From: Johannes E. Schindelin <johannes.schindelin@xxxxxx>
The RawText class converts a byte[] into an indexed map of file
lines, assuming the source content is a UNIX formatted text file.
This fits in line with Git's usage of libxdiff, where typically
the file content is treated as a UNIX formatted text file, unless
binary content was previously detected in the file stream.
Signed-off-by: Shawn O. Pearce <spearce@xxxxxxxxxxx>
---
.../tst/org/spearce/jgit/diff/RawTextTest.java | 93 +++++++++++
.../src/org/spearce/jgit/diff/RawText.java | 172 ++++++++++++++++++++
.../src/org/spearce/jgit/diff/Sequence.java | 78 +++++++++
3 files changed, 343 insertions(+), 0 deletions(-)
create mode 100644 org.spearce.jgit.test/tst/org/spearce/jgit/diff/RawTextTest.java
create mode 100644 org.spearce.jgit/src/org/spearce/jgit/diff/RawText.java
create mode 100644 org.spearce.jgit/src/org/spearce/jgit/diff/Sequence.java
diff --git a/org.spearce.jgit.test/tst/org/spearce/jgit/diff/RawTextTest.java b/org.spearce.jgit.test/tst/org/spearce/jgit/diff/RawTextTest.java
new file mode 100644
index 0000000..a7c621e
--- /dev/null
+++ b/org.spearce.jgit.test/tst/org/spearce/jgit/diff/RawTextTest.java
@@ -0,0 +1,93 @@
+/*
+ * Copyright (C) 2009, Google Inc.
+ *
+ * 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 Git Development Community 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.spearce.jgit.diff;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+
+import junit.framework.TestCase;
+
+import org.spearce.jgit.lib.Constants;
+import org.spearce.jgit.util.RawParseUtils;
+
+public class RawTextTest extends TestCase {
+ public void testEmpty() {
+ final RawText r = new RawText(new byte[0]);
+ assertEquals(0, r.size());
+ }
+
+ public void testEquals() {
+ final RawText a = new RawText(Constants.encodeASCII("foo-a\nfoo-b\n"));
+ final RawText b = new RawText(Constants.encodeASCII("foo-b\nfoo-c\n"));
+
+ assertEquals(2, a.size());
+ assertEquals(2, b.size());
+
+ // foo-a != foo-b
+ assertFalse(a.equals(0, b, 0));
+ assertFalse(b.equals(0, a, 0));
+
+ // foo-b == foo-b
+ assertTrue(a.equals(1, b, 0));
+ assertTrue(b.equals(0, a, 1));
+ }
+
+ public void testWriteLine1() throws IOException {
+ final RawText a = new RawText(Constants.encodeASCII("foo-a\nfoo-b\n"));
+ final ByteArrayOutputStream o = new ByteArrayOutputStream();
+ a.writeLine(o, 0);
+ final byte[] r = o.toByteArray();
+ assertEquals("foo-a", RawParseUtils.decode(r));
+ }
+
+ public void testWriteLine2() throws IOException {
+ final RawText a = new RawText(Constants.encodeASCII("foo-a\nfoo-b"));
+ final ByteArrayOutputStream o = new ByteArrayOutputStream();
+ a.writeLine(o, 1);
+ final byte[] r = o.toByteArray();
+ assertEquals("foo-b", RawParseUtils.decode(r));
+ }
+
+ public void testWriteLine3() throws IOException {
+ final RawText a = new RawText(Constants.encodeASCII("a\n\nb\n"));
+ final ByteArrayOutputStream o = new ByteArrayOutputStream();
+ a.writeLine(o, 1);
+ final byte[] r = o.toByteArray();
+ assertEquals("", RawParseUtils.decode(r));
+ }
+}
diff --git a/org.spearce.jgit/src/org/spearce/jgit/diff/RawText.java b/org.spearce.jgit/src/org/spearce/jgit/diff/RawText.java
new file mode 100644
index 0000000..1d10082
--- /dev/null
+++ b/org.spearce.jgit/src/org/spearce/jgit/diff/RawText.java
@@ -0,0 +1,172 @@
+/*
+ * Copyright (C) 2008, Johannes E. Schindelin <johannes.schindelin@xxxxxx>
+ * Copyright (C) 2009, Google Inc.
+ *
+ * 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 Git Development Community 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.spearce.jgit.diff;
+
+import java.io.IOException;
+import java.io.OutputStream;
+
+import org.spearce.jgit.util.IntList;
+import org.spearce.jgit.util.RawParseUtils;
+
+/**
+ * A Sequence supporting UNIX formatted text in byte[] format.
+ * <p>
+ * Elements of the sequence are the lines of the file, as delimited by the UNIX
+ * newline character ('\n'). The file content is treated as 8 bit binary text,
+ * with no assumptions or requirements on character encoding.
+ * <p>
+ * Note that the first line of the file is element 0, as defined by the Sequence
+ * interface API. Traditionally in a text editor a patch file the first line is
+ * line number 1. Callers may need to subtract 1 prior to invoking methods if
+ * they are converting from "line number" to "element index".
+ */
+public class RawText implements Sequence {
+ /** The file content for this sequence. */
+ protected final byte[] content;
+
+ /** Map of line number to starting position within {@link #content}. */
+ protected final IntList lines;
+
+ /** Hash code for each line, for fast equality elimination. */
+ protected final IntList hashes;
+
+ /**
+ * Create a new sequence from an existing content byte array.
+ * <p>
+ * The entire array (indexes 0 through length-1) is used as the content.
