Using a cached Repository instance when opening an alternate object
database ensures that if multiple repositories share the same base
repository (e.g. 4 forks of the Linux kernel all share the same
base "linus-2.6.git" repository) then the base object directory is
only monitored and tracked once in the JVM, instead of 4 times. In
the case of the WindowCache, this means we will have greater reuse
of the windows from the base, as they won't be loaded 4 different
times under different keys.
Signed-off-by: Shawn O. Pearce <spearce@xxxxxxxxxxx>
---
.../jgit/lib/AlternateRepositoryDatabase.java | 127 ++++++++++++++++++++
.../src/org/spearce/jgit/lib/ObjectDatabase.java | 16 ++-
.../src/org/spearce/jgit/lib/ObjectDirectory.java | 18 +++-
3 files changed, 155 insertions(+), 6 deletions(-)
create mode 100644 org.spearce.jgit/src/org/spearce/jgit/lib/AlternateRepositoryDatabase.java
diff --git a/org.spearce.jgit/src/org/spearce/jgit/lib/AlternateRepositoryDatabase.java b/org.spearce.jgit/src/org/spearce/jgit/lib/AlternateRepositoryDatabase.java
new file mode 100644
index 0000000..ee4c4cf
--- /dev/null
+++ b/org.spearce.jgit/src/org/spearce/jgit/lib/AlternateRepositoryDatabase.java
@@ -0,0 +1,127 @@
+/*
+ * 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.lib;
+
+import java.io.IOException;
+import java.util.Collection;
+
+/**
+ * An ObjectDatabase of another {@link Repository}.
+ * <p>
+ * This {@code ObjectDatabase} wraps around another {@code Repository}'s object
+ * database, providing its contents to the caller, and closing the Repository
+ * when this database is closed. The primary user of this class is
+ * {@link ObjectDirectory}, when the {@code info/alternates} file points at the
+ * {@code objects/} directory of another repository.
+ */
+public final class AlternateRepositoryDatabase extends ObjectDatabase {
+ private final Repository repository;
+
+ private final ObjectDatabase odb;
+
+ /**
+ * @param alt
+ * the alternate repository to wrap and export.
+ */
+ public AlternateRepositoryDatabase(final Repository alt) {
+ repository = alt;
+ odb = repository.getObjectDatabase();
+ }
+
+ /** @return the alternate repository objects are borrowed from. */
+ public Repository getRepository() {
+ return repository;
+ }
+
+ public void closeSelf() {
+ repository.close();
+ }
+
+ public void create() throws IOException {
+ repository.create();
+ }
+
+ public boolean exists() {
+ return odb.exists();
+ }
+
+ @Override
+ protected boolean hasObject1(final AnyObjectId objectId) {
+ return odb.hasObject1(objectId);
+ }
+
+ @Override
+ protected boolean tryAgain1() {
+ return odb.tryAgain1();
+ }
+
+ @Override
+ protected boolean hasObject2(final String objectName) {
+ return odb.hasObject2(objectName);
+ }
+
+ @Override
+ protected ObjectLoader openObject1(final WindowCursor curs,
+ final AnyObjectId objectId) throws IOException {
+ return odb.openObject1(curs, objectId);
+ }
+
+ @Override
+ protected ObjectLoader openObject2(final WindowCursor curs,
+ final String objectName, final AnyObjectId objectId)
+ throws IOException {
+ return odb.openObject2(curs, objectName, objectId);
+ }
+
+ @Override
+ void openObjectInAllPacks1(final Collection<PackedObjectLoader> out,
+ final WindowCursor curs, final AnyObjectId objectId)
+ throws IOException {
+ odb.openObjectInAllPacks1(out, curs, objectId);
+ }
+
+ @Override
+ protected ObjectDatabase[] loadAlternates() throws IOException {
+ return odb.getAlternates();
+ }
+
+ @Override
+ protected void closeAlternates(final ObjectDatabase[] alt) {
+ // Do nothing; these belong to odb to close, not us.
+ }
+}
diff --git a/org.spearce.jgit/src/org/spearce/jgit/lib/ObjectDatabase.java b/org.spearce.jgit/src/org/spearce/jgit/lib/ObjectDatabase.java
index 6a9ba4e..a547052 100644
--- a/org.spearce.jgit/src/org/spearce/jgit/lib/ObjectDatabase.java
+++ b/org.spearce.jgit/src/org/spearce/jgit/lib/ObjectDatabase.java
@@ -108,9 +108,7 @@ public final void closeAlternates() {
ObjectDatabase[] alt = alternates.get();
if (alt != null) {
alternates.set(null);
- for (final ObjectDatabase d : alt) {
- d.close();
- }
+ closeAlternates(alt);
}
}
@@ -364,4 +362,16 @@ protected boolean tryAgain1() {
protected ObjectDatabase[] loadAlternates() throws IOException {
return NO_ALTERNATES;
}
+
+ /**
+ * Close the list of alternates returned by {@link #loadAlternates()}.
+ *
+ * @param alt
+ * the alternate list, from {@link #loadAlternates()}.
+ */
+ protected void closeAlternates(ObjectDatabase[] alt) {
+ for (final ObjectDatabase d : alt) {
+ d.close();
+ }
+ }
}
diff --git a/org.spearce.jgit/src/org/spearce/jgit/lib/ObjectDirectory.java b/org.spearce.jgit/src/org/spearce/jgit/lib/ObjectDirectory.java
index d3c43da..7cc459c 100644
--- a/org.spearce.jgit/src/org/spearce/jgit/lib/ObjectDirectory.java
+++ b/org.spearce.jgit/src/org/spearce/jgit/lib/ObjectDirectory.java
@@ -52,6 +52,7 @@
import java.util.concurrent.atomic.AtomicReference;
import org.spearce.jgit.errors.PackMismatchException;
+import org.spearce.jgit.lib.RepositoryCache.FileKey;
import org.spearce.jgit.util.FS;
/**
@@ -415,11 +416,11 @@ public boolean accept(final File baseDir, final String n) {
@Override
protected ObjectDatabase[] loadAlternates() throws IOException {
final BufferedReader br = open(alternatesFile);
- final List<ObjectDirectory> l = new ArrayList<ObjectDirectory>(4);
+ final List<ObjectDatabase> l = new ArrayList<ObjectDatabase>(4);
try {
String line;
while ((line = br.readLine()) != null) {
- l.add(new ObjectDirectory(FS.resolve(objects, line)));
+ l.add(openAlternate(line));
}
} finally {
br.close();
@@ -428,11 +429,22 @@ public boolean accept(final File baseDir, final String n) {
if (l.isEmpty()) {
return NO_ALTERNATES;
}
- return l.toArray(new ObjectDirectory[l.size()]);
+ return l.toArray(new ObjectDatabase[l.size()]);
}
private static BufferedReader open(final File f)
throws FileNotFoundException {
return new BufferedReader(new FileReader(f));
}
+
+ private ObjectDatabase openAlternate(final String location)
+ throws IOException {
+ final File objdir = FS.resolve(objects, location);
+ final File parent = objdir.getParentFile();
+ if (FileKey.isGitRepository(parent)) {
+ final Repository db = RepositoryCache.open(FileKey.exact(parent));
+ return new AlternateRepositoryDatabase(db);
+ }
+ return new ObjectDirectory(objdir);
+ }
}
--
1.6.4.rc0.117.g28cb
--
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