The v2 format is more robust for delta reuse as it has a CRC
element that covers the entire packed representation, permitting
more efficient delta-reuse during packing. It also can address
objects in pack files larger than 4 GB, making it a better format
for the future.
Signed-off-by: Shawn O. Pearce <spearce@xxxxxxxxxxx>
---
.../src/org/spearce/jgit/lib/PackIndexWriter.java | 21 ++++
.../org/spearce/jgit/lib/PackIndexWriterV2.java | 101 ++++++++++++++++++++
.../src/org/spearce/jgit/pgm/IndexPack.java | 4 +
.../src/org/spearce/jgit/transport/IndexPack.java | 22 ++++-
4 files changed, 146 insertions(+), 2 deletions(-)
create mode 100644 org.spearce.jgit/src/org/spearce/jgit/lib/PackIndexWriterV2.java
diff --git a/org.spearce.jgit/src/org/spearce/jgit/lib/PackIndexWriter.java b/org.spearce.jgit/src/org/spearce/jgit/lib/PackIndexWriter.java
index c9b27d2..2d9d822 100644
--- a/org.spearce.jgit/src/org/spearce/jgit/lib/PackIndexWriter.java
+++ b/org.spearce.jgit/src/org/spearce/jgit/lib/PackIndexWriter.java
@@ -122,6 +122,8 @@ public abstract class PackIndexWriter {
switch (version) {
case 1:
return new PackIndexWriterV1(dst);
+ case 2:
+ return new PackIndexWriterV2(dst);
default:
throw new IllegalArgumentException(
"Unsupported pack index version " + version);
@@ -203,6 +205,25 @@ public abstract class PackIndexWriter {
protected abstract void writeImpl() throws IOException;
/**
+ * Output the version 2 (and later) TOC header, with version number.
+ * <p>
+ * Post version 1 all index files start with a TOC header that makes the
+ * file an invalid version 1 file, and then includes the version number.
+ * This header is necessary to recognize a version 1 from a version 2
+ * formatted index.
+ *
+ * @param version
+ * version number of this index format being written.
+ * @throws IOException
+ * an error occurred while writing to the output stream.
+ */
+ protected void writeTOC(final int version) throws IOException {
+ out.write(TOC);
+ NB.encodeInt32(tmp, 0, version);
+ out.write(tmp, 0, 4);
+ }
+
+ /**
* Output the standard 256 entry first-level fan-out table.
* <p>
* The fan-out table is 4 KB in size, holding 256 32-bit unsigned integer
diff --git a/org.spearce.jgit/src/org/spearce/jgit/lib/PackIndexWriterV2.java b/org.spearce.jgit/src/org/spearce/jgit/lib/PackIndexWriterV2.java
new file mode 100644
index 0000000..8fa4d1a
--- /dev/null
+++ b/org.spearce.jgit/src/org/spearce/jgit/lib/PackIndexWriterV2.java
@@ -0,0 +1,101 @@
+/*
+ * Copyright (C) 2008, Shawn O. Pearce <spearce@xxxxxxxxxxx>
+ *
+ * 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.lib;
+
+import java.io.IOException;
+import java.io.OutputStream;
+
+import org.spearce.jgit.transport.PackedObjectInfo;
+import org.spearce.jgit.util.NB;
+
+/**
+ * Creates the version 2 pack table of contents files.
