X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/7c77f33480e32a3a5f142850ac0e9605d0c05381..de4983f3236c2043479abb21857aca958a7b61f0:/include/wx/buffer.h

diff --git a/include/wx/buffer.h b/include/wx/buffer.h
index a18b85c762..e3e1ac0e66 100644
--- a/include/wx/buffer.h
+++ b/include/wx/buffer.h
@@ -15,7 +15,9 @@
 #include "wx/chartype.h"
 #include "wx/wxcrtbase.h"
 
+#ifndef __WXPALMOS5__
 #include <stdlib.h>             // malloc() and free()
+#endif // ! __WXPALMOS5__
 
 class WXDLLIMPEXP_FWD_BASE wxCStrData;
 
@@ -24,141 +26,298 @@ class WXDLLIMPEXP_FWD_BASE wxCStrData;
 // of new/delete
 // ----------------------------------------------------------------------------
 
+// helpers used by wxCharTypeBuffer
+namespace wxPrivate
+{
+
+struct UntypedBufferData
+{
+    enum Kind
+    {
+        Owned,
+        NonOwned
+    };
+
+    UntypedBufferData(void *str, Kind kind = Owned)
+        : m_str(str), m_ref(1), m_owned(kind == Owned) {}
+
+    ~UntypedBufferData()
+    {
+        if ( m_owned )
+            free(m_str);
+    }
+
+    void *m_str;
+
+    // "short" to have sizeof(Data)=8 on 32bit archs
+    unsigned short m_ref;
+
+    bool m_owned;
+};
+
+// this has to be defined inside the DLL (and not e.g. as a static variable
+// inside an inline function) as otherwise MSVC gives link errors when the
+// functions are effectively inlined (i.e. in non-debug build)
+//
+// NB: this is defined in string.cpp and not the (non-existent) buffer.cpp
+extern WXDLLIMPEXP_DATA_BASE(UntypedBufferData * const) untypedNullDataPtr;
+
+} // 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 WXDLLIMPEXP_BASE wxCharTypeBuffer
+class wxScopedCharTypeBuffer
 {
 public:
     typedef T CharType;
 
-    wxCharTypeBuffer(const CharType *str = NULL)
-        : m_str(str ? wxStrdup(str) : NULL),
-          m_owned(true)
+    wxScopedCharTypeBuffer()
     {
+        m_data = GetNullData();
     }
 
-    wxCharTypeBuffer(size_t len)
-        : m_str((CharType *)malloc((len + 1)*sizeof(CharType))),
-          m_owned(true)
+    // 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)
     {
-        m_str[len] = (CharType)0;
+        wxScopedCharTypeBuffer buf;
+        if ( str )
+            buf.m_data = new Data(const_cast<CharType*>(str), Data::NonOwned);
+        return buf;
     }
 
-    static const wxCharTypeBuffer CreateNonOwned(const CharType *str)
+    // Creates "owned" buffer, i.e. takes over ownership of 'str' and frees it
+    // in dtor (if ref.count reaches 0).
+    static const wxScopedCharTypeBuffer CreateOwned(const CharType *str)
     {
-        wxCharTypeBuffer buf;
-        buf.m_str = wx_const_cast(CharType*, str);
-        buf.m_owned = false;
+        wxScopedCharTypeBuffer buf;
+        if ( str )
+            buf.m_data = new Data(wxStrdup(str));
         return buf;
     }
 
-    /* no need to check for NULL, free() does it */
-    ~wxCharTypeBuffer()
+    wxScopedCharTypeBuffer(const wxScopedCharTypeBuffer& src)
     {
-        if ( m_owned)
-            free(m_str);
+        m_data = src.m_data;
+        IncRef();
     }
 
-    /*
-        WARNING:
+    wxScopedCharTypeBuffer& operator=(const wxScopedCharTypeBuffer& src)
+    {
+        if ( &src == this )
+            return *this;
 
-        the copy ctor and assignment operators change the passed in object
-        even although it is declared as "const", so:
+        DecRef();
+        m_data = src.m_data;
+        IncRef();
 
-        a) it shouldn't be really const
-        b) you shouldn't use it afterwards (or know that it was reset)
+        return *this;
+    }
 
-        This is very ugly but is unfortunately needed to make the normal use
-        of wxCharTypeBuffer buffer objects possible and is very similar to what
-        std::auto_ptr<> does (as if it were an excuse...)
-    */
+    ~wxScopedCharTypeBuffer()
+    {
+        DecRef();
+    }
 
-    /*
-       because of the remark above, release() is declared const even if it
-       isn't really const
-     */
+    // 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
     {
-        wxASSERT_MSG( m_owned, _T("can't release non-owned buffer") );
-        return DoRelease();
+        if ( m_data == GetNullData() )
+            return NULL;
+
+        wxASSERT_MSG( m_data->m_owned, _T("can't release non-owned buffer") );
+        wxASSERT_MSG( m_data->m_ref == 1, _T("can't release shared buffer") );
+
+        CharType * const p = m_data->Get();
+
+        wxScopedCharTypeBuffer *self = const_cast<wxScopedCharTypeBuffer*>(this);
+        self->m_data->Set(NULL);
+        self->DecRef();
+
+        return p;
     }
 
     void reset()
     {
-        if ( m_owned )
-            free(m_str);
-        m_str = NULL;
+        DecRef();
     }
 
