ICE-6852 - allow OutputStream to marshal to user-supplied buffer

1 files changed, 36 insertions, 11 deletions

diff --git a/cpp/src/Ice/Buffer.cpp b/cpp/src/Ice/Buffer.cpp
index fe6c5490f78..33cbaeabc34 100644
--- a/cpp/src/Ice/Buffer.cpp
+++ b/cpp/src/Ice/Buffer.cpp
@@ -25,31 +25,36 @@ IceInternal::Buffer::Container::Container() :
     _buf(0),
     _size(0),
     _capacity(0),
-    _shrinkCounter(0)
+    _shrinkCounter(0),
+    _owned(true)
 {
 }
 
 IceInternal::Buffer::Container::Container(const_iterator beg, const_iterator end) :
     _buf(const_cast<iterator>(beg)),
     _size(end - beg),
-    _capacity(0),
-    _shrinkCounter(0)
+    _capacity(end - beg),
+    _shrinkCounter(0),
+    _owned(false)
 {
 }
 
 IceInternal::Buffer::Container::Container(const vector<value_type>& v) :
-    _capacity(0),
     _shrinkCounter(0)
 {
     if(v.empty())
     {
         _buf = 0;
         _size = 0;
+        _capacity = 0;
+        _owned = true;
     }
     else
     {
         _buf = const_cast<value_type*>(&v[0]);
         _size = v.size();
+        _capacity = _size;
+        _owned = false;
     }
 }
 
@@ -61,24 +66,27 @@ IceInternal::Buffer::Container::Container(Container& other, bool adopt)
         _size = other._size;
         _capacity = other._capacity;
         _shrinkCounter = other._shrinkCounter;
+        _owned = other._owned;
 
         other._buf = 0;
         other._size = 0;
         other._capacity = 0;
         other._shrinkCounter = 0;
+        other._owned = true;
     }
     else
     {
         _buf = other._buf;
         _size = other._size;
-        _capacity = 0;
+        _capacity = other._capacity;
         _shrinkCounter = 0;
+        _owned = false;
     }
 }
 
 IceInternal::Buffer::Container::~Container()
 {
-    if(_buf && _capacity > 0)
+    if(_buf && _owned)
     {
         ::free(_buf);
     }
@@ -91,25 +99,27 @@ IceInternal::Buffer::Container::swap(Container& other)
     std::swap(_size, other._size);
     std::swap(_capacity, other._capacity);
     std::swap(_shrinkCounter, other._shrinkCounter);
+    std::swap(_owned, other._owned);
 }
 
 void
 IceInternal::Buffer::Container::clear()
 {
-    if(_buf && _capacity > 0)
+    if(_buf && _owned)
     {
-        free(_buf);
+        ::free(_buf);
     }
+
     _buf = 0;
     _size = 0;
     _capacity = 0;
+    _shrinkCounter = 0;
+    _owned = true;
 }
 
 void
 IceInternal::Buffer::Container::reserve(size_type n)
 {
-    assert(!_buf || _capacity > 0);
-
     size_type c = _capacity;
     if(n > _capacity)
     {
@@ -125,11 +135,26 @@ IceInternal::Buffer::Container::reserve(size_type n)
         return;
     }
 
-    pointer p = reinterpret_cast<pointer>(::realloc(_buf, _capacity));
+    pointer p;
+    if(_owned)
+    {
+        p = reinterpret_cast<pointer>(::realloc(_buf, _capacity));
+    }
+    else
+    {
+        p = reinterpret_cast<pointer>(::malloc(_capacity));
+        if(p)
+        {
+            ::memcpy(p, _buf, _size);
+            _owned = true;
+        }
+    }
+
     if(!p)
     {
         _capacity = c; // Restore the previous capacity.
         throw std::bad_alloc();
     }
+
     _buf = p;
 }