// Purpose: interface of wxMemoryBuffer
// Author: wxWidgets team
// RCS-ID: $Id$
-// Licence: wxWindows license
+// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
/**
- wxCharTypeBuffer<T> is a template class for storing characters.
+ wxScopedCharTypeBuffer<T> is a template class for storing characters.
+
+ Data are stored in reference-counted buffer. In other words, making a copy
+ of wxScopedCharTypeBuffer<T> will @em not make another copy of the stored
+ string data, it will still point to the same location in memory.
+
+ wxScopedCharTypeBuffer<T> supports two storage modes: owned and non-owned.
+ "Owned" data buffer (created with CreateOwned() or wxCharTypeBuffer<T>
+ derived class) owns the data and frees them when the last buffer pointing
+ to them is destroyed.
- @todo provide better docs for this class
+ "Non-owned" buffer (created with CreateNonOwned()), on the other hand,
+ references data owned by somebody else -- typical use is by
+ wxString::mb_str() or wxString::wc_str(), which may return non-owned buffer
+ pointing to wxString's internal store.
+
+ Because of this, the validity of data stored in wxScopedCharTypeBuffer<T>
+ is limited by the lifetime of the "parent" object that created the
+ buffer (e.g. the wxString on which mb_str() was called).
+
+ If you need to preserve the data for longer, assign it to
+ wxCharTypeBuffer<T> instead of wxScopedCharTypeBuffer<T>. On the other
+ hand, use wxScopedCharTypeBuffer<T> if the buffer is to be destroyed before
+ the "parent" object -- typical use would be creating it on the stack and
+ destroying when it goes out of scope (hence the class' name).
@tparam T
The type of the characters stored in this class.
+ @since 2.9.0
+
@nolibrary
@category{data}
*/
template <typename T>
-class wxCharTypeBuffer
+class wxScopedCharTypeBuffer
{
public:
+ /// Stored characters type.
typedef T CharType;
- wxCharTypeBuffer(const CharType *str = NULL);
+ /// Default constructor, creates NULL buffer.
+ wxScopedCharTypeBuffer();
+
+ /**
+ Creates non-owned buffer from string data @a str.
+
+ The buffer's destructor will not destroy @a str. The returned buffer's
+ data is valid only as long as @a str is valid.
+
+ @param str String data.
+ @param len If specified, length of the string, otherwise the string
+ is considered to be NUL-terminated.
+ */
+ static const wxScopedCharTypeBuffer CreateNonOwned(const CharType *str, size_t len = wxNO_LEN);
+
+ /**
+ Creates owned buffer from @a str and takes ownership of it.
+
+ The buffer's destructor will free @a str when its reference count
+ reaches zero (initial count is 1).
+
+ @param str String data.
+ @param len If specified, length of the string, otherwise the string
+ is considered to be NUL-terminated.
+ */
+ static const wxScopedCharTypeBuffer CreateOwned(CharType *str, size_t len = wxNO_LEN);
+
+ /**
+ Copy constructor.
+
+ Increases reference count on the data, does @em not make wxStrdup()
+ copy of the data.
+ */
+ wxScopedCharTypeBuffer(const wxScopedCharTypeBuffer& src);
+
+ /// Assignment operator behaves in the same way as the copy constructor.
+ wxScopedCharTypeBuffer& operator=(const wxScopedCharTypeBuffer& src);
+
+ /**
+ Destructor. Frees stored data if it is in "owned" mode and data's
+ reference count reaches zero.
+ */
+ ~wxScopedCharTypeBuffer();
+
+ /// Resets the buffer to NULL, freeing the data if necessary.
+ void reset();
+
+ /// Returns pointer to the stored data.
+ CharType *data();
+
+ /// Returns const pointer to the stored data.
+ const CharType *data() const;
+
+ /// Returns length of the string stored.
+ size_t length() const;
+
+ /// Implicit conversion to C string.
+ operator const CharType *() const;
+
+ /// Random access to the stored C string.
+ CharType operator[](size_t n) const;
+};
+
+/// Scoped char buffer.
+typedef wxScopedCharTypeBuffer<char> wxScopedCharBuffer;
+
+/// Scoped wchar_t buffer.
+typedef wxScopedCharTypeBuffer<wchar_t> wxScopedWCharBuffer;
+
+/**
+ wxCharTypeBuffer<T> is a template class for storing characters.
+
+ The difference from wxScopedCharTypeBuffer<T> is that this class
+ doesn't have non-owned mode and the data stored in it are valid for
+ as long as the buffer instance exists. Other than that, this class'
+ behaviour is the same as wxScopedCharTypeBuffer<T>'s -- in particular,
+ the data are reference-counted and copying the buffer is cheap.
+
+ wxScopedCharTypeBuffer<T> buffers can be converted into wxCharTypeBuffer<T>.
+
+ @tparam T
+ The type of the characters stored in this class.
+
+ @since 2.9.0
+
+ @nolibrary
+ @category{data}
+*/
+template <typename T>
+class wxCharTypeBuffer : public wxScopedCharTypeBuffer<T>
+{
+public:
+ /**
+ Creates (owned) buffer from @a str and takes ownership of it.
