None
+\wxheading{Include files}
+
+<wx/stream.h>
+
+\wxheading{Library}
+
+\helpref{wxBase}{librarieslist}
+
\wxheading{See also}
\helpref{wxStreamBase}{wxstreambase}
-% ---------------------------------------------------------------------------
-% Members
-% ---------------------------------------------------------------------------
\latexignore{\rtfignore{\wxheading{Members}}}
-% -----------
-% ctor & dtor
-% -----------
-\membersection{wxStreamBuffer::wxStreamBuffer}
+
+\membersection{wxStreamBuffer::wxStreamBuffer}\label{wxstreambufferctor}
\func{}{wxStreamBuffer}{\param{wxStreamBase\&}{ stream}, \param{BufMode}{ mode}}
-Constructor, creates a new stream buffer using \it{stream} as a parent stream
-and \it{mode} as the IO mode. \it{mode} can be: wxStreamBuffer::read,
+Constructor, creates a new stream buffer using {\it stream} as a parent stream
+and {\it mode} as the IO mode. {\it mode} can be: wxStreamBuffer::read,
wxStreamBuffer::write, wxStreamBuffer::read\_write.
-One stream can have many stream buffers but only one is used internally to
-pass IO call (e.g. wxInputStream::Read() -> wxStreamBuffer::Read()). But you
-can call directly wxStreamBuffer::Read without any problems.
-\wxheading{Warning}
+One stream can have many stream buffers but only one is used internally to
+pass IO call (e.g. wxInputStream::Read() -> wxStreamBuffer::Read()), but you
+can call directly wxStreamBuffer::Read without any problems. Note that
+all errors and messages linked to the stream are stored in the stream, not
+the stream buffers:
-All errors and messages linked to the stream are stored in the stream object.
\begin{verbatim}
- streambuffer.Read(...);
- streambuffer2.Read(...); /* This one erases previous error messages set by
- ``streambuffer'' */
+ streambuffer.Read(...);
+ streambuffer2.Read(...); /* This call erases previous error messages set by
+ ``streambuffer'' */
\end{verbatim}
\func{}{wxStreamBuffer}{\param{BufMode}{ mode}}
Constructor, creates a new empty stream buffer which won't flush any data
-to a stream. \it{mode} specifies the type of the buffer (read, write, read\_write). This stream buffer has the advantage to be stream independent and to
+to a stream. {\it mode} specifies the type of the buffer (read, write, read\_write).
+This stream buffer has the advantage to be stream independent and to
work only on memory buffers but it is still compatible with the rest of the
wxStream classes. You can write, read to this special stream and it will
grow (if it is allowed by the user) its internal buffer. Briefly, it has all
-functionnalities of a ``normal'' stream.
+functionality of a ``normal'' stream.
\wxheading{Warning}
-The "read\_write" mode may not work: it isn't completely finished.
+The "read\_write" mode doesn't currently work for standalone stream buffers.
-\wxheading{See also}
-
-\helpref{wxStreamBuffer:SetBufferIO}{wxstreambufsetbufferio}
-
-\func{}{wxStreamBuffer}{\param{const wxStreamBuffer &}{buffer}}
+\func{}{wxStreamBuffer}{\param{const wxStreamBuffer\&}{buffer}}
Constructor. It initializes the stream buffer with the data of the specified
-stream buffer. The new stream buffer is nearly exactly the same as the
-original: it has the same attributes, the same size, the same position, shares
-the same internal buffer. The interresting point is that they can differ
-in the future but the root is the same.
+stream buffer. The new stream buffer has the same attributes, size, position
+and they share the same buffer. This will cause problems if the stream to
+which the stream buffer belong is destroyed and the newly cloned stream
+buffer continues to be used, trying to call functions in the (destroyed)
+stream. It is advised to use this feature only in very local area of the
+program.
-\wxheading{Warning}
+\wxheading{See also}
+
+\helpref{wxStreamBuffer:SetBufferIO}{wxstreambuffersetbufferio}
-The fact that the two stream buffers shared the same buffer could generate
-segmentation violation if the parent is destroyed and the children continues
-operating. It is advised to use this feature only in very local area of the
-program.
-\membersection{wxStreamBuffer::\destruct{wxStreamBuffer}}
+\membersection{wxStreamBuffer::\destruct{wxStreamBuffer}}\label{wxstreambufferdtor}
\func{}{wxStreamBuffer}{\destruct{wxStreamBuffer}}
Destructor. It finalizes all IO calls and frees all internal buffers if
-necessary. In the case of a children stream buffer, the internal buffer isn't
-freed, this is the job of the parent.
-The "Write-Back" buffer is freed.
+necessary.
