diff --git a/java/src/main/java/org/softwareheritage/graph/algo/TopologicalTraversal.java b/java/src/main/java/org/softwareheritage/graph/algo/TopologicalTraversal.java
new file mode 100644
index 0000000..bdbb60d
--- /dev/null
+++ b/java/src/main/java/org/softwareheritage/graph/algo/TopologicalTraversal.java
@@ -0,0 +1,70 @@
+package org.softwareheritage.graph.algo;
+
+import com.google.common.primitives.Longs;
+import it.unimi.dsi.big.webgraph.LazyLongIterator;
+import it.unimi.dsi.bits.LongArrayBitVector;
+import it.unimi.dsi.fastutil.Arrays;
+import it.unimi.dsi.fastutil.BigArrays;
+import it.unimi.dsi.fastutil.longs.LongBigArrays;
+import it.unimi.dsi.io.ByteDiskQueue;
+import it.unimi.dsi.logging.ProgressLogger;
+import org.softwareheritage.graph.Graph;
+import org.softwareheritage.graph.Traversal;
+import org.softwareheritage.graph.experiments.forks.ForkCC;
+
+import java.io.File;
+import java.io.IOException;
+
+public class TopologicalTraversal {
+    public static void run(final Graph graph, Traversal.NodeIdConsumer cb) throws IOException {
+        final long[][] indegree = LongBigArrays.newBigArray(graph.numNodes());
+        final ProgressLogger pl = new ProgressLogger();
+
+        pl.itemsName = "nodes";
+        pl.expectedUpdates = graph.numNodes();
+
+        pl.start("Fetching indegrees...");
+        long n = graph.numNodes();
+        for (long i = 0; i < graph.numNodes(); ++i) {
+            BigArrays.add(indegree, i, graph.indegree(i));
+        }
+        pl.done();
+
+        LongArrayBitVector visited = LongArrayBitVector.ofLength(n);
+
+        int bufferSize = (int) Math.min(Arrays.MAX_ARRAY_SIZE & ~0x7, 8L * n);
+        final File queueFile = File.createTempFile(ForkCC.class.getSimpleName(), "queue");
+        final ByteDiskQueue queue = ByteDiskQueue.createNew(queueFile, bufferSize, true);
+        final byte[] byteBuf = new byte[Long.BYTES];
+
+        pl.start("Traversal in topological order...");
+        for (long i = 0; i < graph.numNodes(); ++i) {
+            if (visited.getBoolean(i) || BigArrays.get(indegree, i) != 0L) {
+                continue;
+            }
+
+            queue.enqueue(Longs.toByteArray(i));
+            visited.set(i);
+
+            while (!queue.isEmpty()) {
+                queue.dequeue(byteBuf);
+                final long currentNode = Longs.fromByteArray(byteBuf);
+
+                cb.accept(currentNode);
+
+                final LazyLongIterator iterator = graph.successors(currentNode);
+                long succ;
+                while ((succ = iterator.nextLong()) != -1) {
+                    BigArrays.add(indegree, succ, -1L);
+                    if (visited.getBoolean(succ) || BigArrays.get(indegree, succ) != 0)
+                        continue;
+                    visited.set(succ);
+                    queue.enqueue(Longs.toByteArray(succ));
+                }
+
+                pl.update();
+            }
+        }
+        pl.done();
+    }
+}