git/list[1] front-page[2] threads[3] people[4] search[5] about
 

[JGIT PATCH 5/6] Teach FileHeader, HunkHeader how to create an EditList

From
Shawn O. Pearce <spearce@spearce.org>
Date
May 2, 2009, 02:08 UTC
Message-ID
<1241230127-28279-6-git-send-email-spearce@spearce.org>
In-Reply-To
<1241230127-28279-5-git-send-email-spearce@spearce.org>

The EditList type along with its member Edit instances can be very useful when mining a patch for information about the change it is trying to represent to the content. This can be useful to create a modified version of the patch, such as with larger or smaller number of context lines.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
---
 .../spearce/jgit/patch/testEditList_Types.patch    |   24 +++++
 .../tst/org/spearce/jgit/patch/EditListTest.java   |   95 ++++++++++++++++++++
 .../src/org/spearce/jgit/patch/FileHeader.java     |    9 ++
 .../src/org/spearce/jgit/patch/HunkHeader.java     |   48 ++++++++++
 4 files changed, 176 insertions(+), 0 deletions(-)
 create mode 100644 org.spearce.jgit.test/tst-rsrc/org/spearce/jgit/patch/testEditList_Types.patch
 create mode 100644 org.spearce.jgit.test/tst/org/spearce/jgit/patch/EditListTest.java
diff --git a/org.spearce.jgit.test/tst-rsrc/org/spearce/jgit/patch/testEditList_Types.patch b/org.spearce.jgit.test/tst-rsrc/org/spearce/jgit/patch/testEditList_Types.patch
new file mode 100644
index 0000000..e5363eb
--- /dev/null
+++ b/org.spearce.jgit.test/tst-rsrc/org/spearce/jgit/patch/testEditList_Types.patch
@@ -0,0 +1,24 @@
+diff --git a/X b/X
+index a3648a1..2d44096 100644
+--- a/X
++++ b/X
+@@ -2,2 +2,3 @@ a
+ b
++c
+ d
+@@ -16,4 +17,2 @@ p
+ q
+-r
+-s
+ t
+@@ -22,4 +21,8 @@ v
+ w
+-x
+-y
++0
++1
++2
++3
++4
++5
+ z
diff --git a/org.spearce.jgit.test/tst/org/spearce/jgit/patch/EditListTest.java b/org.spearce.jgit.test/tst/org/spearce/jgit/patch/EditListTest.java
new file mode 100644
index 0000000..452f661
--- /dev/null
+++ b/org.spearce.jgit.test/tst/org/spearce/jgit/patch/EditListTest.java
@@ -0,0 +1,95 @@
+/*
+ * 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.patch;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+import junit.framework.TestCase;
+
+import org.spearce.jgit.diff.Edit;
+import org.spearce.jgit.diff.EditList;
+
+public class EditListTest extends TestCase {
+	public void testHunkHeader() throws IOException {
+		final Patch p = parseTestPatchFile("testGetText_BothISO88591.patch");
+		final FileHeader fh = p.getFiles().get(0);
+
+		final EditList list0 = fh.getHunks().get(0).toEditList();
+		assertEquals(1, list0.size());
+		assertEquals(new Edit(4 - 1, 5 - 1, 4 - 1, 5 - 1), list0.get(0));
+
+		final EditList list1 = fh.getHunks().get(1).toEditList();
+		assertEquals(1, list1.size());
+		assertEquals(new Edit(16 - 1, 17 - 1, 16 - 1, 17 - 1), list1.get(0));
+	}
+
+	public void testFileHeader() throws IOException {
+		final Patch p = parseTestPatchFile("testGetText_BothISO88591.patch");
+		final FileHeader fh = p.getFiles().get(0);
+		final EditList e = fh.toEditList();
+		assertEquals(2, e.size());
+		assertEquals(new Edit(4 - 1, 5 - 1, 4 - 1, 5 - 1), e.get(0));
+		assertEquals(new Edit(16 - 1, 17 - 1, 16 - 1, 17 - 1), e.get(1));
+	}
+
+	public void testTypes() throws IOException {
+		final Patch p = parseTestPatchFile("testEditList_Types.patch");
+		final FileHeader fh = p.getFiles().get(0);
+		final EditList e = fh.toEditList();
+		assertEquals(3, e.size());
+		assertEquals(new Edit(3 - 1, 3 - 1, 3 - 1, 4 - 1), e.get(0));
+		assertEquals(new Edit(17 - 1, 19 - 1, 18 - 1, 18 - 1), e.get(1));
+		assertEquals(new Edit(23 - 1, 25 - 1, 22 - 1, 28 - 1), e.get(2));
+	}
+
+	private Patch parseTestPatchFile(final String patchFile) throws IOException {
+		final InputStream in = getClass().getResourceAsStream(patchFile);
+		if (in == null) {
+			fail("No " + patchFile + " test vector");
+			return null; // Never happens
+		}
+		try {
+			final Patch p = new Patch();
+			p.parse(in);
+			return p;
+		} finally {
+			in.close();
+		}
+	}
+}
diff --git a/org.spearce.jgit/src/org/spearce/jgit/patch/FileHeader.java b/org.spearce.jgit/src/org/spearce/jgit/patch/FileHeader.java
index 7d341d8..c64f742 100644
--- a/org.spearce.jgit/src/org/spearce/jgit/patch/FileHeader.java
+++ b/org.spearce.jgit/src/org/spearce/jgit/patch/FileHeader.java
@@ -52,6 +52,7 @@
 import java.util.Collections;
 import java.util.List;
 
