mirror of
https://github.com/openssl/openssl.git
synced 2024-12-03 05:41:46 +08:00
70 lines
2.5 KiB
Plaintext
70 lines
2.5 KiB
Plaintext
=pod
|
|
|
|
=head1 NAME
|
|
|
|
BIO_f_buffer - buffering BIO
|
|
|
|
=head1 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)
|
|
|
|
=head1 DESCRIPTION
|
|
|
|
BIO_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 B<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 B<num>
|
|
bytes of B<buf>. If B<num> is larger than the current buffer size the buffer
|
|
is expanded.
|
|
|
|
=head1 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.
|
|
|
|
=head1 RETURN VALUES
|
|
|
|
BIO_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.
|
|
|
|
=head1 SEE ALSO
|
|
|
|
TBA
|