Annotation of src/usr.bin/aucat/abuf.c, Revision 1.26
1.25 ratchov 1: /* $OpenBSD$ */
1.1 ratchov 2: /*
1.26 ! ratchov 3: * Copyright (c) 2008-2012 Alexandre Ratchov <alex@caoua.org>
1.1 ratchov 4: *
5: * Permission to use, copy, modify, and distribute this software for any
6: * purpose with or without fee is hereby granted, provided that the above
7: * copyright notice and this permission notice appear in all copies.
8: *
9: * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10: * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11: * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12: * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13: * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14: * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15: * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16: */
17: /*
1.26 ! ratchov 18: * Simple byte fifo.
1.1 ratchov 19: *
20: * The abuf data is split in two parts: (1) valid data available to the reader
21: * (2) space available to the writer, which is not necessarily unused. It works
22: * as follows: the write starts filling at offset (start + used), once the data
23: * is ready, the writer adds to used the count of bytes available.
1.7 ratchov 24: */
1.1 ratchov 25: #include <stdio.h>
26: #include <stdlib.h>
1.4 ratchov 27: #include <string.h>
1.1 ratchov 28:
1.13 ratchov 29: #include "abuf.h"
1.26 ! ratchov 30: #include "utils.h"
1.1 ratchov 31:
1.17 ratchov 32: #ifdef DEBUG
33: void
1.26 ! ratchov 34: abuf_log(struct abuf *buf)
1.17 ratchov 35: {
1.26 ! ratchov 36: log_putu(buf->start);
! 37: log_puts("+");
! 38: log_putu(buf->used);
! 39: log_puts("/");
! 40: log_putu(buf->len);
1.17 ratchov 41: }
1.26 ! ratchov 42: #endif
1.17 ratchov 43:
44: void
1.26 ! ratchov 45: abuf_init(struct abuf *buf, unsigned int len)
1.1 ratchov 46: {
1.26 ! ratchov 47: buf->data = xmalloc(len);
! 48: buf->len = len;
1.1 ratchov 49: buf->used = 0;
50: buf->start = 0;
51: }
52:
53: void
1.26 ! ratchov 54: abuf_done(struct abuf *buf)
1.1 ratchov 55: {
1.26 ! ratchov 56: #ifdef DEBUG
! 57: if (buf->used > 0) {
! 58: if (log_level >= 3) {
! 59: log_puts("deleting non-empty buffer, used = ");
! 60: log_putu(buf->used);
! 61: log_puts("\n");
1.17 ratchov 62: }
63: }
64: #endif
1.26 ! ratchov 65: xfree(buf->data);
! 66: buf->data = (void *)0xdeadbeef;
1.1 ratchov 67: }
68:
69: /*
1.26 ! ratchov 70: * return the reader pointer and the number of bytes available
1.1 ratchov 71: */
72: unsigned char *
1.26 ! ratchov 73: abuf_rgetblk(struct abuf *buf, int *rsize)
1.1 ratchov 74: {
1.26 ! ratchov 75: int count;
1.1 ratchov 76:
1.26 ! ratchov 77: count = buf->len - buf->start;
! 78: if (count > buf->used)
! 79: count = buf->used;
1.1 ratchov 80: *rsize = count;
1.26 ! ratchov 81: return buf->data + buf->start;
1.3 ratchov 82: }
83:
84: /*
1.26 ! ratchov 85: * discard "count" bytes at the start postion.
1.3 ratchov 86: */
87: void
1.26 ! ratchov 88: abuf_rdiscard(struct abuf *buf, int count)
1.3 ratchov 89: {
1.17 ratchov 90: #ifdef DEBUG
1.26 ! ratchov 91: if (count < 0 || count > buf->used) {
! 92: log_puts("abuf_rdiscard: bad count = ");
! 93: log_putu(count);
! 94: log_puts("\n");
! 95: panic();
1.22 ratchov 96: }
1.17 ratchov 97: #endif
1.3 ratchov 98: buf->used -= count;
99: buf->start += count;
100: if (buf->start >= buf->len)
101: buf->start -= buf->len;
102: }
103:
104: /*
1.26 ! ratchov 105: * advance the writer pointer by "count" bytes
1.3 ratchov 106: */
107: void
1.26 ! ratchov 108: abuf_wcommit(struct abuf *buf, int count)
1.3 ratchov 109: {
1.17 ratchov 110: #ifdef DEBUG
1.26 ! ratchov 111: if (count < 0 || count > (buf->len - buf->used)) {
! 112: log_puts("abuf_wcommit: bad count = ");
! 113: log_putu(count);
! 114: log_puts("\n");
! 115: panic();
1.17 ratchov 116: }
117: #endif
1.3 ratchov 118: buf->used += count;
1.1 ratchov 119: }
120:
121: /*
1.26 ! ratchov 122: * get writer pointer and the number of bytes writable
1.1 ratchov 123: */
124: unsigned char *
1.26 ! ratchov 125: abuf_wgetblk(struct abuf *buf, int *rsize)
1.1 ratchov 126: {
1.26 ! ratchov 127: int end, avail, count;
1.1 ratchov 128:
1.26 ! ratchov 129: end = buf->start + buf->used;
1.1 ratchov 130: if (end >= buf->len)
131: end -= buf->len;
1.26 ! ratchov 132: avail = buf->len - buf->used;
1.1 ratchov 133: count = buf->len - end;
134: if (count > avail)
1.26 ! ratchov 135: count = avail;
1.1 ratchov 136: *rsize = count;
1.26 ! ratchov 137: return buf->data + end;
1.1 ratchov 138: }
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