From ca2c57b2ec5400db9c9446056b001a83adc5ccd8 Mon Sep 17 00:00:00 2001
From: Ivan Frade <ifrade@google.com>
Date: Tue, 28 Dec 2021 14:23:40 -0800
Subject: PackWriter: offer to write an object-size index for the pack

PackWriter callers tell the writer what do the want to include in the
pack and invoke #writePack(). Afterwards, they can invoke #writeIndex()
to write the corresponding pack index.

Mirror this for the object-size index, adding a #writeObjectSizeIndex()
method.

Change-Id: Ic319975c72c239cd6488303f7d4cced797e6fe00
---
 .../jgit/internal/storage/pack/PackWriter.java     | 45 ++++++++++++++++++++++
 1 file changed, 45 insertions(+)

(limited to 'org.eclipse.jgit')

diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/pack/PackWriter.java b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/pack/PackWriter.java
index d42d348a1c..bad572459a 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/pack/PackWriter.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/pack/PackWriter.java
@@ -61,6 +61,7 @@ import org.eclipse.jgit.internal.JGitText;
 import org.eclipse.jgit.internal.storage.file.PackBitmapIndexBuilder;
 import org.eclipse.jgit.internal.storage.file.PackBitmapIndexWriterV1;
 import org.eclipse.jgit.internal.storage.file.PackIndexWriter;
+import org.eclipse.jgit.internal.storage.file.PackObjectSizeIndexWriter;
 import org.eclipse.jgit.lib.AnyObjectId;
 import org.eclipse.jgit.lib.AsyncObjectSizeQueue;
 import org.eclipse.jgit.lib.BatchingProgressMonitor;
@@ -1091,6 +1092,50 @@ public class PackWriter implements AutoCloseable {
 		stats.timeWriting += System.currentTimeMillis() - writeStart;
 	}
 
+	/**
+	 * Create an object size index file for the contents of the pack file just
+	 * written.
+	 * <p>
+	 * Called after
+	 * {@link #writePack(ProgressMonitor, ProgressMonitor, OutputStream)} that
+	 * populates the list of objects to pack and before
+	 * {@link #writeBitmapIndex(OutputStream)} that destroys it.
+	 * <p>
+	 * Writing this index is only required for local pack storage. Packs sent on
+	 * the network do not need to create an object size index.
+	 *
+	 * @param objIdxStream
+	 *            output for the object size index data. Caller is responsible
+	 *            for closing this stream.
+	 * @throws IOException
+	 *             errors while writing
+	 */
+	public void writeObjectSizeIndex(OutputStream objIdxStream)
+			throws IOException {
+		if (config.getMinBytesForObjSizeIndex() < 0) {
+			return;
+		}
+
+		long writeStart = System.currentTimeMillis();
+		// We only need to populate the size of blobs
+		AsyncObjectSizeQueue<ObjectToPack> sizeQueue = reader
+				.getObjectSize(objectsLists[OBJ_BLOB], /* reportMissing= */false);
+		try {
+			while (sizeQueue.next()) {
+				ObjectToPack otp = sizeQueue.getCurrent();
+				long sz = sizeQueue.getSize();
+				otp.setFullSize(sz);
+			}
+		} finally {
+			sizeQueue.release();
+		}
+		PackObjectSizeIndexWriter iw = PackObjectSizeIndexWriter.createWriter(
+				objIdxStream, config.getMinBytesForObjSizeIndex());
+		// All indexed objects because their positions must match primary index order
+		iw.write(sortByName());
+		stats.timeWriting += System.currentTimeMillis() - writeStart;
+	}
+
 	/**
 	 * Create a bitmap index file to match the pack file just written.
 	 * <p>
-- 
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