2010-02-11 Tatsuhiro Tsujikawa <t-tujikawa@users.sourceforge.net>

	Destroyed digest context after getting calculated hash.
	* src/Piece.cc
	* src/Piece.h

3 files changed, 13 insertions, 4 deletions

diff --git a/ChangeLog b/ChangeLog
index 2271faec..23237bc0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,11 @@
 2010-02-11  Tatsuhiro Tsujikawa  <t-tujikawa@users.sourceforge.net>
 
+	Destroyed digest context after getting calculated hash.
+	* src/Piece.cc
+	* src/Piece.h
+
+2010-02-11  Tatsuhiro Tsujikawa  <t-tujikawa@users.sourceforge.net>
+
 	Removed BitfieldManFactory class.
 	* src/BitfieldManFactory.cc
 	* src/BitfieldManFactory.h
diff --git a/src/Piece.cc b/src/Piece.cc
index 4c88dd9a..3c71bd8c 100644
--- a/src/Piece.cc
+++ b/src/Piece.cc
@@ -250,13 +250,14 @@ bool Piece::isHashCalculated() const
   return !_mdctx.isNull() && _nextBegin == length;
 }
 
-// TODO should be getHashString()
 std::string Piece::getHashString()
 {
   if(_mdctx.isNull()) {
     return A2STR::NIL;
   } else {
-    return util::toHex(_mdctx->digestFinal());
+    std::string hash = util::toHex(_mdctx->digestFinal());
+    destroyHashContext();
+    return hash;
   }
 }
 
diff --git a/src/Piece.h b/src/Piece.h
index af2a7a92..02cdeb87 100644
--- a/src/Piece.h
+++ b/src/Piece.h
@@ -164,8 +164,10 @@ public:
 
   bool isHashCalculated() const;
 
-  // Returns hash value in ASCII hexadecimal form.
-  // WARN: This function must be called only once.
+  // Returns hash value in ASCII hexadecimal form, which is calculated
+  // by updateHash().  Please note that this function returns hash
+  // value only once. Second invocation without updateHash() returns
+  // empty string.
   std::string getHashString();
 
   void destroyHashContext();