BIO_f_readbuffer - read only buffering BIO that supports BIO_tell() and
BIO_seek()
#include <openssl/bio.h>
const BIO_METHOD *BIO_f_readbuffer(void);
BIO_f_readbuffer() returns the read buffering BIO method.
This BIO filter can be inserted on top of BIO's that do not support
BIO_tell() or
BIO_seek() (e.g. A file BIO that uses stdin).
Data read from a read buffering BIO comes from an internal buffer which is
filled from the next BIO in the chain.
BIO_gets() is supported for read buffering BIOs. Writing data to a read
buffering BIO is not supported.
Calling
BIO_reset() on a read buffering BIO does not clear any buffered
data.
Read buffering BIOs implement
BIO_read_ex() by using
BIO_read_ex()
operations on the next BIO (e.g. a file BIO) in the chain and storing the
result in an internal buffer, from which bytes are given back to the caller as
appropriate for the call.
BIO_read_ex() is guaranteed to give the
caller the number of bytes it asks for, unless there's an error or end of
communication is reached in the next BIO. The internal buffer can grow to
cache the entire contents of the next BIO in the chain.
BIO_seek() uses
the internal buffer, so that it can only seek into data that is already read.
BIO_f_readbuffer() returns the read buffering BIO method.
bio(7),
BIO_read(3),
BIO_gets(3),
BIO_reset(3),
BIO_ctrl(3).
Copyright 2021 The OpenSSL Project Authors. All Rights Reserved.
Licensed under the Apache License 2.0 (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
<
https://www.openssl.org/source/license.html>.