From 316d447fe1c7110b6f13ae59a16dcd496ced43d9 Mon Sep 17 00:00:00 2001
From: Marcus Holland-Moritz <github@mhxnet.de>
Date: Wed, 9 Dec 2020 13:59:10 +0100
Subject: [PATCH] Pre-sorting

---
 src/dwarfs/inode_manager.cpp | 36 ++++++++++++++++++++++++++++++------
 1 file changed, 30 insertions(+), 6 deletions(-)

diff --git a/src/dwarfs/inode_manager.cpp b/src/dwarfs/inode_manager.cpp
index b2c3eb6d..3cfe69df 100644
--- a/src/dwarfs/inode_manager.cpp
+++ b/src/dwarfs/inode_manager.cpp
@@ -445,12 +445,36 @@ void inode_manager_<LoggerPolicy>::order_inodes_by_nilsimsa2(
 
     log_.info() << "nilsimsa: depth=" << depth << ", limit=" << limit;
 
-    std::sort(index.begin(), index.end(), [&](auto a, auto b) {
-      auto const& ia = *inodes[a];
-      auto const& ib = *inodes[b];
-      return (ia.size() < ib.size() ||
-              (ia.size() == ib.size() && ia.any()->path() < ib.any()->path()));
-    });
+    {
+      auto ti = log_.timed_info();
+      size_t num_name = 0;
+      size_t num_path = 0;
+
+      std::sort(index.begin(), index.end(), [&](auto a, auto b) {
+        auto const& ia = *inodes[a];
+        auto const& ib = *inodes[b];
+        auto sa = ia.size();
+        auto sb = ib.size();
+        if (sa < sb) {
+          return true;
+        } else if (sa > sb) {
+          return false;
+        }
+        ++num_name;
+        auto fa = ia.any();
+        auto fb = ib.any();
+        if (fa->name() < fb->name()) {
+          return true;
+        } else if (fa->name() > fb->name()) {
+          return false;
+        }
+        ++num_path;
+        return fa->path() < fb->path();
+      });
+
+      ti << "pre-sorted index (" << num_name << " name, " << num_path
+         << " path lookups)";
+    }
 
     finalize_inode();