Packs with newer modification dates are more likely to contain data
related to recent commits, and thus will have a better probability
of containing an object we care about when we are looking only at
recent history.
In some cases, this may permit JGit to avoid reading a very large
historical pack's index file into memory if the only data we ever
need is available in newer pack files.
Signed-off-by: Shawn O. Pearce <spearce@xxxxxxxxxxx>
---
.../src/org/spearce/jgit/lib/PackFile.java | 11 +++++++++++
.../src/org/spearce/jgit/lib/Repository.java | 1 +
2 files changed, 12 insertions(+), 0 deletions(-)
diff --git a/org.spearce.jgit/src/org/spearce/jgit/lib/PackFile.java b/org.spearce.jgit/src/org/spearce/jgit/lib/PackFile.java
index 3542560..7a16bf7 100644
--- a/org.spearce.jgit/src/org/spearce/jgit/lib/PackFile.java
+++ b/org.spearce.jgit/src/org/spearce/jgit/lib/PackFile.java
@@ -43,6 +43,7 @@
import java.io.IOException;
import java.io.OutputStream;
import java.util.Collections;
+import java.util.Comparator;
import java.util.Iterator;
import java.util.zip.CRC32;
import java.util.zip.CheckedOutputStream;
@@ -57,10 +58,19 @@
* objects are similar.
*/
public class PackFile implements Iterable<PackIndex.MutableEntry> {
+ /** Sorts PackFiles to be most recently created to least recently created. */
+ public static Comparator<PackFile> SORT = new Comparator<PackFile>() {
+ public int compare(final PackFile a, final PackFile b) {
+ return b.packLastModified - a.packLastModified;
+ }
+ };
+
private final File idxFile;
private final WindowedFile pack;
+ private int packLastModified;
+
private PackIndex loadedIdx;
private PackReverseIndex reverseIdx;
@@ -75,6 +85,7 @@
*/
public PackFile(final File idxFile, final File packFile) {
this.idxFile = idxFile;
+ this.packLastModified = (int) (packFile.lastModified() >> 10);
pack = new WindowedFile(packFile) {
@Override
protected void onOpen() throws IOException {
diff --git a/org.spearce.jgit/src/org/spearce/jgit/lib/Repository.java b/org.spearce.jgit/src/org/spearce/jgit/lib/Repository.java
index b9c7b2e..96c62df 100644
--- a/org.spearce.jgit/src/org/spearce/jgit/lib/Repository.java
+++ b/org.spearce.jgit/src/org/spearce/jgit/lib/Repository.java
@@ -823,6 +823,7 @@ public void scanForPacks() {
scanForPacks(new File(d, "pack"), p);
final PackFile[] arr = new PackFile[p.size()];
p.toArray(arr);
+ Arrays.sort(arr, PackFile.SORT);
synchronized (this) {
packFileList = arr;
}
--
1.6.2.rc0.204.gf6b427
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