-    wxCharTypeBuffer(const wxCharTypeBuffer& src)
+    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]; }
+
+protected:
+    // reference-counted data
+    struct Data : public wxPrivate::UntypedBufferData
     {
-        CopyFrom(src);
+        Data(CharType *str, Kind kind = Owned)
+            : wxPrivate::UntypedBufferData(str, kind)
+        {
+        }
+
+        CharType *Get() const { return static_cast<CharType *>(m_str); }
+        void Set(CharType *str) { m_str = str; }
+    };
+
+    // placeholder for NULL string, to simplify this code
+    static Data *GetNullData()
+    {
+        return static_cast<Data *>(wxPrivate::untypedNullDataPtr);
     }
 
-    wxCharTypeBuffer& operator=(const CharType *str)
+    void IncRef()
     {
-        if ( m_owned )
-            free(m_str);
-        m_str = str ? wxStrdup(str) : NULL;
-        m_owned = true;
-        return *this;
+        if ( m_data == GetNullData() ) // exception, not ref-counted
+            return;
+        m_data->m_ref++;
     }
 
-    wxCharTypeBuffer& operator=(const wxCharTypeBuffer& src)
+    void DecRef()
     {
-        if ( m_owned )
-            free(m_str);
-        CopyFrom(src);
-        return *this;
+        if ( m_data == GetNullData() ) // exception, not ref-counted
+            return;
+        if ( --m_data->m_ref == 0 )
+            delete m_data;
+        m_data = GetNullData();
     }
 
-    bool extend(size_t len)
+    // 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)
     {
-        wxASSERT_MSG( m_owned, _T("cannot extend non-owned buffer") );
+        this->DecRef();
 
-        CharType *
-            str = (CharType *)realloc(m_str, (len + 1)*sizeof(CharType));
-        if ( !str )
-            return false;
+        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(wxStrdup(src.m_data->Get()));
+        }
+    }
+
+protected:
+    Data *m_data;
+};
 
-        m_str = str;
+typedef wxScopedCharTypeBuffer<char> wxScopedCharBuffer;
+typedef wxScopedCharTypeBuffer<wchar_t> wxScopedWCharBuffer;
 
-        return true;
+
+// this buffer class always stores data in "owned" (persistent) manner
+template <typename T>
+class wxCharTypeBuffer : public wxScopedCharTypeBuffer<T>
+{
+protected:
+    typedef typename wxScopedCharTypeBuffer<T>::Data Data;
+
+public:
+    typedef T CharType;
+
+    wxCharTypeBuffer(const CharType *str = NULL)
+    {
+        if ( str )
+            this->m_data = new Data(wxStrdup(str));
+        else
+            this->m_data = this->GetNullData();
     }
 
-    CharType *data() { return m_str; }
-    const CharType *data() const { return m_str; }
-    operator const CharType *() const { return m_str; }
-    CharType operator[](size_t n) const { return m_str[n]; }
+    wxCharTypeBuffer(size_t len)
+    {
+        this->m_data = new Data((CharType *)malloc((len + 1)*sizeof(CharType)));
+        this->m_data->Get()[len] = (CharType)0;
+    }
 
+    wxCharTypeBuffer(const wxCharTypeBuffer& src)
+    {
+        this->m_data = src.m_data;
+        this->IncRef();
+    }
 
-private:
-    CharType *DoRelease() const
+    wxCharTypeBuffer& operator=(const CharType *str)
     {
-        CharType *p = m_str;
-        ((wxCharTypeBuffer *)this)->m_str = NULL;
-        return p;
+        this->DecRef();
+
+        if ( str )
+            this->m_data = new Data(wxStrdup(str));
+        return *this;
+    }
+
+    wxCharTypeBuffer& operator=(const wxCharTypeBuffer& src)
+    {
+        if ( &src == this )
+            return *this;
+
+        this->DecRef();
+        this->m_data = src.m_data;
+        this->IncRef();
+
+        return *this;
     }
 
-    void CopyFrom(const wxCharTypeBuffer& src)
+    wxCharTypeBuffer(const wxScopedCharTypeBuffer<T>& src)
     {
-        m_owned = src.m_owned;
-        m_str = src.DoRelease();
+        MakeOwnedCopyOf(src);
     }
 