-% -----------
-% Filtered IO
-% -----------
-\membersection{wxStreamBuffer::Read}\label{wxstreambufread}
-\func{size\_t}{Read}{\param{void *}{buffer}, \param{size\_t }{size}}
+\membersection{wxStreamBuffer::FillBuffer}\label{wxstreambufferfillbuffer}
-Reads a block of the specified \it{size} and stores datas in \it{buffer}.
-This function uses also the "Write-Back" buffer: in the case there are datas
-waiting in this buffer, they are used before anything else. After that, if there
-are still datas to be read, the stream is read and the stream buffer position
-is incremented.
+\func{bool}{FillBuffer}{\void}
-\wxheading{Return value}
+Fill the IO buffer.
-It returns the real read size. If returned size is different of the specified
-\it{size}, an error occured and should be tested using
-\helpref{LastError}{wxstreambaselasterror}.
+
+\membersection{wxStreamBuffer::Fixed}\label{wxstreambufferfixed}
+
+\func{void}{Fixed}{\param{bool}{ fixed}}
+
+Toggles the fixed flag. Usually this flag is toggled at the same time as
+{\it flushable}. This flag allows (when it has the false value) or forbids
+(when it has the true value) the stream buffer to resize dynamically the IO buffer.
\wxheading{See also}
-\helpref{wxStreamBuffer::WriteBack}{wxstreambufwriteback}
+\helpref{wxStreamBuffer::SetBufferIO}{wxstreambuffersetbufferio}
-\func{size\_t}{Read}{\param{wxStreamBuffer *}{buffer}}
-Reads a \it{buffer}. The function returns when \it{buffer} is full or
-when there aren't datas anymore in the current buffer.
+\membersection{wxStreamBuffer::Flushable}\label{wxstreambufferflushable}
-\membersection{wxStreamBuffer::Write}
+\func{void}{Flushable}{\param{bool}{ flushable}}
-\func{size\_t}{Write}{\param{const void *}{buffer}, \param{size\_t }{size}}
+Toggles the flushable flag. If {\it flushable} is disabled, no data are sent
+to the parent stream.
-Writes a block of the specified \it{size} using datas of \it{buffer}. The datas
-are cached in a buffer before being sent in one block to the stream.
-\func{size\_t}{Write}{\param{wxStreamBuffer *}{buffer}}
+\membersection{wxStreamBuffer::FlushBuffer}\label{wxstreambufferflushbuffer}
-See \helpref{Read}{wxstreambufreadbuf}
+\func{bool}{FlushBuffer}{\void}
+
+Flushes the IO buffer.
-\membersection{wxStreamBuffer::WriteBack}\label{wxstreambufwriteback}
-\func{size\_t}{WriteBack}{\param{const char*}{ buffer}, \param{size\_t}{ size}}
+\membersection{wxStreamBuffer::GetBufferEnd}\label{wxstreambuffergetbufferend}
-This function is only useful in \it{read} mode. It is the manager of the "Write-Back"
-buffer. This buffer acts like a temporary buffer where datas which has to be
-read during the next read IO call are put. This is useful when you get a big
-block of data which you didn't want to read: you can replace them at the top
-of the input queue by this way.
+\constfunc{void *}{GetBufferEnd}{\void}
-\wxheading{Return value}
+Returns a pointer on the end of the stream buffer.
+
+
+\membersection{wxStreamBuffer::GetBufferPos}\label{wxstreambuffergetbufferpos}
+
+\constfunc{void *}{GetBufferPos}{\void}
-Returns the amount of bytes saved in the Write-Back buffer.
+Returns a pointer on the current position of the stream buffer.
+
+
+\membersection{wxStreamBuffer::GetBufferSize}\label{wxstreambuffergetbuffersize}
+
+\constfunc{size\_t}{GetBufferSize}{\void}
-\func{size\_t}{WriteBack}{\param{char }{c}}
+Returns the size of the buffer.
-This function acts like the previous one except that it takes only one
-character: it is sometimes shorter to use than the generic function.
-\membersection{wxStreamBuffer::GetChar}
+\membersection{wxStreamBuffer::GetBufferStart}\label{wxstreambuffergetbufferstart}
+
+\constfunc{void *}{GetBufferStart}{\void}
+
+Returns a pointer on the start of the stream buffer.
+
+
+\membersection{wxStreamBuffer::GetChar}\label{wxstreambuffergetchar}
\func{char}{GetChar}{\void}
\wxheading{Problem}
-You aren't directly notified if an error occured during the IO call.
+You aren't directly notified if an error occurred during the IO call.
