BIO_f_buffer(3) OpenSSL BIO_f_buffer(3)NAMEBIO_f_buffer - buffering BIO
SYNOPSIS
#include <openssl/bio.h>
BIO_METHOD * BIO_f_buffer(void);
#define BIO_get_buffer_num_lines(b) BIO_ctrl(b,BIO_C_GET_BUFF_NUM_LINES,0,NULL)
#define BIO_set_read_buffer_size(b,size) BIO_int_ctrl(b,BIO_C_SET_BUFF_SIZE,size,0)
#define BIO_set_write_buffer_size(b,size) BIO_int_ctrl(b,BIO_C_SET_BUFF_SIZE,size,1)
#define BIO_set_buffer_size(b,size) BIO_ctrl(b,BIO_C_SET_BUFF_SIZE,size,NULL)
#define BIO_set_buffer_read_data(b,buf,num) BIO_ctrl(b,BIO_C_SET_BUFF_READ_DATA,num,buf)
DESCRIPTIONBIO_f_buffer() 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
BIO_gets() and BIO_puts() are supported.
Calling BIO_reset() on a buffering BIO clears any buffered
data.
BIO_get_buffer_num_lines() returns the number of lines
currently buffered.
BIO_set_read_buffer_size(), BIO_set_write_buffer_size()
and BIO_set_buffer_size() set the read, write or both read
and write buffer sizes to size. The initial buffer size is
DEFAULT_BUFFER_SIZE, currently 1024. Any attempt to reduce
the buffer size below DEFAULT_BUFFER_SIZE is ignored. Any
buffered data is cleared when the buffer is resized.
BIO_set_buffer_read_data() clears the read buffer and
fills it with num bytes of buf. If num is larger than the
current buffer size the buffer is expanded.
NOTES
Buffering BIOs implement BIO_gets() by using BIO_read()
operations on the next BIO in the chain. By prepending a
buffering BIO to a chain it is therefore possible to
provide BIO_gets() 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 BIO_flush() is called. It is
therefore important to call BIO_flush() whenever any
pending data should be written such as when removing a
buffering BIO using BIO_pop(). BIO_flush() may need to be
retried if the ultimate source/sink BIO is non blocking.
RETURN VALUESBIO_f_buffer() returns the buffering BIO method.
BIO_get_buffer_num_lines() returns the number of lines
buffered (may be 0).
BIO_set_read_buffer_size(), BIO_set_write_buffer_size()
and BIO_set_buffer_size() return 1 if the buffer was
successfully resized or 0 for failure.
BIO_set_buffer_read_data() returns 1 if the data was set
correctly or 0 if there was an error.
SEE ALSO
TBA
18/Sep/2000 0.9.6j BIO_f_buffer(3)