+import org.spearce.jgit.diff.EditList;
 import org.spearce.jgit.lib.AbbreviatedObjectId;
 import org.spearce.jgit.lib.Constants;
 import org.spearce.jgit.lib.FileMode;
@@ -423,6 +424,14 @@ public BinaryHunk getReverseBinaryHunk() {
 		return reverseBinaryHunk;
 	}
 
+	/** @return a list describing the content edits performed on this file. */
+	public EditList toEditList() {
+		final EditList r = new EditList();
+		for (final HunkHeader hunk : hunks)
+			r.addAll(hunk.toEditList());
+		return r;
+	}
+
 	/**
 	 * Parse a "diff --git" or "diff --cc" line.
 	 *
diff --git a/org.spearce.jgit/src/org/spearce/jgit/patch/HunkHeader.java b/org.spearce.jgit/src/org/spearce/jgit/patch/HunkHeader.java
index e9c55e3..af128ab 100644
--- a/org.spearce.jgit/src/org/spearce/jgit/patch/HunkHeader.java
+++ b/org.spearce.jgit/src/org/spearce/jgit/patch/HunkHeader.java
@@ -44,6 +44,8 @@
 import java.io.IOException;
 import java.io.OutputStream;
 
+import org.spearce.jgit.diff.Edit;
+import org.spearce.jgit.diff.EditList;
 import org.spearce.jgit.lib.AbbreviatedObjectId;
 import org.spearce.jgit.util.MutableInteger;
 
@@ -161,6 +163,52 @@ public int getLinesContext() {
 		return nContext;
 	}
 
+	/** @return a list describing the content edits performed within the hunk. */
+	public EditList toEditList() {
+		final EditList r = new EditList();
+		final byte[] buf = file.buf;
+		int c = nextLF(buf, startOffset);
+		int oLine = old.startLine;
+		int nLine = newStartLine;
+		Edit in = null;
+
+		SCAN: for (; c < endOffset; c = nextLF(buf, c)) {
+			switch (buf[c]) {
+			case ' ':
+			case '\n':
+				in = null;
+				oLine++;
+				nLine++;
+				continue;
+
+			case '-':
+				if (in == null) {
+					in = new Edit(oLine - 1, nLine - 1);
+					r.add(in);
+				}
+				oLine++;
+				in.extendA();
+				continue;
+
+			case '+':
+				if (in == null) {
+					in = new Edit(oLine - 1, nLine - 1);
+					r.add(in);
+				}
+				nLine++;
+				in.extendB();
+				continue;
+
+			case '\\': // Matches "\ No newline at end of file"
+				continue;
+
+			default:
+				break SCAN;
+			}
+		}
+		return r;
+	}
+
 	void parseHeader() {
 		// Parse "@@ -236,9 +236,9 @@ protected boolean"
 		//
-- 
1.6.3.rc3.212.g8c698
Previous: Shawn O. PearceNext: Shawn O. Pearce
Message 6 of 15 in “Diff processing utilities”
  1. 0/6 Diff processing utilitiesShawn O. Pearce, May 2, 2009
  2. 1/6 Add set to IntListShawn O. Pearce, May 2, 2009
  3. 2/6 Add diff.Edit to describe an edit region within a fileShawn O. Pearce, May 2, 2009
  4. 3/6 Add diff.EditList to provide for a list of Edit instancesShawn O. Pearce, May 2, 2009
  5. 4/6 Add diff.RawText to index a file content for later comparesShawn O. Pearce, May 2, 2009
  6. 5/6 Teach FileHeader, HunkHeader how to create an EditListShawn O. Pearce, May 2, 2009
  7. 6/6 Add diff.DiffFormatter to create Git style unified patch scriptsShawn O. Pearce, May 2, 2009
  8. 6/6 Add diff.DiffFormatter to create Git style unified patch scriptsShawn O. Pearce, May 3, 2009
  9. 6/6 Add diff.DiffFormatter to create Git style unified patch scriptsShawn O. Pearce, May 3, 2009
  10. Robin RosenbergMay 3, 2009
  11. Shawn O. PearceMay 4, 2009
  12. Johannes SchindelinMay 4, 2009
  13. Shawn O. PearceMay 4, 2009
  14. Johannes SchindelinMay 4, 2009
  15. Johannes SchindelinMay 3, 2009

Read the whole thread, see it on lore, or plain text.

$ cat FOOTERMessages come from the public archive at lore.kernel.org/git, fetched every hour. The front page is chosen and written each morning by an AI editor and can be wrong; the threads themselves are the record. About and API. For agents: an MCP server at https://gitlist.dev/mcp, and any thread, story or person page as Markdown by adding .md to its URL (or sending Accept: text/markdown). Details in /llms.txt.