\wxheading{See also}
-\helpref{wxStreamBuffer::Read}{wxstreambufread}
+\helpref{wxStreamBuffer::Read}{wxstreambufferread}
+
+
+\membersection{wxStreamBuffer::GetDataLeft}\label{wxstreambuffergetdataleft}
+
+\func{size\_t}{GetDataLeft}{\void}
+
+Returns the amount of available data in the buffer.
+
+
+\membersection{wxStreamBuffer::GetIntPosition}\label{wxstreambuffergetintposition}
+
+\constfunc{off\_t}{GetIntPosition}{\void}
+
+Returns the current position (counted in bytes) in the stream buffer.
+
+
+\membersection{wxStreamBuffer::GetLastAccess}\label{wxstreambuffergetlastaccess}
+
+\constfunc{size\_t}{GetLastAccess}{\void}
+
+Returns the amount of bytes read during the last IO call to the parent stream.
+
-\membersection{wxStreamBuffer::PutChar}
+\membersection{wxStreamBuffer::PutChar}\label{wxstreambufferputchar}
\func{void}{PutChar}{\param{char }{c}}
\wxheading{Problem}
-You aren't directly notified if an error occured during the IO call.
+You aren't directly notified if an error occurred during the IO call.
\wxheading{See also}
-\helpref{wxStreamBuffer::Read}{wxstreambufwrite}
+\helpref{wxStreamBuffer::Read}{wxstreambufferwrite}
-\membersection{wxStreamBuffer::Tell}
-\constfunc{off\_t}{Tell}{\void}
+\membersection{wxStreamBuffer::Read}\label{wxstreambufferread}
-Gets the current position in the stream. This position is calculated from
-the \it{real} position in the stream and from the internal buffer position: so
-it gives you the position in the \it{real} stream counted from the start of
-the stream.
+\func{size\_t}{Read}{\param{void *}{buffer}, \param{size\_t }{size}}
+
+Reads a block of the specified {\it size} and stores the data in {\it buffer}.
+This function tries to read from the buffer first and if more data has been
+requested, reads more data from the associated stream and updates the buffer
+accordingly until all requested data is read.
\wxheading{Return value}
-Returns the current position in the stream if possible, wxInvalidOffset in the
-other case.
+It returns the size of the data read. If the returned size is different of the specified
+{\it size}, an error has occurred and should be tested using
+\helpref{GetLastError}{wxstreambasegetlasterror}.
+
+\func{size\_t}{Read}{\param{wxStreamBuffer *}{buffer}}
+
+Copies data to {\it buffer}. The function returns when {\it buffer} is full or when there isn't
+any more data in the current buffer.
+
+\wxheading{See also}
+
+\helpref{wxStreamBuffer::Write}{wxstreambufferwrite}
+
+
+\membersection{wxStreamBuffer::ResetBuffer}\label{wxstreambufferresetbuffer}
+
+\func{void}{ResetBuffer}{\void}
+
+Resets to the initial state variables concerning the buffer.
+
\membersection{wxStreamBuffer::Seek}\label{wxstreambufferseek}
Changes the current position.
-\it{mode} may be one of the following:
+{\it mode} may be one of the following:
\twocolwidtha{5cm}
\begin{twocollist}\itemsep=0pt
Upon successful completion, it returns the new offset as measured in bytes from
the beginning of the stream. Otherwise, it returns wxInvalidOffset.
-% --------------
-% Buffer control
-% --------------
-\membersection{wxStreamBuffer::ResetBuffer}
-\func{void}{ResetBuffer}{\void}
-
-Resets to the initial state variables concerning the buffer.
-
-\membersection{wxStreamBuffer::SetBufferIO}\label{wxstreambufsetbufferio}
+\membersection{wxStreamBuffer::SetBufferIO}\label{wxstreambuffersetbufferio}
\func{void}{SetBufferIO}{\param{char*}{ buffer\_start}, \param{char*}{ buffer\_end}}
Specifies which pointers to use for stream buffering. You need to pass a pointer on the
-start of the buffer end and another on the end.
+start of the buffer end and another on the end. The object will use this buffer
+to cache stream data. It may be used also as a source/destination buffer when
+you create an empty stream buffer (See \helpref{wxStreamBuffer::wxStreamBuffer}{wxstreambufferctor}).
-\func{void}{SetBufferIO}{\param{size\_t}{ bufsize}}
+\wxheading{Remarks}
-Changes the size of the current IO buffer.
+When you use this function, you will have to destroy the IO buffers yourself
+after the stream buffer is destroyed or don't use it anymore.
+In the case you use it with an empty buffer, the stream buffer will not resize
+it when it is full.
