2 * Copyright (c) 1988, 1993
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29 * @(#)ring.h 8.1 (Berkeley) 6/6/93
37 #if defined(__STDC__) || defined(LINT_ARGS)
44 * This defines a structure for a ring buffer.
46 * The circular buffer has two parts:
48 * full: [consume, supply)
49 * empty: [supply, consume)
54 unsigned char *consume, /* where data comes out of */
55 *supply, /* where data comes in to */
56 *bottom, /* lowest address in buffer */
57 *top, /* highest address+1 in buffer */
58 *mark; /* marker (user defined) */
60 unsigned char *clearto; /* Data to this point is clear text */
61 unsigned char *encryyptedto; /* Data is encrypted to here */
62 #endif /* ENCRYPTION */
63 int size; /* size in bytes of buffer */
64 u_long consumetime, /* help us keep straight full, empty, etc. */
68 /* Here are some functions and macros to deal with the ring buffer */
70 /* Initialization routine */
72 ring_init(Ring *ring, unsigned char *buffer, int count);
74 /* Data movement routines */
76 ring_supply_data(Ring *ring, unsigned char *buffer, int count);
79 ring_consume_data(Ring *ring, unsigned char *buffer, int count);
82 /* Buffer state transition routines */
84 ring_supplied(Ring *ring, int count),
85 ring_consumed(Ring *ring, int count);
87 /* Buffer state query routines */
90 ring_empty_count(Ring *ring),
91 ring_empty_consecutive(Ring *ring),
92 ring_full_count(Ring *ring),
93 ring_full_consecutive(Ring *ring);
97 ring_encrypt(Ring *ring, void (*func)(unsigned char *, int)),
98 ring_clearto(Ring *ring);
99 #endif /* ENCRYPTION */
102 ring_clear_mark(Ring *),