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.
-\membersection{wxStreamBuffer::wxStreamBuffer}
+\wxheading{Warning}
+
+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'' */
+\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).
+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.
-\membersection{wxStreamBuffer::wxStreamBuffer}
+\wxheading{Warning}
+
+The "read\_write" mode may not work: it isn't completely finished.
+
+\wxheading{See also}
+
+\helpref{wxStreamBuffer:SetBufferIO}{wxstreambufsetbufferio}
+
+\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.
-\func{}{wxStreamBuffer}{\param{const wxStreamBase\&}{ buffer}}
+\wxheading{Warning}
-Constructor, creates a new stream buffer from the specified stream \it{buffer}.
+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}}
\func{}{wxStreamBuffer}{\destruct{wxStreamBuffer}}
-Destructor, destroys the stream buffer.
+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.
% -----------
% Filtered IO
\func{size\_t}{Read}{\param{void *}{buffer}, \param{size\_t }{size}}
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.
\wxheading{Return value}
\it{size}, an error occured and should be tested using
\helpref{LastError}{wxstreambaselasterror}.
-\membersection{wxStreamBuffer::Read}\label{wxstreambufreadbuf}
+\wxheading{See also}
+
+\helpref{wxStreamBuffer::WriteBack}{wxstreambufwriteback}
\func{size\_t}{Read}{\param{wxStreamBuffer *}{buffer}}
\func{size\_t}{Write}{\param{const void *}{buffer}, \param{size\_t }{size}}
-Writes a block of the specified \it{size} using datas of \it{buffer}.
-
-\membersection{wxStreamBuffer::Write}
+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}}
See \helpref{Read}{wxstreambufreadbuf}
-\membersection{wxStreamBuffer::WriteBack}
+\membersection{wxStreamBuffer::WriteBack}\label{wxstreambufwriteback}
\func{size\_t}{WriteBack}{\param{const char*}{ buffer}, \param{size\_t}{ size}}
-This function is only useful in ``read'' mode. It puts the specified \it{buffer}
-in the input queue of the stream buf. By this way, the next
-\helpref{Read}{wxstreambufread} call will first use these datas.
+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.
-\membersection{wxStreamBuffer::WriteBack}
+\wxheading{Return value}
+
+Returns the amount of bytes saved in the Write-Back buffer.
\func{size\_t}{WriteBack}{\param{char }{c}}
-As for the previous function, it puts the specified byte in the input queue of the
-stream 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}
\func{char}{GetChar}{\void}
-Gets a single char from the stream buffer.
+Gets a single char from the stream buffer. It acts like the Read call.
+
+\wxheading{Problem}
+
+You aren't directly notified if an error occured during the IO call.
+
+\wxheading{See also}
+
+\helpref{wxStreamBuffer::Read}{wxstreambufread}
\membersection{wxStreamBuffer::PutChar}
Puts a single char to the stream buffer.
+\wxheading{Problem}
+
+You aren't directly notified if an error occured during the IO call.
+
+\wxheading{See also}
+
+\helpref{wxStreamBuffer::Read}{wxstreambufwrite}
+
\membersection{wxStreamBuffer::Tell}
\constfunc{off\_t}{Tell}{\void}
-Gets the current position in the \it{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.
+
+\wxheading{Return value}
+
+Returns the current position in the stream if possible, wxInvalidOffset in the
+other case.
\membersection{wxStreamBuffer::Seek}\label{wxstreambufferseek}
\func{off\_t}{Seek}{\param{off\_t }{pos}, \param{wxSeekMode }{mode}}
-Changes the current position. (TODO)
+Changes the current position.
+
+\it{mode} may be one of the following:
+
+\twocolwidtha{5cm}
+\begin{twocollist}\itemsep=0pt
+\twocolitem{{\bf wxFromStart}}{The position is counted from the start of the stream.}
+\twocolitem{{\bf wxFromCurrent}}{The position is counted from the current position of the stream.}
+\twocolitem{{\bf wxFromEnd}}{The position is counted from the end of the stream.}
+\end{twocollist}
+
+\wxheading{Return value}
+
+Upon successful completion, it returns the new offset as measured in bytes from
+the beginning of the stream. Otherwise, it returns wxInvalidOffset.
% --------------
% Buffer control
\func{void}{ResetBuffer}{\void}
-Frees all internal buffers and resets to initial state all variables.
+Resets to the initial state variables concerning the buffer.
-\membersection{wxStreamBuffer::SetBufferIO}
+\membersection{wxStreamBuffer::SetBufferIO}\label{wxstreambufsetbufferio}
\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.
-\membersection{wxStreamBuffer::SetBufferIO}
-
\func{void}{SetBufferIO}{\param{size\_t}{ bufsize}}
Changes the size of the current IO buffer.
\func{wxStreamBase*}{Stream}{\void}
-Returns the stream parent of the stream buffer.
+Returns the parent stream of the stream buffer.
projects / wxWidgets.git / commitdiff
