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BIO_F_BUFFER(3)			    OpenSSL		       BIO_F_BUFFER(3)

       BIO_get_buffer_num_lines, BIO_set_read_buffer_size,
       BIO_set_write_buffer_size, BIO_set_buffer_size,
       BIO_set_buffer_read_data, BIO_f_buffer -	buffering BIO

	#include <openssl/bio.h>

	const BIO_METHOD *BIO_f_buffer(void);

	long BIO_get_buffer_num_lines(BIO *b);
	long BIO_set_read_buffer_size(BIO *b, long size);
	long BIO_set_write_buffer_size(BIO *b, long size);
	long BIO_set_buffer_size(BIO *b, long size);
	long BIO_set_buffer_read_data(BIO *b, void *buf, long num);

       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

       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 4096. 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.

       These functions,	other than BIO_f_buffer(), are implemented as macros.

       Buffering BIOs implement	BIO_gets() by using BIO_read_ex() 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.

       BIO_f_buffer() returns the buffering BIO	method.

       BIO_get_buffer_num_lines() returns the number of	lines buffered (may be

       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.

       bio(7), BIO_reset(3), BIO_flush(3), BIO_pop(3), BIO_ctrl(3).

       Copyright 2000-2016 The OpenSSL Project Authors.	All Rights Reserved.

       Licensed	under the OpenSSL license (the "License").  You	may not	use
       this file except	in compliance with the License.	 You can obtain	a copy
       in the file LICENSE in the source distribution or at

1.1.1d				  2019-09-10		       BIO_F_BUFFER(3)


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