+
+ @param str String data.
+ @param len If specified, length of the string, otherwise the string
+ is considered to be NUL-terminated.
+
+ @see wxScopedCharTypeBuffer<T>::CreateOwned()
+ */
+ wxCharTypeBuffer(const CharType *str = NULL, size_t len = wxNO_LEN);
+
+
+ /**
+ Creates (owned) buffer of size @a len.
+
+ @see wxScopedCharTypeBuffer<T>::CreateOwned()
+ */
wxCharTypeBuffer(size_t len);
+
+ /**
+ Copy constructor.
+
+ Increases reference count on the data, does @em not make wxStrdup()
+ copy of the data.
+ */
wxCharTypeBuffer(const wxCharTypeBuffer& src);
- ~wxCharTypeBuffer();
- void reset();
+ /**
+ Makes a copy of scoped buffer @a src.
+
+ If @a src is a non-owned buffer, a copy of its data is made using
+ wxStrdup(). If @a src is an owned buffer, this constructor behaves
+ in the usual way (reference count on buffer data is incremented).
+ */
+ wxCharTypeBuffer(const wxScopedCharTypeBuffer<T>& src);
+ /**
+ Assigns @a str to this buffer and takes ownership of it (i.e.\ the
+ buffer becomes "owned").
+ */
wxCharTypeBuffer& operator=(const CharType *str);
+
+ /// Assignment operator behaves in the same way as the copy constructor.
wxCharTypeBuffer& operator=(const wxCharTypeBuffer& src);
+ /**
+ Assigns a scoped buffer to this buffer.
+
+ If @a src is a non-owned buffer, a copy of its data is made using
+ wxStrdup(). If @a src is an owned buffer, the assignment behaves
+ in the usual way (reference count on buffer data is incremented).
+ */
+ wxCharTypeBuffer& operator=(const wxScopedCharTypeBuffer<T>& src);
+
+ /**
+ Extends the buffer to have size @a len.
+
+ Can only be called on buffers that don't share data with another
+ buffer (i.e. reference count of the data is 1).
+
+ @see shrink()
+ */
bool extend(size_t len);
- CharType *data();
- const CharType *data() const;
- operator const CharType *() const;
- CharType operator[](size_t n) const;
+ /**
+ Shrinks the buffer to have size @a len and NUL-terminates the string
+ at this length.
+
+ Can only be called on buffers that don't share data with another
+ buffer (i.e. reference count of the data is 1).
+
+ @param len Length to shrink to. Must not be larger than current length.
+
+ @note The string is not reallocated to take less memory.
+
+ @since 2.9.0
+
+ @see extend()
+ */
+ bool shrink(size_t len);
};
/**
This is a specialization of wxCharTypeBuffer<T> for @c char type.
- @todo provide better docs for this class
-
@nolibrary
@category{data}
*/
{
public:
typedef wxCharTypeBuffer<char> wxCharTypeBufferBase;
+ typedef wxScopedCharTypeBuffer<char> wxScopedCharTypeBufferBase;
wxCharBuffer(const wxCharTypeBufferBase& buf);
+ wxCharBuffer(const wxScopedCharTypeBufferBase& buf);
wxCharBuffer(const CharType *str = NULL);
wxCharBuffer(size_t len);
wxCharBuffer(const wxCStrData& cstr);
/**
This is a specialization of wxCharTypeBuffer<T> for @c wchar_t type.
- This class is available only when <tt>wxUSE_WCHAR_T==1</tt>
@nolibrary
@category{data}
{
public:
typedef wxCharTypeBuffer<wchar_t> wxCharTypeBufferBase;
+ typedef wxScopedCharTypeBuffer<wchar_t> wxScopedCharTypeBufferBase;
wxWCharBuffer(const wxCharTypeBufferBase& buf);
+ wxWCharBuffer(const wxScopedCharTypeBufferBase& buf);
wxWCharBuffer(const CharType *str = NULL);
wxWCharBuffer(size_t len);
wxWCharBuffer(const wxCStrData& cstr);
Create a new buffer.
@param size
- size of the new buffer.
+ size of the new buffer, 1KiB by default.
*/
- wxMemoryBuffer(size_t size = DefBufSize);
+ wxMemoryBuffer(size_t size = 1024);
/**
Append a single byte to the buffer.
*/
void AppendByte(char data);
+ /**
+ Single call to append a data block to the buffer.
+
+ @param data
+ Pointer to block to append to the buffer.
+ @param len
+ Length of data to append.
+ */
+ void AppendData(const void *data, size_t len);
+
+ /**
+ Clear the buffer contents.
+
+ The buffer won't contain any data after this method is called.
+
+ @see IsEmpty()
+
+ @since 2.9.4
+ */
+ void Clear();
+
/**
Ensure that the buffer is big enough and return a pointer to the start
of the empty space in the buffer. This pointer can be used to directly
*/
void* GetWriteBuf(size_t sizeNeeded);
+ /**
+ Returns true if the buffer contains no data.
+
+ @see Clear()
+
+ @since 2.9.4
+ */
+ bool IsEmpty() const;
+
/**
Ensures the buffer has at least @a size bytes available.
*/
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