-\membersection{wxStreamBuffer::GetBufferStart}
+\wxheading{See also}
-\constfunc{char *}{GetBufferStart}{\void}
+\helpref{wxStreamBuffer constructor}{wxstreambufferctor}\\
+\helpref{wxStreamBuffer::Fixed}{wxstreambufferfixed}\\
+\helpref{wxStreamBuffer::Flushable}{wxstreambufferflushable}
-Returns a pointer on the start of the stream buffer.
+\func{void}{SetBufferIO}{\param{size\_t}{ bufsize}}
-\membersection{wxStreamBuffer::GetBufferEnd}
+Destroys or invalidates the previous IO buffer and allocates a new one of the
+specified size.
-\constfunc{char *}{GetBufferEnd}{\void}
+\wxheading{Warning}
-Returns a pointer on the end of the stream buffer.
+All previous pointers aren't valid anymore.
-\membersection{wxStreamBuffer::GetBufferPos}
+\wxheading{Remark}
-\constfunc{char *}{GetBufferPos}{\void}
+The created IO buffer is growable by the object.
-Returns a pointer on the current position of the stream buffer.
+\wxheading{See also}
-\membersection{wxStreamBuffer::GetIntPosition}
+\helpref{wxStreamBuffer::Fixed}{wxstreambufferfixed}\\
+\helpref{wxStreamBuffer::Flushable}{wxstreambufferflushable}
-\constfunc{off\_t}{GetIntPosition}{\void}
-Returns the current position in the stream buffer.
+\membersection{wxStreamBuffer::SetIntPosition}\label{wxstreambuffersetintposition}
-\membersection{wxStreamBuffer::SetIntPosition}
+\func{void}{SetIntPosition}{\param{size\_t}{ pos}}
-\func{void}{SetIntPosition}{\void}
+Sets the current position (in bytes) in the stream buffer.
-Sets the current position in the stream buffer.
+\wxheading{Warning}
-\membersection{wxStreamBuffer::GetLastAccess}
+Since it is a very low-level function, there is no check on the position:
+specifying an invalid position can induce unexpected results.
-\constfunc{size\_t}{GetLastAccess}{\void}
-Returns the amount of bytes read during the last IO call to the parent stream.
+\membersection{wxStreamBuffer::Stream}\label{wxstreambufferstream}
-\membersection{wxStreamBuffer::Fixed}
+\func{wxStreamBase*}{Stream}{\void}
-\func{void}{Fixed}{\param{bool}{ fixed}}
+Returns the parent stream of the stream buffer.
-Toggles the fixed flag. Usually this flag is toggled at the same time as
-\it{flushable}. This flag allows (when it is FALSE) or forbids (when it is TRUE)
-the stream buffer to resize dynamically the IO buffer.
-\membersection{wxStreamBuffer::Flushable}
+\membersection{wxStreamBuffer::Tell}\label{wxstreambuffertell}
-\func{void}{Flushable}{\param{bool}{ flushable}}
+\constfunc{off\_t}{Tell}{\void}
-Toggles the flushable flag. If \it{flushable} is disabled, no datas are sent
-to the parent stream.
+Gets the current position in the stream. This position is calculated from
+the {\it real} position in the stream and from the internal buffer position: so
+it gives you the position in the {\it real} stream counted from the start of
+the stream.
-\membersection{wxStreamBuffer::FlushBuffer}
+\wxheading{Return value}
-\func{bool}{FlushBuffer}{\void}
+Returns the current position in the stream if possible, wxInvalidOffset in the
+other case.
-Flushes the IO buffer.
-\membersection{wxStreamBuffer::FillBuffer}
+\membersection{wxStreamBuffer::Truncate}\label{wxstreambuffertruncate}
-\func{bool}{FillBuffer}{\void}
+\func{void}{Truncate}{\void}
-Fill the IO buffer.
+Truncates the buffer to the current position.
-\membersection{wxStreamBuffer::GetDataLeft}
+Note: Truncate() cannot be used to enlarge the buffer. This is
+usually not needed since the buffer expands automatically.
-\func{size\_t}{GetDataLeft}{\void}
-Returns the amount of available datas in the buffer.
+\membersection{wxStreamBuffer::Write}\label{wxstreambufferwrite}
-% --------------
-% Administration
-% --------------
-\membersection{wxStreamBuffer::Stream}
+\func{size\_t}{Write}{\param{const void *}{buffer}, \param{size\_t }{size}}
-\func{wxStreamBase*}{Stream}{\void}
+Writes a block of the specified {\it size} using data of {\it buffer}. The data
+are cached in a buffer before being sent in one block to the stream.
-Returns the parent stream of the stream buffer.
+\func{size\_t}{Write}{\param{wxStreamBuffer *}{buffer}}
+
+See \helpref{Read}{wxstreambufferread}.
projects / wxWidgets.git / blobdiff