+ *
+ * @param input
+ * the content array. The array is never modified, so passing
+ * through cached arrays is safe.
+ */
+ public RawText(final byte[] input) {
+ content = input;
+ lines = RawParseUtils.lineMap(content, 0, content.length);
+ hashes = computeHashes();
+ }
+
+ public int size() {
+ // The line map is always 2 entries larger than the number of lines in
+ // the file. Index 0 is padded out/unused. The last index is the total
+ // length of the buffer, and acts as a sentinel.
+ //
+ return lines.size() - 2;
+ }
+
+ public boolean equals(final int i, final Sequence other, final int j) {
+ return equals(this, i + 1, (RawText) other, j + 1);
+ }
+
+ private static boolean equals(final RawText a, final int ai,
+ final RawText b, final int bi) {
+ if (a.hashes.get(ai) != b.hashes.get(bi))
+ return false;
+
+ int as = a.lines.get(ai);
+ int bs = b.lines.get(bi);
+ final int ae = a.lines.get(ai + 1);
+ final int be = b.lines.get(bi + 1);
+
+ if (ae - as != be - bs)
+ return false;
+
+ while (as < ae) {
+ if (a.content[as++] != b.content[bs++])
+ return false;
+ }
+ return true;
+ }
+
+ /**
+ * Write a specific line to the output stream, without its trailing LF.
+ * <p>
+ * The specified line is copied as-is, with no character encoding
+ * translation performed.
+ * <p>
+ * If the specified line ends with an LF ('\n'), the LF is <b>not</b>
+ * copied. It is up to the caller to write the LF, if desired, between
+ * output lines.
+ *
+ * @param out
+ * stream to copy the line data onto.
+ * @param i
+ * index of the line to extract. Note this is 0-based, so line
+ * number 1 is actually index 0.
+ * @throws IOException
+ * the stream write operation failed.
+ */
+ public void writeLine(final OutputStream out, final int i)
+ throws IOException {
+ final int start = lines.get(i + 1);
+ int end = lines.get(i + 2);
+ if (content[end - 1] == '\n')
+ end--;
+ out.write(content, start, end - start);
+ }
+
+ private IntList computeHashes() {
+ final IntList r = new IntList(lines.size());
+ r.add(0);
+ for (int lno = 1; lno < lines.size() - 1; lno++) {
+ final int ptr = lines.get(lno);
+ final int end = lines.get(lno + 1);
+ r.add(hashLine(content, ptr, end));
+ }
+ r.add(0);
+ return r;
+ }
+
+ /**
+ * Compute a hash code for a single line.
+ *
+ * @param raw
+ * the raw file content.
+ * @param ptr
+ * first byte of the content line to hash.
+ * @param end
+ * 1 past the last byte of the content line.
+ * @return hash code for the region <code>[ptr, end)</code> of raw.
+ */
+ protected int hashLine(final byte[] raw, int ptr, final int end) {
+ int hash = 5381;
+ for (; ptr < end; ptr++)
+ hash = (hash << 5) ^ (raw[ptr] & 0xff);
+ return hash;
+ }
+}
\ No newline at end of file
diff --git a/org.spearce.jgit/src/org/spearce/jgit/diff/Sequence.java b/org.spearce.jgit/src/org/spearce/jgit/diff/Sequence.java
new file mode 100644
index 0000000..8e754e0
--- /dev/null
+++ b/org.spearce.jgit/src/org/spearce/jgit/diff/Sequence.java
@@ -0,0 +1,78 @@
+/*
+ * Copyright (C) 2008, Johannes E. Schindelin <johannes.schindelin@xxxxxx>
+ *
+ * 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 Git Development Community 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.spearce.jgit.diff;
+
+/**
+ * Arbitrary sequence of elements with fast comparison support.
+ * <p>
+ * A sequence of elements is defined to contain elements in the index range
+ * <code>[0, {@link #size()})</code>, like a standard Java List implementation.
+ * Unlike a List, the members of the sequence are not directly obtainable, but
+ * element equality can be tested if two Sequences are the same implementation.
+ * <p>
+ * An implementation may chose to implement the equals semantic as necessary,
+ * including fuzzy matching rules such as ignoring insignificant sub-elements,
+ * e.g. ignoring whitespace differences in text.
+ * <p>
+ * Implementations of Sequence are primarily intended for use in content
+ * difference detection algorithms, to produce an {@link EditList} of
+ * {@link Edit} instances describing how two Sequence instances differ.
+ */
+public interface Sequence {
+ /** @return total number of items in the sequence. */
+ public int size();
+
+ /**
+ * Determine if the i-th member is equal to the j-th member.
+ * <p>
+ * Implementations must ensure <code>equals(thisIdx,other,otherIdx)</code>
+ * returns the same as <code>other.equals(otherIdx,this,thisIdx)</code>.
+ *
+ * @param thisIdx
+ * index within <code>this</code> sequence; must be in the range
+ * <code>[ 0, this.size() )</code>.
+ * @param other
+ * another sequence; must be the same implementation class, that
+ * is <code>this.getClass() == other.getClass()</code>.
+ * @param otherIdx
+ * index within <code>other</code> sequence; must be in the range
+ * <code>[ 0, other.size() )</code>.
+ * @return true if the elements are equal; false if they are not equal.
+ */
+ public boolean equals(int thisIdx, Sequence other, int otherIdx);
+}
\ No newline at end of file
--
1.6.3.rc3.212.g8c698
--
To unsubscribe from this list: send the line "unsubscribe git" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html