+ *
+ * @see PackIndexWriter
+ * @see PackIndexV2
+ */
+class PackIndexWriterV2 extends PackIndexWriter {
+ PackIndexWriterV2(final OutputStream dst) {
+ super(dst);
+ }
+
+ @Override
+ protected void writeImpl() throws IOException {
+ writeTOC(2);
+ writeFanOutTable();
+ writeObjectNames();
+ writeCRCs();
+ writeOffset32();
+ writeOffset64();
+ writeChecksumFooter();
+ }
+
+ private void writeObjectNames() throws IOException {
+ for (final PackedObjectInfo oe : entries)
+ oe.copyRawTo(out);
+ }
+
+ private void writeCRCs() throws IOException {
+ for (final PackedObjectInfo oe : entries) {
+ NB.encodeInt32(tmp, 0, oe.getCRC());
+ out.write(tmp, 0, 4);
+ }
+ }
+
+ private void writeOffset32() throws IOException {
+ int o64 = 0;
+ for (final PackedObjectInfo oe : entries) {
+ final long o = oe.getOffset();
+ if (o < Integer.MAX_VALUE)
+ NB.encodeInt32(tmp, 0, (int) o);
+ else
+ NB.encodeInt32(tmp, 0, (1 << 31) | o64++);
+ out.write(tmp, 0, 4);
+ }
+ }
+
+ private void writeOffset64() throws IOException {
+ for (final PackedObjectInfo oe : entries) {
+ final long o = oe.getOffset();
+ if (o > Integer.MAX_VALUE) {
+ NB.encodeInt64(tmp, 0, o);
+ out.write(tmp, 0, 8);
+ }
+ }
+ }
+}
diff --git a/org.spearce.jgit/src/org/spearce/jgit/pgm/IndexPack.java b/org.spearce.jgit/src/org/spearce/jgit/pgm/IndexPack.java
index 5a82a35..60926c1 100644
--- a/org.spearce.jgit/src/org/spearce/jgit/pgm/IndexPack.java
+++ b/org.spearce.jgit/src/org/spearce/jgit/pgm/IndexPack.java
@@ -47,10 +47,13 @@ class IndexPack extends TextBuiltin {
void execute(final String[] args) throws Exception {
boolean fixThin = false;
int argi = 0;
+ int version = 0;
for (; argi < args.length; argi++) {
final String a = args[argi];
if ("--fix-thin".equals(a))
fixThin = true;
+ else if (a.startsWith("--index-version="))
+ version = Integer.parseInt(a.substring(a.indexOf('=') + 1));
else if ("--".equals(a)) {
argi++;
break;
@@ -69,6 +72,7 @@ class IndexPack extends TextBuiltin {
in = new BufferedInputStream(System.in);
ip = new org.spearce.jgit.transport.IndexPack(db, in, base);
ip.setFixThin(fixThin);
+ ip.setIndexVersion(version);
ip.index(new TextProgressMonitor());
}
}
diff --git a/org.spearce.jgit/src/org/spearce/jgit/transport/IndexPack.java b/org.spearce.jgit/src/org/spearce/jgit/transport/IndexPack.java
index 047f0dc..06ef7cc 100644
--- a/org.spearce.jgit/src/org/spearce/jgit/transport/IndexPack.java
+++ b/org.spearce.jgit/src/org/spearce/jgit/transport/IndexPack.java
@@ -125,6 +125,8 @@ public class IndexPack {
private boolean fixThin;
+ private int outputVersion;
+
private final File dstPack;
private final File dstIdx;
@@ -185,6 +187,18 @@ public class IndexPack {
}
/**
+ * Set the pack index file format version this instance will create.
+ *
+ * @param version
+ * the version to write. The special version 0 designates the
+ * oldest (most compatible) format available for the objects.
+ * @see PackIndexWriter
+ */
+ public void setIndexVersion(final int version) {
+ outputVersion = version;
+ }
+
+ /**
* Configure this index pack instance to make a thin pack complete.
* <p>
* Thin packs are sometimes used during network transfers to allow a delta
@@ -466,8 +480,12 @@ public class IndexPack {
final FileOutputStream os = new FileOutputStream(dstIdx);
try {
- PackIndexWriter.createOldestPossible(os, list)
- .write(list, packcsum);
+ final PackIndexWriter iw;
+ if (outputVersion <= 0)
+ iw = PackIndexWriter.createOldestPossible(os, list);
+ else
+ iw = PackIndexWriter.createVersion(os, outputVersion);
+ iw.write(list, packcsum);
} finally {
os.close();
}
--
1.5.6.74.g8a5e
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