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inetutils/telnet/ring.h
2025-01-01 18:21:25 +01:00

102 lines
3.8 KiB
C

/*
Copyright (C) 1995-2025 Free Software Foundation, Inc.
This file is part of GNU Inetutils.
GNU Inetutils is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or (at
your option) any later version.
GNU Inetutils is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see `http://www.gnu.org/licenses/'. */
/*
* Copyright (c) 1988, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* This defines a structure for a ring buffer.
*
* The circular buffer has two parts:
*(((
* full: [consume, supply)
* empty: [supply, consume)
*]]]
*
*/
typedef struct
{
unsigned char *consume, /* where data comes out of */
*supply, /* where data comes in to */
*bottom, /* lowest address in buffer */
*top, /* highest address+1 in buffer */
*mark; /* marker (user defined) */
#ifdef ENCRYPTION
unsigned char *clearto; /* Data to this point is clear text */
unsigned char *encryyptedto; /* Data is encrypted to here */
#endif /* ENCRYPTION */
int size; /* size in bytes of buffer */
unsigned long consumetime, /* help us keep straight full, empty, etc. */
supplytime;
} Ring;
/* Here are some functions and macros to deal with the ring buffer */
/* Initialization routine */
extern int ring_init (Ring * ring, unsigned char *buffer, int count);
/* Data movement routines */
extern void ring_supply_data (Ring * ring, unsigned char *buffer, int count);
/* Buffer state transition routines */
extern void
ring_supplied (Ring * ring, int count),
ring_consumed (Ring * ring, int count);
/* Buffer state query routines */
extern int
ring_empty_count (Ring * ring),
ring_empty_consecutive (Ring * ring),
ring_full_count (Ring * ring), ring_full_consecutive (Ring * ring);
#ifdef ENCRYPTION
extern void
ring_encrypt (Ring * ring, void (*encryptor) (unsigned char *, int)),
ring_clearto (Ring * ring);
#endif /* ENCRYPTION */
extern void ring_clear_mark (Ring *);
extern void ring_mark (Ring *);
extern int ring_at_mark (Ring *);