source: buchla-68k/libcio/write.c@ fa38804

Last change on this file since fa38804 was fa38804, checked in by Thomas Lopatic <thomas@…>, 7 years ago

Removed form-feed comments.
  • Property mode set to 100644
File size: 5.0 KB
Line 
1/*
2 ============================================================================
3 write.c -- write() and friends
4 Version 17 -- 1987-10-27 -- D.N. Lynx Crowe
5 ============================================================================
6*/
7
8#define DEBUGIT 0
9
10#include "ram.h"
11
12/* write routine dispatch table */
13
14static int16_t (*wr_tab[])(io_arg arg, int8_t *buff, int16_t len) = {
15
16 _badfio, /* 0 - invalid entry */
17 _filewr, /* 1 - disk file */
18 _conwr /* 2 - console device */
19};
20
21/*
22 ============================================================================
23 _putsec(fp, buf, len) -- write 'len' bytes from 'buf' on file 'fp'
24 ============================================================================
25*/
26
27int16_t _putsec(struct fcb *fp, int8_t *buf, uint16_t len)
28{
29#if DEBUGIT
30 if (fsdebug)
31 printf("_putsec($%08lX, $%08lx, %d): initial curlsn=%ld\n",
32 fp, buf, len, fp->curlsn);
33#endif
34
35 if ((errno = ReadRN(fp, Wrkbuf)) EQ 1) { /* try to read sector */
36
37#if DEBUGIT
38 if (fsdebug)
39 printf("_putsec(): ReadRN saw EOF at curlsn=%ld, asects=%ld\n",
40 fp->curlsn, fp->asects);
41#endif
42
43 errno = 0; /* we're at EOF */
44 memset(Wrkbuf, 0x1A, BPSEC); /* pad end of sector */
45
46 } else if (errno)
47 return(FAILURE);
48
49 memcpy(Wrkbuf + fp->offset, buf, len); /* move in the new data */
50
51 if ((errno = WriteRN(fp, Wrkbuf)) NE 0) { /* write the sector */
52
53#if DEBUGIT
54 if (fsdebug)
55 printf("_putsec(): WriteRN() FAILED (%d) - curlsn=%ld\n",
56 errno, fp->curlsn);
57#endif
58
59 return(FAILURE);
60 }
61
62 if ((fp->offset = (fp->offset + len) & (BPSEC - 1)) EQ 0) {
63
64 ++fp->curlsn; /* update file position */
65
66 if (_seek(fp) < 0) {
67
68#if DEBUGIT
69 if (fsdebug)
70 printf("_putsec(): _seek() failed - curlsn=%ld, asects=%ld\n",
71 fp->curlsn, fp->asects);
72#endif
73
74 return(FAILURE);
75 }
76 }
77
78#if DEBUGIT
79 if (fsdebug)
80 printf("_putsec(): final curlsn=%ld, offset=%d, len=%d\n",
81 fp->curlsn, fp->offset, len);
82#endif
83
84 return(SUCCESS);
85}
86
87/*
88 ============================================================================
89 _filewr(fp, buffer, len) -- write 'len' bytes on file 'fp'
90 from 'buffer'.
91 ============================================================================
92*/
93
94int16_t _filewr(struct fcb *fp, int8_t *buffer, uint16_t len)
95{
96 register uint16_t j, k, l;
97 int16_t clustr;
98 register int32_t curpos;
99
100 curpos = fp->offset + (fp->curlsn << FILESHFT); /* get position */
101
102 if (fp->de.bclust EQ 0) { /* see if we need to allocate */
103
104#if DEBUGIT
105 if (fsdebug)
106 if (curpos)
107 printf("_filewr(): ERROR - bclust EQ 0 and curpos (%ld) NE 0\n",
108 curpos);
109#endif
110
111 if (0 EQ (clustr = _newcls())) { /* allocate a cluster */
112
113 errno = EIO;
114 return(len);
115 }
116
117 fp->de.bclust = micons(clustr); /* update FCB */
118 _ptcl12(_thefat, clustr, 0x0FF8); /* update FAT */
119 _fatmod = TRUE;
120 fp->curdsn = _cl2lsn(_thebpb, clustr); /* set curdsn */
121 fp->curcls = clustr;
122 fp->clsec = 0;
123 fp->asects = _thebpb->clsiz;
124#if DEBUGIT
125 if (fsdebug) {
126
127 printf("_filewr(): allocated initial cluster=%d, asects=%ld\n",
128 clustr, fp->asects);
129 SnapFCB(fp);
130 }
131#endif
132 }
133
134 l = 0; /* zero the length-written counter */
135
136#if DEBUGIT
137 if (fsdebug)
138 printf("_filewr(): init pos=%ld, len=%u, curcls=%u, offset=%u\n",
139 curpos, len, fp->curcls, fp->offset);
140#endif
141
142 if (fp->offset) { /* see if we have a partial sector to fill */
143
144 if ((l = (BPSEC - fp->offset)) > len)
145 l = len;
146
147 if (_putsec(fp, buffer, l)) /* fill up the sector */
148 return(-1);
149 }
150
151 if (k = (len - l) / BPSEC) { /* write out any full sectors */
152
153 if ((j = blkwr(fp, buffer + l, k)) NE 0) {
154
155 l += (k - j) * BPSEC; /* update amount written */
156
157 if ((curpos + l) > fp->curlen) /* udpate file length */
158 fp->de.flen = miconl(fp->curlen = curpos + l);
159
160#if DEBUGIT
161 if (fsdebug)
162 printf("_filewr(): ERROR - curlen=%ld, curlsn=%ld, curdsn=%ld\n",
163 fp->curlen, fp->curlsn, fp->curdsn);
164#endif
165
166 return(l);
167 }
168
169 l += k * BPSEC; /* update amount written */
170 }
171
172 if (l < len) { /* write out partial sector at end */
173
174 if (_putsec(fp, buffer + l, len - l)) {
175
176 if ((curpos + l) > fp->curlen) /* update file length */
177 fp->de.flen = miconl(fp->curlen = curpos + l);
178
179#if DEBUGIT
180 if (fsdebug)
181 printf("_filewr(): ERROR - curlen=%ld, curlsn=%ld, curdsn=%ld\n",
182 fp->curlen, fp->curlsn, fp->curdsn);
183#endif
184
185 return(l);
186 }
187 }
188
189 if ((curpos + len) > fp->curlen) /* update file length */
190 fp->de.flen = miconl(fp->curlen = curpos + len);
191
192#if DEBUGIT
193 if (fsdebug)
194 printf("_filewr(): final curlen=%ld, flen=$%08lX, curlsn=%ld, curdsn=%ld\n",
195 fp->curlen, fp->de.flen, fp->curlsn, fp->curdsn);
196#endif
197
198 return(len);
199}
200
201/*
202 ============================================================================
203 write(fd, buff, len) -- write 'len' bytes from 'buff' on file 'fd'
204 ============================================================================
205*/
206
207int16_t write(int16_t fd, int8_t *buff, uint16_t len)
208{
209 register struct channel *chp;
210
211 if ((fd < 0) OR (fd > MAXCHAN)) {
212
213 errno = EBADF;
214 return(-1);
215 }
216
217 chp = &chantab[fd];
218
219 return((*wr_tab[chp->c_write])(chp->c_arg, buff, len));
220}
221
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