+// helpers used by wxCharTypeBuffer
+namespace wxPrivate
+{
+
+struct UntypedBufferData
+{
+ enum Kind
+ {
+ Owned,
+ NonOwned
+ };
+
+ UntypedBufferData(void *str, size_t len, Kind kind = Owned)
+ : m_str(str), m_length(len), m_ref(1), m_owned(kind == Owned) {}
+
+ ~UntypedBufferData()
+ {
+ if ( m_owned )
+ free(m_str);
+ }
+
+ void *m_str;
+ size_t m_length;
+
+ // "short" to have sizeof(Data)=12 on 32bit archs
+ unsigned short m_ref;
+
+ bool m_owned;
+};
+
+// NB: this is defined in string.cpp and not the (non-existent) buffer.cpp
+WXDLLIMPEXP_BASE UntypedBufferData * GetUntypedNullData();
+
+} // namespace wxPrivate
+
+
+// Reference-counted character buffer for storing string data. The buffer
+// is only valid for as long as the "parent" object that provided the data
+// is valid; see wxCharTypeBuffer<T> for persistent variant.
+template <typename T>
+class wxScopedCharTypeBuffer
+{
+public:
+ typedef T CharType;
+
+ wxScopedCharTypeBuffer()
+ {
+ m_data = GetNullData();
+ }
+
+ // Creates "non-owned" buffer, i.e. 'str' is not owned by the buffer
+ // and doesn't get freed by dtor. Used e.g. to point to wxString's internal
+ // storage.
+ static
+ const wxScopedCharTypeBuffer CreateNonOwned(const CharType *str,
+ size_t len = wxNO_LEN)
+ {
+ if ( len == wxNO_LEN )
+ len = wxStrlen(str);
+
+ wxScopedCharTypeBuffer buf;
+ if ( str )
+ buf.m_data = new Data(const_cast<CharType*>(str), len, Data::NonOwned);
+ return buf;
+ }
+
+ // Creates "owned" buffer, i.e. takes over ownership of 'str' and frees it
+ // in dtor (if ref.count reaches 0).
+ static
+ const wxScopedCharTypeBuffer CreateOwned(CharType *str,
+ size_t len = wxNO_LEN )
+ {
+ if ( len == wxNO_LEN )
+ len = wxStrlen(str);
+
+ wxScopedCharTypeBuffer buf;
+ if ( str )
+ buf.m_data = new Data(str, len);
+ return buf;
+ }
+
+ wxScopedCharTypeBuffer(const wxScopedCharTypeBuffer& src)
+ {
+ m_data = src.m_data;
+ IncRef();
+ }
+
+ wxScopedCharTypeBuffer& operator=(const wxScopedCharTypeBuffer& src)
+ {
+ if ( &src == this )
+ return *this;
+
+ DecRef();
+ m_data = src.m_data;
+ IncRef();
+
+ return *this;
+ }
+
+ ~wxScopedCharTypeBuffer()
+ {
+ DecRef();
+ }
+
+ // NB: this method is only const for backward compatibility. It used to
+ // be needed for auto_ptr-like semantics of the copy ctor, but now
+ // that ref-counting is used, it's not really needed.
+ CharType *release() const
+ {
+ if ( m_data == GetNullData() )
+ return NULL;
+
+ wxASSERT_MSG( m_data->m_owned, wxT("can't release non-owned buffer") );
+ wxASSERT_MSG( m_data->m_ref == 1, wxT("can't release shared buffer") );
+
+ CharType * const p = m_data->Get();
+
+ wxScopedCharTypeBuffer *self = const_cast<wxScopedCharTypeBuffer*>(this);
+ self->m_data->Set(NULL, 0);
+ self->DecRef();
+
+ return p;
+ }
+
+ void reset()
+ {
+ DecRef();
+ }
+
+ CharType *data() { return m_data->Get(); }
+ const CharType *data() const { return m_data->Get(); }
+ operator const CharType *() const { return data(); }
+ CharType operator[](size_t n) const { return data()[n]; }
+
+ size_t length() const { return m_data->m_length; }
+
+protected:
+ // reference-counted data
+ struct Data : public wxPrivate::UntypedBufferData
+ {
+ Data(CharType *str, size_t len, Kind kind = Owned)
+ : wxPrivate::UntypedBufferData(str, len, kind)
+ {
+ }
+
+ CharType *Get() const { return static_cast<CharType *>(m_str); }
+ void Set(CharType *str, size_t len)
+ {
+ m_str = str;
+ m_length = len;
+ }
+ };
+
+ // placeholder for NULL string, to simplify this code
+ static Data *GetNullData()
+ {
+ return static_cast<Data *>(wxPrivate::GetUntypedNullData());
+ }
+
+ void IncRef()
+ {
+ if ( m_data == GetNullData() ) // exception, not ref-counted
+ return;
+ m_data->m_ref++;
+ }
+
+ void DecRef()
+ {
+ if ( m_data == GetNullData() ) // exception, not ref-counted
+ return;
+ if ( --m_data->m_ref == 0 )
+ delete m_data;
+ m_data = GetNullData();
+ }
+
+ // sets this object to a be copy of 'other'; if 'src' is non-owned,
+ // a deep copy is made and 'this' will contain new instance of the data
+ void MakeOwnedCopyOf(const wxScopedCharTypeBuffer& src)
+ {
+ this->DecRef();
+
+ if ( src.m_data == this->GetNullData() )
+ {
+ this->m_data = this->GetNullData();
+ }
+ else if ( src.m_data->m_owned )
+ {
+ this->m_data = src.m_data;
+ this->IncRef();
+ }
+ else
+ {
+ // if the scoped buffer had non-owned data, we have to make
+ // a copy here, because src.m_data->m_str is valid only for as long
+ // as 'src' exists
+ this->m_data = new Data
+ (
+ StrCopy(src.data(), src.length()),
+ src.length()
+ );
+ }
+ }
+
+ static CharType *StrCopy(const CharType *src, size_t len)
+ {
+ CharType *dst = (CharType*)malloc(sizeof(CharType) * (len + 1));
+ memcpy(dst, src, sizeof(CharType) * (len + 1));
+ return dst;
+ }
+
+protected:
+ Data *m_data;
+};
+
+typedef wxScopedCharTypeBuffer<char> wxScopedCharBuffer;
+typedef wxScopedCharTypeBuffer<wchar_t> wxScopedWCharBuffer;
+
+
+// this buffer class always stores data in "owned" (persistent) manner
+template <typename T>
+class wxCharTypeBuffer : public wxScopedCharTypeBuffer<T>
projects / wxWidgets.git / blobdiff