BIOfbuffer(3) OpenSSL BIOfbuffer(3)

NAME
       BIOfbuffer - buffering BIO

SYNOPSIS
        #include 

        BIOMETHOD * BIOfbuffer(void);

        #define BIOgetbuffernumlines(b)    BIOctrl(b,BIOCGETBUFFNUMLINES,0,NULL)
        #define BIOsetreadbuffersize(b,size) BIOintctrl(b,BIOCSETBUFFSIZE,size,0)
        #define BIOsetwritebuffersize(b,size) BIOintctrl(b,BIOCSETBUFFSIZE,size,1)
        #define BIOsetbuffersize(b,size)    BIOctrl(b,BIOCSETBUFFSIZE,size,NULL)
        #define BIOsetbufferreaddata(b,buf,num) BIOctrl(b,BIOCSETBUFFREADDATA,num,buf)

DESCRIPTION
       BIOfbuffer() returns the buffering BIO method.

       Data written to a buffering BIO is buffered and periodically written to
       the next BIO in the chain. Data read from a buffering BIO comes from an
       internal buffer which is filled from the next BIO in the chain.  Both
       BIOgets() and BIOputs() are supported.

       Calling BIOreset() on a buffering BIO clears any buffered data.

       BIOgetbuffernumlines() returns the number of lines currently
       buffered.

       BIOsetreadbuffersize(), BIOsetwritebuffersize() and
       BIOsetbuffersize() set the read, write or both read and write buffer
       sizes to ssiizzee. The initial buffer size is DEFAULTBUFFERSIZE,
       currently 1024. Any attempt to reduce the buffer size below
       DEFAULTBUFFERSIZE is ignored. Any buffered data is cleared when the
       buffer is resized.

       BIOsetbufferreaddata() clears the read buffer and fills it with nnuumm
       bytes of bbuuff. If nnuumm is larger than the current buffer size the buffer
       is expanded.

NNOOTTEESS
       Buffering BIOs implement BIOgets() by using BIOread() operations on
       the next BIO in the chain. By prepending a buffering BIO to a chain it
       is therefore possible to provide BIOgets() functionality if the
       following BIOs do not support it (for example SSL BIOs).

       Data is only written to the next BIO in the chain when the write buffer
       fills or when BIOflush() is called. It is therefore important to call
       BIOflush() whenever any pending data should be written such as when
       removing a buffering BIO using BIOpop(). BIOflush() may need to be
       retried if the ultimate source/sink BIO is non blocking.

RETURN VALUES
       BIOfbuffer() returns the buffering BIO method.

       BIOgetbuffernumlines() returns the number of lines buffered (may be
       0).

       BIOsetreadbuffersize(), BIOsetwritebuffersize() and
       BIOsetbuffersize() return 1 if the buffer was successfully resized
       or 0 for failure.

       BIOsetbufferreaddata() returns 1 if the data was set correctly or 0
       if there was an error.

SEE ALSO
       TBA



0.9.7l                            2000-09-18                   BIOfbuffer(3)