len == 0)
+			return 0;
+
+		if (cnt == -1)
+			return -1;
+
+		final int startOff = off;
+		final int end = off + len;
+
+		while (off < end) {
+			if (ptr == cnt && !fillBuffer())
+				break;
+
+			byte b = buf[ptr++];
+			if (isBinary || b != '\n') {
+				// Logic for binary files ends here
+				bs[off++] = last = b;
+				continue;
+			}
+
+			if (b == '\n') {
+				if (last == '\r') {
+					bs[off++] = last = b;
+					continue;
+				}
+				bs[off++] = last = '\r';
+				ptr--;
+			} else
+				bs[off++] = last = b;
+		}
+		int n = startOff == off ? -1 : off - startOff;
+		if (n > 0)
+			last = bs[off - 1];
+		return n;
+	}
+
+	@Override
+	public void close() throws IOException {
+		in.close();
+	}
+
+	private boolean fillBuffer() throws IOException {
+		cnt = in.read(buf, 0, buf.length);
+		if (cnt < 1)
+			return false;
+		if (detectBinary) {
+			isBinary = RawText.isBinary(buf, cnt);
+			detectBinary = false;
+		}
+		ptr = 0;
+		return true;
+	}
+}