1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
|
# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
include <mach.h>
include <config.h>
include "ki.h"
# KT_ZGET -- Get all or part of a line of text from a text device. We are
# called only if the device does not reside on the local node.
procedure kt_zget (device, chan, obuf, maxch, status)
int device # device driver code
int chan # channel assigned device
char obuf[maxch] # receives text
int maxch # max chars to read
int status # receives nchars read or ERR
pointer bd, bp, ip, rp
int server, nchars, nleft, reclen
int ki_sendrcv()
long ki_decode()
include "kichan.com"
include "kii.com"
begin
bd = k_bufp[chan]
# Text file input is buffered; each input buffer returned by the kernel
# server may contain any number of lines of text. Each line of text
# is preceded by a record header containing the record length and seek
# offset of the line.
if (maxch == 1 || B_RP(bd) >= B_ITOP(bd)) {
# Refill buffer.
server = k_node[chan]
p_arg[1] = k_oschan[chan]
# Read only one character if this is a raw mode read.
if (maxch == 1)
p_arg[2] = 1
else
p_arg[2] = SZ_TXBUF
if (ki_sendrcv (server, device, TX_GET) == ERR)
status = ERR
else if (p_arg[1] <= 0)
status = p_arg[1] # EOF or ERR
else {
nchars = p_arg[1]
bp = B_BUFPTR(bd)
# If the record is small it is returned in the string buffer,
# else it is returned as a second record. Each line is
# contained entirely in a single buffer.
if (nchars <= SZ_SBUF)
call amovc (p_sbuf, Memc[bp], nchars)
else {
call ks_aread (server, Memc[bp], nchars)
call ks_await (server, status)
if (status != nchars) {
call ki_error (server)
B_ITOP(bd) = bp
B_OTOP(bd) = bp
status = ERR
return
}
call chrupk (Memc[bp], 1, Memc[bp], 1, nchars)
}
B_RP(bd) = bp
B_ITOP(bd) = bp + nchars
B_OTOP(bd) = bp
B_CI(bd) = 0
}
}
# Return characters from the current record until it is exhausted.
# When the current record is empty, leave the record pointer pointing
# to the start of the next record and the character index pointing
# to the first char of that record.
rp = B_RP(bd)
ip = R_DATA(rp) + B_CI(bd)
reclen = ki_decode (R_RECLEN(rp), NCHARS_INT)
nleft = R_GETNCHARS (reclen) - B_CI(bd)
if (maxch >= nleft) {
# Return the remainder of the buffer.
call amovc (Memc[ip], obuf, nleft)
status = nleft
B_RP(bd) = B_RP(bd) + reclen
B_CI(bd) = 0
} else {
# Return a portion of the data remaining in the buffer.
call amovc (Memc[ip], obuf, maxch)
status = maxch
B_CI(bd) = B_CI(bd) + maxch
}
end
|
