From 8435bfc4febe19bc5a79f0fbd7b30eede73d17ee Mon Sep 17 00:00:00 2001
From: Mathieu Lacage <mathieu.lacage@sophia.inria.fr>
Date: Thu, 7 Jun 2007 12:25:40 +0200
Subject: [PATCH] add back optimization option

---
 src/common/packet-history.cc | 101 +++++++++++++++++++++++++++++++++++
 src/common/packet-history.h  |   9 ++--
 utils/bench-packets.cc       |   2 +-
 3 files changed, 107 insertions(+), 5 deletions(-)

diff --git a/src/common/packet-history.cc b/src/common/packet-history.cc
index 36dd29a6a..f845fd678 100644
--- a/src/common/packet-history.cc
+++ b/src/common/packet-history.cc
@@ -35,6 +35,7 @@ bool PacketHistory::m_enable = false;
 uint32_t PacketHistory::m_maxSize = 0;
 uint16_t PacketHistory::m_chunkUid = 0;
 PacketHistory::DataFreeList PacketHistory::m_freeList;
+bool g_optOne = false;
 
 void 
 PacketHistory::Enable (void)
@@ -42,6 +43,12 @@ PacketHistory::Enable (void)
   m_enable = true;
 }
 
+void 
+PacketHistory::SetOptOne (bool optOne)
+{
+  g_optOne = optOne;
+}
+
 void
 PacketHistory::ReserveCopy (uint32_t size)
 {
@@ -278,6 +285,71 @@ PacketHistory::TryToAppend (uint32_t value, uint8_t **pBuffer, uint8_t *end)
   return false;
 }
 
+void
+PacketHistory::AppendValueExtra (uint32_t value, uint8_t *buffer)
+{
+  if (value < 0x200000)
+    {
+      uint8_t byte = value & (~0x80);
+      buffer[0] = 0x80 | byte;
+      value >>= 7;
+      byte = value & (~0x80);
+      buffer[1] = 0x80 | byte;
+      value >>= 7;
+      byte = value & (~0x80);
+      buffer[2] = value;
+      return;
+    }
+  if (value < 0x10000000)
+    {
+      uint8_t byte = value & (~0x80);
+      buffer[0] = 0x80 | byte;
+      value >>= 7;
+      byte = value & (~0x80);
+      buffer[1] = 0x80 | byte;
+      value >>= 7;
+      byte = value & (~0x80);
+      buffer[2] = 0x80 | byte;
+      value >>= 7;
+      buffer[3] = value;
+      return;
+    }
+  {
+    uint8_t byte = value & (~0x80);
+    buffer[0] = 0x80 | byte;
+    value >>= 7;
+    byte = value & (~0x80);
+    buffer[1] = 0x80 | byte;
+    value >>= 7;
+    byte = value & (~0x80);
+    buffer[2] = 0x80 | byte;
+    value >>= 7;
+    byte = value & (~0x80);
+    buffer[3] = 0x80 | byte;
+    value >>= 7;
+    buffer[4] = value;
+  }
+}
+
+void
+PacketHistory::AppendValue (uint32_t value, uint8_t *buffer)
+{
+  if (value < 0x80)
+    {
+      buffer[0] = value;
+      return;
+    }
+  if (value < 0x4000)
+    {
+      uint8_t byte = value & (~0x80);
+      buffer[0] = 0x80 | byte;
+      value >>= 7;
+      buffer[1] = value;
+      return;
+    }
+  AppendValueExtra (value, buffer);
+}
+
 void
 PacketHistory::UpdateTail (uint16_t written)
 {
@@ -331,6 +403,35 @@ uint16_t
 PacketHistory::AddSmall (const struct PacketHistory::SmallItem *item)
 {
   NS_ASSERT (m_data != 0);
+  if (g_optOne)
+    {
+      uint32_t typeUidSize = GetUleb128Size (item->typeUid);
+      uint32_t sizeSize = GetUleb128Size (item->size);
+      uint32_t n = typeUidSize + sizeSize + 2 + 2 + 2;
+    restart:
+      if (m_used + n <= m_data->m_size &&
+      (m_head == 0xffff ||
+       m_data->m_count == 1 ||
+       m_used == m_data->m_dirtyEnd))
+        {
+          uint8_t *buffer = &m_data->m_data[m_used];
+          Append16 (item->next, buffer);
+          buffer += 2;
+          Append16 (item->prev, buffer);
+          buffer += 2;
+          AppendValue (item->typeUid, buffer);
+          buffer += typeUidSize;
+          AppendValue (item->size, buffer);
+          buffer += sizeSize;
+          Append16 (item->chunkUid, buffer);
+        }
+      else
+        {
+          ReserveCopy (n);
+          goto restart;
+        }
+      return n;
+    }
  append:
   uint8_t *start = &m_data->m_data[m_used];
   uint8_t *end = &m_data->m_data[m_data->m_size];
diff --git a/src/common/packet-history.h b/src/common/packet-history.h
index 084893bfb..a0424c8f6 100644
--- a/src/common/packet-history.h
+++ b/src/common/packet-history.h
@@ -27,10 +27,6 @@
 #include "ns3/assert.h"
 #include "packet-printer.h"
 
-namespace {
-class ItemList;
-}
-
 namespace ns3 {
 
 class Chunk;
@@ -39,6 +35,7 @@ class Buffer;
 class PacketHistory {
 public:
   static void Enable (void);
+  static void SetOptOne (bool optOne);
 
   inline PacketHistory (uint32_t uid, uint32_t size);
   inline PacketHistory (PacketHistory const &o);
@@ -64,6 +61,8 @@ public:
   void PrintDefault (std::ostream &os, Buffer buffer) const;
   void Print (std::ostream &os, Buffer buffer, PacketPrinter const &printer) const;
 
+  static void PrintStats (void);
+
 private:
   /**
      head -(next)-> tail
@@ -113,6 +112,8 @@ private:
   inline bool TryToAppendFast (uint32_t value, uint8_t **pBuffer, uint8_t *end);
   inline bool TryToAppend32 (uint32_t value, uint8_t **pBuffer, uint8_t *end);
   inline bool TryToAppend16 (uint16_t value, uint8_t **pBuffer, uint8_t *end);
+  void AppendValue (uint32_t value, uint8_t *buffer);
+  void AppendValueExtra (uint32_t value, uint8_t *buffer);
   inline void Reserve (uint32_t n);
   void ReserveCopy (uint32_t n);
   uint32_t DoPrint (struct PacketHistory::SmallItem *item, uint32_t current,
diff --git a/utils/bench-packets.cc b/utils/bench-packets.cc
index e3c66011c..c18444536 100644
--- a/utils/bench-packets.cc
+++ b/utils/bench-packets.cc
@@ -179,7 +179,7 @@ int main (int argc, char *argv[])
           char const *nAscii = argv[0] + strlen ("--n=");
           n = atoi (nAscii);
         }
-      if (strncmp ("--enable-history", argv[0], strlen ("--enable-metadata")) == 0)
+      if (strncmp ("--enable-metadata", argv[0], strlen ("--enable-metadata")) == 0)
         {
           Packet::EnableMetadata ();
         }