ICE-5198: zero-copy OutputStream::finished method

5 files changed, 45 insertions, 21 deletions

diff --git a/CHANGES b/CHANGES
index b7488ee2a0a..644918d9444 100644
--- a/CHANGES
+++ b/CHANGES
@@ -92,6 +92,12 @@ General Changes
 C++ Changes
 ===========
 
+- Added support for zero-copy Ice::OutputStream::finished() method. If
+  supported by the stream implementation, the memory returned by this
+  method points to the output stream internal buffer. Special care
+  must be taken to ensure the memory isn't accessed after the
+  de-allocation of the output stream object.
+
 - Added support for zero-copy on x86_64 processors when using the
   sequence C++ array mapping.
 
diff --git a/cpp/include/Ice/Stream.h b/cpp/include/Ice/Stream.h
index 4af0bc8b930..0251d3dcbfe 100644
--- a/cpp/include/Ice/Stream.h
+++ b/cpp/include/Ice/Stream.h
@@ -175,17 +175,17 @@ public:
     virtual void endSlice() = 0;
     virtual void skipSlice() = 0;
 
-    virtual Ice::EncodingVersion startEncapsulation() = 0;
+    virtual EncodingVersion startEncapsulation() = 0;
     virtual void endEncapsulation() = 0;
-    virtual Ice::EncodingVersion skipEncapsulation() = 0;
+    virtual EncodingVersion skipEncapsulation() = 0;
 
-    virtual Ice::EncodingVersion getEncoding() const = 0;
+    virtual EncodingVersion getEncoding() const = 0;
 
     virtual void readPendingObjects() = 0;
 
     virtual void rewind() = 0;
 
-    virtual void skip(Ice::Int) = 0;
+    virtual void skip(Int) = 0;
     virtual void skipSize() = 0;
 
     virtual void read(bool&) = 0;
@@ -226,14 +226,14 @@ public:
         StreamHelper<T, StreamableTraits<T>::helper>::read(this, v);
     }
 
-    template<typename T> inline void read(Ice::Int tag, IceUtil::Optional<T>& v)
+    template<typename T> inline void read(Int tag, IceUtil::Optional<T>& v)
     {
         if(readOptional(tag, StreamOptionalHelper<T, 
-                                                  Ice::StreamableTraits<T>::helper, 
-                                                  Ice::StreamableTraits<T>::fixedLength>::optionalFormat))
+                                                  StreamableTraits<T>::helper, 
+                                                  StreamableTraits<T>::fixedLength>::optionalFormat))
         {
             v.__setIsSet();
-            StreamOptionalHelper<T, Ice::StreamableTraits<T>::helper, Ice::StreamableTraits<T>::fixedLength>::read(this, *v);
+            StreamOptionalHelper<T, StreamableTraits<T>::helper, StreamableTraits<T>::fixedLength>::read(this, *v);
         }
     }
 
@@ -298,15 +298,16 @@ public:
     virtual void startSlice(const ::std::string&, int, bool) = 0;
     virtual void endSlice() = 0;
 
-    virtual void startEncapsulation(const Ice::EncodingVersion&, FormatType) = 0;
+    virtual void startEncapsulation(const EncodingVersion&, FormatType) = 0;
     virtual void startEncapsulation() = 0;
     virtual void endEncapsulation() = 0;
 
-    virtual Ice::EncodingVersion getEncoding() const = 0;
+    virtual EncodingVersion getEncoding() const = 0;
 
     virtual void writePendingObjects() = 0;
 
     virtual void finished(::std::vector<Byte>&) = 0;
+    virtual std::pair<const Byte*, const Byte*> finished() = 0;
 
     virtual size_type pos() = 0;
     virtual void rewrite(Int, size_type) = 0;
@@ -348,14 +349,14 @@ public:
         StreamHelper<T, StreamableTraits<T>::helper>::write(this, v);
     }
 