-private:
-    CharType *m_str;
-    bool m_owned;
+    wxCharTypeBuffer& operator=(const wxScopedCharTypeBuffer<T>& src)
+    {
+        MakeOwnedCopyOf(src);
+        return *this;
+    }
+
+    bool extend(size_t len)
+    {
+        wxASSERT_MSG( this->m_data->m_owned, "cannot extend non-owned buffer" );
+        wxASSERT_MSG( this->m_data->m_ref == 1, "can't extend shared buffer" );
+
+        CharType *str =
+            (CharType *)realloc(this->data(), (len + 1) * sizeof(CharType));
+        if ( !str )
+            return false;
+
+        if ( this->m_data == this->GetNullData() )
+        {
+            this->m_data = new Data(str);
+        }
+        else
+        {
+            this->m_data->Set(str);
+            this->m_data->m_owned = true;
+        }
+
+        return true;
+    }
 };
 
 WXDLLIMPEXP_TEMPLATE_INSTANCE_BASE( wxCharTypeBuffer<char> )
 
-class WXDLLIMPEXP_BASE wxCharBuffer : public wxCharTypeBuffer<char>
+class wxCharBuffer : public wxCharTypeBuffer<char>
 {
 public:
     typedef wxCharTypeBuffer<char> wxCharTypeBufferBase;
+    typedef wxScopedCharTypeBuffer<char> wxScopedCharTypeBufferBase;
 
     wxCharBuffer(const wxCharTypeBufferBase& buf)
         : wxCharTypeBufferBase(buf) {}
+    wxCharBuffer(const wxScopedCharTypeBufferBase& buf)
+        : wxCharTypeBufferBase(buf) {}
 
     wxCharBuffer(const CharType *str = NULL) : wxCharTypeBufferBase(str) {}
     wxCharBuffer(size_t len) : wxCharTypeBufferBase(len) {}
@@ -169,13 +328,16 @@ public:
 #if wxUSE_WCHAR_T
 WXDLLIMPEXP_TEMPLATE_INSTANCE_BASE( wxCharTypeBuffer<wchar_t> )
 
-class WXDLLIMPEXP_BASE wxWCharBuffer : public wxCharTypeBuffer<wchar_t>
+class wxWCharBuffer : public wxCharTypeBuffer<wchar_t>
 {
 public:
     typedef wxCharTypeBuffer<wchar_t> wxCharTypeBufferBase;
+    typedef wxScopedCharTypeBuffer<wchar_t> wxScopedCharTypeBufferBase;
 
     wxWCharBuffer(const wxCharTypeBufferBase& buf)
         : wxCharTypeBufferBase(buf) {}
+    wxWCharBuffer(const wxScopedCharTypeBufferBase& buf)
+        : wxCharTypeBufferBase(buf) {}
 
     wxWCharBuffer(const CharType *str = NULL) : wxCharTypeBufferBase(str) {}
     wxWCharBuffer(size_t len) : wxCharTypeBufferBase(len) {}
@@ -189,12 +351,14 @@ template <typename T>
 class wxWritableCharTypeBuffer : public wxCharTypeBuffer<T>
 {
 public:
-    typedef typename wxCharTypeBuffer<T>::CharType CharType;
+    typedef typename wxScopedCharTypeBuffer<T>::CharType CharType;
 
-    wxWritableCharTypeBuffer(const wxCharTypeBuffer<T>& src)
+    wxWritableCharTypeBuffer(const wxScopedCharTypeBuffer<T>& src)
         : wxCharTypeBuffer<T>(src) {}
     // FIXME-UTF8: this won't be needed after converting mb_str()/wc_str() to
     //             always return a buffer
+    //             + we should derive this class from wxScopedCharTypeBuffer
+    //               then
     wxWritableCharTypeBuffer(const CharType *str = NULL)
         : wxCharTypeBuffer<T>(str) {}
 
@@ -226,6 +390,13 @@ typedef wxWritableCharTypeBuffer<wchar_t> wxWritableWCharBuffer;
     #define wxWX2WCbuf wxWCharBuffer
 #endif // Unicode/ANSI
 
+// type of the value returned by wxString::utf8_str()
+#if wxUSE_UNICODE_UTF8
+    #define wxUTF8Buf char *
+#else
+    #define wxUTF8Buf wxCharBuffer
+#endif
+
 // ----------------------------------------------------------------------------
 // A class for holding growable data buffers (not necessarily strings)
 // ----------------------------------------------------------------------------
@@ -284,11 +455,11 @@ private:
     // the reference count
     size_t m_ref;
 
-    DECLARE_NO_COPY_CLASS(wxMemoryBufferData)
+    wxDECLARE_NO_COPY_CLASS(wxMemoryBufferData);
 };
 
 
-class WXDLLIMPEXP_BASE wxMemoryBuffer
+class wxMemoryBuffer
 {
 public:
     // ctor and dtor
@@ -310,9 +481,12 @@ public:
 
     wxMemoryBuffer& operator=(const wxMemoryBuffer& src)
     {
-        m_bufdata->DecRef();
-        m_bufdata = src.m_bufdata;
-        m_bufdata->IncRef();
+        if (&src != this)
+        {
+            m_bufdata->DecRef();
+            m_bufdata = src.m_bufdata;
+            m_bufdata->IncRef();
+        }
         return *this;
     }