2 * Sherlock Library -- Fast File Buffering
4 * (c) 1997 Martin Mares, <mj@atrey.karlin.mff.cuni.cz>
16 struct fastbuf *__bfdopen(int fd, uns buffer, byte *name)
18 struct fastbuf *b = xmalloc(sizeof(struct fastbuf));
21 b->buffer = xmalloc(buffer);
22 b->bptr = b->bstop = b->buffer;
23 b->bufend = b->buffer + buffer;
24 b->name = stralloc(name);
25 b->pos = b->fdpos = 0;
31 bopen(byte *name, uns mode, uns buffer)
33 int fd = open(name, mode, 0666);
36 die("Unable to %s file %s: %m",
37 (mode & O_CREAT) ? "create" : "open", name);
38 return __bfdopen(fd, buffer, name);
42 bfdopen(int fd, uns buffer)
46 sprintf(x, "fd%d", fd);
47 return __bfdopen(fd, buffer, x);
50 void bclose(struct fastbuf *f)
60 rdbuf(struct fastbuf *f)
62 int l = read(f->fd, f->buffer, f->buflen);
65 die("Error reading %s: %m", f->name);
67 f->bstop = f->buffer + l;
74 wrbuf(struct fastbuf *f)
76 int l = f->bptr - f->buffer;
80 if (write(f->fd, f->buffer, l) != l)
81 die("Error writing %s: %m");
88 void bflush(struct fastbuf *f)
90 if (f->bptr != f->buffer)
91 { /* Have something to flush */
92 if (f->bstop > f->buffer) /* Read data? */
94 f->bptr = f->bstop = f->buffer;
97 else /* Write data... */
102 inline void bsetpos(struct fastbuf *f, uns pos)
104 if (pos >= f->pos && (pos <= f->pos + (f->bptr - f->buffer) || pos <= f->pos + (f->bstop - f->buffer)))
105 f->bptr = f->buffer + (pos - f->pos);
109 if (f->fdpos != pos && lseek(f->fd, pos, SEEK_SET) < 0)
110 die("lseek on %s: %m", f->name);
111 f->fdpos = f->pos = pos;
115 void bseek(struct fastbuf *f, uns pos, int whence)
122 return bsetpos(f, pos);
124 return bsetpos(f, btell(f) + pos);
127 l = lseek(f->fd, pos, whence);
129 die("lseek on %s: %m", f->name);
130 f->fdpos = f->pos = l;
133 die("bseek: invalid whence=%d", whence);
137 int bgetc_slow(struct fastbuf *f)
139 if (f->bptr < f->bstop)
146 int bpeekc_slow(struct fastbuf *f)
148 if (f->bptr < f->bstop)
155 void bputc_slow(struct fastbuf *f, byte c)
157 if (f->bptr >= f->bufend)
162 word bgetw_slow(struct fastbuf *f)
164 word w = bgetc_slow(f);
165 #ifdef CPU_BIG_ENDIAN
166 return (w << 8) | bgetc_slow(f);
168 return w | (bgetc_slow(f) << 8);
172 ulg bgetl_slow(struct fastbuf *f)
174 ulg l = bgetc_slow(f);
175 #ifdef CPU_BIG_ENDIAN
176 l = (l << 8) | bgetc_slow(f);
177 l = (l << 8) | bgetc_slow(f);
178 return (l << 8) | bgetc_slow(f);
180 l = (bgetc_slow(f) << 8) | l;
181 l = (bgetc_slow(f) << 16) | l;
182 return (bgetc_slow(f) << 24) | l;
186 void bputw_slow(struct fastbuf *f, word w)
188 #ifdef CPU_BIG_ENDIAN
189 bputc_slow(f, w >> 8);
193 bputc_slow(f, w >> 8);
197 void bputl_slow(struct fastbuf *f, ulg l)
199 #ifdef CPU_BIG_ENDIAN
200 bputc_slow(f, l >> 24);
201 bputc_slow(f, l >> 16);
202 bputc_slow(f, l >> 8);
206 bputc_slow(f, l >> 8);
207 bputc_slow(f, l >> 16);
208 bputc_slow(f, l >> 24);
212 void bread_slow(struct fastbuf *f, void *b, uns l)
216 uns k = f->bstop - f->bptr;
221 k = f->bstop - f->bptr;
223 die("bread on %s: file exhausted", f->name);
227 memcpy(b, f->bptr, k);
234 void bwrite_slow(struct fastbuf *f, void *b, uns l)
238 uns k = f->bufend - f->bptr;
243 k = f->bufend - f->bptr;
247 memcpy(f->bptr, b, k);
254 byte * /* Non-standard */
255 bgets(struct fastbuf *f, byte *b, uns l)
265 if (k == '\n' || k == EOF)
273 die("%s: Line too long", f->name);
276 void bbcopy(struct fastbuf *f, struct fastbuf *t, uns l)
278 uns rf = f->bstop - f->bptr;
279 uns rt = t->bufend - t->bptr;
290 memcpy(t->bptr, f->bptr, k);
295 while (l >= t->buflen)
298 if (read(f->fd, t->buffer, t->buflen) != t->buflen)
299 die("bbcopy: %s exhausted", f->name);
300 f->fdpos += t->buflen;
306 uns k = t->bufend - t->bptr;
311 k = t->bufend - t->bptr;
315 bread(f, t->bptr, k);
323 int main(int argc, char **argv)
325 struct fastbuf *f, *t;
328 f = bopen("/etc/profile", O_RDONLY, 16);