-    template<typename T> inline void write(Ice::Int tag, const IceUtil::Optional<T>& v)
+    template<typename T> inline void write(Int tag, const IceUtil::Optional<T>& v)
     {
         if(v)
         {
             writeOptional(tag, StreamOptionalHelper<T,
-                                                    Ice::StreamableTraits<T>::helper, 
-                                                    Ice::StreamableTraits<T>::fixedLength>::optionalFormat);
-            StreamOptionalHelper<T, Ice::StreamableTraits<T>::helper, Ice::StreamableTraits<T>::fixedLength>::write(this, *v);
+                                                    StreamableTraits<T>::helper, 
+                                                    StreamableTraits<T>::fixedLength>::optionalFormat);
+            StreamOptionalHelper<T, StreamableTraits<T>::helper, StreamableTraits<T>::fixedLength>::write(this, *v);
         }
     }
 
@@ -364,7 +365,7 @@ public:
     // 
     template<typename T> void write(const T* begin, const T* end)
     {
-        writeSize(static_cast<Ice::Int>(end - begin));
+        writeSize(static_cast<Int>(end - begin));
         for(const T* p = begin; p != end; ++p)
         {
             write(*p);
diff --git a/cpp/src/Ice/StreamI.cpp b/cpp/src/Ice/StreamI.cpp
index 04e616c0a49..08487647785 100644
--- a/cpp/src/Ice/StreamI.cpp
+++ b/cpp/src/Ice/StreamI.cpp
@@ -671,6 +671,19 @@ OutputStreamI::finished(vector<Byte>& bytes)
     vector<Byte>(_os->b.begin(), _os->b.end()).swap(bytes);
 }
 
+pair<const Byte*, const Byte*>
+OutputStreamI::finished()
+{
+    if(_os->b.empty())
+    {
+        return pair<const Byte*, const Byte*>(reinterpret_cast<Ice::Byte*>(0), reinterpret_cast<Ice::Byte*>(0));
+    }
+    else
+    {
+        return pair<const Byte*, const Byte*>(&_os->b[0], &_os->b[0] + _os->b.size());
+    }
+}
+
 void
 OutputStreamI::reset(bool clearBuffer)
 {
diff --git a/cpp/src/Ice/StreamI.h b/cpp/src/Ice/StreamI.h
index f1490faddc2..30b21efe76b 100644
--- a/cpp/src/Ice/StreamI.h
+++ b/cpp/src/Ice/StreamI.h
@@ -57,17 +57,17 @@ public:
     virtual void endSlice();
     virtual void skipSlice();
 
-    virtual Ice::EncodingVersion startEncapsulation();
+    virtual EncodingVersion startEncapsulation();
     virtual void endEncapsulation();
-    virtual Ice::EncodingVersion skipEncapsulation();
+    virtual EncodingVersion skipEncapsulation();
 
-    virtual Ice::EncodingVersion getEncoding() const;
+    virtual EncodingVersion getEncoding() const;
 
     virtual void readPendingObjects();
 
     virtual void rewind();
 
-    virtual void skip(Ice::Int);
+    virtual void skip(Int);
     virtual void skipSize();
     
     virtual void read(bool&);
@@ -163,15 +163,16 @@ public:
     virtual void startSlice(const std::string&, int, bool);
     virtual void endSlice();
 
-    virtual void startEncapsulation(const Ice::EncodingVersion&, FormatType);
+    virtual void startEncapsulation(const EncodingVersion&, FormatType);
     virtual void startEncapsulation();
     virtual void endEncapsulation();
 
-    virtual Ice::EncodingVersion getEncoding() const;
+    virtual EncodingVersion getEncoding() const;
 
     virtual void writePendingObjects();
 
     virtual void finished(std::vector< Byte >&);
+    virtual std::pair<const Byte*, const Byte*> finished();
 
     virtual void reset(bool);
 
diff --git a/cpp/test/Ice/stream/Client.cpp b/cpp/test/Ice/stream/Client.cpp
index f8c72f07ebe..bc3bb6f95f9 100644
--- a/cpp/test/Ice/stream/Client.cpp
+++ b/cpp/test/Ice/stream/Client.cpp
@@ -175,6 +175,9 @@ run(int, char**, const Ice::CommunicatorPtr& communicator)
         out->write(true);
         out->endEncapsulation();
         out->finished(data);
+        pair<const Ice::Byte*, const Ice::Byte*> d = out->finished();
+        test(d.second - d.first == data.size());
+        test(vector<Ice::Byte>(d.first, d.second) == data);
         out = 0;
 
         in = Ice::createInputStream(communicator, data);