From 674f6136783fb82e4dbdaa50a9a784ffafdabf10 Mon Sep 17 00:00:00 2001
From: "Peter D. Barnes, Jr." <barnes26@llnl.gov>
Date: Tue, 13 Nov 2012 16:35:21 -0800
Subject: [PATCH] Add Hash::clear() to restore initial internal state of hasher

---
 src/core/model/hash-fnv.cc           | 5 +++++
 src/core/model/hash-fnv.h            | 4 ++++
 src/core/model/hash-implementation.h | 4 ++++
 src/core/model/hash-murmur3.cc       | 5 +++++
 src/core/model/hash-murmur3.h        | 4 ++++
 src/core/model/hash.cc               | 9 ++++++++-
 src/core/model/hash.h                | 6 ++++++
 7 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/src/core/model/hash-fnv.cc b/src/core/model/hash-fnv.cc
index a6bd98456..5b2d89b5e 100644
--- a/src/core/model/hash-fnv.cc
+++ b/src/core/model/hash-fnv.cc
@@ -742,6 +742,11 @@ Fnv1a::GetHash64  (const char * buffer, const size_t size)
   return result;
 }
       
+void
+Fnv1a::clear (void)
+{
+}
+
   }  // namespace HashFunction
   
 } // namespace ns3
diff --git a/src/core/model/hash-fnv.h b/src/core/model/hash-fnv.h
index eee495059..7ceb53e24 100644
--- a/src/core/model/hash-fnv.h
+++ b/src/core/model/hash-fnv.h
@@ -52,6 +52,10 @@ public:
    * \return 64-bit hash of the buffer
    */
   Hash64_t  GetHash64  (const char * buffer, const size_t size);
+  /**
+   * Restore initial state
+   */
+  virtual void clear (void);
 
 private:
   /**
diff --git a/src/core/model/hash-implementation.h b/src/core/model/hash-implementation.h
index 774530e67..b26d7337d 100644
--- a/src/core/model/hash-implementation.h
+++ b/src/core/model/hash-implementation.h
@@ -60,6 +60,10 @@ public:
    * \return 64-bit hash of the buffer
    */
   virtual Hash64_t  GetHash64  (const char * buffer, const size_t size);
+  /**
+   * Restore initial state
+   */
+  virtual void clear (void) = 0;
   /*
    * Destructor
    */
diff --git a/src/core/model/hash-murmur3.cc b/src/core/model/hash-murmur3.cc
index 0fd786f78..f21375757 100644
--- a/src/core/model/hash-murmur3.cc
+++ b/src/core/model/hash-murmur3.cc
@@ -374,6 +374,11 @@ Murmur3::GetHash64  (const char * buffer, const size_t size)
   return result[0];
 }
 
+void
+Murmur3::clear (void)
+{
+}
+
   }  // namespace HashFunction
   
 } // namespace ns3
diff --git a/src/core/model/hash-murmur3.h b/src/core/model/hash-murmur3.h
index 591e85662..522d6db9b 100644
--- a/src/core/model/hash-murmur3.h
+++ b/src/core/model/hash-murmur3.h
@@ -61,6 +61,10 @@ public:
    * \return 64-bit hash of the buffer
    */
   Hash64_t  GetHash64  (const char * buffer, const size_t size);
+  /**
+   * Restore initial state
+   */
+  virtual void clear (void);
 
 private:
   /**
diff --git a/src/core/model/hash.cc b/src/core/model/hash.cc
index b0f864e45..bb387a661 100644
--- a/src/core/model/hash.cc
+++ b/src/core/model/hash.cc
@@ -41,5 +41,12 @@ Hash::Hash (Ptr<HashImplementation> hp)
 {
   NS_ASSERT (m_impl != 0);
 }
-  
+
+Hash *
+Hash::clear (void)
+{
+  m_impl->clear();
+  return this;
+}
+
 } // namespace ns3
diff --git a/src/core/model/hash.h b/src/core/model/hash.h
index 784882687..6fa2ff031 100644
--- a/src/core/model/hash.h
+++ b/src/core/model/hash.h
@@ -104,6 +104,12 @@ public:
    * \return 64-bit hash of the string
    */
   Hash64_t  GetHash64  (const std::string s);
+  /**
+   * Restore initial state
+   *
+   * \return this
+   */
+  Hash * clear (void);
   
 private:
   Ptr<HashImplementation> m_impl;    /** Hash implementation */