1 files changed, 59 insertions, 2 deletions

diff --git a/lttng/org.eclipse.linuxtools.ctf.core/src/org/eclipse/linuxtools/ctf/core/trace/StreamInputPacketIndex.java b/lttng/org.eclipse.linuxtools.ctf.core/src/org/eclipse/linuxtools/ctf/core/trace/StreamInputPacketIndex.java
index eae9dc4776..ed044eaf07 100644
--- a/lttng/org.eclipse.linuxtools.ctf.core/src/org/eclipse/linuxtools/ctf/core/trace/StreamInputPacketIndex.java
+++ b/lttng/org.eclipse.linuxtools.ctf.core/src/org/eclipse/linuxtools/ctf/core/trace/StreamInputPacketIndex.java
@@ -12,7 +12,6 @@
 
 package org.eclipse.linuxtools.ctf.core.trace;
 
-import java.util.Collection;
 import java.util.ListIterator;
 import java.util.Vector;
 
@@ -37,7 +36,7 @@ public class StreamInputPacketIndex {
     // Getters/Setters/Predicates
     // ------------------------------------------------------------------------
 
-    public Collection<StreamInputPacketIndexEntry> getEntries() {
+    public Vector<StreamInputPacketIndexEntry> getEntries() {
         return this.entries;
     }
 
@@ -139,5 +138,63 @@ public class StreamInputPacketIndex {
 
         return this.entries.listIterator(guessI);
     }
+    /**
+     * Given a rank, this methods returns the first PacketIndexEntry that
+     * could include the rank, that is the last packet with a begin
+     * rank smaller than the given rank.
+     *
+     * @param index
+     *            The rank to look for.
+     * @return The StreamInputPacketEntry that corresponds to the packet that
+     *         includes the given timestamp.
+     */
+    public ListIterator<StreamInputPacketIndexEntry> searchIndex(final long index) {
+        /*
+         * Start with min and max covering all the elements.
+         */
+        int max = this.entries.size() - 1;
+        int min = 0;
+
+        int guessI;
+        StreamInputPacketIndexEntry guessEntry = null;
+
+        if (index < 0) {
+            throw new IllegalArgumentException("rank is negative"); //$NON-NLS-1$
+        }
+
+        for (;;) {
+            /*
+             * Guess in the middle of min and max. The +1 is so that in case
+             * (min + 1 == max), we choose the packet at the subscript "max"
+             * instead of the one at "min". Otherwise, it would give an infinite
+             * loop.
+             */
+            guessI = (max + min + 1) / 2;
+            guessEntry = this.entries.get(guessI);
+
+            /*
+             * If we reached the point where we focus on a single packet, our
+             * search is done.
+             */
+            if (min == max) {
+                break;
+            }
+
+            if (index < guessEntry.indexBegin) {
+                /*
+                 * If the timestamp if before the begin timestamp, we know that
+                 * the packet to return is before the guess.
+                 */
+                max = guessI - 1;
+            } else if (index >= guessEntry.indexBegin) {
+                /*
+                 * If the timestamp is after the begin timestamp, we know that
+                 * the packet to return is after the guess or is the guess.
+                 */
+                min = guessI;
+            }
+        }
 
+        return this.entries.listIterator(guessI);
+    }
 }